NUTRIENT DYNAMICS OF LITTERFALL IN LOWER SUBTROPICAL MONS0ON EVERGREEN BROAD-LEAVED FOREST OF DINGHUSHAN
鼎湖山南亚热带季风常绿阔叶林凋落物的养分动态

This paper deals with nutrient characteristics of litterfall in forest of Dinghushansituated at 23°08'N, 112 ° 35'E. The dynamics, variation among seasons and species, and composition of litter nutrient were investigated during 1991. It was shown that 1itter nitrogen content slightly changed seasonally with variation coefficient below l5% for most species. Seasonal variation of P, K and Na contents in litterfall was greater than that of N. No significant correlation between elements was found in litterfall. The analysis of variance indicated that litter nutrient except for phosphorus differed significantly among species, and the litter nutrient except for magnesium did not differ significantly among seasons. The annual nutrient return through litterfall amounted to 37.1 1 kg hm-2 N, 15.03 kg hm-2 P, 27.01 kg hm-2 K, 37.1 1 kg hm-2 Ca, and 12.19 kg hm-2 Mg. The amount of nutrients in litter of Castanopsis chinensis ranked first, following by Schima superb a. The nutrient peak in littelfall occurred in August when typhoon brought down lots of branches and feares. Another peak was detected in April. Lowest litter nutrient appeared in December.