The Diversity Maintaining Mechanism Study Of Bryophytes In Xiaoqinling Nature Reserve

We studied the vertical distribution pattern and diversity maint enance mechanism of bryophytes species in Xiao Qinling Mountains.We constructed 53 plots in a 400-m2 area(20 m × 20 m)along the altitude gradient in Xiaoqinling,collected all bryophytes species encountered in these 53 plots,and recorded habitat types such as ground,tree trunks,roots,and rotten wood.With the number of ecology research method and statistical analysis method,analysis the effects of moss species vertical distribution pattern in Xiao Qinling Mountains area comprehensively,moss species coexistence mechanism and stand structure,terrain factor,space factor of the construction in bryophytes communities.The result are as follows:(1)The collected 1378 bryophytes specimens belonged to 33 families,89 genera,and 240 species,including 226 species of mosses and 14 species of liverworts.Thuidiaceae,Mniaceae,Bryaceae and Hypnaceae are the dominant families in Xiao Qin Ling area.The bryophyte community was divided into four categories by cross validation: Brachythecium populeum + Plagiomnium succulentum +Plagiomnium vesicatum;Brachythecium albicans + Brachythecium curtum + Thuidium kanedae + Mnium laevinerve;Thuidium kanedae + Jungermannia leiantha + Leskea polycarpa + Trachyphyllum inflexum;Brachythecium curtum + Plagiothecium nemorale + Plagiomnium integrum.(2)The interpretation of the elevation,slope,and aspect to the distribution of the bryophytes species was 7.29%.The bryophytes species diversity increased with the increase in altitude.In this study,we examined the species composition,classification,and distribution range along elevation gradients of the bryophytes species in Xiaoqinling.The diversity of the bryophytes species along the altitude showed an increasing tendency and differed from the distribution patterns of trees,shrubs,and herbs.(3)Based on canonical correspondence analysis,the effects of stand structure,topographic factors and spatial factors on bryophytes communities were studied,and the relative contribution of this three factors to the distribution of bryophytes species was evaluated by variance decomposition.Tree diversity,herbaceous layer and spatial factor are important environmental factors affecting the distribution of bryophytes.The pure terrain factor,pure stand structure and pure spatial factor contributed respectively to the distribution of bryophytes species in the area,5.76%,17.65%,9.86%.They show that Niche theory and neutral theory play an important role in the coexistence of bryophytes communities in alpine ecosystems.Therefore,in the process of protecting the diversity of bryophytes species,when the dispersal limitation exists,the reproductive species of some moss species can be added individually.Actually the special habitat formed by the stand structure is more important than the diffusion limitation,so we should pay attention to the protection of climate that formed by trees,shrubs and herbs.