Nutrient Characteristics in Incident Rainfall, Throughfall, and Stemflow in the Monsoon Evergreen Broad-leaved Forest at Dinghushan

Abstract:

The characteristics of five nutrient elements (K, Ca, Mg, N and P) in precipitation, throughfall and stemflow were studied in an monsoon broad-leaved evergreen forest at Dinghushan, Guangdong Province. Based on the precipitation allocation principles, the variation and input characteristics of these nutrients were calculated. The results showed that the contents of nutrient elements were in order as rainfall < throughfall < stemfall, in which the contents of K+ and total nitrogen (TN) were the highest, and those of total phosphorus (TP), HPO42- and total organic phosphorus (TOP) were the lowest. The biggest variation coefficient (Cv) of ion contents in precipitation was 1.282 for total organic nitrogen (TON), and the smallest was 0.502 for NO3-, while those in throughfall were 2.357 for TOP and 0.621 for TN, respectively. There were no significant relation between tree species and the contents of element (P>0.05). The annual inputs of nutrient elements from throughfall and stemflow into the soil were in the order as: TN>K+> Ca2+>Mg2+>TP. The annual input of Ca2+ from throughfall and stemflow were higher than that from litterfall decomposition. It concluded that rainfall was an important factor in transferring nutrient elements from forest canopy to soils.

Key words:Dinghushan; Precipitation; Throughfall; Stemflow