Study On The Conservation Evaluation And Optimization Design Of Rural Plant Communities In The Yangtze River Delta

Rural natural ecosystem is the basic ecosystem for human and rural plant communities play an important role in ecological service.But since the 1990 s,the rapid development of rural urbanization lead to the fast disappearing of rural habitats and the seriously damage of rural plant communities.Since 18 major countries,the establishment of the beautiful villages became more and more important.The protection and restoration of the rural natural ecosystem has received more and more attention.But the implementation of specific path is not clearly guided,especially for rural plant communities.Yangtze river delta is the fastest developing area in our country,one of the most concentrated area of population and the urbanization process of rural areas is in the lead.How to reasonably protect the original plant communities in the village is urgent to research.This article firstly choosed 28 different village in four major types,and seven small class habitat.Then analysised the features of plant communities of different rurality and different habitats.Then based on the investigation and expert opinions,a rural vegetation protection evaluation system is formed from four aspects: stability,typicality,rarity and local coulture.Then we evaluated the plant communities in the Yangtze river delta,analysised problems and protective value of them.Accordingly,the protection measures and optimization model for different habitats are proposed.At last,taking fuwei village as an example,the evaluation system was applied and the protection and optimization design was put forward according to the local conditions.The main conclusions are as follows:(1)Plant community characteristics: the community type is dominated by deciduous broad-leaved forest and evergreen broad-leaved forest,and the dominant species are mostly economic tree species.Joe and shrubs have fewer species and biennial herb species are abundant.The number of species of cruciferae in rural vegetation is significantly higher than that of urban vegetation.They are mainly cultivated vegetables and natural invasive weeds.The species diversity of the housefront plant community was the highest,and the species diversity of landscape forest was poor.The economic forest`s canopy was the largest,and the housefront plant community was the smallest.The rural vegetation community was mainly composed of complex structure,with a higher proportion of T2 community and less application of tall trees.(2)Evaluation system construction: rural conservation plant communities are defined as those who have the important value in ecology,production and culture or those who contain rare and endangered plants.From the ecological effect,social effect,economic effect and aesthetic effect of rural plant communities,we find the highest correlation between various functions and community characteristics,summarizes four criterion layers.They are the stability,typicality,scarcity and culturality.And for each,a total of 13 corresponding indicators were choosed.(3)Status evaluation of plant community: in each habitat,the proportion of high protection value plant communities on the back of buildings,natural revetment and economic forest are high,while the proportion in landscape forest and roadside is low.From the analysis of the scores of each index,it is found that the scores of the house background,natural revetment and economic forest are all higher,and the protection value is higher.The building facade and natural revetment have poor performance in community stability,while they performed well in community typicality and local culture.The overall performance of roadside community and landscape forest was poor.In high rurality areas,the quality of plant communities are significantly higher than that in low rural areas.(4)The village should pay special attention to the sensitive habitats,such as houseside,natural revetment,and economic forest.In rural construction,these plant communities are facing the risk of being destroyed,mainly from the demolition of houses and the construction of rural greening.In the process of rural urbanization,it is suggested to have strict regulation and control on the process of housing demolition and reform.In the construction of village greening,it is necessary to avoid the unity and repetition of large areas,and fully retain and exert the function of the original plant community.