Research On Horizontal Plants Coexistence Network Influenced By Climate Change

Based on the vertical pattern of altitude distribution,the complex network is modeled and optimized by using Bray-Curtis distance,random pruning and percolation theory.The network structures of Changbai Mountain and Kunlun Mountain are quite different.The network of Changbai Mountain presents a more average and dispersed sub-network state,while Kunlun Mountain is composed of a large sub-network which account for 77%of all species in the network and other smaller sub-networks.The interspecific symmetry of Changbai Mountain network is stronger.Among the indicators,only the degree of Kunlun Mountain shows power law distribution.In the remaining cases,the indicators show a small number of maximum measurements and a large number of smaller measurements,but do not constitute a power law distribution.According to the basic principle of network construction,network is a representation of the relationship between plants.Climate change will inevitably lead to the change of vegetation in the network.Therefore,the structural characteristics of network can also be regarded as the corresponding situation of vegetation in the face of climate change.The response of mountain vegetation to climate change was analyzed according to the relationship between network index and altitude.The types of forest belts in Changbai Mountains have a significant impact on the network indicators.The results showed that:in Changbai Mountains,birch forest belt,alpine tundra belt,Alpine desert belt,Korean pine needle expanded mixed forest belt and summer green broad-leaved Mongolian oak forest belt were affected more easily and weakened gradually.The elevation of Kunlun Mountains has a significant impact on the network indicators.At the highest and lowest altitudes,Kunlun Mountains are more susceptible to climate change and have a greater impact,which show a better stability at higher altitudes.For the species of Kunlun Mountains that are susceptible to and have a greater impact,they are mostly distributed at low or high altitudes.Meanwhile,the species at middle altitudes are more stable and less susceptible to strong impacts.The vegetation of Changbai Mountains(30 species)and Kunlun Mountains(15 species)has zero degree and strength in/out.These species are the most vulnerable and most affected,but the direction of impact is uncertain,so we need to pay more attention to them when facing climate change.Birch has been cross-validated by previous studies.The climate factors(MAT and MAP)of Kunlun Mountains were significantly correlated with the network indicators(degree,strength in/out)at a significant level of 95%.In this paper,the vegetation network of elevation pattern was established by using complex network tools,and the impacts of climate change on vegetation were explored,which provided a new idea for studying the application of complex network and the response of vegetation to climate change.