The Amount And Nutrient Dynamics Of Litterfall In Mid-subtropical Forests With Different Regeneration Patterns

Litterfall represents a major biological pathway for element transfer from vegetation to soil. The amount and seaonal patterns of litterfall play an important role in regulating energy flow and nutrient cycling, and maintaining the soil fertility of forest ecosystems. The variations in litterfall in turn determine the amounts of nutrients recycled the composition of soil microbial and faunal communities, and the resulting availability of nutrients. Study on the litterfall is important for understanding the function of forest ecosystems.From September2009to October2010, the Iitterfall characteristics, such as amount, component, seasonal dynamics, nutrient content and return was studied for six forests in Sanming, Fujian.The results show that:the litterfall of different species differed significantly. The litterfall of nature forest was the largest, amounted to13.39±0.36t·hm-2·a-1, PIM, the smallest,6.39±0.18t·hm-2·a*1. The components of litterfall were of the most complexity. The leaf of the six forests was the most major part of litterfall, account for78.38%-86.55%of the total litterfall, and branch litterfall of CUL is higher significantly than any other species.There are three patterns of monthly variation of litterfall mass:unimodal, bimodal and multi-modal.Nature forest followed unimodal, second forest and PIM complied with bimodal, others showen three peaks. There was significan difference in nutrient content among six forests.The rank order of nutrient content of the six forest was N>K>P. Foliage fall is the principal part of returient to the forest due to the largest amount and nutrient content. The monthly variety pattern of returned nutrient showed similar trend to that of foliage fall.