Forest Litter Ecology in Masson′s Pine Stand and Its Mixed Forests Formed by Inter-planting with Hardwood Tree Species II.Dynamics of Nutrient Return From Litterfall

Five unevenaged coniferhardwood forest communities were developed after Castanopsis lamontii,Cyclobalanopsis myrsinaefolia,Castanopsis fissa,Castanopsis kawakamii,and Castanopsis sclerophylla,were separately interplanted under the canopy of mature Masson′s pine plantationsMonthly collection of litterfall was conducted in the above five mixedspecies communities and also in pure Masson′s pine standChemical analysis of the litter samples indicated that nutrient concentrations of various litter components were different,with N ranging from 0325% to 1298%, P 0037% to 0655%,K 0024% to 0097%,Ca 1277% to 3540%,and Mg 0235% to 0610%Seasonal patterns were significant for the concentrations of nitrogen,phosphorus and potassium,but not for calcium and magnesiumTotal nutrient return of the five elements for the six stands consistently decreased in the order:CaNMgKP,amounting to 993~18818 kg·hm-2,2062~6746 kg·hm-2,1624~4059 kg·hm-2,39~1308 kg·hm-2,and 195~407 kg·hm-2,respectivelyAnnual nutrient return amounts from forest litterfall were,respectively,23805,21377,22393,28990,30412 kg·hm-2,for the above five mixed communities,and 14201 kg·hm-2 for pure Pinus masssoniana standSeasonal dynamics of nutrient return in the mixed stands showed binomial patterns,generally with the first peak occurring between February and April,and the second peak in August or September