环境地球化学国家重点实验室知识库

Litterfall plays an important role in carbon and nutrient cycling of a forest ecosystem which is generally affected by climate, vegetation, forest type and age. The majority of the subtropical forests of China are occurring in nutrient poor environment, and thus there is a need to understand the role of litterfall on the recycling of C and nutrients in these forests for their proper management. We measured litter production, and carbon and nutrient return in an evergreen broad-leaved primary forest (Mt. Ailao, SW China) and a deciduous broad-leaved secondary forest (Mt. Damei, East China). The annual litterfall productions were 1124 and 490 g m(-2) at the primary evergreen forest and secondary deciduous forest, respectively. Carbon return in primary evergreen forest was approximately three times greater than that in secondary deciduous forest. Litter N concentrations in the secondary deciduous forest were higher than that of the primary evergreen forest and consequently, the use efficiency of N of the secondary deciduous forest was lower than the primary evergreen forest. This reflects a stronger nutrient conservation mechanism in the primary evergreen forest than in the secondary forest.