| China has been committed to the conservation of biodiversity resources in recent years,and at the 18 th Party Congress,the Party Central Committee emphasized the construction of ecological civilization,while China is implementing the world’s largest ecological restoration project.In the context of biodiversity conservation,the potential of urban environments to support wildlife needs to be emphasized,and the conservation and enhancement of biodiversity in urban environments will be an important issue in future urban construction and development,as well as an effective way to curb biodiversity loss.Most sponge facilities are usually small microhabitats with good heterogeneity.Such habitats can break the homogeneity of the urban environment and can provide urban green spaces with diverse plant types,as well as habitats that satisfy the survival of birds.At present,domestic research on sponge habitats is mainly focused on the performance of stormwater management and regulation,and there is insufficient research on the monitoring and optimization of biodiversity benefits in sponge habitats.International studies have shown that sponge habitats have the potential to enhance urban biodiversity and play an important ecological function in the conservation of urban plant and animal diversity,providing habitats for pollinators,birds or other animals.Dry ponds and wet ponds in sponge facilities are pond-like facilities with aquifer space that are attractive to birds,an ecologically sensitive indicator species,as small microhabitats that provide shelter,roosting,drinking and foraging functions and act as key stepping stones for birds during their activities.This study focuses on the pond-type sponge facilities in the pilot sponge city area of Yuelai International Convention and Exhibition City,which has a ponding space and a similar functional structure,including dry ponds and wet ponds.The bird diversity data were continuously observed for four seasons,and the effects of pond sponge habitat area characteristics,pond sponge habitat vegetation characteristics,and pond sponge habitat surrounding anthropogenic disturbance environmental factors on bird diversity characteristics in the habitat were investigated.The results of the analysis were used to propose reasonable design strategies to enhance bird diversity in pond sponge habitats.This study is valuable for exploring the biodiversity of small microhabitats in urban green spaces and promoting the fine construction of sponge cities.Firstly,to understand the current characteristics of bird community diversity in pond sponge facilities,a total of 64 bird species were observed in the pond sponge habitat through a year-long field study,with a total of 1622 bird observations.All diversity indicators were higher in the wet pond habitat than in the dry pond habitat,but no significant differences were found in the bird community diversity indicators in the wet and dry pond habitats after t-test analysis.The bird diversity indicators in the pond sponge habitat were low compared with those in natural habitats in previous studies,but high compared with those in other urban green space habitats in some studies,especially in the wet pond habitat where birds were more abundant.All bird species observed in the study were assigned values based on bird feeding,activity range,and migratory habits and subjected to K-modes cluster analysis to study resource partitioning among bird communities and bird community structure,and habitat modification methods could be proposed for a particular group.The bird groups were finally divided into four categories based on Hamming distance.The first bird group is aquatic feeding,surface active birds;the second bird group is insectivorous or phytophagous,forest canopy active birds;the third bird group is insectivorous,understory scrub active birds;and the fourth bird group is omnivorous,forest canopy or herbaceous active birds.Secondly,to investigate the effects of habitat characteristics factors on bird community diversity in pond sponge facilities,this study used structural equation modeling to quantify the effects of habitat characteristics factors on bird abundance,richness,diversity,and evenness,and the model demonstrated that area characteristics factors,vegetation characteristics factors,and human disturbance environmental factors in pond sponge habitats all had significant effects on bird community diversity characteristics.The area of aquifer,shrub layer species diversity,and noise had significant positive effects on bird multiplicity,and the distance from woodland had significant negative effects on bird multiplicity;habitat area had significant positive effects on bird richness,and woodland distance and tree diameter at breast height had significant negative effects on bird richness;habitat area and tree layer species diversity had significant positive effects on bird diversity;habitat area and tree layer species diversity There were also significant positive effects of habitat area and arboreal species diversity on bird evenness,and significant negative effects of aquifer area and arboreal cover on bird evenness.To further analyze how the habitat characteristics factors affected the diversity of birds in each group,the correlation analysis and ANOVA between the habitat characteristics factors of pond sponges and the bird community diversity index of each group showed that the community diversity characteristics of different bird groups would be correlated with habitat area,aquifer area,tree layer species diversity,herb layer species diversity,tree diameter at breast height,tree cover,tall grass ratio,surrounding green space maintenance intensity,distance to non-green space construction,and the distance to non-green space construction.The factors of maintenance intensity,distance from nongreenfield construction sites,and distance from woodland were correlated.After the field research and data analysis,it is clear that the existing pond sponge facilities have outstanding and serious problems,and the optimization strategies to improve the diversity of bird communities in pond sponge habitats are proposed by combining the analysis results and field conditions:(1)When creating pond sponge habitats,under the premise of meeting the requirements of rainfall management index,the sponge facilities should be built by making full use of the catchment area as much as possible,or by digging and filling to create sufficient habitat patches and aquifer area.Smaller pond sponge facilities can be built in larger green areas to provide more diverse habitat types for birds;increase the area of the aquifer to increase the border area between land and water,and set up a gentle slope border around the pond to enhance the attraction of the aquifer to land birds and provide habitat resources for both water birds and land birds to enhance habitat heterogeneity;create a boundary buffer between birds and human activities through the design of topography and plant boundaries.(2)The pond perimeter is planted with plants that have the potential to attract birds.(2)Plant trees with high diversity and bird food source around the pond,emphasize mixed planting of coniferous and broad-leaved trees,avoid excessive tree cover,create a sparse forest habitat with mixed coniferous and broad-leaved forests instead of high-density trees with a single vertical structure,and increase the diameter at breast height of trees and food source plants;improve the structural integrity of vegetation,optimize the vertical plant structure levels,and supplement the lacking levels to improve the pond sponge habitat.The structure of large trees-small trees-large shrubs-small shrubs-herbs-ground cover plants in the habitat;plant water-supporting herbs,and build a mixed module of various herbs between 30cm-60 cm in height.(3)Pond sponge facilities should be located as close as possible to the woodland,and can provide habitat for migratory birds and attract migratory and travel birds by supplementing the installation of artificial bird nests and other facilities that help birds to roost beside the slope of the catchment. |
