Temporal And Spatial Distribution Pattern Of Biodiversity And Evaluation Of Environmental Changes In The Alpine And Canyon Region In Southwestern China

The Alpine and Canyon Region in Southwestern China is an important part of the "Three Parallel Rivers".It is the junction of temperate zone and tropical zone,and is one of the most biodiverse regions in the world.In recent decades,due to the rapid population and economic growth,the plundering and exploitation of the natural resources of the area have been increased,which has broken the habitat of the area,the loss of species and species habitats,and threatened biodiversity.It is of great significance to protect and repair the fragile forest ecosystem which is increasingly damaged by human beings and to ensure the effective and sustainable utilization of biodiversity resources in the region.Based on the multi-source data of biodiversity and environmental diversity.1)The revised APG III(The Angiosperm Phylogeny Group)classification system was used to determine the family of species,and further use of computer software for statistical and data analysis.Analyzed the status of species diversity in the Alpine and Canyon Region in Southwestern China;2)The spatial and temporal distribution pattern of species and their basic characteristics were studied,and the effects of natural environment and human activities on the distribution of biodiversity were discussed;3)The PSR environmental system evaluation model and AHP Method were used to quantitatively evaluate the level of biodiversity in the Alpine and Canyon Region in Southwestern China,and then the biodiversity of the area was evaluated,so as to divide the key conservation areas.The main conclusions are as follows:(1)The current distribution of species in the Alpine and Canyon Region in Southwestern China is that there are many rare and endangered species,ancient flora and strong plant species differentiation.With the increase of altitude,the proportion of plant species in tropical and subtropical regions decreased gradually,while the proportion of plant species in temperate regions increased.However,tropical plants are distributed at higher altitudes.(2)The vertical natural belt of the forest ecosystem in the Alpine and Canyon Region in Southwestern China has significant regional differentiation characteristics.The endemic species are distributed in a "single-peak mode" along the altitude.The peak occurs in the middle elevation and the optimal distribution range of endemic species is relatively narrow,with a high degree of potential threat.The endogenous plant groups differ greatly in their genera.The endemic rate of different species varies along the altitude.The maximum endemic rate occurs in different altitude ranges.(3)In the past 30 years,there have been differences in the quantity of organisms in different habitat types in the Alpine and Canyon Region in Southwestern China.The number of beasts in alpine meadows has increased significantly,and the distribution of bird species in semi-humid evergreen broad-leaved forests has increased significantly.The distribution of animal species shows a trend of upward migration along the altitude gradient,and the number of species in high altitude habitat types has increased.The proportion of plant species in tropical nature and temperate nature in the total number of families has changed from 43.75% and 26.56% in 1986 to 40.26% and 24.68% in 2008.In the past 20 years,the number of plant types distributed in the area has decreased and each plant area.The total number of departments in the department decreased significantly.(4)The distribution of endemic plants is greatly affected by climate factors.There are extremely significant(P <0.01)positive correlations between annual average rainfall,annual average temperature,humidity index and endemic species in climatic factors.The number of endemic species has a complex relationship with accumulated temperature ?10 ?.When the accumulated temperature is less than a certain value,the two are positively correlated,otherwise,they are negatively correlated.(5)The biodiversity in the Alpine and Canyon Region in Southwestern China is significantly affected by agricultural economic activities,industrialization,and urbanization.Industrialization and urbanization are the main factors that lead to the decrease of cultivated land area.The increase in urban area and the decrease in cultivated land area have a significant negative impact on agricultural planting.As the development and utilization of cultivated land increases,the area that can be occupied by species decreases,leading to a reduction in species,and the destruction of habitat that divides the population and species into small and isolated patches results in the upward movement of the peak vertical distribution of species(6)Based on the analysis of biodiversity evaluation,the conservation priority levels of the Alpine and Canyon Region in Southwestern China from the central region to the north and south sides gradually decreased.In the central region,Gongshan County,Deqin County,and Luding County have a conservation priority level of one,with a high biodiversity index.The second priority of species protection is mainly around the middle of the study area,and the distribution is relatively scattered;The third priority protection area is mainly distributed in Yunnan Province in the Alpine and Canyon Region in Southwestern China;The plants in the Alpine and Canyon Region in Southwestern China with protection priority level 4 are relatively less distributed,mainly north of the central area,and the area is the smallest compared to the other four protection priority levels.This study can provide a theoretical basis for the conservation of biodiversity in the Alpine and Canyon Region in Southwestern China.