Network Structure And Biodiversity Effect Of Small And Micro Wetlands In Two Intermontane Basins Of Yunnan Plateau

As an important habitat and migration channel for a large number of land animals,plants and benthos,micro wetland provides all kinds of resources needed for life for all kinds of animals and plants,and plays an important role in the survival,reproduction and population development of animals and plants.Compared with large wetlands,small and micro wetlands have more boundaries,larger perimeter area ratio,and provide more diverse habitats for animals and plants.Therefore,it is of great significance to explore the network structure and biodiversity effect of small and micro wetlands for the management and biodiversity protection of small and micro wetlands.Based on the geographic information technology and MSPA analysis,combined with the field investigation of wetland plants and benthos,this paper analyzes the network structure of small and micro wetlands and their biodiversity effects.The results are as follows:(1)Based on MSPA analysis,the small and micro wetland on the North Bank of Fuxian Lake is a typical urban constructed wetland with poor connectivity,small core area,scattered distribution,small number of corridors and stepping stones,poor landscape connectivity,infrequent exchange of species and material energy in the wetland,weak branch like connection level of the whole wetland,unidirectional radiation development of water system,connection between water systems There are few points,the water network is scattered,there is a trend of isolation and planarization.Heqing Caohai has a relatively natural rural wetland appearance,with good connectivity of wetland landscape,large and evenly distributed core area,frequent species exchange and material energy flow in the wetland,small but abundant stepping stone area,complex network connection of the whole wetland,large number of corridors and nodes,multi-directional radiation development of water system,dense water network and wetland water network It has a strong role as habitat,channel and barrier.(2)The ecological types and plant coverage of micro wetland with different network structure and connectivity are different.The connectivity of Caohai small and micro wetland in Heqing is significantly better than that of the small and micro wetland on the North Bank of Fuxian Lake.There are 56 species of wetland plants in 26 families,49 genera and 56 species in total in the small and micro wetland on the North Bank of Fuxian Lake,which are mainly hygroscopic plants.The ecological type composition is relatively simple,there are many alien species,the localization characteristics are not obvious,and the artificial degree is high.There are 43 species of wetland plants belonging to 36 genera,21 families in total in Caohai small and micro wetland of Heqing.The composition of ecological types is relatively balanced.The localization and proto biochemical characteristics of wetland plants are relatively obvious,and the degree of naturalization is relatively high.(3)The microenvironment of small and micro wetlands has different influences on the distribution and habitat of plants and benthos,and animals and plants have different preferences for different microenvironment.Comparing the richness and coverage of plants in different microenvironment,wetland plants prefer rivers and ditches with static water,sand and gravel bottom material and covered artificial revetment,while benthos snails prefer rivers and ditches with slow water flow,silt bottom material and artificial revetment.Small and micro wetlands are rich in animal and plant resources,and their wetland network connectivity affects the ecological types and sources of plants.The habitat and reproduction of plants and benthos are affected by the wetland micro environment such as corridor material,corridor type and node number.