Global Comparative Analysis And World Heritage Values Of Abies In Fanjingshan

Fanjingshan in Guizhou Province has been listed into the Tentative Lists of World Natural Heritage Sites in 2015 and has become the inscription project of China in 2018,for its worldwide outstanding universal value in natural aesthetics,ecological process and biological diversity.Abies fanjingshanensis(Fanjingshan fir),a subtropical rare,endangered and relict species endemic to Fanjingshan,and its community enrich the global representativeness and outstanding value of biological process and biological diversity in Fanjingshan.Therefore,the studies on the habitat,population and community of Abies fanjingshanensis will provide powerful theory basis for the world natural heritage inscription of Fanjingshan and the conservation and management of this endangered species.Based on the theories and methods of phytogeography like environmental factors analysis,population ecology like static life table,population distribution pattern and dynamic change index,etc.,community ecology like species diversity index,life form spectrum,importance value index,etc.,and comparative analysis,the studies and analysis on the habitat indicators like hydrothermal conditions,terrain and soil,etc.,the population characteristics indicators like quantity and age structure,etc.,the community characteristics indicators like species diversity and space structure,etc.will be carried out by field survey and plants sample plot investigation(2 sample plot with area of 30m×30m)in Fanjingshan,the nominated property of world heritage site,during 2015 to 2018.Furthermore,the world heritage value of the population and community of Abies fanjingshanensis will be discussed after a global comparative analysis between Abies fanjingshanensis and other six subtropical rare,endangered and relict species of Abies.(1)Abies fanjingshanensis is mainly distributed over the schattenseite slopes of Lanchading,Baiyunsi and Juchishan areas with elevation range 2,100 to 2,350 m in Fanjingshan.Its habitat is characterized by steep landscape(with a gradient among 30-60°),plentiful precipitation(with an annual precipitation of 1,313.8mm),low temperature(with a annual average temperature of 7.07?),heavy humidity(with a relative humidity of 80.75%),mountainous dark yellow brown soil type and shallow and fertile solum.Because it is highly limited by hydrothermal conditions,especially temperature,the population has a confined ecological amplitude.The population of Abies fanjingshanensis is characterized by rare quantity(about 9,000),the distribution pattern with dispersion in large area and concentration in small area during its narrow habitat,the age structure with static type(Deevey-? type)and the dynamic structure with low growth type.Fanjingshan,which is located in the area where cold current must through and owns relatively huge mountains,is the refuge and the only habitat of Abies fanjingshanensis distributed in subtropic,so the population origins of this species is southwest mountain local origin.(2)The community of Abies fanjingshanensis owns rich species diversity with 24 families,35 genera and 50 species of angiosperm,2 families,3 genera and 3 species of gymnosperm,4 families,4 genera and 4 species of fern,18 families,21 genera and 37 species of mosses.Evergreen coniferous trees and deciduous broad-leaved trees are mixed in the forest and form a complicated flora with a variety of southern or northern plants and endemic plants.The temperate nature and endemic nature are both significant.Physiognomy is characterized by luxuriant forest form and evergreen seasonal aspect.The community,with a integrated vertical structure,is dominated by Abies fanjingshanensis and Tsuga chinensis.There are abundant mosses in the ground layer and inter layer,like Sphagnum junghuhnianum,Polytrichum commune,Sphagnum acutifolioides,etc.,which maintain a damp environment and has certain symbiosis relationship with some endemic species like Abies fanjingshanensis and Corybas fanjingshanensis,etc.The study has found a special compound correlative relationship of species symbiosis and coexistence within the community,which would provide a early warming for preventing the secondary extinction of Abies fanjingshanensis community and enhance its deeper value.(3)After a comparative analysis,the habitat conditions,population features and community environment of each subtropical rare and endangered Abies species are irreplaceable,and Abies fanjingshanensis shows its unique global representativeness.Its process of origin,evolution and preservation has recorded the ecological evolution process and environmental change history,and the complicated species composition and flora has reflected the plant intersection process in Fanjingshan.The abundant biodiversity and endemic species with the community has increased the plant diversity and endemism for Fanjingshan and a dark coniferous forest for the vertical band in mid-subtropical subalpine zone.The community forms the only pure dark coniferous forest in middle-upper mountain in middle subtropical zone,that has enhanced the richness and particularity of gymnosperm in Fanjingshan.The straight and evergreen community appearance has enriched a splendid and enchanting natural landscape for Fanjingshan.All of these by Abies fanjingshanensis have strengthened the OUV and global representativeness of Fanjingshan.(4)The unique habitat and species composition of the Abies fanjingshanensis community maintain the the survival and propagation of the species and the stability of the community.But it weak habitat makes the species sensitive to climate change.Because of the rare population quantity and low natural regeneration ability,the species is in highly endangered.Otherwise,the complicated symbiosis relationships of plants within the forest may make the community under the threat of secondary extinction.And the competition pressure form broad-leaved trees and the threat from natural disaster will also impact the community.Therefore,it is necessary to take some protection actions,including enhance in-situ conservation by moderate man-made interference for natural regeneration of the population,develop ex-situ conservation and breeding cultivation in order to improve the population quantity,and carry out scientific popularization,protection education and cooperative study.The response mechanism of the population to climate change and the mechanism of species symbiosis and coexistence need to be further studied.