The monthly dynamics of nitrogen (N) and phosphorus (P) concentrations and stocks in leaves, resorption efficiency, and resorption proficiency as well as leaf-level use efficiency, nutrient productivity, and mean residence time were studied to understand the effect of stem density of dwarf bamboo (Fargesia denudata Yi) on leaf-level N and P use efficiency in three dwarf bamboo stands with different stem densities under bamboo-fir (Picea purpurea Mast.) forest over one growing period in the Wanglang National Nature Reserve, Sichuan, China. Dwarf bamboo density had little effect on the dynamics pattern of both N and P concentrations, stocks, resorption efficiency, and resorption proficiency, but strongly affected their absolute values and leaf-level use efficiency. Higher density stands stored more nutrients but had lower concentrations. There was a clear difference in the resorption of limiting nutrient (N) and non-limiting nutrient (P) among the stands. Phosphorus resorption efficiency, N resorption proficiency, and P resorption proficiency increased with increase of stem density, but no significant variation of N resorption efficiency was found among the stands. Moreover, the higher density stands used both N and P more efficiently with higher N productivity and higher P mean residence time, respectively. Higher P productivity was found in the lower density stands, but there was no clear variation in the N mean residence time among stands. These suggested that the higher density stands may have more efficient strategies for utilizing nutrients, especially those which are limiting.
