关键词: 食物源, 稳定同位素, 营养关系, 食物网结构, 湿地生态系统

Abstract: The decomposition rate of litters and their variations of energy and nutrient release in Hexi subtropical rain forest of Fujian are determined with litter bags. The results show that the dry matter loss is faster from 8 mm than from 2mm mesh bages. The half-timeof decomposition in Zmm and 8mm mesh bages is 4.9 and 3.7 months, respectively. During decomposition, the N and P contents of residual leaf are higher than those of original one. The loss rate of 5 elements from decomposing litter is in the order of K>Mg>Ca>N>P. Residuals have a decreased caloric value.

Key words: Subtropical rain forest, Litter decomposition, Nutrient loss, stable isotope, food web structure, wetland ecosystem, trophic relationship, food source