Construction Mechanism And Functional Groups Of Lichen Community On The Northern Slope Of Bogda Peak,Xinjiang

As a pioneer,lichens can can be distributed in arid areas in large numbers and play an important role in the ecosystem.In order to ascertain the resource utilization and distribution of various the lichen species on the northern slope of Bogda Peak,the lichen community was examined from the perspective of functional traits and phylogenetic structure.To do this,the north slope of Bogda Peak was divided into 25 sample plots.Based on field investigations and environmental factors,the niche characteristics,functional traits and the phylogenetic structure of lichen communities were analyzed.This study is a supplement of the construction model of the lichen communities and the results showed:1)The niche width of most macrolichens on the north slope of Bogda Peak was narrow.A few of macrolichens have a wide niche width,the widest being Cladonia pyxidata(L.)Hoffm.This indicated that such lichens can adapt to a wider range of ecology,strong intensity and disturbance.The niche width of most crustose lichens was narrow to medium,the widest niche being Rinodina bohlinii H.Magn.(Bi =0.2765;Ba = 1.5089),and the narrowest was Calogaya ferrugineoides(H.Magn.)Arup et al.(Bi = 0.1229;Ba = 0.7613).2)The niche overlap of most lichens on the northern slope of Bogda peak was low.The wider the niche width,the more common was the niche overlap between macrolichens,but the overlap value is not high.The high niche overlap occurs when lichens coexist in large numbers using a specific resource.Crustose lichens with wider niche width also had higher overlap with other species.It shows that the interspecies competition among crustose lichens is stronger.3)The distribution of lichen’s functional groups is affected by altitude,humidity,canopy closure,and interference,and is less affected by slope and light intensity.The five functional traits all have significant phylogenetic signals.Among them,the growth form and reproduction are phylogenetically conservative,indicating that environmental filtration affects distribution;The distribution of photosynthesis,reproductive organs and growth substrates was more divergent than that predicted by the zero model.It shows that evolutionary history,has little influence on them.4)The phylogenetic structure and phylogenetic diversity of lichen communities in the various environments of Bogda peak is differed.In the suitable sample plots,the community phylogenetic structure was clustering,and the environmental filtering effect drove the community construction;while in other plots that had more stressed conditions,the community phylogenetic structure overdispersion,and the similarity restriction effect drove the community construction.The phylogenetic diversity was highest in plots that had moderate conditions and it was noted that as the environmental index decreased,the phylogenetic diversity decreased.In summary,the composition of the Bogda Peak lichen community was affected by evolutionary history,the interaction between species and the environment.Humidity and human disturbance are the main environmental sieves that screen the coexistence of specific species in specific plots.Finally,coexisting species occupy their respective niches through niche differentiation.