Studies on the Evergreen Broad-leaved Forests of Yunnan, Southwestern China.
The Yunnan Province of southwestern China lies between 21[degrees]09' and 29[degrees] 15' N, 97[degrees]32' and 106[degrees] 12' E (Fig. 1) and occupies an area of 394,100 [km.sup.2]. It has a mountainous topography with the mountain ridges generally running in a north-south direction, decreasing in elevation southward. Its elevation ranges from 77 m at the lowest valley bottom in the southeast (Red river) to 6740 m at the highest mountain summit in the northwest (Fig. 2). Yunnan is extremely diverse in habitat and topography. The general climatic pattern consists of tropical wet climates in the southern lowlands (annual mean temperature 19-22[degrees]C, and annual precipitation 1300-1800 mm), subtropical climates on the central plateau (14-17[degrees]C, 900-1200 mm), and temperate to cold temperate climates in the northern high mountains (5-14[degrees]C, 600-1100 mm). The climate changes conspicuously with altitude. Due to the complicated topography, hot and dry valleys with tropical climate (effective accumulative temperature of 8000[degrees]C with >10[degrees]C daily mean temperature and annual mean temperature > 20[degrees]C) exist in the deep bottoms of three big rivers below 1200 m altitude: the Jinshajiang (the upper reaches of the Yangtze River), the Yuanjiang (the upper reaches of the Red River), and the lower reaches of the Nujiang (the upper reaches of the Salween River) despite of latitude. Yunnan is therefore a region with tropical areas as the horizontal base and the distribution of vegetation corresponds more with elevation than latitude (Zhu, 2008a).
Yunnan supports an extremely rich biodiversity and various vegetation types, but evergreen broad-leaved forests dominate the area (Wu, 1980,1987). The forest vegetation of Yunnan was briefly mentioned for the first time by C.W. Wang (1939), but information about the region's vegetation was limited because of poor accessibility. A China-Russia expedition penetrated deep into southwestern China, including Yunnan, in the late 1950s, and some descriptive works on the tropical and subtropical forest vegetation of this part of China were published (Wang, 1961). More recently, there has been community level research on the forest vegetation and flora of southern Yunnan (Zhu, 1997, 2004, 2005, 2006, 2008b, c, 2011; Zhu et al., 1998a, 1998b, 1998c, 2004, 2005, 2006a, 2006b, Cao & Zhang, 1997), central Yunnan (Jin & Peng, 1998; Shen et al., 2005; Yang, 2010), and northern Yunnan (Jin & Ou, 1981; Ou et al., 2006), although little has been published in English. Several comprehensive vegetation studies (Wu, 1987; Shimizu, 1991, Jin, 1979, 1992) have also been published. Previously, the evergreen broad-leaved forest was treated as a vegetation type in the vegetation classification of Yunnan (Jin, 1979; Wu, 1987). It was further classified into three vegetation sub-types as: the monsoon evergreen broad-leaved forest on tropical mountains in southern Yunnan, the semi-wet evergreen broad-leaved forest mainly on plateaus, and the mid-montane wet evergreen broad-leaved forest on upper mountains in central and northern Yunnan (Jin, 1979, Wu, 1987). The monsoon evergreen broadleaved forest is a tropical montane evergreen broad-leaved forest based on its habitats, physiognomy and floristic composition (Zhu et al., 2005), while the mid-montane wet evergreen broad-leaved forest on upper mountains has been likened to cloud forests or mossy forests of Asia (Shi et al., 2009, Zhu et al., 2016). In Wu's and Jin's works (Jin, 1979, Wu, 1987), the three evergreen broad-leaved forests were considered to be unique to southwestern China. Song (2004) revised the classification of evergreen broad-leaved forest of China, and changed the names of the three evergreen broadleaved forests as the following: monsoon evergreen broad-leaved forest into subtropical seasonal evergreen broad-leaved forest of western China under the vegetation type of subtropical seasonal evergreen broad-leaved forest; semi-wet evergreen broad-leaved forest and mid-montane wet evergreen broad-leaved forest included in the vegetation sub-type of semi-moist typical evergreen broad-leaved forest of western China under the vegetation type of typical evergreen broad-leaved forest. Except the name and rank changes, no essential changes were made in Song's system.
After extensive studies on the floristic composition and physiognomy of these evergreen broad-leaved forests in Yunnan, we break from the classification of these forests put forth by Jin (1979) and Wu (1087), suggest that the former monsoon evergreen broad-leaved forest (on tropical lower mountains) be suitably renamed as the lower montane evergreen broad-leaved forest (Zhu, 2006, 2007; Zhu et al., 2005, 2006a, 2015a, b) and recommend that the mid-montane wet evergreen broad-leaved forest be renamed as the upper montane evergreen broad-leaved forest (Zhu et al., 2016). The term "monsoon forest" was used for a tropical deciduous forest under the influence of a strong monsoon climate in southeast Asia, as defined by Schimper (1903). Therefore, using "monsoon" for the evergreen broad-leaved forest in Yunnan, is easy to confuse deciduous forest. On the other hand, the so-called mid-montane wet evergreen broad-leaved forest occurs on upper mountains above the lower montane evergreen broad-leaved forest and usually semi-wet evergreen broad-leaved forest. Using "upper montane" for this kind of forest should be more suitable in logical vegetation terminology. We refer to these forest types in the remainder of this paper using the new classification names.
The three evergreen broad-leaved forests of Yunnan are generally different in distribution, habitat and floristic composition (Table 1). Their distribution generally corresponds to altitude. The lower montane evergreen broad-leaved forest (LMEB) occurs mainly at an elevation between 900 m-2200 m in southern and southwestern Yunnan. The semi-wet evergreen broad-leaved forest (SWEB) occurs mainly on plateaus between 1500 m-2600 m altitude, while the upper montane evergreen broad-leaved forest (UMEB) occurs above 2100 m altitude but below temperate coniferous forest in central and northern Yunnan. However, the three forest types, especially the SWEB and the UMEB overlap in altitude. This could be partly affected by the 'Massenerhebung' effect (Grubb, 1971; Bruijnzeel et al., 1993). On large mountain masses, the SWEB occurs in higher altitude, while on small isolated mountain peaks the UMEB occurs in lower altitude than the usual. Presently, most the SWEB have lost. The remnants of this forest are also heavily disturbed contributing to the transition to shrub-like patches of sprouts and secondary forests with Pinns yunnanensis through secondary succession. The altitudinal boundary of the three forest types becomes vague in some extent due to their secondary succession under the seriously human disturbance.
This article will focus on floristic composition, species diversity, physiognomy and floristic variation with geography of the three main evergreen broad-leaved forests of Yunnan, based on sampling plots, and their biogeographical affinities will be discussed, as well as suggestions for their conservation will be provided.
Six 1-ha sampling plots, representing the three evergreen broad-leaved forests in Yunnan were established (see Fig. 3). Setting up plots is mainly restricted by the present distributions of primary forest of the three types. The primary semi-wet evergreen broad-leaved forest (SWEB) remains only in several small patches, where our SWEB plots have to be located. The large and continuous primary upper montane evergreen broad-leaved forest (UMEB) exists in Ailao mountain in central Yunnan, where a national nature reserve was established, and an ecological observation station of the Chinese Academy of Sciences was there. Therefore, we established our UMEB plots there both for the well-protected forest and for convenient field wok. The plots for the lower montane evergreen broad-leaved forest (LMEB) were chosen in southern Yunnan mainly due to our research institute there. The SWEB occurs on both limestone and non-limestone habitats and the sampling plots were setted up on the limestone and non-limestone sections of the forest respectively. All trees in each plot were identified and their d.b.h. (minimum 5 cm) and height measured. Among four plots of them, all plants, including understory shrubs, herbs, lianas and epiphytes were surveyed for life forms and biogeographical elements evaluations. Importance value indices (IVI) (Curtis and Mcintosh, 1951) and species diversities were calculated for each plot. Physiognomy (life forms for all plants and leaf size for trees) was analyzed using Raunkiaer's criteria (1934) as revised by Mueller-Dombois and Ellenberg (1974). Biogeographical elements (attributes) of each forest type were analyzed based on distribution of each species, by referring Wu's works (Wu, 1991; Wu et al., 2006). Wu documented biogeographical elements for Chinese seed plants at generic level based on their distributions world-wide in the following categories: Cosmopolitan, Pantropic, Tropical Asia and Tropical America disjuncted, Old World Tropics, Tropical Asia to Tropical Australia, Tropical Asia to Tropical Africa, Tropical Asia, North Temperate, East Asia and North America disjuncted, Old World Temperate, Temperate Asia, Mediterranean region, West to Central Asia, Central Asia, East Asia and Endemic to China. We obtain authorities and the distributions of all seed plant species in the plots from Flora of China- English version for species attributes. Comparisons of floristic composition, species diversity, physiognomy and biogeography of the three major evergreen broad-leaved forest-types were made to assess their similarities and variation.
These evergreen broad-leaved forests are very diverse in species composition, even in dominant species (Tables 2,3), although they are commonly dominated by species of the families Fagaceae, Theaceae and Lauraceae. In the tropical lower montane evergreen broad-leaved forest (LMEB), Fagaceae species Castanopsis echidnocarp, Castanopsis fleuryi, Castanopsis hystrix, Lithocarpus craibianus, Lithocarpus fenestratus, and Theaceae species Schima wallichii dominate. In the semi-wet evergreen broad-leaved forest (SWEB), Cyclobalanopsis glaucoides (Fagaceae) is the most predominant species on both limestone and non-limestone habitats, and Castanopsis delavayi and Castanopsis orthacantha dominate on non-limestone habitats. However, Anacardiaceae species Pistacia weinmannifolia, and Lauraceae species Neolitsea homilantha, as well as Oleaceae species Olea yunnanensis are also abundant on limestone. In the upper montane evergreen broad-leaved forest (UMEB), Fagaceae and Theaceae species are dominant, such as Castanopsis wattii, Lithocarpus xylocarpus, Schima noronhae, Camellia taliensis, Camellia forrestii, but species from various families, such as Litsea honghoensis and Machilus bombycina (Lauraceae), Manglietia insignis (Magnoliacaea), Ilex gintungensis (Aquifoliaceae), Mahonia duclouxiana (Berberidaceae), Symplocos anomala (Symplococaceae) are also abundant.
Although Fagaceae, Theaceae and Lauraceae are the most dominant families in the LMEB and the UMEB, the family Anacardiaceae (mainly species Pistacia weinmannifolia and Pistacia chinensis) replaces Thaceae as one of the most dominant families in limestone plot in the SWEB, and Euphorbiaceae and Rubiaceae constitute the sub-dominant families in the LMEB, and Oleaceae and Betulaceae are relatively abundant in the SWEB, as are Symplococaceae, Aquifoliaceae, Magnoliaceae, and Berberiaceae in the UMEB (Table 3).
In 1 ha sampling plot for all life forms, 360 vascular plant species were identified in the LMEB, and 174 species in the SWEB, and 144 species in the SWEB on limestone, as well as 166 species in the UMEB.
The LMEB is extremely rieh in species, having 138 and 104 tree species with dbh > 5 cm recorded from the two 1-ha plots respectively, while 53 tree species recorded in the SWEB and 40 tree species in the SWEB on limestone, as well as 41 and 45 tree species recorded from UMEB in 1-ha plots respectively.
Figure 4 shows abundant species sequences ranked by IVI (Importance Value Index) within each of the six forest plots. The abundant species sequences of the three forests show long tails, indicating that most species have a low IVI. However, the LMEB is overwhelmingly dominated by a single tree species but have more rare species presented, while the UMEB is co-dominated by several species and have less rare species presented. The SWEB shows the pattern between the LMEB and the UMEB. Abundant species sequences ranked by stems of the six plots showed the similar patterns as the species sequences ranked by IVI: the presence of more rare species in the LMEB plots (Fig. 5).
These evergreen broad-leaved forests are diverse in plant life forms (Table 4). The LMEB has some megaphanerophytes, more microphanerophytes, and conspicuously less hemicryptophytes and epiphytes than the other two forests. The UMEB has the highest proportion of mesophanerophytes, and conspicuously more epiphytes, while the SWEB on limestone has more hemicryptophytes and lianas.
Leaf features of tree species from the three forests are analyzed in Table 5. The LMEB has more macrophylls, and more compound and entire leaved species than the other two forests. The UMEB has fewer entire leaved species than the other two forest types.
Excluding ferns, 329 seed plant species in LMEB, 164 species in SWEB, 129 species in SWEB on limestone, and 142 species in UMEB, are analyzed for biogeographical attributes based on Wu's works (Wu, 1991; Wu et al., 2006) (see the Methods section). Biogeographical elements at specific level of these evergreen broad-leaved forests are shown in Table 6. Tropical elements (including Pantropic, Tropical Asia and Tropical America disjuncted, Old World Tropics, Tropical Asia to Tropical Australia, Tropical Asia to Tropical Africa, and Tropical Asia in total) contribute to 70.52% of species in the LMEB, of which tropical Asia elements make up the majority. In the SWEB and the UMEB, temperate species (including North Temperate, East Asia and North America disjuncted. Old World Temperate, Temperate Asia, Mediterranean region. West to Central Asia, Central Asia, East Asia, Endemic to China and Yunnan in total) make up the majority of the flora, contributing more than 72%, of which species endemic to China, Sino-Himalayas and east Asia are abundant.
The low-lying tropical montane evergreen broad-leaved forest (LMEB) of southern Yunnan, has a higher diversity of tree species. Except the species of Fagaceae, Theaceae and Lauraceae commonly in evergreen broad-leaved forests, it is characterized by higher numbers of Euphorbiaceae and Rubiaceae species and also features megaphanerophytes, compound and entire leaved species, and fewer hemicryptophytes in physiognomy. In geographical elements, the tropical species in total contribute to 70.52% in the LMEB. Furthermore, the tropical Asia element makes up the majority of its total flora as it is a typical tropical lower montane forest of SE Asia (Ashton, 2003).
The semi-wet evergreen broad-leaved forest (SWEB) occurs on the subtropical plateau in central Yunnan. Except the dominant Fagaceae and Lauraceae species, Anacardiaceae, Betulaceae and Oleaceae species have higher phytosociological importance. Additionally, the forest SWEB occurs on both limestone and non-limestone habitats. The common limestone species, such as Pistacia weinmannifolia and Pistacia chinensis (Anacardiaceae), Olea yunnanensis (Oleaceae), and Toxicodendron griffithii (Anacardiaceae), as well as Ulmaceae species, Carpinus mobeigiana and Ceitis tetrandra, are frequently present in the SWEB on limestone section. SWEB on limestone has also conspicuously more lianas and Hemicryptophytes than the other two forest types. Tropical species (see above) contribute to 20-26% of the total number of species, but the majority is temperate species, of which Chinese endemics contribute 37.98% on the limestone section of the forest. Obviously, the limestone habitat diverges from non-limestone SWEB forest to some extent.
The upper montane evergreen broad-leaved forest (UMEB) is also dominated by Fagaceae, Lauraceae and Theaceae species. However, the montane elements of east Asia, such as species of Symplococaceae, Aquifoliaceae, Magnoliaceae and Berberiaceae, are of high phytosociological importance. The forest has more mesophanerophytes, conspicuously more epiphytes, and less entire leaved species of trees. In floristic composition, it is close to the SWEB with temperate species dominated. The UMEB is equal to a cloud forest or mossy forest on wet mountains in Asia (Ohsawa, 1991).
Within the three evergreen broad-leaved forests, no common tree species were shared in our plots. The LMEB is conspicuously different from the other two forests in habitats, floristic composition, species diversity, physiognomy and geographical elements, and should be classified as a different vegetation type. With a tropical physiognomy and tropical floristic nature, it is a type of tropical lower montane forest of SE Asia. The SWEB and the UMEB have a subtropical distribution, similar species diversity and temperate floristic elements making up the majority of their flora, in which Chinese endemic and Sino-Himalayan species are dominant. They are a subtropical evergreen broad-leaved forest in southwestern China with Chinese and Sino-Himalayan floristic features. However, the SWEB and UMEB have different species composition and physiognomy, we agree to deal with them as different sub-types in a same vegetation type in classification.
In summary, the LMEB, with physiognomic and floristic similarities to the lower montane evergreen broad-leaved forest in mainland southeast Asia, is part of the later; the SWEB and UMEB, which have the highest ratio of Sino-Himalayan and Chinese endemic species in their floristic compositions, are unique in southwestern China, although the UMEB has similar physiognomic features to the upper montane forest in tropical Asia.
The evergreen broad-leaved forests of Yunnan are very diverse in floristic composition, physiognomy, geographical elements and habitats, although they are characterized by the dominant species of the families Fagaceae, Theaceae and Lauraceae, and evergreen broad-leaved trees. The LMEB in southern Yunnan, which is dominated by tropical species, especially tropical Asian elements, is a type of tropical lower montane forest of southeast Asia. The SWEB and the UMEB, dominated by species endemic to China and Sino-Himalayan species, are subtropical forests unique in southwestern China, but the UMEB has evolved to a cloudy forest on upper wet mountains. The physiognomic differences of these three forests are related to their habitats. It is also implicated that the SWEB and the UMEB should be given high conservation values due to their abundant Chinese and Yunnan endemic species, especially for the SWEB, the highest protection should be given because most remnants of the forest found outside of nature reserves are heavily disturbed contributing to the transition to shrub-like patches of sprouts and replacement of secondary forests with Pinus yunnanensis through secondary succession.
Acknowledgments This project was funded by The National Natural Science Foundation of China (41471051. 31170195, 41071040). The figures were drawn by Yan Jianbo from Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences. We also thank reviewers' constructive suggestions on this article.
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Hua Zhu (1,2) * Shisun Zhou (1) * Lichun Yan (1) * Jipu Shi (1) * Youxin Shen (1)
(1) Center for Integrative Conservation. Xishuangbanna Tropical Botanical Garden. Chinese Academy of Sciences, Mengia. Yunnan 666.303, People's Republic of China
(2) Author for Correspondence; e-mail: email@example.com Published online: 7 May 2019
Caption: Fig. 1 Location of Yunnan. (The figure was made by the Landscape Ecology Lab.. Xishuangbanna Tropical Botanical Garden. CAS)
Caption: Fig. 2 Topography map of Yunnan province (The figure was made by the Landscape Ecology Lab.. Xishuangbanna Tropical Botanical Garden, CAS)
Caption: Fig. 3 Distribution map of the evergreen broad-leaved forests in Yunnan (The figure was made by the Landscape Ecology Lab.. Xishuangbanna Tropical Botanical Garden, CAS. based on 2016 GIS data with ground truing). LMEB: lower montane evergreen broad-leaved forest; UMEB: upper montane evergreen broad-leaved forest; SWEB: semi-wet evergreen broad-leaved forest. l.LMEB lplot; 2. LMEB 2 plot; 3. SWEB I plot; 4. SWEB 2 plot; 5 UMEB 1 plot; 6 UMEB 2 plot
Caption: Fig. 4 Species sequences ranked by I VI (Importance Value Index) of the three forests. LMEB: lower montane evergreen broad-leaved forest; UMEB: upper montane evergreen broad-leaved forest; SWEB: semi-wet evergreen broad-leaved forest
Caption: Fig. 5 Species sequences ranked by % of number of stems of the three forests. LMEB: lower montane evergreen broad-leaved forest; UMEB: upper montane evergreen broad-leaved forest; SWEB: semi-wet evergreen broad-leaved forest
Table 1 General characteristics of the three major evergreen broad-leaved forests in Yunnan Forest types Distribution areas General Annual mean altitude temperature distribution ([degrees]C) (m) Lower montane Lower mountains in 900-2200 18-20 evergreen broad- southern and leaved forest southwestern Yunnan (*1) Semi-wet Plateaus of 1500-2600 14-17 evergreen broad- central Yunnan leaved forest Upper montane Upper mountains in 2100-2900 10-12 evergreen broad- central and leaved forest northern Yunnan (*2) Forest types Annual Most dominant precipitation plant species (mm) Lower montane 1350-1600 Castanopsis echinocarpa, evergreen broad- Castanopsis fleuryi, leaved forest Schima wallichii, Anneslea (*1) fragratis, Castanopsis hystrix Semi-wet 900-1200 Cvclobalanopsis glaucoides, evergreen broad- Castanopsis delavayi, Castanopsis leaved forest orthacantha, Cyclobalanopsis delavayi, Lithocarpus mairei Upper montane 1800-2000 Lithocarpus xylocarpus, evergreen broad- Castanopsis wattii, Schima leaved forest noronhae, Manglietia insignis, (*2) Camellia forrestii (*1) is formerly monsoon evergreen broad-leaved forest; (*2) is formerly mid-montane wet evergreen broad leaved forest and mossy forest (Jin, 1979) Table 2 Dominant families ranked by the Importance Value Index (IVI) in the six 1-ha plots from the three forests * LMEB 1 No. IVI LMEB 2 No. IVI Location: sp. Location: sp. Xishuangbanna. Simao, southern Yunnan southern Alt: 1170m Yunnan Plot size: 1 ha Alt: 1380 m Plot size: 1 ha Lauraceae 13 25.80 Fagaceae 13 118.80 Euphorbiaceae 11 28.30 Theaceae 6 44.12 Rubiaceae 9 7.90 Lauraceae 17 34.63 Fagaceae 8 71.83 Ericaceae 3 12.70 Fabaeeae 7 21.19 Oleaceae 3 11.47 Moraceae 6 5.88 Euphorbiaceae 7 9.70 Elaeocarpaceae 5 4.4 Rubiaceae 5 9.08 Meliaceae 5 2.94 Myrsinaceae 1 7.46 Sapingdaceae 5 3.67 Magnoliaceae 2 6.03 Anacardiaceae 4 7.52 Staphylaceae 1 5.67 SWEB 1 No. IVI SWEB 2 on No. IVI Location: sp. limestone sp. Jizushan, Location: centre Shilin. centre Yunnan Yunnan Alt: 2450 m Alt: 1950 m Plot size: Plot size: 1 ha 1 ha Fagaceae 7 118.66 Fagaceae 3 74.12 Theaceae 5 52.66 Anacardiaceae 5 72.31 Ericaceae 6 32.93 Lauraceae 3 47.75 Caprifoliaceae 5 17.61 Oleaceae 1 34.57 Oleaceae 1 16.54 Betulaceae 1 15.56 Lauraceae 3 9.68 Moraceae 6 9.71 Myrsinaceae 1 7.86 Fabaeeae 2 7.28 Rosaceae 8 7.84 Aquifoliaceae 1 7.26 Cornaceae 3 7.82 Rosaceae 5 7.02 Sabiaceae 1 6.41 Ulmaceae 3 5.95 UMEB 1 No. IVI UMEB 2 No. IVI Location: sp. Location: sp. Xujiaba. Ailao Qianjiazai, Mts., centre Ailao Mts., Yunnan centre Alt: 2450 m Yunnan Plot size: 1 ha Alt: 2320 m 1 ha Plot size: Theaceae 6 77.49 Fagaceae 4 77.73 Fagaceae 4 62.92 Lauraceae 8 61.82 Lauraceae 7 46.07 Theaceae 7 56.57 Symplococaceae 4 44.30 Magloniaceae 2 36.45 Aquifoliaceae 4 20.47 Rosaceae 3 18.44 Magnoliaceae 2 14.15 Berberiaceae 1 15.1 Rosaceae 4 12.57 Myrsinaceae 1 9.83 Schisandraceae 1 11.72 Symplocaceae 1 6.19 Sabiaceae 1 4.71 Styracaceae 1 3.33 Araliaceae 3 1.22 Sabiaceae 1 2.86 * LMEB: lower montane evergreen broad-leaved forest; SWEB: semi-wet evergreen broad-leaved forest; UMEB: upper montane evergreen broad-leaved forest Table 3 Dominant tree species (top 20) in the six I-ha plots from the three forests * LMEB 1 IVI LMEB 2 Plot size: 1 ha Plot size: 1 ha Total tree species Total tree species (> 5 cm dbh): 138 (> 5 cm dbh): 104 Castanopsis 46.36 Castanopsis fleuryi 72.77 echinocarpa Millettia 16.42 Schima wallichii 25.06 ieptobotrya Aporusa 15.57 Machilus bombycina 16.58 yunnanensis Syzygium oblatum 10.56 Anneslea fragrans 15.33 Schefflera 9.57 Lithocarpus 15.27 octophylia craibianus Lithocarpus 9.09 Castanopsis hystrix 10.98 fenestratus Canarium album 8.62 Olea rosea 9.94 Phoebe lanceolata 7.42 Rhododendron 8.98 moulmainense Croton kongensis 7.40 Myrsine seguinii 7.46 Schima wallichii 7.16 Lithocarpus 7.38 fenestratus Engelharclia 6.61 Turpinia montana 5.67 roxburghiana Actinodaphne 5.72 Lithocarpus 5.17 henryi truncates SWEB 1 IVI SWEB 2 IVI Plot size: 1 ha on limestone Total tree species Plot size: 1 ha (> 5 cm dbh): 53 Total tree species (> 5 cm dbh): 40 Castanopsis 41.56 Cyclobalanopsis 73.44 delavayi glaucoides Cyclobalanopsis 30.36 Pistacia 43.20 glaucoides weinmannifolia Castanopsis 29.58 Neolitsea 39.35 orthacantha homilantha Camellia 23.68 Olea yunnanensis 34.73 yunnanensis Osmanthus armatus 16.54 Carpinus 15.64 mobeigiana Vaccinium pubicalyx 11.66 Toxicodendron 10.81 griffithii Lithocarpus 10.80 Pistacia chinensis 10.4 hypoglaucus Temstroemia 9.63 Ilex macrocarpa 7.7 gymnanthera Schima argentea 9.15 Toxicodendron 7.43 succedaneum Camellia 8.70 Ficus virens 7.06 saluenensis Myrsine 7.86 Ceitis tetrandra 5.0 semiserrata Viburnum 7.64 Machilus 4.66 atrocyaneum yunnanensis UMEB 1 IVI UMEB 2 Plot size: 1 ha Plot size: 1 ha Total tree species Total tree species (> 5 cm dbh): 41 (> 5 cm dbh): 45 Castanopsis wattii 33.57 Lithocarpus 39.14 xylocarpus Schima noronhae 31.13 Camellia taliensis 35.88 Lithocarpus 25.24 Litsea honghoensis 30.15 xylocarpus Camellia forrestii 25.06 Manglietia insignis 28.77 Machilus 21.74 Castanopsis wattii 18.13 bombycina Ilex gintungensis 18.33 Mahonia 15.10 duclouxiana Symplocos anomala 13.03 Lithocarpus hancei 13.91 Manglietia insignis 12.68 Actinodaphne 13.12 cupularis Symplocos 12.4 Camellia pitardii 12.92 sumuntia Machilus 12.02 Laurocerasus 11.95 yunnanensis undulata Ulicium 11.72 Myrsine 9.83 macranthum semiserrata Stewartia 11.25 Neolitsea polycarpa 8.52 pteropetiolata LMEB 1 IVI LMEB 2 Plot size: 1 ha Plot size: 1 ha Total tree species Total tree species (> 5 cm dbh): 138 (> 5 cm dbh): 104 Castanopsis indicas 5.62 Symplocos sulcata 4.75 Phoebe puwenensis 5.52 Litsea garrettii 4.26 Svzygium 5.36 Michelia floribunda 4.19 szemaoense Rapanea neriifolia 5.08 Gomphandra 4.17 tetrandra Olea rosea 4.78 Aporosa dioica 3.82 Xanthophyllum 4.71 Elaeocarpus 3.61 siamense prunifolioides Cratoxylum 4.60 Tarennoidea 3.35 cochinchinense wallichii Ilex godajam 4.55 Vaccinium 3.30 mandarinorum Other 108 species 109.27 Other 84 species: 67.95 SWEB 1 IVI SWEB 2 IVI Plot size: 1 ha on limestone Total tree species Plot size: 1 ha (> 5 cm dbh): 53 Total tree species (> 5 cm dbh): 40 Cinnamomum 7.44 Pittosporum 4.56 glanduliferum brevicalyx Gaultheria 15.29 Albizia mollis 4.36 griffithiana Dendrobenthamia 6.53 Lindera communis 3.99 capitata Meliosma cuneifolia 6.41 Myrsine semiserrata 3.68 var. glabriuscula Juglans sigillata 5.10 Prunus zippeliana 2.8 Alnus nepalensis 4.92 Pentapanax henryi 2.13 Cyclobalanopsis 4.42 Milletia dielsiana 1.96 kerrii Viburnum oliganthum 4.19 Distyliopsis 1.79 laurifolia Other 33 species 38.56 Other 20 species 15.31 SWEB 1 IVI SWEB 2 IVI Plot size: 1 ha on limestone Total tree species Plot size: 1 ha (> 5 cm dbh): 53 Total tree species (> 5 cm dbh): 40 Cinnamomum 7.44 Pittosporum 4.56 glanduliferum brevicalyx Gaultheria 15.29 Albizia mollis 4.36 griffithiana Dendrobenthamia 6.53 Lindera communis 3.99 capitata Meliosma cuneifolia 6.41 Myrsine semiserrata 3.68 var. glabriuscula Juglans sigillata 5.10 Prunus zippeliana 2.8 Alnus nepalensis 4.92 Pentapanax henryi 2.13 Cyclobalanopsis 4.42 Milletia dielsiana 1.96 kerrii Viburnum oliganthum 4.19 Distyliopsis 1.79 laurifolia Other 33 species 38.56 Other 20 species 15.31 * LMEB: lower montane evergreen broad-leaved forest; SWEB: semi-wet evergreen broad-leaved forest; UMEB: upper montane evergreen broad-leaved forest Table 4 Comparisons of plant life forms in the four 1-ha plots from the three forests Forest type LMEB SWEB Life forms No. % of No. % of sp. sp. sp. sp. Megaphanerophytes 22 6.11 0 0.00 Mesophanerophytes 59 16.39 27 15.52 Microphanerophytes 108 30.00 35 20.11 Nanophanerophytes 33 9.17 16 9.20 Chamaephytes & Herbaceous 42 11.67 36 20.69 phancrophytes Geophytes 19 5.28 4 2.30 Hemieryptophytes 16 4.44 16 9.20 Liana 54 15.00 35 20.11 Epiphytes 7 1.94 5 2.87 Total species 360 100.00 174 100.00 Forest type SWEB on UMEB limestone Life forms No. % of No. % of sp. sp. sp. sp. Megaphanerophytes 0 0 1 0.60 Mesophancrophytes 20 13.89 43 25.90 Microphanerophytes 20 13.89 13 7.83 Nanophanerophytes 10 6.94 9 5.42 Chamaephytes & Herbaceous 26 18.06 30 18.07 phancrophytes Geophytes 5 3.47 7 4.22 Hemieryptophytes 25 17.36 21 12.65 Liana 32 22.22 18 10.84 Epiphytes 6 4.17 24 14.46 Total species 144 100.00 166 100.00 * LMEB: lower montane evergreen broad-leaved forest; SWEB: semi-wet evergreen broad-leaved forest; UMEB: upper montane evergreen broad-leaved forest Table 5 Comparisons of leaf features of tree spccies in the four 1-ha plots from the three forests * LMEB (138 tree SWEB (53 species) species) Forest type No. of sp. % No. of sp. % Leaf size ** Macrophyll 14 10.14 0 0 Mesophyll 81 58.70 30 56.60 Microphyll 41 29.71 23 43.40 Nanophyll 2 1.45 0 0 Leaf type Compound. 29 20.29 3 5.66 Single 109 78.99 50 94.34 Leaf maigin Entile 122 88.41 36 67.92 None entile 16 11.59 17 36.08 SWEB on UMEB (41 tree Limestone (40 species) tree species) Forest type No. sp. % No. of sp. % Leaf size ** Macrophyll 0 0 1 2.44 Mesophyll 21 52.50 23 56.10 Microphyll 17 42.50 17 41.46 Nanophyll 2 5.00 0 0 Leaf type Compound. 6 15.00 4 9.76 Single 34 85.00 37 90.24 Leaf maigin Entile 23 57.50 20 48.78 None entile 17 42.50 21 51.22 * LMEB: lower montane evergreen broad-leaved forest; SWEB: semi-wet evergreen broad-leaved forest; UMEB: upper montane evergreen broad-leaved forest ** Webb (1959) split off the lower end of Raunkiaer' big mcsophyll class (2025-18,225 [mm.sup.2]) as notophylls (2025-4500 [mm.sup.2]). Although it is better for detailing categories of leaf size spectrum. Chinese botanists are more familiar with Raunkiaer' big mesophyll class, and here we use Raunkiaer' big mesophyll class for the evergreen broad-leaved forest in Yunnan Table 6 Geographical elements at specific level for each of the four 1-ha plots from the three forests Forest type LMEB SWEB Geographical elements No. % No. % at specific level of sp. of sp. Cosmopolitan 1 0.30 1 0.61 Pantropic 4 1.22 0 0 Tropical Asia and Tropical 0 0.00 0 0 America disjuncted Old World Tropic 4 1.22 2 1.22 Tropical Asia to Tropical 7 2.13 0 0 Australia Tropical Asia to Tropical Africa 4 1.22 2 1.22 Tropical Asia: Indo-Malcsia 72 21.88 6 3.66 S Asia to mainland SE Asia 49 14.89 20 12.20 Mainland SE Asia 92 27.96 4 2.44 (Tropical elements in all) 232 70.52 34 20.74 North Temperate 0 0.00 0 0 East Asia and North America 1 0.30 1 0.61 disjuncted Old World Temperate 0 0.00 0 0 East Asia 7 2.13 20 12.20 Sino-Himalayas 7 2.13 49 29.88 Endemic to China 43 13.07 44 26.83 Endemic to Yunnan 38 11.55 15 9.15 (Temperate elements in all) 96 29.18 129 78.67 Total 329 100 164 100 Forest type SWEB on limestone UMEB Geographical elements No. of % No. % at specific level sp. of sp. Cosmopolitan 1 0.78 0 0.00 Pantropic 1 0.78 0 0.00 Tropical Asia and Tropical 3 2.33 0 0.00 America disjuncted Old World Tropic 1 0.78 0 0.00 Tropical Asia to Tropical 0 0.00 0 0.00 Australia Tropical Asia to Tropical Africa 1 0.78 1 0.70 Tropical Asia: Indo-Malesia 15 11.63 10 7.04 S Asia to mainland SE Asia 9 6.98 14 9.86 Mainland SE Asia 4 3.10 3 2.11 (Tropical elements in all) 33 26.38 28 19.71 North Temperate 1 0.78 2 1.41 East Asia and North America 0 0.00 0 0.00 disjuncted Old World Temperate 5 3.88 0 0.00 East Asia 15 11.63 20 14.08 Sino-Himalayas 19 14.73 36 25.35 Endemic to China 49 37.98 39 27.46 Endemic to Yunnan 5 3.88 17 11.97 (Temperate elements in all) 94 72.88 114 80.27 Total 129 100 142 100 * LMEB: lower montane evergreen broad-leaved forest; SWEB: semi-wet evergreen broad-leaved forest; UMEB: upper montane evergreen broad-leaved forest
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|Author:||Zhu, Hua; Zhou, Shisun; Yan, Lichun; Shi, Jipu; Shen, Youxin|
|Publication:||The Botanical Review|
|Date:||Jun 1, 2019|
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