Canopy interception and changes in nutrient concentrations in a Liquidambar formosana plantation in Tianjiling forestry farm

Located observation method was used to measure nutrients concentration in rainfall,throughfall and stemflow in a Liquidambar formosana plantation in Changsha Tianjiling forestry farm in Changsha during the period from May 2007 to March 2008.The results showed that the concentration of Ca was the highest in rainfall and throughfall while that of NH4+-N was the highest in stemflow.The concentrations of NH4+-N,NO3——N,P,Ca,K,Mg,Cu and Mn increased in throughfall and stemflow.The increase in concentration of Mn is the highest. However,the concentrations Fe,Zn and Cd decreased in throughfall and stemflow.The concentration of all elements in throughfall and stemflow declined with increase in rainfall.