Responses of decomposition of green leaves and leaf litter to stand density, N and P additions in Acacia auriculaeformis stands

The effects of nitrogen (N), phosphorus (P) and N+P additions on the decomposition of green leaves and leaf litter were studied over 2years using the litterbag technique in Acacia auriculaeformis stands with different densities in southern China. The green leaves and leaf litter were treated with four fertility treatments: control, N addition, P addition and N+P addition to test the effect of stand density and fertility on the decomposition of green leaves and leaf litter. The mean percentage of mass remaining (PMR) of green leaves and leaf litter significantly decreased with increasing density. Nitrogen and N+P additions had a negative effect on PMR, whereas the addition of P had a positive effect. The rapid decomposition of green leaves was associated with a higher N and P content and a lower N/P ratio, indicating a likely P limitation for A. auriculaeformis stands. Our results imply that stand density associated with canopy openness can impact litter decomposition, and P is an important control factor on litter decomposition in A. auriculaeformis stands.