A Study Of Soil Biological And Chemical Properities Under Different Plant Communities In Shanghai Green Space

Urbanization represents one of the most striking forms of the changes of natural ecosystem to man-made ecosystem,which may bring abPPt a series of changes in ecological and environmental conditions and qualities.Urbanization has a profPPnd and far-reaching impact on the quantity and quality of soil resPPrces,which includes aspects such as the disappearance of soil ecological functions ;the worsening of soil physical propertes; the strong influence of human activities on soil morphology and soil genesis; the increase in short-range variability; the aggravation of soil contamination and the soil nutrient enrichment. The soil of green space ,which is one of important types of urban soil,has the same and different characteristics as urban soil and forest soil. The soil of green space is not only the key in keeping urban ecosystem sustainable development,but also is the absolutely necessary material base for urban landscaping.It is therefore urgent to study the quality change and specific distribution of soils of green space.This paper studies 16 soil factors of 3 soil properties in Ecological corridor of Jiangwan,Shanghai Botanical Garden,Shanghai Ecology Conservation Area of Jiangwan which built up for three different priods.The soil properties concludes microorganism,enzyme activity and chemical propeties.Meanwhile, we analysis the ralationships (correlation coefficients, r) between different factors for the three types of urban soil of green space. The results are as follows:1. Compared with forest ecosystem, urban soils of green space under different periods had specific quantities of microbial flora and vertical distribution of soil microorganism.The results indicated that bacteria were the main microbes,followed by actinomycetes, fungi which was the least present under different plant communities in Shanghai Botanical Garden and Shanghai Ecology Conservation Area of Jiangwan ;In Ecological corridor of Jiangwan was maximum quantity of bacteria, but difference between actinomyces and fungi was insignificant .The quantities of total microbes ,bacteria , actinomyces and fungi were largest in upper layer(0-20cm) under most of plant communities .The microbial flora and vertical distribution of soil microorganism were affected by the pirod of soil development.There is a significant difference in upper layer (0-20cm) under different plant communities : Shanghai Ecology Conservation Area of Jiangwan >Shanghai Botanical Garden>Ecological corridor of Jiangwan; trees>shrubs>herbs.And the quantities of microorganism increased as the development of soil went by.2. Under different plant communities the vertical variation rules of soil enzyme activities are specific for different types of soil of green space.Urease activities basically presented the trend of gradual decrease with the increase of the soil layer depth under different plant communities. And urease activitiy is significant difference in upperlayer (0-20cm) under different plant communities: Shanghai Ecology Conservation Area of Jiangwan >Shanghai Botanical Garden>Ecological corridor of Jiangwan;Invertase activities has different total vertical change trend. Its activities is highest in upper layer(0-20cm) for Shanghai Botanical Garden. But its activities is lower in upper layer for Ecological corridor of Jiangwan and Shanghai Ecology Conservation Area of Jiangwan. And invertase activitiy is significant difference in upper layer (0-20cm) under different plant communities : trees and shrubs>herbs.Protease and catalase activities both have irregular distribution in soil profiles for different types of soil of green space.Meanwhile, in the same type of soil of green space they are different under different plant communities.3. Every chemical factors have different features under different plant communities for 3 types of soil of green space.First, soil reaction is different for different area .The upper layer(0-20cm) are alkaline for Ecology Conservation Area of Jiangwan and Shanghai Botanical Garden,but are neutral in Ecological corridor of Jiangwan; And pH value distribution is irregular in soil profiles for Shanghai Botanical Garden and Ecological corridor of Jiangwan,but the surface soil(0-20cm) is lower than the subsurface in Ecological corridor of Jiangwan. Sencond, Total nitrogen presented the trend of gradual decrease with the increase of the soil layer depth in soil of green space. And in the upper layer (0-20cm): trees community and shrubs community is higher than herbs community.Third,soil organic matter, alkaline hydrolytle and total phosphor generally decreased with soil depth in Shanghai Botanical Garden and Ecology Conservation Area of Jiangwan,but they irregularly distributed in soil profiles in Ecological corridor of Jiangwan.Vegetation could improve the soil organic matter, alkaline hydrolytle and total phosphor ,but it is a long-term cPPrse. Rapidly Available irregular distributed in soil profiles under under different plant communities for different green space.4. All the factors of humus composition irruglar distributed in soil profiles in Ecological corridor of Jiangwan.There are three factors of humus composition are rugular distribution in soil profiles in Shanghai Botanical Garden.And fPPr factors of humus composition are rugular distribution in Ecology Conservation Area of Jiangwan. HA/FA ratio,FA,HA are different in upper layer(0-20cm): trees community and shrubs community are higher than herbs community.The results showed that vertical distribution regularity may improve step by step as time goes by.5. Analyzing the relationships (correlation coefficients, r) between 16 factors for the three types of urban soil of green space,we find that relationships between factors for different green space are different.And every properties have specific factors which have significant relation with other properties...