plant diversity, forest ecosystems and influence forecasts of ......taxonomic categories no. of...
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Plant diversity, forest ecosystems and influence forecasts of disturbance in
Yunnan, SW China
Min CAO
Xishuangbanna Tropical Botanical Garden Chinese Academy of Sciences
Points
Floristic BackgroundMajor EcosystemsDisturbanceEcosystem Assessment
Natural environment
Location: 21o08’32”-29o15’08”N97o31’39”-106o11’47”E
Bordered with Vietnam, Laos & MyanmarElevation: 76 m - 6740 m (6664 m difference)Size: 394,000 km2 ( 4.1% of China )About 600 rivers belong to 6 major river systems (Yangtze R., Pear R., Red. R., Mekong R., Salwin R., Irrawaddy R.) Population: 44.15 Million (2004)
Natural environmentClimate: Monsoon
City LatitudeAltitude
(m)
28º27’ 3485
1890
552
25º01’
22º00’
TypeAverage
temperature(℃)
Average precipitation
(mm)
Deqing Subalpine 4.7 664
Kunming Subtropics 14.7 1094
Jinghong Tropics 21.7 1211
Rainy: May – Oct.; Dry: Nov. – Apr.
Floristic BackgroundFloristic Background
Magnolia Magnolia officinalisofficinalis
Number of plant species
Taxonomic categories
No. of species in Yunnan
No. of species in
China
Proportion (Y/C)
Mosses and liverworts 1,500 2,600 58%
Ferns 1,500 2,500 60%
Seed plants 17,000 30,000 57%
Areas (x 1000 km2)
394
1200
560
230
36
0
200
400
600
800
1000
1200
Yunnan Xizang(Tibet)
Sichuan Guangxi Taiwan
Seed plants: Genus
2136
1145
1491 1549
1100
0
500
1000
1500
2000
2500
Yunnan Xizang(Tibet)
Sichuan Guangxi Taiwan
Seed plants: Species14000
5296
8541
5463
4300
0
2000
4000
6000
8000
10000
12000
14000
Yunnan Xizang(Tibet)
Sichuan Guangxi Taiwan
Endemic genera
China Yunnan
224
83
0
50
100
150
200
250
Com
p osi
tion
of th
e pr
o vi n
cial
f lor
a at
the
l eve
l of g
e nu s Distribution Patterns No. of genera
in YunnanProportion
(%)No. of genera
in China1. Cosmopolitan 92 -- 1072. Pantropic 313 16.54 3733. Trop. Amer. & Asia disjuncted 70 3.70 964. Old World Tropics 124 6.55 1625. Trop. Asia to Trop. Australia 99 5.23 1526. Trop. Asia to Trop. Africa 126 6.66 1607. Trop. Asia (Indo-Malaysia) 439 23.21 5708. North Temperate 226 11.95 2979. E. Asia & N. Amer. disjuncted 76 4.02 12010. Old World Temperate 91 4.80 16311. Temperate Asia 18 0.95 5812. Mediterranean, W. Asia to C. Asia 24 1.27 16913. C. Asia 5 0.26 11314. E. Asia 198 10.47 29415. Endemic to China 83 4.39 224
Total 1984 100 3058
61.89%
Demarcation line
HolarcticHolarctic
PaleotropicPaleotropic
Subalpin
Major Forest Ecosystems
Subtropical
Tropical
Shorea wangtianshuea
Tropical seasonal rain forestSouth Yunnan
Evergreen broad-leaved forest – subtropical mountains
Middle Yunnan
Northwest Yunnan
Abies georgeiSubalpine coniferous forest
Jinghong
Menghai
Mengla
XTBGMyanmar
Total land area: 19,124 km2
0.2% of China
人口与森林覆盖率
0
100000
200000
300000
400000
500000
600000
700000
800000
900000
1949 1953 1956 1958 1962 1966 1968 1972 1979 1982 1985 1994 1995 1996 1998
人口(人)
0
5
10
15
20
25
30
35
40
45
50
森林覆盖率(
%)
Population (persons) Forest cover (%)
Population andforest of
Xishuangbanna
Rubber plantation
Mountain agriculture
Imperata cylindrica Chromolaena odorata
Secondary Communities
Macaranga denticulata Thysanolaena maxima
Soil seed bank
RestorationSeed rain
Seedling bank
Resprouting
Third group in mature forest: Nonconstituent?
Nonconstituent
WeedExotic
Asynchronism in forest growth
Above ground
Climax Pioneer
Nonconstituent
Under ground
Pioneer
Shift: Underground → Aboveground
Climax Pioneer
Pioneer
Disturbance
Nonconstituent
Major findings
•Extraordinarily larger soil seed banks
•More nonconstituent components
•Increasing proportion of woody species in SSB with forest succession
•Decreasing similarity of SSB to above-ground vegetation
Implications
1. Disturbance assessment (Quantifingdisturbance)
2. Forest fragmentation (Surveying edge effect)
3. Vegetation restoration (Examining potentials of forest restoration)
4. Detecting biological invasion
Monitoring Ecosystem Processes Underground !
Forest ecosystem
assessment?
Linking the temperate with
the tropics
A FEA Network in continental SE Asia?
Thank you
Forest growth cycle in time
BuildingPioneer Climax
Gap Mature