Changes in biological nitrogen fixation activity and organic composition of leaf litter with decomposition of evergreen species

Changes in biological nitrogen fixation activity (C2H2-reduction activity; ARA) and organic composition of leaf litter with decomposition were measured with the wire-netting cage method at evergreen broad-leaved secondary forest. Ilex chinensis and Cinnamomum camphora were chosen as the investigated species. The result indicated that the change of weight loss and ARA of leaf litter with decomposition were different in species. ARA of the leaf litter was not closely related to C/N ratio. Higher ARA was recorded in I. chinensis at early stage of decomposition in which water soluble fraction and benzene-ethanol soluble fraction were mostly remained. Compared with I. chinensis, ARA of C. camphora leaf litter was smaller but slightly increased with decomposition. We estimate that the amount of nitrogen fixed in leaf litter of both species was 0.521 kg·ha-1·yr-1, and most of them might be fixed on leaf litter of I. chinensis in this site.