长江河口九段沙中沙互花米草湿地植物-土壤间营养元素含量灰色关联分析

Gray Correlation Analysis on Nutrient Element Contents between Plants and Soils in Spartina alterniflora Wetlands in the Middle Shoal of Jiuduansha,Yangtze River Estuary

于2005年5—12月,采用GPS定位,逐月对长江河口九段沙中沙的互花米草(Spartina alterniflora)湿地植物样品与土壤样品进行采集,分析植物与土壤中的w(N),w(P)和w(K)并研究其动态变化.利用灰色关联分析方法,对湿地植物与土壤中w(N),w(P)和w(K)的时空分布进行了研究,旨在探明互花米草生长过程中对不同深度土壤营养元素与不同种类营养元素的吸收程度.结果表明,灰色关联分析是湿地生态系统植物与土壤营养元素动态关系研究的行之有效的方法.互花米草的生长与上层土壤(0～≤15 cm)中的w(N)、中层土壤(15～≤40 cm)中的w(K)和下层土壤(40～60 cm)中的w(P)关联密切.互花米草与上层、中层和下层土壤中营养元素的关联序分别为N>P>K,N>K>P和P>N>K.在互花米草整个生长过程中,初期植物-土壤间营养元素的关联较小;旺盛生长期,植物-土壤间N和P元素的关联度大,K元素的关联度小;生长末期,植物-土壤间K元素关联度增强.

From May to December 2005,plant and soil samples of Spartina alterniflora wetlands from the middle shoal of Jiuduansha,in the Yangtze river estuary,were sampled monthly by GPS fixed position.Their nutrient element（N,P,K） contents were determined,and the dynamics of nutrient element contents were analyzed.Gray correlation analysis method was applied to study the temporal and spatial distribution relationships of nutrient element contents between Spartina alterniflora plants and soils in order to understand the absorbing extent of nutrient elements from different depths of soil,as well as the absorbing extent of different types of nutrient elements in the process of Spartina alterniflora plant growth.Results showed that the gray correlation analysis was an effective method for dynamic research of nutrient elements between plants and soils in the wetland ecosystem.Element N in the upper layer of soil（0≤15 cm）,element K in the middle layer of soil（15≤40 cm） and element P in the lower layer of soil（40-60 cm） had closer correlation with Spartina alterniflora plant growth.The associated order between Spartina alterniflora plant and different layers of soil was as follows： N P K for the upper layer of soil,N K P for the middle layer of soil,and P N K for the lower layer of soil.In the whole process of Spartina alterniflora plant growth,at the beginning growth period,the association of nutrient elements between plant and soil was less.At the blooming period,elements N and P were all important to plant growth,but element K was not important.At the end of the growth period,correlation of element K increased gradually.