The allocation of nitrogen (N) and phosphorus (P) among organs reflects plants adaptation to environmental changes and the N-P scaling exponent is an important parameter for plant growth and vegetation productivity prediction. However, few studies have focused on the N and P stoichiometric characteristics of non-photosynthetic organs. We systematically investigated nutrient contents of different organs (leaf, stem, root and fine root) of 1532 shrubs from 13 sites across eastern China to explore the N-P scaling exponent and its influencing factors.
Results/Conclusions
We found that the N and P contents in leaves and fine roots were significantly higher than those of the stems and roots. The N-P scaling exponent were the highest in the fine roots at both the individual and species level. The effect of plant functional groups (PFGs) on the N-P scaling exponent among different organs is not consistent. PFGs had no effect on the N-P scaling exponent of leaf and fine root, but had a significant effect of stem and root. Furthermoreļ¼the responses of N-P scaling exponent to soil total nitrogen (STN) and soil total phosphorus (STP) gradients as well as different climatic regions were not consistent. Our results suggest that the differences in organ nutrient content and allocation should be considered when N-P scaling was incorporated in the model as which were affected by both PFGs, climate and soil factors. These results suggest that climate change (such as nitrogen deposition and global warming) may change the nutrient allocation strategies of shrubs, thus affecting ecosystems structure and function.