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4 Protected areas and biosphere reserves of the hot deserts and subdeserts.

1. Protected hot deserts

1.1 General considerations

The unique biological characteristics of the deserts cover a limited (although extensive) geographical area and are highly adapted to the harsh environmental conditions. Desert ecosystems adapt relatively well to long-term cyclic changes and can withstand regular local events such as droughts, floods, and fires. They are, however, unable to withstand continued human activity, especially in many developing countries where rapid population growth and general poverty exert additional pressure on the already scarce desert resources.

On the other hand, approximately half of the world's arid and semiarid regions suffer problems related to the expansion of the deserts. One problem common to all the deserts and subdeserts is that the balance of their ecosystems, subtly modulated by the local conditions in each area, is becoming more and more fragile.

In comparison with the rain forests or other wet biomes, deserts are little known and poorly understood. This has been confirmed by ten years of international research stimulated by the drought in the Sahel. Many erroneous ideas are still held about 1) the condition of the desert in relation to its use and abuse and 2) the relative importance to conservation efforts of certain plant and animal species--ones that are often isolated.

The limited knowledge of desert ecosystems has also been shown by the relatively limited extent of the protected desert areas and their often inadequate management. Several international projects coordinated by the United Nations Environment Programme (UNEP), including the UNEP/ UNESCO Integrated Project for Arid Lands and other similar schemes for cold deserts, seek to improve management of arid zones and to recognize new ones to be protected and restored. It is hoped that by the year 2000, desert biodiversity will be as well protected as that of other biomes, and desertification can be halted.

Biological diversity and the protected deserts

The number of plants and animals in the deserts is low in comparison with other biomes, although some families may show great diversity, and there may be many endemic species. The slow formation of deserts over millions of years has allowed some plants and animals to adapt to the extremely arid conditions. Plants avoid the harsh conditions by completing their life cycle in the very short rainy seasons; the cacti produce swollen stems that store water, spines to prevent animals eating them, and a waxy cuticle to reduce water loss by transpiration. Some animals, like plants, can resist the dry season in dormancy. The most successful are the small rodents and small reptiles, which can hide from the heat. They are rarely seen, as they spend most of the day sheltering in their burrows.

In some protected deserts, such as the Ahaggar Massif in Algeria, adaptation to the desert climate has taken place in almost total isolation. The small oases with permanent or intermittent water supplies, sheltered from the invading desert in rocky outcrops or in isolated valleys, are among the most fragile desert ecosystems but are also among the most biologically rich. They often contain relict species that separated from their nearest relatives many thousands of years ago. The few permanent watercourses also show great biodiversity and are sometimes staging posts for large natural populations of migratory species. These areas are so important for the local human populations that preserving viable wild bird populations in the protected areas has become extremely difficult. This is exemplified by the tributaries of the River Indus in Pakistan and some of the tributaries flowing into the Okavango Delta in the Kalahari Desert.

Over the twentieth century, human activities have reduced biodiversity so quickly that the long-term consequences of this loss to the desert ecosystems may never be thoroughly understood. Some protected areas, which were established because they were very remote and undisturbed, are almost unknown and lack resources to carry out inventories to measure their loss of biodiversity. A conservative estimate is that by the year 2000, about 15% of the species that were present in 1980 will have become extinct.

The sustainable management of desert ecosystems

No system of protected areas can be really effective unless it takes the human factor into account. Human dependence on water resources is so great that most of the 55 million inhabitants of the Sahara are settled on the banks of the Nile, the Niger, and the shores of Lake Chad and the banks of the rivers flowing into it. Only two million of the inhabitants of the Sahara can be said to live in the desert, making the Sahara one of the most sparsely populated regions of the world. Over the course of the year, the Saharan shepherds travel through the areas with enough rainfall to provide grazing for their herds. In the summer, the Tuareg move to the pastures of the northern desert, while the Teda head south to the permanent lakes of Lake Chad and the Niger River. In the winter, the Teda remain on the pastures of the mountains in the Tibesti, Air, and Ahaggar.

The lifestyle followed by the Sahara's inhabitants for thousands of years is being threatened by the increase in the amount of ground that is cultivated. Those in charge of many of the protected areas of the Sahara such as Tassili N-'Ajjer have tried to carry out regional projects so that the nomadic population can continue using the land in a sustainable way (as they had been doing for thousands of years), but these efforts have failed. In fact, most governments in northern Africa have tried to make nomads settle down. In addition, the exploitation of natural resources--oil in Algeria and Libya, copper in Mauritania--have provided new opportunities for the people of the Sahara. Although the customs of the former tribal societies still dominate, the lifestyle of the inhabitants of the Sahara shown by the rock paintings and carvings in the central mountains and in other archeological sites throughout the desert is rapidly disappearing.

Over many generations, several human populations, among them the Tuareg and the Teda in the Sahara, the Australian Aborigines, and the inhabitants of the Indus Valley, have adapted to the harsh desert environment. Traces of very old settlements (possibly among the first agrarian civilizations) have been found in the heart of some hot deserts. Generation after generation, these peoples have had to meet the same basic requirements, protecting themselves from an extreme climate and finding sources of food, water, and energy. Most of the world's hot deserts now support larger human populations than at any time in their entire history. The fact that a protected desert is very remote is no longer enough to protect it. Furthermore, with new technologies for the handling and transport of raw materials like minerals, oil, gas, and water, the problems of the protected deserts are no longer local problems but general ones.

By assessing environmental impacts and undertaking active management to ensure sustainable use of resources, many threats can be averted. But because the climate is becoming drier and drier, other less direct threats are also getting worse (erosion and habitat loss, for example). Those responsible for the protected areas have almost no solutions apart from trying to understand the desert environment better and applying strategies that allow its conservation while taking into account the needs of the inhabitants and their lifestyle.

Pastoralism has always been the most important economic sector in the desert regions, not only because stockraising can be carried out in almost any environment but also because it is the traditional lifestyle of many of the nomadic peoples of the deserts. The inherent low productivity of desert pastoralism, combined with the general deterioration of the environment, means that most fertile oases are becoming more and more vulnerable. Furthermore, in order to maintain a minimum living standard, the inhabitants of the deserts have increased the number of heads of cattle in their herds, as well as exploitation of other resources such as fuelwood and agricultural land, especially where human populations are greatest. In some developing countries, this has caused conflicts that have endangered the effective management of the protected zones. Most protected desert zones are located in sites where there are trees or shrubs to browse, fertile soil for crops, water to drink, and often wild animals that have been restricted to their natural habitat by the desert sands. The opposite happens in developed countries that have deserts; these marginal spaces are open to all sorts of undesirable uses, ranging from nuclear tests to dumping of dangerous wastes to tourist activities to military maneuvers.

Because of intensive research, there have been some notable successes in converting protected areas, formerly used for hunting or grazing purposes, into biological reserves. This has been relatively easy in developed countries such as Australia and the United States, where this transformation has only represented a slight extension of the national park system. The basis for maintaining these protected areas already existed, and the new means of self-financing (such as low-impact tourism) are not normally in opposition to conservation aims. In poorer and more densely populated countries such as Pakistan, India, and Mexico, maintaining protected areas has, however, been much more difficult. Many of the protected areas have some tourism, but they are mainly places where people live. In order to survive, the inhabitants of these protected areas often have to intensify their agricultural practices, usually to the detriment of endangered species.

In the deserts of southern Asia, for example, the establishment and management of protected areas is limited by several factors. The most important are the high population density, high levels of illegal hunting, and the destruction of habitat by drainage. The great Thar Desert, on the frontier between India and Pakistan, is the largest hot desert in Asia, and it provides the best examples. Its history is similar to the Baluchistan Deserts in Pakistan, as it was also used as a hunting ground by the former princes, nawabs, and maharajahs. Even now, hunting laws are hard to enforce, above all as a result of the political inconsistencies among the different provinces of India and the frontier tensions between India and Pakistan. The Thar Desert occupies 9% of the land area of India, but less than 2% of the Indian Thar enjoys any form of protection, while its population density is the highest of any of the world's deserts. Most of the population lives in small, scattered villages and raises livestock in the dry meadows and spine scrub. Until the 1950s, when work started on the Indira Gandhi Nahar Canal Project (IGNP), the inhabitants of the Thar Desert were nomads; their lifestyle allowed the vegetation and wildlife to recover from damage caused by hunting and overgrazing. But modern irrigation techniques have led the inhabitants to become more sedentary, as extensive croplands have replaced the natural vegetation and the wildlife has declined.

Though artificial irrigation provides the croplands that are so necessary to support a growing population, it may have a disastrous effect on the natural vegetation and, therefore, on the animal population. The more water that is diverted to desert regions, the more the subterranean waters increase, and the greater the danger of flooding and erosion during the monsoon season. Another effect, less evident but potentially even more disastrous, is the increase in soil salinity, which may cause large areas to become unsuitable for agriculture. Plants take up water with mineral salts from the soil, but the water they lose by transpiration is pure, and the salts are deposited near the soil surface. Salinization is a problem common to all the irrigated desert areas in Pakistan and India and has given rise to increasingly heavy pressure on the nature reserves located in marginal lands.

Those responsible for the management of protected areas in hot deserts have few really effective methods available to ensure that biological resources are not exhausted. So far, the system that has been most effective is the zoning conceived for UNESCO's MAB program, which complements traditional uses of the desert with management and research to ensure the highest sustainable productivity of these traditional practices. Core areas containing uncommon species of plants and animals, usually the least disturbed, are strictly protected, and normally only scientific research and inventories are permitted. This has paradoxically shown that if local participation is encouraged and education programs are incorporated, it is possible to make compatible, and even attractive, a mixture of conservation research and exploitation. At the Mapimi Biosphere Reserve (Mexico), research has led to a better and more efficient management of grazing, and the local population now protects the areas occupied by the endangered bolson tortoise, which could not be controlled by the staff available to manage the reserve.

Protection from desertification

Desertification is the greatest danger facing people living in deserts. It is generally accepted that the increasing rate of desertification in the last few years is the consequence of the inherent vulnerability of the deserts to the use made of them: grazing livestock, practicing unsustainable agriculture, diverting watercourses, deforestation, and mineral extraction. Together with suitable use of technologies to slow down desertification, social solutions can be applied. The Instituto Argentino de Investigaciones de las Zonas Aridas (Argentinean Institute for Research into Arid Areas; IADIZA) has discovered that the desertification of the Mendoza region has caused a decline in rural production of 20-40%. This fall is due mainly to impoverishment and marginalization of the rural population. Those responsible for the protected areas have found that these people resist changing their methods in order to apply techniques for the control of desertification. The IADIZA has introduced crop and grazing rotation schemes, protected grazing with fencing, and offered help to maintain pastures as long as they were used seasonally. Unfortunately, rehabilitation is slow (it takes up to four years to restock fodder plants), and more and more ranchers are leaving for the city. The only solution is to convince the ranchers that they need to change their methods in order to improve their quality of life. In the Kalahari Desert in southern Africa, to give a further example, large protected areas were closed to the growing number of cattle without realizing the enormous impact this would have on the main migratory routes in the Okavango delta.

There are many technological and economic aspects to bear in mind, but those dealt with here are enough to illustrate the difficulties involved in applying technology and research to the developed regions of the hot deserts. The most important barrier is social and is related to the type of subsistence economy and the nomadic lifestyle of the herders. It would be perfectly possible to increase the productivity of the protected areas in the hot deserts (and especially of the biosphere reserves with their research centers) by means of suitable soil management, better water supply, and the application of genetic improvement programs. It should not be forgotten that water and good pastures are so highly valued in the hot deserts that in the beginning the new technologies will only represent to the herders another way of increasing the number of their cattle--the cattle that in the long run have totally degraded the grazing.

1.2 The protected parks and areas

The hot tropical deserts and subdeserts represent more than 20% of all dry land, but they contain very few protected areas. Furthermore, the size of the protected area varies greatly from desert to desert. None of the Sechura Desert in Peru is protected, while about 23.5% of the Thar Desert in Pakistan is protected. In some regions, the Sahara, which accounts for 55% of the total area occupied by the world's hot deserts and includes parts of 11 countries, has less than 1% of its surface area protected. Protected areas in the hot deserts represent less than 2% of the total, meaning that this is one of the least protected biomes, especially when compared to open tropical forests (5% of their area protected) or tropical rain forests (8%).

The protected deserts in the Old World

Even so, because of their isolation and low human population, protected areas in the hot deserts are usually very large. The Khali National Reserve (3,430,000 ha; 1 ha=2.5 acres) in Oman, and the Ar-Rub' al-Khali Wildlife Management Area (5,000,000 ha) in Saudi Arabia are two of the largest protected areas, but their management requires few special measures. There are other protected areas that show it is possible to have efficient management while meeting the needs of the small indigenous populations and respecting their lifestyle.

In the Air and Tenere National Reserve (7,736,000 ha) in Niger, the active participation of the population is encouraged, and there is compensation for the strict protection given to the Integral Natural Reserve of the Addax Sanctuary (1,280,500 ha). Other examples in the Sahara Desert include the Tassili N-'Ajjer Biosphere Reserve (7,200,000 ha) and the Ahaggar National Park, both in Algeria, where wildlife management projects try to incorporate the ancient nomadic cultures that still remain in these remote mountainous regions.

In 1987, the Algerian authorities declared the Ahaggar Massif a natural park, meaning that both the mountainous regions of the Sahara within Algeria now enjoy protection. (Tassili N-'Ajjer was already protected). The aim of the Algerian government is to protect the natural and cultural heritage of the Sahara while promoting socioeconomic activities that respect the environment and encourage low intensity tourism. The network of protected areas in Niger, most of whose land area is desert or subdesert, contains all the animal species and all the threatened types of vegetation. The Air and Tenere National Reserve, a UNESCO World Heritage Site, is the largest managed protected area in Africa. It has been divided into zones in order to protect endangered species such as the addax (Addax nasomaculatus) more effectively and reestablish the characteristic Sahara-montane vegetation.

In general, few countries can carry out really effective management, and even then only in a small part of their protected areas. This is the situation in the hot deserts of Asia, whose human population density is the highest of any of the world's deserts. In the Cholistan Game Reserve (2,032,667 ha), the protected spaces in both India and Pakistan, the Kachi/Sibi/Nasiribad Natural Sanctuary (2,335,653 ha), the Great Rann National Park (700,000 ha), and the Kareka Great Indian Bustard Sanctuary (849,644 ha), the laws protecting some species are normally respected. In general, effective management can only be carried out in small areas such as the Lal Suhanra Biosphere Reserve (31,355 ha) or the Kirthar National Park (308,733 ha), both in Pakistan.

The protected deserts of the New World and Australia

The first protected areas in the world's hot deserts and subdeserts were in the United States. About 4,300 ha of subdesert and mountain were protected in 1924 in the Chiricahua National Monument in the Chiricahua Mountains; in the 1930s, some other important spaces were protected, including: Death Valley (1933), covering 772,000 ha; Saguaro National Monument (1933), covering 32,000 ha; and Organ Pipe Cactus National Monument (1937), covering 133,000 ha. Around the same time, Mexico also started a system of national parks, natural reserves, and monuments similar to those of the United States but much less effective, with insufficient attention given to the desert areas. Despite this, the creation and the first years of development of the Mapimi Biosphere Reserve in the Chihuahua Desert has helped transform ideas about the dilemma between protection and development, and it has been the basis of the Mexi-can model of biosphere reserve. Most of the protected areas of desert in Mexico are now biosphere reserves.

In the desert areas of Peru and Chile, there are few protected areas, as these areas are considered marginal in both countries and are not thought to be in such need or as deserving of protection as their mountain or forest reserves. The most important are probably the Paracas Nature Reserve in Peru and the Pampa de Tamarugal Nature Reserve in Chile. There are, however, many protected natural spaces in the Argentinean monte, and new ones are being created. It should be pointed out that what is protected is not the desert but the water holes and the patches of woody vegetation along riverbanks. The most notable are the Lihuel Calel National Park, the border between the monte and the espinar in the province of La Pampa; the Sierra de las Quijadas National Park in the province of San Luis; and the Nacunan Provincial Reserve and Biosphere Reserve in the province of Mendoza.

Australia has had a conservation policy for a long time. It was the first country to follow the example of the United States and created its first national park in 1879, only seven years after the creation of Yellowstone. Even so, greater attention was traditionally paid to forested areas and to the areas relatively close to the population centers of the continent's southeastern coast. Since the 1970s, parks and reserves have been created in most of the Australian deserts. Two of the largest are the South Australian Unnamed Conservation Park (which has been nominated as a biosphere reserve) and the Great Victoria Desert in Western Australia, which exceeds two million ha; there are three more that exceed a million ha (Lake Eyre in South Australia, and the Rudall River and Gibson Desert in Western Australia). A particularly good example is given by the management of the Uluru-Kata Tjuta National Park, which includes the Uluru-Kata Tjuta Biosphere Reserve, where the park's Aboriginal population accounts for most of the management staff.

2. UNESCO biosphere reserves in hot deserts and subdeserts

2.1 Biosphere reserves in hot deserts and subdeserts

There are a total of 28 biosphere reserves in 14 African, American, and Asian countries that are or contain hot deserts or subdeserts. Most of these reserves, which occupy more than 20 million hectares, are very large; the Tassili N-'Ajjer reserve in the Sahara covers 7.2 million ha, more than all the biosphere reserves of this type in North and South America combined. But in Africa there are also very small ones such as the El-Imayed Experimental Research Area in Egypt (covering only a thousand hectares). In almost all these biosphere reserves, the dominant biome is hot desert or subdesert, but some--especially those with steep relief or those crossed by major permanent watercourses--contain areas that can hardly be considered deserts or subdeserts, and others contain only a small area of desert (for instance, the Bosque Fray Jorge y Las Chinchillas Biosphere Reserve in Chile). Even so, the biome of the deserts and subdeserts has been particularly favored by the biosphere reserve model of management. In fact, experience gained in some desert spaces was the basis for the development of the ideas that led to the creation of the first biosphere reserves.

The experience acquired in the early 1970s following the creation in Mexico of the Mapimi and La Michilia Biosphere Reserves (although La Michilia is not a desert) and the creation in Kenya of the Mount Kulal Biosphere Reserve led to the idea of combining nature conservation with economic development. This was done by means of nonexclusive management that did not marginalize local people. In contrast to the blind commitment to development espoused by most economic agents (ranging from states and large companies through local government and small companies to individual economists and administrators), and unlike the strict preservation sought by some minorities, these reserves rejected a type of conservation based on the perpetuation of local misery and social dissatisfaction of populations that considered themselves left out. At the same time, they eschewed forms of development that led to the destruction of natural resources (abuse rather than use). To fulfill this objective they proposed incorporating local people and institutions into the common task of 1) preserving the germ plasm and ecosystems, 2) directing and guiding environmental research without excluding social and economic factors, and 3) attempting to reach alternative, specific, and realistic solutions to the problems of the sustainable use of natural resources while improving the quality of life of the people. This underlying approach, developed through the MAB program and applied with different degrees of conviction and success in many countries all over the world, was the origin of the extensive network of biosphere reserves that now exists.

Surprisingly, Mapimi and Mount Kulal were not among the first the biosphere reserves in the desert to be officially recognized; they were preceded by four of the biosphere reserves in the United States (Big Bend, Jornada, Organ Pipe Cactus, and Beaver Creek) and the two in Iran (Genu and Hara). Mapimi was not made a biosphere reserve until 1977 (together with the three in Australia, two in Tunisia, and the Lal Suhanra in Pakistan), and Mount Kulal became a biosphere reserve in 1978. The most recently created biosphere reserves in the desert are the other three biosphere reserves in Mexico, the Wadi 'Allaqi in Egypt (1993), the Islas del Golfo de California, also in Mexico (1995), the Air et Tenere in Niger (1997), the Arganeraie in Morocco (1998), and the Dana in Jordan (1998).

2.2 Biosphere reserves in hot deserts and subdeserts of North America

The deserts and subdeserts of North America are among the least populated and most poorly studied in the world. However, as already pointed out, they were the birthplace of the concept of the biosphere reserve, largely developed on the basis of the pioneering experiences of the Mapimi reserve. In the Sonoran Desert, there are five biosphere reserves: two of them--El Vizcaino (6,293,229 acres [2,546,790 ha]) and El Pinacate-Gran Desierto de Altar (1,765,699 acres [714,556 ha])--are in Mexico, while the other three--the Organ Pipe Cactus National Monument (329,336 acres [133,278 ha]), the Beaver Creek Experimental Reserve (275,027 acres [111,300 ha]) and the Mojave and Colorado deserts (3,205,596 acres [1,297,264 ha])--are in the United States. The Chihuahua Desert contains three biosphere reserves: the Mapimi reserve in Mexico and the Big Bend National Park (699,916 acres [283,247 ha]) and the Jornada Experimental Range (193,475 acres [78,297 ha]) in the United States. The Islas del Golfo de California Biosphere Reserve lies in the Gulf of California.

The rapid growth of the Mexican population and its great mobility has endangered several of its natural areas. The Mexican deserts and subdeserts are in the north of Mexico, straddling the United States border; this has led to increased population growth and the unyielding effects of rapid economic growth. The construction of large maquiladoras (sweatshop assembly plants) along the U.S.-Mexico border has concentrated the population in this strip, while it has reduced even further the number of inhabitants of the neighboring desert and subdesert regions, although environmental pressure on these areas has increased as a consequence of the use of the land and the oil wells.

Establishing biosphere reserves in remote desert regions diminishes the risk of their being destroyed, as long as the participation of local people is ensured; this is especially true if the natural resources are hard to exploit sustainably. Many of these problems do not occur in the Mapimi Biosphere Reserve, as the local people own their lands and share the scientists' desire to preserve the environment. Any research activity requires the permission of the reserve's inhabitants. The researchers also introduce previously inaccessible technology that makes it possible to continue practicing traditional activities such as stockraising, which is especially important during the critical dry periods. The management of the El Vizcaino Biosphere Reserve, located in the El Vizcaino Desert in Baja California in Mexico, incorporates a zoning system that allows local fishermen and salt-extraction companies to make use of the coastal strip.

The case of the Mapimi Biosphere Reserve

The Mapimi Biosphere Reserve is located in the center of the Chihuahua Desert, on the edge of the Mexican states of Durango, Coahuila, and Chihuahua. This region forms part of the central highlands of northern Mexico and is located within a series of subdesert basins known as the Bolson de Mapimi. Its 254,517 acres [103,000 ha] have an extraordinarily rich range of animal communities for a desert environment. It is the only habitat of the threatened bolson or Mapimi tortoise (Gopherus flavomarginatus), which was in danger of extinction as a result of hunting until the reserve was created.

Characteristics and natural values

The bolsones are subdesert endorheic basins characteristic of the central highlands of the southwestern United States and northern Mexico, generally with a seasonal or permanent lake at the lowest point, surrounded by small hills. The Bolson de Mapimi is, in fact, a large series of interconnected basins of this type, two of which are entirely within the biosphere reserve. Two-thirds of the reserve are occupied by the Laguna de las Palomas basin that runs south along the course of an arroyo (an intermittent watercourse), La India, which provides the reserve with most of its water and sediments when there is strong rain. In the northeast of the reserve, there are two other intermittent arroyos, El Tapado and Las Adjuntas, and after rainfall they flow into the Laguna del Rey, which is one of the largest salt lakes in the entire system of basins.

Each of the basins has a series of similar physical and geographic features, as they all consist of large, almost flat alluvial plains (bajadas), separated by rows of hills (sierras), with flat-bottomed depressions (playas) in their center, into which the temporary waters and most of the eroded materials flow. These materials are mainly gravel, clay, and silt, though in the Laguna de las Palomas, the seasonal rise and fall of the water level (and thus the expansion and contraction of the area covered) has also formed large saline plains. In the relatively flat central and southern regions there are abundant scattered hills of conglomerate rock, and the bajadas are interrupted by basaltic outcrops, lava flows, and inselbergs derived from Pleistocene volcanic eruptions.

The formation of the desert landscape in the Mesa Central of the Mexican highlands has been due largely to the mountains' influence on the region's climate. The Sierra Madre Occidental and the Sierra Madre Oriental isolate the region from the Pacific Ocean and the Gulf of Mexico, respectively, so effectively that oceanic influences on the local climate are very short-lived, little more than violent convective storms in the summer when the moist air flows over the foothills of the mountains from the Gulf of Mexico. In the Mapimi Biosphere Reserve, the lowest mean monthly temperature is 54[degrees]F (12[degrees]C) in January and the highest is 82[degrees]F (28[degrees]C) in June (at the beginning of the rains that will last until September). As in many other arid regions, rain that falls near the top of a slope drains away in a network of streams, while that falling near the base of a slope is lost as surface runoff and does not drain into a watercourse. In this closed system, the mountains are gradually being buried in their own sediments. The most important drainage channel is known as La Vega. This desert environment is in fact being shaped by fluvial processes, although the extensive system of fossil dunes present in the northern part of the area shows that in the past the action of wind was also important.

The Chihuahua Desert can be considered a deciduous subdesert of succulent plants; it has a very rich, though limited, flora with a large number of endemic species. The only zone of true desert in the Mapimi Biosphere Reserve is the playas and the gypsum areas in the north, where the variable plant cover rarely exceeds 25%. Nine different ecological zones have been defined within the reserve, including varied plant communities such as scrub with dominant or subdominant microphyllous shrubs like gobernadora (Larrea tridentata, Zygophyllaceae) and open scrub of sabaneta or tobosa grass (Hilaria mutica) and zacaton grass (Sporobolus airoides).

The more uneven areas of the south and center of the reserve have the most conspicuous plant communities, dominated by magueyales (formations dominated by species of Agave, locally known as maguey) and nopaleras (dominated by nopal, cacti of the genus Opuntia). The playas and the lower areas of the bajadas are dominated by gobernadora scrub that also contains ocotillo (Fouquieria splendens), yucca (Yucca torreyi), and the navajita or blue grama grass (Bouteloua gracilis). The flora of these areas depends, however, on the rock type and the gradient of the slope. On the lower slopes of the hills, the plant communities vary greatly. The alluvial fans of the limestone mountains in the south are covered by a dense scrub of gobernadora, with Cordia gregii (Boraginaceae), frequent isolated patches of mesquite (Prosopis glandulosa), and areas of cambray, or hair grass (Muhlenbergia). In the central zone, the hills of conglomerate and igneous rock have large bajadas, where the main species are gobernadora and ocotillo, together with fleshy-leaved plants such as the maguey (Agave asperrima), the lechuguilla (A. lecheguilla), and the abundant nopal (Opuntia rastrera). One characteristic feature of many bajadas in the reserve is that the vegetation is typically structured in strips known as mogotes, bands of vegetation alternating with bare ground.

The playa of the Laguna de las Palomas has a characteristic halophytic plant cover that includes Suaeda nigrescens, saltbush (Atriplex), and sabaneta with tall clumps and trees of mesquite where there are watercourses bearing fresh water. The vegetation becomes gradually sparser in the lower parts of the bajada, where there are extensive scrublands of sabaneta (Hilaria mutica) and zacaton (Sporobolus airoides). The only vegetation that can support the highly saline conditions of the edge of the lake are some species of Haplopappus (Asteraceae).

The desert environment of Mapimi raises many problems for the animals living there. The high temperatures, predators, and irregular water resources all make their life more difficult. The animals are remarkably well adapted to these difficulties, and there is a surprisingly diverse fauna of mammals, amphibians, reptiles, and birds. The animals in Mapimi are thus well adapted to life in the desert. Lizards, snakes, and turtles, for example, have a thick skin that retains water, so they can remain in the open except during the hottest hours of the day. Most of the reptiles in the reserve are diurnal and are mainly active in the morning and evening, when they roam the sabaneta grasslands in search of food. The most frequent saurians are the iguanas Uta stansburiana, Cophosaurus texanus, Cnemidophorus tigris, and Sceloporus undulatus. The most common snakes include the coachwhip snake Masticophis flagellum and different types of rattlesnake (Crotalus scutulatus, C. atrox). There are few herbivorous reptiles, and the Mapimi or bolson gopher tortoise is one of them. Most reptiles feed on arthropods, and snakes usually eat rodents, eggs, and lizards.

The bolson or Mapimi gopher tortoise (Gopherus flavomarginatus) is the largest cold-blooded terrestrial vertebrate in the North American temperate region, and it is still hunted as an easy and cheap source of protein, even though it is on the list of threatened species. In the past, its range spread as far north as New Mexico and Arizona, but the species is now restricted to an area of little more than 15,000 km2 between the states of Chihuahua, Coahuila, and Durango, with an estimated total population of about 8,000. This gopher tortoise's distribution is affected by many variables, including the climate, the gradient of the site, the substrate, and the vegetation. It occurs in subdesert and desert regions, where rainfall and humidity are low and the temperature range is very large. In the Bolson de Mapimi, there are two areas where the population density of gopher tortoises is high: one (outside the biosphere reserve but close to its northern edge) is in the southeast of the state of Chihuahua, and the other is within the Mapimi Biosphere Reserve; both have similar population densities. This species is usually found in small separated groups. It normally occupies sites with a gradient of between 1[degrees] and 2.5[degrees], and it can dig burrows in hard compacted soils to shelter from the midday sun. Within the reserve, the frequency of gopher tortoise burrows is greatest in the lower areas of the bajadas. If they made their colonies any lower, they would be very vulnerable to flash floods; toward the base of the hills, where vegetation is scarce anyway, the sandy substrate is not suitable for digging a burrow. Despite this animal's apparent dependence on the sabaneta grass, it is an opportunist that grazes and feeds on any plants it comes across.

Before 1977, when the biosphere reserve had not been created, the gopher turtle population received very little legal protection, even though the studies of the Instituto de Ecologia showed that if hunting was not stopped, the gopher turtle was in danger of becoming extinct. The number of individuals is thought to have been declining for the last 10,000 years due to both climate change and hunting by local people, but it has declined very rapidly since the 1940s, possibly for two reasons. The first is the construction of the Monclova-Escalon railway line (112 mi [180 km] long and running east-west) that brought thousands of immigrant workers to the region. The entire population of gopher turtles in a strip 6 mi (10 km) wide on either side of the railway line disappeared, and many animals were taken to the north of Mexico's Pacific coastline, where the gopher tortoises are considered a delicacy. The second reason may be the Mexican agrarian reform program. The introduction of the ejido communal property system in remote areas has favored the spread of agriculture, stockraising, and hunting to regions that used to be uninhabited, and this threatens the viability of the gopher tortoise populations. The tortoise-hunters, tortugueros, are famous for their ruthlessness, and their task is made easier by the animal's restricted range and its slowness. Many are dragged out of their burrows using a stick with a noose at the end or are attracted to the mouth of the burrow by their own reflection in a mirror.

Mammals are also well adapted to this inhospitable environment. The reserve contains few environments suitable for large mammals other than the mule deer (Odocoileus hemionus), whose thick skin absorbs heat and regulates its body temperature. The smallest mammals such as black-tailed jackrabbits (Lepus californicus), desert cottontails (Sylvilagus audubonii), kangaroo rats (Dipodomys spp.), pocket mice (Perognathus spp. and Peromyscus spp.), and the diurnal ground squirrels (Spermophilus spilosoma, S. mexicanus) hide from the midday heat in burrows. During periods of drought, they obtain most of the water they need from the food they store in their burrows. There are few animals in the reserve that are as noteworthy as the mammalian predators. The bobcat (Felis [=Lynx] rufus) and the coyote (Canis latrans) are the most common carnivores. There are also less frequent visitors, among them the American badger (Taxidea taxus), the puma (F. concolor), the gray fox (Urocyon cinereoargenteus), and the threatened kit fox (Vulpes macrotis).

Most deserts have large populations of birds, normally small species that can withstand the high temperatures. Because there are no trees, these birds nest in the sand, burying their eggs to keep them cool and to protect them from predators. In the Chihuahua Desert, there are many birds, including the roadrunner (Geococcyx californianus), the American kestrel (Falco sparverius), the lark bunting (Calamospiza melanocorys), ladder-backed woodpecker (Picoides scalaris), the cactus wren (Campylorhynchus brunneicapillus), and some larger desert birds such as the turkey vulture or turkey buzzard (Cathartes aura).

Management and problems

The desert conditions and great size of the Bolson de Mapimi have been formidable obstacles to the region's human settlement. Even so, there are still the scattered remains of small haciendas that were established in the mid-nineteenth century, when the region was used as grazing for the livestock that provided food for the populations of miners in the nearby mountains.

Herding livestock to grazing is still the main economic activity, and the people living in the reserve suffer the same problems as their predecessors. Of the eleven inhabited settlements within the reserve, three are private cattle ranches and the other eight are ejidos, each with about a dozen families. These settlements have very few services: health care is minimal, and there is no permanent supply of drinking water. The children's only chance of receiving education is when the family has two residences, or when one of the parents lives in a nearby village such as Ceballos or Parral. Raising livestock is the most important source of income. The heifers are sold each winter for export to the United States, while the cows remain on the ejidos.

Other economic activities include collecting the wax of the candelilla (Euphorbia antisyphilitica, Eu-phorbiaceae) and extracting salt from the flood plain of the Laguna de las Palomas. Two of the ejidos depend totally on these activities, but the scale of production indicates that the other ejidos also make use of this source of income. The candelilla shrub grows on the upper parts of the bajadas and at the base of the hills, where it is collected by nomadic groups known as candelilleros. The plant is boiled in an acid solution to extract the wax, which is used industrially in the production of cosmetics, sweets, paints, medicines, and chewing gum. In the past, the ejidos had problems finding a market for the products, but they are heavily supported by the Mexican government.

Efforts have been made to introduce agriculture into the reserve so that the local people could sell their produce in the surrounding villages, but because of the arid climate and saline water, most of these efforts have been fruitless. Even so, some one or two hectare plots (1 ha=2.5 acres) are irrigated with the rainwater runoff from the slopes and produce a small amount of maize and beans that the ejidatarios (the people of the ejido) use for their own consumption and to complement their livestock's diet.

Although there are laws to protect the reserve, it has been the perseverance of the Instituto de Ecologia and the cooperation of the stockraisers on the ranches and ejidos that has prevented soil and habitat degradation in Mapimi on the same scale as has occurred in other desert areas. The first conservation projects in the 1970s focused mainly on halting hunting of the gopher tortoise and maintaining the viability of its population. To begin with, few local people took the results of the scientific research very seriously, but the participation of local people was stimulated when Rosendo Aguilera, a local landowner, ceded 20 ha of land to build a field laboratory. The inhabitants of the ejido La Flor helped to build the laboratory, and a team of consultants was set up consisting of ranchers, communal committees, and scientists to establish the limits of the reserve.

Most current research is into fodder resources, irrigation projects, and stockraising. One recurring problem in all the collaborative projects carried out is the stockraisers' need to get their livestock through the critical drought periods. New spineless varieties of prickly pear (Opuntia ficus-indica) have been introduced, while the local nopal (O. rastrera) is replanted every season after the fires are started to produce grazing in the dry season. A pasture rotation system has been successfully introduced, and many farmers pipe water to their permanent grazing areas.

Although there is no fencing to mark the reserve's limits, these practices lead to few conflicts. The ranchers obtain a double benefit: on the one hand, the deterioration of the permanent water resources (which other animals depend on) is reduced, and on the other, the poorest stockraisers, who possess less productive ground, have more guaranteed access to waterholes.

Because it was the first biosphere reserve in Mexico and one of the first to be recognized by UNESCO's MAB program, Mapimi has demonstrated the immense difficulties of managing a protected area by seeking the full involvement of the local people in conservation work. Even now, only the 49 acres (20 ha) donated by Rosendo Aguilera belong to the Instituto de Ecologia, the body that manages the reserve, while the rest of the site of the biosphere reserve is divided into a complex mosaic of ejidos (communal landholdings split into small family estates) and ranchos (private stockraising estates), but even so, one of the most notable aspects of this reserve is that there are no conflicts between the reserve's inhabitants and the reserve's management.

The development of a management policy with an effective socioeconomic orientation has won the confidence of the local people and has even generated a feeling of collective pride in what has been achieved. This has largely been possible by incorporating local people into senior management positions, especially people from the ejidos who have undertaken studies, and by encouraging the participation of the local population in all levels of research and management. Good examples of the mutual benefits of this relationship are the ejidatarios protecting the gopher tortoise from hunters, and the scientists fighting the threat of rabies transmission by coyotes without endangering the other animals that live in the reserve. Even so, problems remain, mainly due to the landholding regime, as land is largely in the hands of private landowners, which favors invasion of the reserve by livestock from neighboring estates and by tortoise hunters. Instead of following a legalistic and restrictive policy, the Instituto de Ecologia has always chosen to work with the resident population and has even paid for some local stockraisers to go to the Coto de Donana Biosphere Reserve in Spain to see the stockraising techniques used there. The research center serves as the base for some services such as transport to the villages, basic medical attention, and free access to information about the reserve.

Nonetheless, although relations between the re-searchers and the inhabitants of the reserve have traditionally been good, the lack of a single authority has been one of the permanent sources of conflict that has tarnished Mapimi's image as a model reserve. Split between three states (Durango, Coahuila, and Chihuahua) and four municipalities (Mapimi, Tlahualilo, Jimenez, and Sierra Mojada), its ambiguous limits have led to disagreements over the division of the territory and its resources, as these may overlap at the individual or collective level. For the local rancher, the division of the territory is based essentially on grazing activities. Thus, the quality of the pastures, the watering points, the boundary fences, and the availability of fodder are basic considerations for the viability of the reserve. Yet, for the researcher, the zone remains a fragile subdesert environment divided into zones on the basis of their soil type and geomorphology, their fauna and flora, and the interactions between them all.

The protection of the animals that live within the reserve is definitely the most controversial aspect. Hunting of all sorts of wild animals is banned. Signs have been put up in the most conspicuous sites to remind visitors of this fact, but this prohibition is only enforced in the case of the bolson gopher tortoise. The mule deer is one of the few animals that is still hunted because it is not considered to be endangered, but other animals that represent a direct danger to humans and animals (rattlesnakes and coyotes) are not protected. The ranchers usually ignore the warnings to stop killing these species, although occasional outbreaks of rabies have forced the government to allow coyotes to be killed with firearms, even though they continue to advise against use of poisoned bate.

There is also disagreement over how to use some of the important plant communities. For the re-searchers, biodiversity and the distribution of the plant population are important, while the main priority of the stockraisers are the pastures and the types of fodder. The mesquite is the most valuable plant for the ranchers because it can be used as a source of fodder and as fuel, but despite this the researchers have done little to increase its presence in the reserve. Although there have been studies into plants with food value (such as the prickly pear), the stockraisers point out that only a single researcher has been working specifically on improving the yield of the fodder plants. The ranchers and the ejidatarios are putting the basis of their subsistence at risk in following the recommendations given by the research teams on crop rotation and irrigation methods, and the Instituto de Ecologia has to strike a delicate balance in successfully implanting management measures in the reserve without the necessary legal authority and financial support necessary to ensure the continued cooperation of stockraisers.

In any event, the Instituto de Ecologia's policy of adopting a system of cooperation based on the social results rather than on the law has been very fruitful so far. Indiscriminate hunting within the reserve has almost entirely ceased, the number of gopher tortoises has increased, projects are under way to conserve and regenerate degraded areas, and the relations between the researchers and the local population have created some degree of community atmosphere.

Even so, certain issues must be addressed, among them the allocation of responsibilities, the establishment of a management plan, and general policy on local participation. In this respect, there has been criticism of the fact that the reserve may constitute an ideal reserve for gopher tortoises, but it does not provide the same protection to other animals that play an important role in the Bolson de Mapimi ecosystem. On the other hand, much of the research activity is performed around the field laboratory, which is 40 mi (64 km) from the nearest village and thus very isolated from the most important social problems.

Although all decisions on management involve meetings between representatives of the re-searchers, the ranchers, and the ejidatarios, most of the landowners do not live in the region but have the final word about what can be done on their lands. The Instituto de Ecologia cannot, therefore, maintain the same position in its relations with different ranchers as with the ejidatarios; this has major repercussions both within the scientific reserve itself and on the services provided by the scientists.

Despite all this, everybody agrees that the most serious threat to the reserve is the excess livestock and overgrazing. As the researchers do not have the means to set or enforce ecological limits, they have to rely on the cooperation of the local people, even to the extent that people from local settlements are responsible for the monitoring of certain activities of the reserve's research center. The researchers do not have the authority to designate specific grazing areas, but, with the permission of the landowner, they have set up crop rotation schemes and replanted fodder species. The research that is now being performed might generate conflict, but workshops have been organized to educate the local farmers, who are given the opportunity to contribute their own ideas and proposals for projects. One example of this is the study of rainfall and the drainage types of the different soils that have been carried out throughout the Bolson de Mapimi. Thanks to this study, the stockraisers have located the potential grazing areas in the dry season and, based on this information, designed and constructed small dams.

2.3 Biosphere reserves in the hot South American deserts and subdeserts

There are many areas of desert and subdesert in South America, but only the monte in Argentina has any biosphere reserves, although there are a few marginal areas of desert within the Chilean Bosque Fray Jorge y Las Chinchillas Biosphere Reserve (see vol. 5, pp. 411-414) that can also be considered representative of the coastal desert of northern Chile. The latter, together with the Sechura Desert in Peru, runs along the Pacific coastline and the western side of the Andes to form the world's longest hot desert area and one of the driest regions on Earth.

Biosphere reserves in the Argentinean monte

Only one of the six biosphere reserves in Argentina--Nacunan (29,405 acres [11,900 ha])--is in the monte, though a second biosphere reserve (San Guillermo, 242,523 acres [98,146 ha]) shows characteristic features of the desert biome in some areas.

Natural features and values

The biosphere reserve of the Ecological Reserve of Nacunan is located 124 mi (200 km) from the city of Mendoza at an altitude of 1,772 ft (540 m). Among protected areas, it is generally considered the one most representative of the monte biogeographical province. The site consists of rolling plains with intermittent torrents that have given rise to deep gullies. In these gullies are isolated patches of chaco scrub with algorrobo dulce (Prosopis flexuosa), jarrilla hembra (Larrea divaricata), and jarrilla macho (L. cuneifolia). There are also some elements of espinal (high matorral), a biome derived from the chaco but with a colder climate. The tree species of the espinal include the legumes of the genera Acacia, Cassia, and Prosopis, species of Jatropha (Euphorbiaceae) with a shrub layer containing Atriplex lampa (Chenopodiaceae) and Larrea divaricata (Zygophyllaceae), and a herbaceous layer consisting of grasses palatable to livestock (Digitaria, Setaria, Sporobolus, Stipa).

The fauna of the monte is rather poor, but, as with the vegetation, there is a lot of overlap with species from the neighboring biomes. Of the 34 species of reptile, only 4 are truly endemic to the monte, and the same is true of the mammals, as 25 of the 34 species present are also found in a wide range of different habitats. Other notable species include the American red fox (Pseudalopex [=Dusicyon] culpaeus), the puma (Felis concolor), the mara or Patagonian cavy (Dolichotis patagonum), and a few rodents, among which the tuco-tuco (Ctenomys fulvus) and the pampas cavy (Microcavia australis), a type of guinea pig, are especially widespread. In the lowest mountainous regions of the province of Mendoza, within the Nacunan Biosphere Reserve, the most typical animals are the pichiciego (Chlamyphorus), the small gray fox or chilla (Pseudalopex griseus), the jagouarundi (Felis yagouaroundi), and the tortoise (Geochelone chilensis). The area is remarkable for its bird fauna, especially for the species that migrate from Patagonia and arrive in the southern winter and for the Nearctic species that can be seen there during the southern summer.

Management and problems

The monte subdesert is hardly different from the cold desert in Argentinean Patagonia in the sense that both have been used as grazing for livestock. The herds have mainly been concentrated in the lower areas, where many of the typical plant formations have been replaced by herbaceous communities dominated by invasive grass species; these original formations can now only be found in the many medanos, sandbanks in watercourses that are extremely vulnerable to erosion. The human populations that depend on the biodiversity of these dry lands are relatively small, but they are more and more mobile, and their activities may represent a serious threat to the endemic species of the monte.

When it was established, the Nacunan Ecological Reserve Biosphere Reserve was already in an advanced state of degradation, and, despite its protected status, this degradation has continued in some areas. Until the end of the nineteenth century, the region had only been inhabited by Indian tribes. The white colonists who arrived later almost completely eliminated the former forests of mesquite (Prosopis flexuosa) to supply fuelwood and charcoal to the city of Mendoza. Environmental degradation accelerated with the construction of the railway line that runs from Lencinas to Monte Coman and San Rafael. The degradation is even clearer outside the reserve and has forced those in charge of the reserve to assign a 1,482 acre (600 ha) zone for the exclusive use of the people of Nacunan. By doing this, they hope to slow down the invasion of the strictly protected zones. Some positive results have been obtained, and the central part of the reserve has recovered to some extent, although there is still poaching, especially of zorrillos or hog-nosed skunks (Conepatus) and wild cats.

The biosphere reserves in the Peruvian-Chilean coastal deserts

Only the Bosque Fray Jorge y Las Chinchillas Biosphere Reserve contains an area of the coastal subdesert within its coastal sector, although, strictly speaking, the reserve is hardly representative of the Chilean part of the Atacama Desert.

Natural characteristics and values

The Bosque Fray Jorge National Park, the largest of the two areas forming the biosphere reserve (24,609 acres [9,959 ha]), consists of coastal plains and terraces, some sectors of which can be considered as subdesert. The other area, the Las Chinchillas National Reserve (10,450 acres [4,229 ha]), runs along the Cordillera de la Costa and has a relief consisting of low hills dissected by many very narrow valleys formed by torrents, but it does not have a single area with desert or subdesert characteristics.

On the coastal plains of the Bosque Fray Jorge National Park, we can thus find typical subdesert formations of thickets and scrub with herbaceous Asteraceae such as the pichana (Gutierrezia paniculata) and furze (Chuquiraga ulicina), and shrubby Asteraceae such as Flourensa thurifera and huanil (Proustia pungens), the palo negro (Cassia stipulacea, Leguminosae), and the varilla (Adesmia angustifolia). There are few types of mammal in this environment, rodents being the best-represented group, although the culpeo (Pseudalopex culpaeus), the small grison (Galictis cuja), and the chingue or common southern skunk (Conepatus chinga) are also very common.

Management and problems

The core area of the Bosque Fray Jorge Reserve is relatively untouched, and stockraising or grazing are not allowed, though there have been temporary stockraising incursions from the adjacent areas. Overgrazing, logging, and coal mining had caused serious erosion in part of the region, but since the area became protected most of the destructive activities have been stopped; only grazing is now permitted, and this only in certain places. Fray Jorge has no research installations, but the Las Chinchillas area makes this biosphere reserve of great potential interest for research because it is easily accessible and intrinsically interesting. Research is now under way into the microclimate, the vegetation, the fauna (specifically, the reintroduction of the guanaco and the chinchilla), and the natural regeneration of the desert areas.

2.4 The biosphere reserves in the African hot deserts and subdeserts

Most of the biosphere reserves in the African deserts and subdeserts are concentrated in the Sahara and its northern edges. Only a small area of the Mount Kalul Biosphere Reserve in Kenya can be compared to the subdeserts of eastern Africa. There is not a single biosphere reserve in the deserts and subdeserts of southern Africa. The area covered by the protected zones of some northern African regions is relatively large, but only 1.4% of the area of the Sahara is protected, and several threatened vegetation types and animals remain unprotected. In the Sahara, many animals have been isolated in unmanaged areas that are either too small or offer little protection. The desert regions of Algeria are the only exceptions. The managers of the Tassili N-'Ajjer Biosphere Reserve in Algeria are drawing up a management plan to preserve the threatened plant and animal species, and measures are already being applied to reestablish populations of the wild species that still survive.

The case of the Tassili N-'Ajjer Biosphere Reserve

The Biosphere Reserve of the Tassili N-'Ajjer National Park is located in the east of the Ahaggar Massif in southeast Algeria and includes the entire Tassili plateau. This plateau--one of the westernmost outcrops of sandstone in the central Sahara--is at an altitude of 4,921-5,906 ft (1,500-1,800 m). In fact, it consists of two plateaus, the inner Tassili and the outer Tassili, which are separated by the Intra-Tassili pass. These plateaus form part of Ordovician and Devonian detritic strata that, at a distance of 435 mi (700 km), skirt the metamorphic pre-Cambrian Ahaggar Massif, running northwest-southeast. Tassili N-'Ajjer covers an area of 7,200,000 ha and was declared a biosphere reserve in 1986. Initially, efforts to preserve the Tassili plateau (part of which had already been declared a national park in 1972) were concentrated on the numerous archeological and geological sites, but further measures have been necessary to protect the marvelous relict species of plants and animals. The oases, water holes, and wetlands are unique in the Sahara but are threatened by the rapid growth of settlements and tourism.

Natural features and values

The Tassili plateau is a stark geomorpholical contrast with the surrounding desert. Its southern limit consists of a 1,969 ft (600 m) escarpment that rises from the mobile sand dunes (ergs) of Admer and Tihodaine. An intricate network of steep-sided valleys (wadis) runs north-south across this escarpment. In the upper Pleistocene, the areas now covered by ergs were covered by several large lakes that were fed by the water flowing down from the plateau. Most of these lakes have, however, dried up, and the wind and the arid climate have carved a landscape dominated by columns of sandstones and ruiniform sand formations that have been called petrified forests. In the shadiest and rockiest areas at the base of the valleys, water flows from the porous sandstone to form semipermanent pools. Like the Iherir River, the only permanent river in the central Sahara, these pools are surrounded by lush vegetation that transforms them into an almost permanent oasis.

The Tassili plateau is extremely arid. Like the entire Sahara, it has a very constant climate; in the daytime, the average temperature at an altitude of 3,609 ft (1,100 m) is 20.3[degrees]C. There is no hot season, but the temperatures are notably higher between May and September, when the sun is at its highest elevation. The average annual rainfall is a little more than an inch (30 mm), although the rains are very variable and in some years are less than an inch (20 mm). The strong winds that blow during the day and the low levels of humidity mean that the exposed areas of the plateau are hyperarid, where only a sparse and monotonous vegetation can survive. But the wadis and temporary pools fill up with the arrival of the rains and are a suitable habitat for the complex relict Mediterranean flora. The best known species of this Saharo-Mediterranean flora is the tarout (Cupressus dupreziana), of which only 240 specimens exist in the entire world, a hundred of them concentrated in the Valley of the Cypresses in Tamarit.

Over the last 5,000 years, the Sahara's climate has become increasingly arid, and large areas have become totally uninhabitable. The Tassili plateau, however, was the center of flourishing agricultural civilizations that have survived to the present day in the form of the contemporary Ajjeri Tuareg herders. These herders raised goats and led a nomadic lifestyle following different routes over the plateau, but the droughts of the last 20 years have forced many of them to settle permanently in the Djanet and Ilizi oases.

The flora of the Saharan region as a whole belongs to the Saharo-Sindian region, but it contains elements from the more northern Mediterranean flora and from the more southern Sudan-Deccan flora. Most of the Mediterranean plant species such as oleander (Nerium oleander), the occasional olive (Olea europaea subsp. laperrinei), occasional myrtles (Myrtus nivellei), Trianthema pentandra (Aizoaceae), Silene kiliana (Caryophyllaceae), Lupinus pilosus (Leguminosae), and Convolvulus fatmensis (Convolvulaceae) only grow near watercourses. In the valley of the River Iherir--one of the wettest regions of the reserve, with its unpolluted water, travertine dykes, waterfalls, and many pools--there are numerous halophytic plants, including reed mace (Typha), rushes (Juncus), and reeds (Phragmites), in addition to aquatic vegetation with algae of the genus Chara and waterplants of the genera Myriophyllum and Potamogeton. The elements of the Sudanese flora are also very common and include Maurea (Capparidaceae), Salvadora (Salva-doraceae), and Callotropisa (Asclepiadaceae), together with several species of rocky and sandy areas such as Mesembryanthemum gaussenii (Aizoaceae), Pseuderucaria clavata (Brassicaceae), or Acacia scorpioides (Leguminosae).

The Sahara has few truly endemic species, but the flora of the biosphere reserve is remarkable for the rare and endemic species it contains. Most Saharan species have ranges that extend northward to Mediterranean Europe or south toward tropical Africa or are restricted to a few isolated sites that are now separated because of the drying out of the desert over the last few thousand years. The 28 rare species of plant that occur in the Tassili N-'Ajjer Biosphere Reserve include endemic species such as Potamogeton hoggariensis (Potamogetonaceae), Silene hoggariensis (Caryophyl-laceae), Lupinus tassilicus (Leguminosae), and Senecio hoggariensis (Asteraceae), and others such as Ficus ingens (Moraceae), Bergia suffruticosa (Elati-naceae), Hypericum psilophyton (Guttiferae), and Phagnalon garamantum (Asteraceae).

The vegetation sprouts extremely quickly after the slightest rainfall, and, together with the plants growing along the more or less permanent watercourses, this provides abundant food for the animals that live permanently in the reserve and those passing through it. Five species of amphibians, 21 species of reptiles, 31 species of mammals, and 62 species of bird have been recorded in the Tassili area. Some are remnants of when the region was wetter, among them the Nile crocodile (Crocodylus niloticus), which had arrived from Egypt and survived in the Imirhou wadi until the 1940s.

The herbivores are probably the animals best adapted to the climate of the Tassili. Small rodents such as the house mouse (Mus musculus), some spiny mice (Acomys cahirinus), and the large North African gerbil (Gerbillus campestris) have short reproductive cycles that they can complete during the brief periods when there is food in abundance. The large herbivores, however, depend on rain to make the plants bear leaves and fruit, but they compensate for their long reproductive cycles with the ability to survive on a diet of dry plants. The reserve contains a large number of dorcas gazelle (Gazella dorcas), rhiums or slender-horned gazelles (G. leptoceros), and the aoudad or Barbary sheep (Ammotragus lervia). None of these animals is solitary; during the summer months, they can be found in small groups scattered throughout the many valleys, and, in the winter, they often shelter in the mountains. Their population seems to have increased since hunting was restricted, though they are still threatened by competition from domesticated goats. There is great concern over the future of some species such as the roan antelope (Hippotragus equinus), the gemsbok or beisa (Oryx gazella), the scimitar oryx (O. dammah), and the addax (Addax nasomaculatus). Some of these species were thought to have disappeared from the region and become restricted to the Admer plains, but after the heavy rains in 1985 the plant cover became lush, and they have been sighted on several occasions; two dead animals have also been found near the southern limit of the reserve.

The carnivores are also well represented. The most common species are the golden jackal (Canis aureus), the pale fox or African sand fox (Vulpes pallida), Rueppell's fox (Vulpes rueppellii), and the caracal or desert lynx (Felis caracal). All these mammals are opportunistic hunters and live mainly in the valleys, where they can find a large number of saurians, rodents, young Barbary sheep, and gazelles. The cheetah (Acinonyx jubatus) visits the reserve from time to time and has been seen in the sandy valleys near Afara and Tamadjert.

Many Palaearctic birds visit the reserve, mainly species migrating across the Sahara toward sub-Saharan Africa from Europe or in the other direction. They include the Eurasian bittern (Botaurus stellaris), the white stork (Ciconia ciconia), the golden eagle (Aquila chrysaetos), the glossy ibis (Plegadis falcinellus), and the European stone curlew (Burhinus oedicnemus).

The sparse protection provided by the desert environment means that there are very few localities that can provide information about the past evolution of the fauna in relation to the postglacial drying of the climate. Within the reserve, however, the lacustrine deposits associated with the drainage system of the wadis during the Holocene have provided several fossilized remains. The ergs of Tibhodaine, Admer, and Djanet, for example, have yielded remains of several extinct species such as Elephas atlanticus, Equus mauritanicus, Bos ibericus, and Bubalus antiquus. The remains also include those of living species now found in the savannahs of the southern Sahara, among them the white rhinoceros (Ceratotherium simum), the mountain zebra (Equus zebra), the hippopotamus (Hippopotamus buselaphus), the addax (Addax nasomaculatus), and the ibex (Capra ibex).

There are thousands of prehistoric tools from the lower Paleolithic scattered over the Sahara, but the Tassili plateau's excellent Neolithic and prehistoric remains are among its main cultural values. The Ajjeri Tuareg are the latest in a series of civilizations that have existed in the great ergs and mountains of the Tassili since Negroid Saharo-Sudanese hunters arrived in the region for the first time about 8,800 years ago. The abundant remains, including containers, millstones, walled enclosures, and funeral tumuli, have allowed a chronological reconstruction of the development of these societies. These discoveries show the transition from a hunter-gatherer society to an economy based on the domestication of plants and animals, i.e., agriculture and stockraising. They also show that the Sahara then enjoyed a milder climate than it does now. Round-based receptacles used to store seeds, finished stone axes and arrowheads, as well as abundant bone and ivory fishing implements, show that in the past the mountains and valleys of the Tassili were covered with lush lacustrine vegetation and that water and game were abundant.

The most famous archeological remains in the reserve are the rock paintings and carvings. About 30,000 rock paintings have been recorded in the Sahara, and about 15,000 of them are in the Tassili N-'Ajjer plateau. These paintings show a human population in the process of gradually adapting to the increasingly arid climate. As drier conditions made most of the area barren, the inhabitants of the Sahara became sedentary around water points or lakes and adopted seasonal stock migration practices. The wild animals shown in the oldest pictures were replaced by cows and sheep, together with images closer to black African traditions representing vivid human figures of masked dancers and mythological gods.

Management and problems

The Tassili plateau has always been relatively protected by its geographical isolation, but increasing tourism could change this situation, especially if the project to replace the current dirt tracks with asphalt roads goes ahead. The entire plateau is now property of the state. The only responsibility of the organization in charge of the park, the Tassili National Park Office (OPNT), is the preservation of the natural and archeological heritage. Since it was declared a national park, the work of the OPNT has consisted basically of controlling the visitors and protecting the rock paintings.

Since 1978, the OPNT has been carrying out an ambitious program to draw up a complete natural and cultural inventory of the reserve and an assessment of its conservation status. Most of this work is being carried out in an area of the reserve near Djanet. From there, the guards and a researcher act as guides and accompany visitors to the plateau. There is discussion of extending the OPNT's responsibilities to cover the whole plateau, which would have a double benefit: it would obtain more funding and extend the research area. An experimental center has already been set up at the Timenzouzine archeological site, where there has been a weather station since 1979. There are other (poorly equipped) bases like this in the surrounding villages, but projects like the reintroduction and cataloging of the tarout (Cupressus dupreziana) have clearly shown the need for a network of research and management centers specifically for the purpose of studying and drawing up an inventory of the flora and fauna. Although there are still few control centers, the local people generally respect the laws restricting the hunting of certain species and the regulations to limit grazing and extraction of wood.

The repeated droughts the Sahel has suffered since the 1960s have affected the people living in the reserve. The grazing area for their livestock has become smaller, and more and more herders are settling in the In-Amenas Da'ira or in the Djanet Da'ira, which cover most of the plateau. In the mid-1990s, the region's population was about 10,000, with 1,000-3,000 of them members of the Ajjer confederation, a nomadic Tuareg clan.

The demand for urban housing is exerting increasing pressure on the reserve's resources. The effects of this pressure on the vegetation--the only source of water for the animals during the periods of drought--are increasingly clear. Felling trees and shrubs for fuelwood and timber, together with cultivation of the areas around the permanent pools (gueltas) and the most fertile wadis, has reduced the amount of food available to the animals and has deprived them of their shelters. The demand for meat has led to an increase in stockraising activities, especially of goats, and the rich pastures of the wetter valleys such as the 43 mi (70 km) long Ad wadi are now highly coveted. The amount of food consumed by goats is greater than that needed by wild animals, and in spring when the kids are born, their food requirements almost double.

At the request of the Algerian government, in 1987 UNESCO proposed a land management plan that took into account both natural resource aspects and cultural issues in the area. The plan foresees zoning the reserve in order to protect the most vulnerable sections. This is one of the most urgent management problems, as some plant and animal species--the tarout (Cupressus sempervirens dupreziana), for example--might disappear if appropriate measures are not taken to restore and conserve their habitat. This management plan has not yet been implemented, but, in the future, for this or any other plan to be effective, cooperation between the reserve's administrators and the goat herders will be essential if the species now in danger are going to survive. The measures that have been proposed to deal with these problems include the construction of enclosures to protect endangered wild animals, the use of pens for raising goats, replacing fuelwood with gas as a source of energy, and the economic exploitation of the large natural populations of Barbary sheep and common gazelles, which would support the nomadic lifestyle of the Tuareg.

2.5 Biosphere reserves in the hot Asian deserts and subdeserts

Roughly 60% of the land running continuously from the western edges of the Iranian Dasht-e-Kavir Desert to the easternmost point of the Thar Desert in India is arid or semiarid. But not all of this region can be considered as hot desert. The interior of Iran is occupied mostly by a high mountainous plateau with an extremely seasonal climate. Only in the southeast of the country, in the Hamun-e Jaz Murian, is true hot desert. The Hamun-e Jaz Murian joins the Chagai and Hamun-i-Mashkel deserts in Pakistan in a wasteland covered by mobile sands and large sand dunes. The Indus Valley forms a natural barrier between western Pakistan and the eastern Thar and Cholistan deserts that include part of the state of Rajasthan in India.

This area contains four biosphere reserves: the Hara Protected Area (85,685 ha [1 ha=2.5 acres]) and Genu Protected Area (49,000 ha), both in Iran, the Lal Su-hanra National Park in Pakistan (31,355 ha), and the Dana Reserve in Jordan (30,800 ha). These reserves show a few features in common: they are home to a small human population, and the animal and plant life show great diversity due to their location on the border between the Palaearctic and Oriental floral regions. They are also all influenced to some extent by the rain and winds associated with the monsoons. The Lal Suhanra Biosphere Reserve is located in one of the least fertile sites in the alluvial plains of the Indus. Though very few people live there, the reserve is easily accessible to the people of the large nearby towns. The region is famous for the abundance of wild species and migratory birds, but, since the 1950s, hunting and habitat destruction have greatly reduced the wild populations. A management policy has been drawn up that seeks to ensure the cooperation of the local people by promoting tourism, in the hope that it will act as a catalyst to regional development.

The management policies of the Hara and Genu Reserves are very different. Both seek to gradually remove human settlements and agriculture, in the hope that the currently threatened species, including the wild ass (Equus hemionus) and the Persian gazelle (Gazella subgutturosa), will increase. There are still small-scale exploitations inside these two reserves (for example, charcoal production), but studies realized by the research centers show that these industries have only a slight effect on the wildlife.

The case of the Lal Suhanra Biosphere Reserve

Lal Suhanra was the first biosphere reserve set up in Pakistan back in 1977. It was also the first national park in Pakistan when it was designated in 1972. It covers an area of 31,355 ha, including part of the southeast of the Punjab state. These desert regions mark the transition between the Indus Basin, which is densely populated, and the vast Thar Desert. Unlike the vast majority of the plains of the Indus, the combination of high temperatures and low rainfall has kept this area from being exploited for agriculture. However, over the last 150 years, human beings have left their indelible mark on the area: colonization based on an extension of the complex system of canals in the Punjab has profoundly altered the desert.

The need to safeguard the different habitats that were disappearing, as well as the threatened species, became obvious after an official expedition to assess the state of nature in Pakistan. Some of the country's best-known species were in danger of extinction, and it was necessary to start a project to reintroduce animal species and to revise hunting practices within the network of protected spaces. The priority was the protection of suitable breeding areas for two of the most endangered desert species, the blackbuck (Antilope cervicapra) and the chinkara (Gazella gazella).

Lal Suhanra was chosen as a biosphere reserve for two main reasons. Both involve location. First of all, it is 20 mi (32 km) northeast of the city of Bahawalpur, near the highway from Bahawalpur to Bahawalnagar (27[degrees]30'N-72[degrees]20'E), and is thus easily accessible to tourists. The permanent population is very small, but there is continuous demographic pressure on the reserve because of the increasing demand for the conversion of marginal land into agricultural land. The Lal Suhanra management plan seeks to eliminate these pressures through a delicate balance of conservation and good business sense: the plan aims to protect nature and ecosystems while promoting forestry and tourism to boost the development of local communities. The other reason why Lal Suhanra was declared a biosphere reserve involves its proximity to Lake Patisar; it was thought that protecting this desert area would be positive for the wetlands around the lake. The natural limits represented by the lakes and channels would reduce the risk of intrusion, and the small canal keepers houses could be converted into research centers and guard stations. Both would have to be managed and staffed with wardens by those in charge of the reserve; this would greatly reduce expenses, which is essential if government funding is to be obtained.

Characteristics and natural values of the reserve

The Cholistan Desert basically consists of the alluvium deposited by the Indus and its tributaries; it slopes up slightly toward the northeast of the western tip of the flood plains of the upper Indus. The landscape is thus very flat, consisting of rolling dunes interrupted occasionally by rocky outcrops. The dunes may reach a height of a few meters, when the sand can accumulate on the leeward side of shrubs, or they may cover an area of more than 1,000 ha if the sand is laid down parallel to the predominant winds from the southwest.

There are three different habitats in Lal Suhanra: the desert, plantations of trees, and a wetland of international importance. The true desert covers approximately two-thirds of the reserve (20,932 ha) and is the dominant habitat in the southeastern zone, where the sandy soils are deficient in nitrogen and thus unsuitable for cultivation. The vegetation consists of dry scrub and spiny shrubs, with some occasional belts of trees and shrubs in the flat areas between stabilized dunes. Like many areas of Pakistan, the Lal Suhanra Biosphere Reserve depends on the summer monsoon for most of its average annual rainfall of 8 in (214 mm). Much of this water is lost by percolation through the sandy soils or by evaporation, but the desert branch of the Bahawal Canal diverts part of the water, which is then used during the regular droughts. The wetland area, which includes Lake Patisar (1,934 ha) and the canals, stores the excess rainfall. It has become more and more important for the wild animals resident in the reserve and those passing through it. The tree plantations (8,488 ha) are irrigated by the above-mentioned desert branch of the Bahawal Canal and have the double aim of providing a viable economic resource and helping to stabilize the mobile dunes of the desert. When these aims have been achieved, the plantations will form the largest forest area on the plains of the Punjab and the largest irrigated forest area in Pakistan.

The extreme variability of the rains in this particularly arid region of the alluvial plains of the upper Indus creates serious problems for agriculture and means that mosquitoes are abundant--and are, of course, the vectors of several diseases. The only sites in the Lal Suhanra capable of supporting sustainable agriculture are the sandy loam soils around the lake and along the canals. If the monsoon rains are especially intense, most of the region is flooded by the artificial collector canal, and the seeds rot before they germinate. If the rains arrive late, or not at all, the entire harvest may be lost; the amount of water that evaporates from the canals and reservoirs may be ten times greater than the average annual rainfall, and this greatly increases the risk of soil salinization.

In the past, the landscape was chiefly dominated by large tropical spiny forests, called rakhs, that ran from the foothills of the Himalayas in the north to the plains of the southern Punjab in the south. In the early twentieth century, logging and the growing demand for coal for the railways and steamboats caused a gradual reduction in the area of forest. The need for land created by the expansion of the canal system eventually confined the native forests to the most remote regions, where soil conditions were unsuitable for agriculture.

The rakhs, which grow on all soil classes, still survive in the desert region of the reserve, but they are on the edge of the ecological range and are increasingly vulnerable to flooding, soil salinization, and desertification. The dominant tree species in this type of forest are jal (Salvadora oleoides, Salvadoraceae), jand (Prosopis cineraria [=P. spicigera], Leguminosae), and Capparis aphylla (Capparidaceae), which are also grown in the plantations, near cemeteries, and in scattered patches on the clay plains. The shrubs and herbs associated with this formation are still relatively widespread; the most common species are the bubry (Acacia jacquemontii, Leguminosae), phog (Calligonum polygonoides), the seablite (Suaeda fruticosa), and two grasses--gorka (Elionurus hirsutus,) and dab (Eragrostis cynosu-roides). The rakh used to be maintained by the seasonal floods and provided the local people with a large amount of fuelwood and rich grazing, while acting as a good shelter for wild animals. Its economic and ecological value has never been assessed--although several species from the rakh are known for their medicinal properties--and no efforts have been made to study it or to try to regenerate it outside the plantations.

When managed for commercial purposes, the rakh that grows in the plantations consists of shisham (Dalbergia sissoo), white mulberry (Morus alba, Moraceae), kikar (Acacia arabica, Leguminosae), Tamarix articulata (Tamaricaceae), jal (Salvadora oleoides), and jand (Prosopis cineraria [=P. spicigera], Leguminosae), and the herbaceous species include Bermuda grass (Cy-nodon dactylon, Poaceae) and puth kanda (Achyranthes aspera, Amaranthaceae). Areas where these plantations have not prospered or where commercially valuable species have not been planted are resown with typically xerophytic vegetation and transformed into pastures. Replanting with native species is one of the objectives of the management plant, but this is only carried out in the least productive areas, where the local people often collect them for fuelwood or charcoal.

The Palaearctic faunistic region and the Oriental faunistic region are separated by the Indus. This region of Eastern Pakistan has a constantly changing fauna that shows great affinities with the African species of the Middle East and the Indian species. In Lal Suhanra, the great diversity of species is the result of the abundance of different habitats, including sand desert, spiny forests, and wetlands. Human exploitation, however, has caused the number of species to decline, and many of them are now in danger of extinction.

Lake Patisar has 13 islands and is of great biological importance. The islands are covered by lush vegetation, consisting mainly of wild sugarcane, kaha (Saccharum spontaneum, Poaceae), and the small water fern Salvinia natans in the shallow waters. After the monsoon, the vegetation becomes lush and insects abound, providing an ideal stopping point for several Palaearctic migratory birds. In winter, most of the migratory species stop over in areas like this before flying back to India and Sri Lanka. (They follow the flight route along the Indus.) More than 160 species of bird have been recorded in the reserve, 25 of them migratory waterbirds. It is not uncommon for the lake to support 30,000 birds, including abundant mallards (Anas platyrhynchos), the European pochard (Aythya ferina), and the European coot (Fulica atra). Other species worth mentioning include the purple gallinule (Porphyrio porphyrio), the purple heron, (Ardea purpurea), the grey or common heron (A. cinerea), and the common darter (Anhinga melanogaster). The lake also contains the largest population of fish in the region, and the concession of fishing licenses represents an additional source of income for the reserve's staff, though commercial fishing is not allowed. The most common fish are cyprinids, catfish, catla (Catla catla), murrel (Ophicephalus marulius), rohu (Labeo rohita), mullet (Vallago attu), mirgal (Cirrhina mirgala), and the trikanda (Rota rita).

Management and problems

Before the expedition in 1966-1967 financed by the World Wide Fund for Nature (WWF) to evaluate the conservation status of its wildlife, much of the Cholistan Desert was used as a hunting area by the former rulers of the state of Bhawalpur. The Nawabs maintained the region for the breeding and protection of game species, and this is why there were large populations of mountain gazelle, chinkara (Gazella gazella), nilgai (Boselaphus tragocamelus), hog deer (Axis porcinus), and blackbuck (Antilope cervicapra). The blackbuck used to be so abundant that a former governor of the state presented 50 specimens to a group of ranchers from Texas. The populations of nilgai and blackbuck can only survive in enclosed areas; otherwise, they are hunted. Other game species such as the hubara (Chlamydotis undulata) and the great Indian bustard (Ardeotis nigriceps) have met the same fate, due to the ready availability of firearms as a result of different conflicts, and the increasing popularity of four-wheel drive vehicles, which have made the animals easy targets. Furthermore, pollution of rivers, logging, the spreading canal system, and clearing of native scrub to make way for agriculture have seriously disturbed the reserve's fauna.

Many species of the Cholistan Desert have been indiscriminately hunted for their hides or horns. Others have been hunted because they represented a threat to human beings or their crops or livestock; among these are the wolf (Canis lupus), the common jackal (C. aureus), the Bengal fox (Vulpes bengalensis), Oriental civet or rasse (Viverricula indica), the African wild cat (Felis silvestris subsp. libyca), the caracal (F. caracal), the spotted mongoose (Herpestes auropunctatus), and the smooth-coated otter (Lutra perspicillata).

After the findings of the WWF expeditions, the Lal Suhanra was declared a game reserve, but many of its problems continued as a result of the war with India. Very little money was available to apply the most rudimentary protective measures, including the maintenance of observation points. Furthermore, in the early and mid-1970s, there was an alarmingly sharp increase in the illegal export of live animals and their products. The Pakistani government, through the Zoological Studies Department, then limited the number of live animals that could be exported. Unfortunately, many of the species in the area--such as the Indian porcupine (Hystrix indica), the black-naped hare (Lepus nigricollis), the wild boar (Sus scrofa), the Indian cobra (Naja naja), the wolf snake (Lycodon), and several species of saurians and turtles--could not benefit from this new measure.

Since Lal Suhanra became the first national park in Pakistan in 1972, comprehensive protective legislation has been enforced, services have been financed and built, and all activities that might alter nature have been strictly banned. It is strictly forbidden to shoot, trap, or catch any animal within a radius of 3 mi (5 km) of the reserve, and the forest in the reserve can only be cleared if it is within the plantation area. These measures have allowed those in charge to concentrate all the available resources on an ambitious project to reintroduce several species after three decades of persecution.

Several barbed wire fences have been built to hold the animals to protect them from predators during the first stages of reintroduction. These enclosures also make research work and curative veterinary treatments easier. So far, great importance has been given to the blackbuck (Antilope cervicapra), the chinkara (Gazella gazella), and the hog deer (Axis porcinus), but with international help some other species have been introduced outside the enclosures, among them the green peacock (Pavo muticus) and the mandarin duck (Aix galericulata). One of the most remarkable reintroductions, giving an idea of what the reserve might achieve, is that of a pair of Indian rhinoceros (Rhinoceros unicornis). An enormous moat has been dug near the plantation to house these animals; they used to be quite numerous before hunting them became fashionable.

Pakistan's current radical nature conservation policies can be attributed largely to what happened to the blackbuck (Antilope cervicapra), one of only three species of antelope found in the Indian subcontinent. Before World War II (1939-1945), the blackbuck was just another feature of the landscape, and it could be found in herds of several thousand on the most arid plains. Rapid population growth in India and Pakistan and the cultivation of previously unused land confined the blackbuck to the Punjab Province in Pakistan, where the Muslim inhabitants have no religious injunctions against eating meat. They hunted it almost to extinction.

Attempts to reintroduce the blackbuck began in the early 1970s, when a group of ranchers from Texas gave the reserve 10 specimens. From this modest start, the number of animals has increased very slowly, due to several unforeseen problems such as the correct choice of habitats, the effects of disease, predators and snakes, inappropriate feeding, and a lack of suitable protection--all problems that are present when reintroducing any species. Some of these limitations have been especially problematic. The vegetation of Lal Suhanra is dense, and the blackbuck relies on its agility in open spaces to escape from its predators. There were no large predators in the enclosures where it was reintroduced, but there were a large number of poisonous snakes, including the cobra (Naja tripudians), the krait (Bungarus caeruleus), and the saw-scaled viper (Echis carinatus).

Between 1973, when the first blackbuck was reintroduced, and 1977, a total of 10 animals died, 6 from snakebites and the rest from pneumonia. The physical characteristics of the blackbuck and its lack of defenses against disease, especially among the young, has encouraged all sorts of studies into the animal's food and environmental requirements. The blackbuck feeds on 19 of the 22 plants inventoried in the reserve, but it prefers just three of them: the babul (Acacia nilotica), the markh (Leptadenia pyrotechnica), and the prostrate spurge (Euphorbia prostrata). The nutritional value of these plants is not very high, so the animal's diet has to be complemented with the tepary bean (Phaseolus acutifolius) and sorghum (Sorghum vulgare), plants that allow them to lay down fat reserves for the cold months of winter.

There are other problems making the reintroduction of the blackbuck even more difficult, but they cannot be resolved until there is a viable population of this species. One of these problems is the system of enclosures itself. Though it is essential to protect the animals, it exacerbates competition between the males in the breeding season, and the males often get wounded or become exhausted. To avoid this, breeding groups with a smaller number of males have been established in other enclosures with the animals kindly presented by several international zoos.

At the end of the nineteenth century, when the region was still under colonial domination, a major effort was made to bring the area under cultivation. The forests were felled and a vast system of irrigation canals and reservoirs was built. Lake Patisar is one of these reservoirs. It was built to store the water from the desert branch of the Bahawal Canal--it runs right through the middle of the reserve--and is still used to obtain drinking water during the summer dry period. Before the region was declared a natural park, Lake Patisar's future looked grim. During the dry season, the local cattle raisers depended on the rich vegetation of its banks for grazing for their livestock. The surrounding marshes were being degraded, and several native bird species such as the marbled duck (Marmaronetta [=Anas] angustirostris) had disappeared. Stockraising and other activities that have a negative impact on the lake and waterbirds have been eliminated, though other less prejudicial activities are permitted in order to obtain a minimum of cooperation from the reserve's few inhabitants. About 20 families have permission to cultivate a total of 2,002 acres (810 ha) of land around the lake.

The reserve has been divided into zones to rationalize its use as a tourist, nature conservation, and research area. The different zones were established on the basis of ecological criteria and are not equally accessible to the public. From the point of view of tourism, the most important area is the intensive-use recreational area near the plantation. This zone has a visitors' center, a picnic area, and a children's park. The paths are suitably sign-posted and allow the tourists to visit the plantation, the moat, and the first zone. In the following zone, the recreational area for moderate use, there is lodging for visitors (the Hermitage Rest House) on the bank of the lake, and the Irrigation Department's building is on Whispering Hill. This zone includes part of the plantation, a desert sector, and part of Lake Patisar. It is basically intended for nature conservation, but the observation of wildlife is permitted, and there are four camping areas and two observation towers. Furthermore, in response to the demand, guided boat tours have been organized on the lake. The intact zone and the special use zone are the most protected and include much of the desert and the animals' precincts. Access to these two zones is limited, so as not to disturb the wildlife, and economic activities are totally prohibited there. With a permit, tourists can take a guided trip, and--from within the small shelters used almost exclusively by the reserve staff and scientists--they can observe the animals feeding.

Many services such as transport and the guide service are designed to convince the local people that tourism is a possible livelihood. The establishment of the reserve has not brought any sort of economic benefit to the local people, nor have they been taken into account when making management decisions. Even so, tourism has created some jobs in the Forestry Department and Nature Department, and there have been training courses on public relations and the management of open-air recreational activities. Furthermore, the financial operations generated by transport and the market for local products have generated an economic potential much greater than that of traditional agricultural practices.

2.6 The biosphere reserves in the hot deserts and subdeserts of Australia

Three of the twelve biosphere reserves in Australia are within a desert, and each one has its own distinctive physiographic features. The Uluru-Kata Tjuta Biosphere Reserve (132,550 ha [1 ha=2.5 acres]) is located in the Musgrave Ranges in the south of the Northern Territory, and part of it is mountainous desert. This reserve contains the famous Ayers Rock monolith and Mount Olga, which are in sharp contrast to the surrounding plain. The most interesting characteristics of the Danggeli Biosphere Reserve (253,230 ha) are the rolling plains of calcrete and the shallow brown calcareous soils, but the reserve also contains areas of small mobile dunes and layers of brilliant red sand, both of which are common in the alluvial plains and clay plains of the Australian deserts. The Unnamed Biosphere Reserve of South Australia (2,132,600 ha) contains two different types of desert, sand desert and rock desert. The north of the reserve is almost uninhabitable because of the total lack of water. The eolian sands originated as deposits left by the former rivers on deep sandy soils. The area is covered by extensive dunes running east-west; they are not very tall but are hundreds of kilometers long. Toward the south of the reserve, where rocky desert predominates, the occasional banks of clay and the saline areas in river beds periodically fill with water, although this does not happen often.

The drastic reduction of the population of Aborigines and the destruction of their traditional lifestyle after the arrival of the Europeans on the continent are well documented. In the last few years, however, greater understanding of Aboriginal customs and especially of their tjukurpa philosophy (the Aborigines' link to the land) have made it possible to take great steps towards solving the Aborigines' problems over land ownership and land use. The movement promoting these changes, the Outstation Movement, seeks to reestablish the Aborigine desert culture. Both the Uluru-Kata Tjuta Reserve and the Unnamed South Australian Biosphere Reserve are located in Aboriginal areas, but this aspect has only been treated seriously in Uluru-Kata Tjuta Reserve.

Current research leads to the conclusion that very few of the environmental changes caused by human beings have been positive. Only the use of fire and the control of erosion have been based on long-term studies that were carried out in the research stations in the deserts of the Northern Territory. Even so, the most recent studies into the application of fertilizers, irrigation, and the reintroduction of native plants are quite promising. These measures may return the desert ecosystems to stability and may even restore long-degraded areas. The only problem is that measures of this type do not usually generate substantial economic profits, and very little is invested in research outside of the biosphere reserves.

The case of the Uluru-Kata Tjuta

Biosphere Reserve

The Uluru-Kata Tjuta Biosphere Reserve covers an area of 132,550 ha. Approved in 1977, it is one of the 12 biosphere reserves in Australia. It was declared a World Heritage Site in 1987. Known simply as the Uluru (Ayers Rock-Mount Olga), it is located in the center of Australia in the southwest of the Northern Territory, about 208 mi (335 km) southwest of Alice Springs. The Uluru monolith (Ayers Rock) is the most famous landscape feature in Australia.

After the first explorations of the regions by the colonists, Uluru and Kata Tjuta (the Olgas, a nearby group of monoliths) were included in the Southwest Biosphere Reserve that was created in 1920 as part of a larger system of reserves created especially as sanctuaries for the Aboriginal population. In 1958, a zone including Uluru and Kata Tjuta was separated from the Southwest Reserve to form Ayers Rock-Mount Olga National Park. In 1977, the Uluru-Ayers Rock-Mount Olga was declared a National Park in accordance with the (Federal) Law on Parks and Nature Conservation. In 1979, the traditional Aboriginal landholders of the zone, supported by the (Northern Territory) 1976 Aboriginal Land Rights Law, claimed an area of land that included the park. But the national park was held as land alienated by the crown and, therefore, legally exempt from the reclamation. The rest of the claimed land was reclassified as Aboriginal land and now constitutes the area of the Kaitit Territorial Corporation in the north and east of the park. In 1985, the Commonwealth Parliament approved amendments to the (Northern Territory) Aboriginal Land Rights Law and the (Federal) Parks and Nature Conservation Law that ceded the Uluru National Park as an unalienable free land to the Uluru-Kata Tjuta Territorial Corporation.

An essential condition when ceding the Uluru-Kata Tjuta National Park to its traditional owners was that it be rented to the Australian National Parks and Wildlife Service (ANPWS), which would manage the park, together with the traditional owners, through the Uluru-Kata Tjuta Management Council. This management council is the first of its type in the world, as the inhabitants of the Uluru Park truly take part in the decisions affecting their land and are not limited to acting as advisers.

For many centuries, the Uluru region has been one of the main centers of economic, territorial, cultural, and religious relations between the desert peoples--the Pitjantjatjara, the Yankuntjatjara, the Matutjara, the Ngaanyatjarra, and other Aboriginal groups. The Anangu (the name the Pitjantjatjara call themselves) have lived in the Uluru-Kata Tjuta region for at least the last 10,000 years. The landscape of central Australia can thus be said to form an essential part of the culture of the Aboriginal peoples. Their occupation of the land can be reconstructed on the basis of archaeological finds, rock and cave art and drawings, and also from the personal histories of the park's current residents.

Anthropological characteristics and values

Contact with colonists in the first decades of the twentieth century meant that the Anangu living near Uluru made less and less use of the region, mainly for fear of possible conflict with colonists raising livestock. The Anangu started using the Uluru region again shortly after a settlement was established for them at Docker River in 1968. The Docker River Association built Ininti Store and the gas station, and the park became a major supply point for the Anangu living in the region. Some of these buildings were supposed to be demolished by the National Parks Service after the area was declared a national park, but they have been left standing in accordance with the Anangu's wishes. There are about 150 Pitjantjat-jara and Yankuntjatjara who usually live within the area of the park, most of them near Mutitjulu community, near the Uluru monolith itself. If the population varies, it is because of their itinerant lifestyle. The ANPWS's current 99-year lease from the Uluru-Kata Tjuta Territorial Corporation stipulates that an annual rent of $75,000 must be paid, together with 20% of the entrance receipts.

Within the park, traditional activities such as hunting and gathering are still practiced. Wild animals have deep meaning for the Anangu and form part of their religious interpretation of the surroundings and of life known as tjukurpa. For this reason, there is great interest in the possible reintroduction into the park of species like the red hare wallaby (Lagorchestes hirsutus) and the common Australian brush-tailed possum (Trichosurus vulpecula). Most animals used to be considered as a food source, but hunting is now mainly limited to the red kangaroo (Macropus rufus), the Australian bustard (Ardeotis australis), the emu (Dromaius novaehollandiae), and rabbits. The Anangu hunt in remote areas of the park and in the adjacent Aboriginal lands, and there is no proof that this subsistence hunting has any significant effect on the wild animal populations.

Within the park there are many sites of importance to the Aborigines. For the Anangu, however, the importance of the land is not only measured by the existence of these sites. One of the most meaningful aspects of a site is how it is connected to others. Sites inside and outside the park are thus connected by paths that mark the memory of the journeys and activities of one or more of the ancestral characters responsible for creating Earth and the life that it supports. These connections with other sites form an essential element of the way in which the Anangu lay out the park's landscape.

For the Anangu, the tjukurpa--at the same time the creator and the act of creation--gives answers to all the basic questions of existence, the meaning of life, and the continuity of everything. All of Earth, its shapes, and the life it supports were all created by tjukurpa, before which nothing existed. At the time of the tjukurpa, plants, animals, and ancestral beings with a human shape were traveling all over the planet carrying out great acts of creation and destruction. Their journeys are recalled in several elements of the current landscape that provide the Anangu with both a historic account of how the world came to exist and a religious proof of what the Earth means. With few exceptions, the tjukurpa within the park is part of much longer journeys by the ancestral beings, and the park is an important center of many ancestral tracks that converge there.

Thus, when the Anangu talk of the different natural elements within the park, they do so by considering them in relation to specific tjukurpa beings rather than by searching for ecological or geological explanations. The things created from the tjukurpa are not limited to geological features, as plants and animals are also included in this philosophy. This knowledge of the activity of the ancestral beings forms part of their oral tradition and is transmitted together with the systems of exploiting food resources. Thus, tjukurpa as a whole provide a unitary model of life stretching from the beginning of time to the present day.

Tjukurpa also means law; it is the basis of the rules governing behavior among people and between people and Earth. Since the distant past, the Anangu have been able to establish, throughout the Western Desert, ties with family and relatives and a system of social relations with other groups. This allows them to name as a relative, and then treat as a family member, someone they have never met before. One great advantage of this social system is that it makes possible cooperative activities with an egalitarian use of the land and its resources (even between people who may not be in continuous contact).

All around the base of Uluru are hundreds of sites with Aboriginal rock paintings of unknown age, and the Anangu realize the importance of protecting them as a part of their cultural heritage. At both Uluru and Kata Tjuta, there are rock carvings that are thought to be very old, and although they are less vulnerable to vandalism and other forms of deterioration, they are also protected.

Natural characteristics and values

The park consists of large areas of sand, dunes, and alluvial desert interrupted by the Uluru monolith and the nearby Kata Tjuta Massif 20 mi (32 km) to the west. During a period of tectonic activity, probably toward the end of the Ordovician Period (about 450 million years ago), the rocks that form this part of central Australia underwent folding and rose above sea level. Since then, erosive forces have worn most of central Australia down to a huge plain, but some harder rocks have resisted erosion; in a few sites, they have reached the present day in the form of hills and mountains, like Uluru and Kata Tjuta, and are known as inselbergs. At Kata Tjuta, there is at least an 8,202 ft (2,500 m) thickness of exposed conglomerate, while at Uluru there is a thickness of at least 1,969 ft (600 m) of feldspar-rich sandstone.

Erosion since the Tertiary has given rise to the large areas of sand that cover large parts of the park. Uluru rises about 1,115 ft (340 m) above the surrounding deserts. Its circumference at the base is 5.8 mi (9.4 km), with smooth sides with slopes as steep as 85[degrees] and a relatively flat peak. The important surface features of the rock are the areas of laminar erosion, with layers 3-10 ft (1-3 m) thick; deep parallel surface fissures running from the top down the sides of the monolith; and a few caves and overhangs at the base formed by chemical degradation and by wind erosion. The Kata Tjuta Massif covers about 3,500 ha and consists of 36 steep-sided domes of conglomerate. They usually have rounded tops, almost vertical sides, and are separated by gorges; most have been subject to the same erosive processes as Uluru.

Much of the park consists of sand and stone areas lacking defined watercourses. The park has very limited surface water resources, and all the water holes except Mutitjulu (Maggie Springs) can be considered ephemeral, with levels that rise or fall depending on whether conditions are dry or wet. During the rainy season, the surface water is generally limited to temporary pools fed by seasonal watercourses coming from the monoliths. These watercourses are short and have a low volume of flow, as much of the rainfall they intercept is lost by runoff. Temporary pools form in holes in the ground or around the bases of the monoliths (such as Kantju or Inintitjara), where the water may last for months. The Anangu believe that this availability of water is caused by the tjukurpa and has a permanent relation with it.

The park has two different seasons--the winter, between April and October, and the summer, between November and March. The daily maximum and minimum temperatures are 39[degrees]F (4[degrees]C) and 68[degrees]F (20[degrees]C) in winter and 72[degrees]F (22[degrees]C) and 100[degrees]F (38[degrees]C) in summer. The extremes of temperature range from an absolute minimum of 23[degrees]F (-5[degrees]C) to an absolute maximum 111[degrees]F (44[degrees]C), and frosts are frequent between June and August. The annual rainfall can vary greatly but is always between 8-20 in (200-500 mm). Most rainfall is in winter (roughly 67% in June and July). The dominant winds blow from the southwest to northeast in the summer and in the opposite direction in the winter.

The park's vegetation is influenced by its stability and the soil's moisture regime, the climate, the topography, the frequency of fire, and the frequency of Aboriginal gathering of fuelwood and food. The park's landscape is a valuable representative sample of the flora and vegetation of central Australia. It is dominated by low-growing plants that form structurally simple communities. In some areas, the trees and shrubs are irregularly scattered, while in others they are distributed more regularly. As in many of the arid regions of Australia, there are few species of Eucalyptus, and those that are present are normally restricted to the wetter areas. Some species of trees (Acacia aneura), shrubs (Allocasuarina decaisneana), and grasses such as spinifex (Triodia) and Plectrachne resist the drought by remaining dormant when it is dry and renewing growth when favorable conditions return. There are also evergreen species, although less common than drought-resistant species, which avoid the dry periods by allowing their aerial parts to die; they are able to regenerate them later from tubers and rhizomes. This is shown by many perennial tussock grasses such as Eragrostis eriopoda and Themeda australia. Finally, there are ephemeral species that avoid drought by germinating after rain, growing quickly, flowering abundantly while producing their seeds, and then dying when dry conditions return. They are usually low grasses and other small herbaceous plants that often form the herbaceous understory of tree and shrub communities; examples are the white daisy (Helipterum floribundum, Asteraceae) and billy button (Calocephalus platycephalus, Asteraceae), two attractive composites from the Australian desert.

The biosphere reserve contains the three main categories of plant landscape typical of central Australia: Simpson, a hummock-grass formation typical of dunes and sandbanks and one of the most widespread vegetation types in the park; gillen, which consists of Acacia woodlands around the monoliths, at the base of the hills, and on the alluvial fans (because these woodlands contain the rarest and most sensitive species, the area is restricted); and the karree, which consists of the areas of runoff from the plains of mulga (Acacia aneura).

The patches with deep soils are dominated by grasslands of the genus Cymbopogon and sedges of the genus Cyperus (Cyperaceae), while in areas where the soils are very superficial, the grasses and sedges are represented by Tripogon and Fimbristylis. There are also patches of Acacia and porcupine grass (Triodia pungens) with isolated specimens of Ficus platypoda and Eucalyptus terminalis. Porcupine grass forms almost pure stands in the Kata Tjuta Massif, while on the less steep slopes there are species of Acacia, Cassia, and Hakea. Scree slopes support low shrubs of different species of Eucalyptus and Acacia and many other genera. In the area immediately around the base of the rocky outcrops, there are dense patches of the perennial grass Eriachne scleranthoides, while other grasses and sedges dominate the adjacent shallow soils.

The base of the Kata Tjuta dome contains the grasses Aristida contorta and Enneapogon polyphyllus, some low specimens of Acacia aneura, and species of Cassia and Ptilotus. Some species of Eucalyptus, shrubs, and perennial herbs can be found in the beds of the watercourses.

On the alluvial fans and screes around the monoliths, there is a mosaic of open grassland, low trees, and shrubs. The woody species include the long-fruited bloodwood (Eucalyptus terminalis), several species of teatree (Melaleuca), different species of Acacia and Ptilotus, and the grasses Themeda avenacea, Ennea-pogon cylindricus, and Eragrostis eriopoda. This vegetation type may become lush in the rainy periods.

The plains zone supports dense thickets of mulga, other species of Acacia, and different species of emu bushes (Eremophila, Myoporaceae), with a perennial understory of the grass Eragrostis eriopoda. The areas between the thickets are covered by a sparse vegetation.

The dunes and flat or rolling sands are dominated by spinifex and by an open scrub of Eucalyptus gamophylla, Acacia kempeana, and the broom bush (Templetonia hookeri, Leguminosae), with occasional desert oaks (Allocasuarina decaisneana, Casuari-naceae) in wetter sites.

More than 360 species of plant have been recorded from within the park. The endangered species include herbaceous plants like the pink early nancy (Wurmbea centralis, Liliaceae) and Juncus continuus (Juncaceae), shrub species like Sturt's desert rose (Gossypium sturtianum, Malvaceae), Rulingia magniflora (Sterculi-aceae), Hibbertia glaberrima (Dilleniaceae), Baeckea polystemonea (Myrtaceae), and Plectranthus intraterraneus (Lamiaceae). Rare plants confined to the wetter areas include the trigger plant Stylidium inaequepetalum (Stylidiaceae), the rare tussock grass Eriachne scleranthoides, and the adder's-tongue fern Ophioglossum lusitanicum. Thirty-four species of introduced plant have been identified, especially in the disturbed areas. They include Rumex vesicarius (Polygonaceae), known in Australia as ruby dock; Mossman River grass (Cenchrus echinatus); buffel grass (C. ciliaris); the colocynth (Citrullus colocynthis); and the devil's thorn (Tribulus terrestris, Zygophyllaceae).

The biosphere reserve is the habitat for a wide range of animal species, some of them rare and of scientific interest. There are a total of 22 native mammals, including three large species, the dingo (Canis familiaris dingo), the red kangaroo (Macropus rufus), and the wallaroo (M. robustus). Neither the dingo nor the red kangaroo seems to be strictly confined to specific habitats, but the red kangaroo is rarely seen in the rocky Kata Tjuta area or around Uluru. The movements of the two species are essentially determined by the availability of water. The smaller species include the marsupial mole (Notoryctes typhlops), the spinifex kangaroo mouse (Notomys alexis), the brown Australian desert mouse (Pseudomys desertor), the mulgara (Dasycercus cristicauda), and the threatened bilby or rabbit-bandicoot (Macrotis lagotis).

The common echidna (Tachyglossus aculeatus), one of the two egg-laying mammals discovered in Australia, can occasionally be seen in the park. Most of the small mammals are nocturnal and shelter in their burrows or other protected areas during the day, when air and ground temperatures are too high. Just how rainfall and food resources affect many species is little known. A few species of bat have been recorded, including the threatened Australian false vampire (Macroderma gigas), the common Australian pipistrelle (Pipistrellus pumilus), the broad-nosed bat (Scotorepens greyi), and the lesser long-eared bat (Nyctophilus geoffroyi).

Several medium-sized mammals have been extirpated from the park in the twentieth century, including the red hare wallaby (Lagorchestes hirsutus), the short-nosed digging rat kangaroo (Bettongia lesueur)--both of them considered rare species--as well as the brush-tailed possum (Trichosurus vulpecula) and the blackfooted rock wallaby (Petrogale lateralis). The reintroduction of these species is being considered, as they all play an important role in the tjukurpa. The introduced species include the common fox (Vulpes vulpes), the house mouse (Mus musculus), the rabbit (Oryctolagus cuniculus), cats, dogs, and wild camels.

More than 150 species of bird have been recorded within the park, and 66 species are considered resident. There are many parrots and related species (Psittaciformes) such as the mulga parrot (Psephotus varius), the Port Lincoln rosella (Platycercus zonarius), and Bourke's parakeet (Neopsephotus bourkii); birds of prey include the wedge-tailed eagle (Aquila audax), the Australian kestrel (Falco cenchroides), and the locally endangered peregrine falcon (F. peregrinus); the zebra finch (Poephila guttata) and 15 species of thornbill (Pardalotidae) are also present. A few species of mud-living migrants--the sharp-tailed sandpiper (Calidris acuminata), the common sandpiper (Tringa [=Actitis] hypoleucos), and Bering's sandpiper (Calidris tenuirostris)--have been recorded as well. Central Australia's reptile fauna is richer than anywhere else in the world. The species of snake found in the biosphere reserve include large poisonous species like the mulga snake (Pseudechis australia) and the western brown snake (Pseudonaja nuchalis). Though infrequent, Ramsay's python (Aspidites ramsayi) and small digging snakes (Simoselaps spp. and Neelaps spp.) can also be found. All five families of saurians found in Australia are represented, especially different species of monitor lizard such as the pernty (Varanus giganteus) and V. gilleni and V. tristis. Many reptile species are restricted to the patches of spinifex or depend on it, and there is no doubt that this is the main habitat of the reptiles in the biosphere reserve. Other species, including the mottled dtella (Gehyra punctata) and the skink Carlia tricantha, are restricted to the rocky areas, where they live in the cracks in the fissured rock.

The park's amphibians are poorly documented, but frogs such as Cyclorana cultripes and C. platycephalus have been found at the water holes. Most of the species live in specialized habitats that allow them to survive in these arid surroundings. There are, for example, terrestrial species, such as the frog Neobatrachus centralis, that usually dig underground and only emerge aboveground after rainfall.

The invertebrate fauna is little known, but there are some remarkable crustaceans of the genus Imnadopsis and the tadpole shrimp Triops australiensis, which is thought to have existed in its current form for more than 150 million years. These crustaceans live in the temporary pools that form on the top of the Uluru rock.

Management and problems

When formulating the management plant for the park, the local Anangu were consulted on the Aboriginal religious interpretation of the landscape. The Anangu members of the council make important contributions to management policy decisions, and they are consulted on all major undertakings (and most of the less important ones) carried out within the park in order to ensure that the type and siting of the proposed interventions do not violate tjukurpa.

The layout of the access route to Kata Tjuta, the route of the paths on Uluru and Kata Tjuta, and the site of the future cultural center are the result of this type of consultation. There have been some proposed interventions that the Anangu have rejected because they were in conflict with tjukurpa. The Aborigines of Uluru-Kata Tjuta consider there are two basic categories of sites within the national park: those that tourists can visit, and those that they cannot. Settlements or sites with paintings and carvings may be in either category, and in both categories there are secret places to which access is highly restricted. Four secret sacred sites--two of special importance for women and two of special importance for men--have been closed and are legally protected; they cannot be visited or entered for research purposes.

The management of the Uluru-Kata Tjuta Biosphere Reserve is the responsibility of the Uluru-Kata Tjuta Management Council (consisting of a majority of Aborigines), together with the ANPWS. The management plans are worked out jointly by both institutions. The priority management aims include protecting Aboriginal culture, displaying and interpreting the landscape (especially its combination of natural and cultural elements), and conserving the most representative ecosystems.

The park's main values are its cultural and religious heritage, its landscape, its arid ecosystems, and the derived recreational objectives; the park director has the authority to restrict access to certain areas in order to protect traditional Aboriginal customs and values. The rent agreement, which is revised every five years, seeks to strengthen Aboriginal traditions by 1) protecting the areas, sites, and features that are important to them, 2) involving the Aboriginal population as closely as possible in the administration and ways in which the park is used, and 3) using traditional Aboriginal techniques whenever possible. The non-Aboriginal employees are encouraged to learn and understand the language, culture, and techniques of the Aborigines, and the land's traditional proprietors are to be regularly consulted on the park's administration, management, and control. The park is divided into three main areas that differ in degree of use: a zone of intensive activity, an intermediate activity zone, and a minimum activity zone. The restricted access areas are reserved for scientific research and for the Aborigines to live in. They may contain sacred sites or archaeological sites or have a special importance for conservation. The visitors concentrate in the areas around the monoliths; thus, a few sacred sites at the base of Uluru have been closed to the public. The effectiveness of dividing the park into zones is being assessed over the course of the current management plan.

Uluru has been relatively well studied in comparison with other parks in central Australia. Studies have been carried out on the park's climate, geology, hydrology, flora, and fauna, and maps of the vegetation types and territorial units have been drawn up. More studies are planned to determine the distribution of the rare and endangered plant and animal species such as the mulgara (Dasycercus cristicauda), the brown Australian desert mouse (Pseudomys desertor), the striated grasswren (Amytornis striatus), and the great desert skink (Egernia kintorei). Past observations of these species by the Anangu has helped to clarify the characteristics of some species and their relationships with the environment. By 1989, the park's herbarium contained 363 species belonging to 186 genera and 65 families.

Before Europeans introduced livestock, the Aboriginal peoples of central Australia used fire repeatedly and deliberately. The main intention when setting these fires was to manipulate the ecosystem in order to attract the animals to specific areas and to stimulate the growth of the wild plants they feed on. The large number of fire-resistant species found in much of this arid area indicates that fire was a normal component of Australia's arid and semiarid environments. Even so, the fires were often limited to relatively small areas, a few hectares or less, though occasionally a larger fire might cover a few square kilometers. There is some evidence that interrupting the fires traditionally set by the Aborigines has made large-scale natural fires more likely.

There is now a strong focus on policy for handling fires within the park and in the surrounding Aboriginal lands, following strategies based on both the Aborigines' traditional burning practices and on modern studies. Satellite images are used to monitor fires within the reserve, and a geographic information system is also used to draw up maps that show the number of fires for each season and year. Every year, an image is obtained in early autumn to show the sites of the fires in the preceding summer; in the spring, new images are used to detect the patches that burned in the winter. Attempts are being made to eliminate fire from some areas; this protected land will support a wider range of vegetation and habitats that can be used as reserves in case the park burns out of control. There are other sites where small controlled fires are set in accordance with the annual action plan, aimed at reducing the accumulation of tinder and maintaining the diversity of the plant communities. The Anangu also play an important role, as they provide information on the flora and the cultural sites, and this is incorporated in the fire action strategy.

Uluru-Kata Tjuta is the only major tourist attraction in Australia's Northern Territory. The first tourists visited the area in the late 1940s after the construction of a road to Uluru in 1948. Since then, the number of tourists has risen spectacularly, from 2,296 in 1958 to 250,000 in 1991 and even more in later years. The Anangu of the region make sure visitors to the park receive the correct information on Aboriginal culture and on tjukurpa. The older Anangu women have marked out the Liru trail, an excursion with an Anangu guide that gives the visitor some idea of their traditional culture and their ideas, and the Anangu have also collaborated a great deal on other excursions and visits to sites.

The problems facing the managers of the Uluru-Kata Tjuta Biosphere Reserve are in some ways typical of highly exploited natural areas. On the other hand, Uluru-Kata Tjuta presents a further challenge, as all the interventions have to be channeled through the religious and cultural beliefs of the traditional landowners and the Anangu living in the park. Their sacred sites, their rock paintings, and their traditional ceremonies might be threatened by unthinking visitor management, by disturbances caused by inadequate use of vehicles, or by the routes of main roads and trails.

It has been considered desirable to provide the Aborigines with housing, with health, education and communications infrastructure, and with assistance in monitoring alcohol abuse among the population (a problem that seems to have declined greatly). In general, the historic deterioration of the Aborigine culture has been stopped by guaranteeing the right of free access to the land and by permitting the local population to play a relevant role in planning and management.

138 The Joshua tree (Yucca brevifolia, Agava-ceae) dominates the Joshua Tree National Park in the Californian Mojave Desert. The declaration of national parks and other protected spaces within the desert biomes ensures the preservation of unique plant and animal species found no-where else in the world. They are unique because many of them have had to undergo profound changes to adapt to an extremely harsh environment. The Joshua tree is an example of this. It is not a true tree but a lignified arborescent herbaceous plant. It is endemic to the hot regions of southwest North America. In the Joshua Tree National Park, this unusual arborescent monocot forms large very open thickets at altitudes above 2,953 ft (900 m).

[Photo: Carr Clifton / Minden Pictures]

139 The current appearance of the great Thar Desert in northwest India is largely the result of human action. Indiscriminate felling of trees, overgrazing, and continued trampling by livestock have caused the desert to spread into a region that was lush forest 2,000 years ago. Desertification has accelerated in the last century, when dunes have been advancing on the entire perimeter of the desert at a rate of about half a mile (0.8 km) per year. Sand and bare rock now cover 260,000 [km.sup.2]. Most of the Thar Desert is covered by dunes and undulating sandy plains. A shallow soil does form, but soil formation is almost impossible, so the plants cannot root.

[Photo: R.M. Modi / DPA / Images of India]

140 The fixing of dunes by the vegetation is a good method of slowing down the expansion of the deserts. In areas where average annual precipitation exceed 6 in (150 mm), a permanent natural plant cover can be made to grow on the dunes, but the surface has to be stabilized in advance. This can be done by, for example, spraying the surface with a mixture of oil and synthetic rubber, then planting the seedlings later. The plants can survive on the water that accumulates under the dunes after the rains until the next rainy period. Their shoots hold down the sand and then bind the soil. Plants are also a barrier to the wind; the dead leaves and other plant matter accumulate there and help to fix the sand. Eventually, the dunes are fixed, like the ones in this photo of White Sands National Monument in New Mexico (United States).

[Photo: Michael & Patricia Fogden]

141 The Rub' al-Khali Desert in the southeast of the Arabian Peninsula is the largest sea of sand in the world, even though the Sahara contains a larger number of sandy plains. This Arabian desert also contains some of the tallest dunes in the Old World. The Rub' al-Khali, whose name means empty quarter, covers 560,000 km2, and its extreme aridity, the intense heat, the low rainfall, and the lack of vegetation all make it uninhabitable, even for nomadic herders. There are oil fields in the Rub' al-Khali and in the surrounding areas, for example the Lekh-wair dunes, and this has made it necessary for people to work there in the extraction of the oil, despite the suffocating heat and the almost total lack of water.

[Photo: Xavier Eichaker / Bios / Still Pictures]

142 Low scrub vegetation covers large areas of the Big Bend National Park in Texas (United States). The dominant species are the creosote bush (Larrea tridentata), Leucophyllum candidum, and lechuguilla (Agave lecheguilla). There are large areas of plains covered by scrub like this in southern and western Texas, and they mark the transition with the true Chihuahua Desert, which extends from Mexico to the southwestern tip of Texas, southern New Mexico, and southeastern Arizona. In the early nineteenth century, much of this area was covered by grass, but stocking with too many cattle greatly reduced the grassy area. As a result, the soils turned into desert and became unproductive. In many zones, the original vegetation was replaced by species from Mexico, as happened in another American desert, the Sonoran Desert in Arizona.

[Photo: David A. Ponton / Planet Earth Pictures]

143 Biosphere reserves in the hot deserts, showing their area (in hectares; 1 hectare=2.5 acres) and the year they were created. There are deserts and subdesert reserves in all the continents, but they do not always represent all the different types of desert that exist. For example, all the reserves in Africa are concentrated in the Sahara, and there is not a single one in the deserts in southern Africa. Most of the reserves are very large, the largest being the Tassili N-'Ajjer National Park in the Sahara in Algeria, which covers 7,200,000 ha. Some of these reserves not only include desert and subdesert areas but also contain zones that are not arid.

[Drawing: IDEM, from data supplied by the MAB Pro-gram / UNESCO]

144 The landscape of the Mapimi Biosphere Reserve, showing the typical bolsones of the area, which belonged to the Apache and Comanche. The other interesting features include slopes, playas, lomas, and cerros that occupy the center, the south, and the west of the reserve; in the northern sector is a formation of dunes fixed by vegetation. In the east, there is a large mountain massif whose highest point is 5,512 ft (1,680 m) above sea level. Mapimi's plant formations are very varied and of great interest, consisting of extensive xerophytic grasslands and scrub that vary greatly in their composition and physiology and include many endemic species.

[Photo: M. Barrs / Incafo]

145 The ocotillo (Fou-quieria splendens) is a very common plant in the Mapimi Biosphere Reserve (Mexico), where it is one of the dominant species in the candelilla and lechuguilla formations. This shrubby plant, a member of the candlewood family, the Fouquieriaceae, can reach a height of 33 ft (10 m). It has adapted to the desert and semidesert climate by producing its very short-lived leaves immediately after the rains fall in spring and at the end of the summer. They are carried on numerous erect stems that are only rarely branched (see figures 45 and 57). In this period from March to July, the ocotillo produces its bright scarlet flowers. When there is no more moisture, it sheds its leaves, and the plant remains inactive during the rest of the year, awaiting the return of the rains to produce new leaves.

[Photo: John Shaw / NHPA]

146 Radio tracking of the Mapimi, or bolson tortoise (Gopherus flavomarginatus), a species endemic to the Me-xican subprovince of Mapimi. This forms part of the program for the recovery and conservation of this reptile included within the reserve's plan of activity. The nineteenth century saw a drastic reduction in the turtle's area of distribution (by 30-50%) and its population (by 60-80%). Studies began in 1978, the year after the reserve was created, and their objective was to set up a protection program based on assessing the species' breeding success in wild populations. One of the most important factors behind the continued decline of the turtle's population has been its growing use as a protein source for humans (tortoise hunters, hunter-gatherer groups in the arid zones of North America), together with natural predation and the degradation of the environment. Yet, despite the fact that pressure from humans persists, the species has survived, presumably due to its underground ha-bits. The program's activities include the protection of several breeding populations. In 1983, a strategy was devised to recover egg-laying sites. Eggs were incubated in captivity, and the survival rate of specimens reared in captivity and released into the wild was later assessed.

[Photo: G. Beutter / Instituto de Ecologia, Xalapa]

147 The kit fox (Vulpes macrotis) lives in the desert and steppe environments of southwestern North America, in areas with a minimum herbaceous and shrub cover. A nocturnal species, it may cover several kilometers in a single night in search of its prey, basically rodents and lagomorphs. The kit fox is neither timid nor cautious, and its populations have been greatly reduced by traps, shotguns, and poisons. Habitat destruction and the spread of irrigated agriculture have also caused its numbers to decline. The Mapimi Biosphere Reserve, in the heart of the Chihuahua Desert in Mexico, is one of the few places where this carnivore can still roam undisturbed.

[Photo: B. & C. Calhoun / Bruce Coleman Limited]

148 The candelilla shrub (Euphorbia antisyphilitica) is exploited to produce a wax, candelilla wax, used in the manufacture of cosmetics. As for many other wild plants, exploitation has been one of the factors that has most directly caused its populations to decline in the Mapimi Reserve. In the zone now within the biosphere reserve, the human population has fluctuated greatly over the last few decades; rapid migration from the rural centers has recently been detected, which is at least partly due to the poor economic prospects in the region, where productivity is very low. The most important activity is stockraising, and it has been responsible for the most damage to the natural resources, although there are also extractive forestry activities based on species not collected for their wood, such as the candelilla shrub. Lack of knowledge regarding appropriate technologies for rational exploitation represents a serious threat to the ecosystem.

[Photo: Mary Clay / Planet Earth Pictures]

149 A study of the productivity of the perennial grasses Hilaria mutica and Sporobolus aeroides, the two main fodder resources in the Mapimi Biosphere Reserve. Because extensive stockraising is the main human activity in the area, research was started into the use of water resources by these two species; this has led to a better understanding of their adaptations to aridity and has shown the two species' great ability to extract water from the soil. Hilaria mutica, tobosa grass, is dominant in the local bolsones and shows a double adaptation. Many of its roots are in the top layer of soil, 90% of them at a depth of 0-16 in (0-40 cm), and its growth when water is available is very fast. These features are very effective responses to two of the main features of the environment, the clay soils and the summer rains. Rainwater cannot penetrate very deep into clay soils, and most of the rain falls in summer, when evapotranspiration is highest; together, they allow very fast growth. During the dry periods, however, the leaves and stems dry out, and the plant remains inactive until the next rains.

[Photo: Agustin Estrada / Instituto de Ecologia, Xalapa]

150 A branch of the creosote bush Larrea divaricata, a common shrub of many American subdeserts. This plant genus is named after a Spanish promoter of science, Juan Antonio Larrea, and is a member of the Zygophyllaceae family. The creosote bush is an evergreen, resinous xerophytic shrub that reaches a height of 3-13 ft (1-4 m). It often grows at the base of other shrubs and trees, with which it will later compete for water when it is adult.

[Photo: Ramon Folch / ERF]

151 The yellow aromatic flowers of mesquite (Pro-sopis pubescens) brighten up the plant landscape of the southwest of the United States and the northwest of Mexico. They are an excellent source of nectar, with which bees produce a clear aromatic honey. The sugar-rich legume fruits of the mesquite curl up like a corkscrew and are used as feed for livestock and to make a drink known by the plant's name in Spanish, mezquite de caracol (snail mesquite, a reference to the spiral pod). This treelike shrub with spines up to 3 in (8 cm) long is usually the dominant species in desert and semidesert environments with rainfall of less than 3 in (80 mm) per year. It grows on sandy or stony substrates along watercourses and in areas with relatively abundant underground water. It is also very common in overgrazed areas. In dry environments, honey mesquite thickets constitute an impressive landscape. Very drought resistant, with a broad deep root system, this species is often planted in arid areas to check erosion and stabilize dunes. It also serves as hedging to divide fields.

[Photo: Stan Osolinski / Oxford Scientific Films]

152 The ruiniform rocky landscape of the Tassili N-'Ajjer is full of archeological and natural treasures, the reason why it is a conservation area. The sandstone spires, up to 98 ft (30 m) tall, have been sculpted into weird shapes by erosion, and together with the numerous examples of rock art, they make the land a wonderful open air museum. But its great interest means that Tassili N-'Ajjer now faces new threats. Tourism is filling the area with rubbish, overexploiting its water resources, and degrading the gueltas, while poaching now endangers the mouflon, gazelles, and even some reptiles.

[Photo: Georges Lopez / Bios / Still Pictures]

153 The apple of Sodom (Calotropis procera, Ascle-piadaceae) is a tough shrubby plant of the deserts of North Africa and the Near East, normally growing on sandy nitrate-rich soils, frequently at the base of dunes. The front of dunes is one of the most favorable habitats for plants in sandy deserts, as this is where moisture levels are highest because the runoff rainwater descends and infiltrates towards the base. This tough member of the Asclepiadaceae is essential for the survival of many small desert animals, especially for the several insects that feed on its leaves and lay their eggs under the protective fibers of its fruits. One such insect is Spilothetus pandurus, a brightly colored lygaeid bug that is very common in the deserts of northern Sudan.

[Photo: Jordi Bartolome]

154 The Tassili cypress or tarout (Cupressus sempervirens dupreziana) is one of the few trees that grows in the Sahara, and it is threatened by the demand for fuelwood and by overgrazing. This cypress is a reminder of a time when the Sahara Desert had a milder climate. Long-lived (specimens up to 2,000 years old have been recorded) and one of the most drought-resistant trees known, the tarout is threatened by browsing by animals (they eat the shoots and sprouts) and by the indiscriminate felling of its branches for fuelwood. The specimen in the photo is one of the few remaining specimens left on the Tassili plateau in southern Algeria, but it has been severely cut back.

[Photo: Tuck Goh / The Hut-chison Library]

155 The archeological remains of the Cholistan Desert are testimony to the existence of an ancient civilization that flourished along the Hakra River and are one of the attractions of the Lal Suhanra Biosphere Reserve in the southeastern Punjab, Pakistan. About 20,932 ha (1 ha=2.5 acres) of the 37,426 that the reserve covers are relatively flat desert with sand dunes covering large areas, up to 1,000 ha, to a height of 13 ft (4 m). The zone has a typical tropical xerophytic vegetation, well adapted to the arid climate with its sporadic rains, high temperatures, low humidity, and high rates of evaporation. The fauna is also interesting, with an abundance of large herbivores of arid environments such as nilgai (Boselaphus tragocamellus), chinkara (Ga-zella gazella), and blackbuck (Antilope cervicapra), which was on the brink of becoming extinct in the desert but was released into large enclosures in the reserve (see also figure 157). The fauna also contains carnivores and reptiles; in Lake Patisar, the wettest area in the reserve, there are many waterbirds and fish.

[Photo: Mauri Rautkari / WWF International]

156 Lake Patisar is the largest wetland in the area of the Lal Suhanra Reserve. This lake was originally built as a reservoir to store water for irrigating crops, but it fell into disuse. It is fed by a branch of the Bahawal Canal and receives other inputs of water from the surrounding irrigated ground. It covers an area of 1,935 ha and has a relatively constant average depth of 15 ft (4.5 m) all year-round. Aquatic vegetation is abundant with large areas of reeds and floating and submerged water plants. Dense thickets cover the banks, the shallow areas, and the shoreline in general. Lake Patisar is also an important overwintering area for many waterbirds, especially ducks, and a staging post for many other birds, especially in autumn. It has a substantial fish population, including carp and catfish.

[Photo: WWF Pakistan]

157 The blackbuck (Anti-lope cervicapra) is one of the species protected in the Lal Suhanra Biosphere Reserve in Bahawalpur (Pakistan). The males and the females differ in color (very unusual among antelopes). Only the males (the bucks) have horns, and they are darker (black)--the reason the species is called the blackbuck. The blackbuck used to roam the grasslands of the Indian subcontinent in huge herds, but intense hunting and habitat destruction have greatly reduced its populations. In the nineteenth century, there were an estimated four million blackbucks; by 1947, there were 80,000; by 1964, there were only 8,000 left. The establishment of reserves such as Lal Suhanra, where blackbuck were not in danger, stabilized their numbers, and there are now an estimated 40,000 individuals. Another region where they can be seen in great numbers is around the villages of Rajasthan and Gujarat in northern India, where the villagers consider them sacred and protect them.

[Photo: Mary Rautkari / WWF International]

158 Uluru, as Ayers Rock is known by the Australian Aborigines, is one of the symbols of Australia and the most visited landscape feature in the whole country. The apparent changes in color over the course of the day are stunning. At night it is just a black block, but with the first light of dawn it changes to a deep violet that becomes clearer as the day arrives. When the Sun is high and Uluru is fully lit, it turns a beautiful shade of gold. Sacred to the Aborigines, the first white man to see it was British explorer Ernest Giles (1835-1897). He was forced to cut his journey short but returned the next year. However, the expedition led by William Gosse (1842-1881) had beaten him and climbed the rock first. Gosse, who did not know the Aboriginal name, named the rock after the then-Prime Minister of South Australia, Sir Henry Ayers (1821-1897).

[Photo: Oriol Alamany]

159 Snakes play a major role in the Aboriginal dreamtime paintings. According to Aborigine beliefs, dreamtime was the mythical time when everything started, when the totemic ancestors--half human and half animal-- created the landscape. In the beginning, the nonpoisonous desert snakes, the totemic ancestors of the Linuya, arrived from the west and settled a sand hill on which there was a spring. The hill of sand turned into the Uluru Moun-tain. The Kuniya women, cooking round the campfire, were turned into the large, rounded stones in the Tjukiki Gorge. Their piti (foodbags) were turned into stone and formed the pile of small boulders at the entrance to the gorge. A hole in the rock represents the campfire, and the grass growing nearby represents the hair of the women. The men of the Kuniya clan--the largest rocks dominating the gorge--are guarding their women and the campfire. Deep in a hole, the ancestral snake Wanambi rests. When offended, he springs up and adopts the form of a rainbow. Violent wars started between the Kuniya and the Liru, whose totemic ancestor is a poisonous snake from Mount Olga. The combat and death of the warriors, the curses hurled by the women, and the scars made by the spears are all written in the rock. Other clans--such as the Male, who identify with wallabies--came from the north to circumcise their boy children after a long initiatory journey. Uluru is a genuine pantheon, a sacred site where the symbols, history, and myths that form the identity of the Aboriginal people are written for eternity in the rock.

[Photo: Michael & Patricia Fogden]

160 The silky oak (Grev-illea eriostachya), represented by a specimen near Uluru, is very important for the Aborigines of the southwest portion of Northern Territory. The local tribes, the Yankun-tjatjara and Pitjantjara, regard Uluru as a spiritual center to meet their ancestors, and they decorated the caves with paintings. The many tourists who now visit this magnificent geological monument are banned from entering the caves. The flowers of the silky oak were used by the Aborigines as a source of nectar, which they enjoyed greatly.

[Photo: ANT / NHPA]

161 The marsupial mole (Notoryctes typhlops), a strange mammal found in the sandy deserts of Australia, is one of the most interesting animals of the Uluru-Kata Tjuta Biosphere Reserve. This yellowish white mole has a horny structure above its nose that it uses as a drill when it digs its underground burrows. The third and fourth digits of each hand, very long and with triangular nails, are used as shovels, and it then kicks the loose earth with its rear legs. The preferred habitats of this strange animal are riverbanks, scrub, and acacia thickets. It is on the move all day and night in search of the beetles, ants and other small animals that make up its diet. The specimen in the photo is devouring a scolopendrid.

[Photo: M.W. Gillam Auscape International]

162 Walking up Uluru is one of the most popular of all the activities offered in the Uluru National Park in Northern Territory, Australia. Seventy-eight percent of all visitors decide to do so. The safe path to this enormous peak of arkose (coarse-grained feldspathic sandstone) is marked by spikes set in the rock's western slopes. A plaque halfway up records the tragic deaths of those who tried to climb by other routes. The rock is only 1,142 ft (348 m) high, but the route is more than a kilometer and a half long. Other activities available in the park include guided visits to different places of interest, walks, flights to see the landscape, views of sunrise and sunset, on-land motor excursions, picnics, and photography.

[Photo: S. Wilby & C. Ciantar / Auscape International]
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Publication:Encyclopedia of the Biosphere
Article Type:Report
Geographic Code:8AUST
Date:Apr 1, 2000
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