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Studies on the Evergreen Broad-leaved Forests of Yunnan, Southwestern China.

Introduction

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.

Methods

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.

Results

Floristic Composition

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).

Species Diversity

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).

Physiognomy

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.

Geographical Elements

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.

Discussion

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.

Conclusion

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: zhuh@xtbg.ac.cn 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
Geographic Code:90SOU
Date:Jun 1, 2019
Words:6361
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