盐碱地柽柳“盐岛”和“肥岛”效应及其碳氮磷生态化学计量学特征

Characteristics of ‘salt island'and ‘fertile island'for Tamarix chinensis and soil carbon,nitrogen and phosphorus ecological stoichiometry in saline-alkali land

为了探讨＂盐岛＂和＂肥岛＂效应影响下盐碱土的养分特征,对黄河三角洲盐碱地柽柳植株周围不同土层的pH值、电导率和碳氮磷含量及其生态化学计量学特征进行了研究.结果表明：土壤pH和电导率均随土层的加深而升高,0-20 cm土层土壤电导率随离植株距离的增加而降低,全磷含量则升高.20-40 cm土层土壤有机碳、全氮、N/P和C/P随离柽柳植株距离的增加而降低,C/N则升高.随着土层的加深,有机碳和全氮均呈降低趋势,而全磷则先降低后升高.土壤pH与电导率呈显著正相关,且二者与土壤碳氮磷及其生态化学计量比之间均呈显著负相关.

To clarify the nutrient characteristics of ‘salt island＇and ‘fertile island＇effects in saline-alkali soil,the native Tamarix chinensis of the Yellow River Delta（ YRD） was selected to measure its soil p H,electrical conductivity（ EC）,organic carbon（ SOC）,total nitrogen（ N）,total phosphorus（ P） and their stoichiometry characteristics at different soil depths. The results showed that soil pH and EC increased with the increasing soil depth. Soil EC and P in the 0-20 cm layer decreased and increased from canopied area to interspace,respectively. SOC,N,N / P and C / P in the 20-40 cm soil layer decreased,and C / N increased from the shrub center to interspace.SOC and N contents between island and interspace both decreased but P content decreased firstly and then increased with the increasing soil depth. Soil pH correlated positively with EC. In addition,pH and EC correlated negatively with C,N,P contents and their ecological stoichiometry.