Stability Of Davidia Involucrata Community In Daxiangling Nature Reserve

The Daxiangling Nature Reserve is located at the turning point of the two topographic steps in the western plateau mountainous region and the Chengdu Plain.It is divided into the National Giant Panda Park geographic area and at the same time as the natural distribution area of ??China’s endangered species Ⅰ D.involucrata,With extremely high ecological value and scientific research value.Based on multiple investigations,this study investigated the flora composition,community structure,renewal status,community succession period,important values ??and interspecific associations,species diversity,and plant community of Davidia involucrata community in Sichuan Daxiangling Nature Reserve.Biomass,soil physicochemical properties,and soil enzyme activity were explored,and multi-factors were used to evaluate community stability,with a view to providing theoretical support for the protection and continuation of D.involucrata community.The results show:(1)The vegetation in the Daxiangling Nature Reserve is a subtropical to temperate transitional type.The existence of a large number of ancient relics reflects the relictness and ancientness of the flora of the D.involucrata community.The flora of D.involucrata community has a strong regionality in China.The overall diameter-level structure of the community is a partial normal distribution type,and the height-level structure is an inverted J type.The development trend of the community structure is relatively stable.(2)The overall age structure of the D.involucrata population in the Daxiangling Nature Reserve is approximately pyramidal,and it is an increasing population.D.involucrata pure forest(type C community)has the best collocation dominance and is in the later stage of stable succession.It is the climax community of D.involucrata community in Daxiangling Nature Reserve.(3)D.involucrata in Daxiangling Nature Reserve occupies the most important value and is the dominant species in the community.The arbor layer has a high degree of negative association and fierce competition.As the succession progresses,the community species diversity index generally decreases first,then increases,and then returns to a stable state.The interaction between species diversity at different levels is relatively strong.Shrub biomass and herbaceous biomass have complementary forms at each succession stage,and the understory structure is relatively stable.(4)D.involucrata is suitable for growing in a slightly acidic environment.It should increase nitrogen input in the early succession stage and increase phosphorus input in the late succession stage.The enzyme activity of the community in the stable succession stage is at a lower or lowest point,and the community succession process significantly inhibits the enzyme activity response.(5)The type C stability of D.involucrata community is the highest.As the succession progresses,the stability of the community gradually increases.The comprehensive evaluation results suggest that the establishment of a special D.involucrata protection area to carry out in-situ conservation is an effective protection method for such D.involucrata native communities.