B53D-0588
Nutrient Allocation Strategies of Woody Plants: An Approach From the Scaling of Nitrogen and Phosphorus Between Twigs and Leaves

Friday, 18 December 2015
Poster Hall (Moscone South)
Zhengbing Yan1, Peng Li1, Yahan Chen2, Wenxuan Han3 and Jingyun Fang1, (1)Peking University, Department of Ecology, Beijing, China, (2)Institute of Botany, Chinese Academy of Sciences, Beijing, China, (3)China Agricultural University, Department of Ecology, Beijing, China
Abstract:
Allocation of limited nutrients, such as nitrogen (N) and phosphorus (P), among plant organs reflects the influences of evolutionary and ecological processes on functional traits of plants, and thus is related to functional groups and environmental conditions. In this study, we tested this hypothesis by exploring the stoichiometric scaling of N and P concentrations between twigs and leaves of 335 woody species from 12 forest sites across eastern China. There were significant scaling relationships between twig N (or P) and leaf N (or P) using reduced major axis (RMA) regression analysis; yet their scaling exponents varied among functional groups and changed with environmental factors. Evergreen broad-leaved plants had a higher exponent (αP) of twig P to leaf P than that of deciduous broad-leaved plants (1.26 vs. 0.96, p < 0.05), but they had a similar exponent (αN) of twig N to leaf N (1.20 vs. 1.19). For both N and P, legume species exhibited a higher exponent than non-legume species (1.44 vs. 0.99 for αN; 1.86 vs. 0.88 for αP). Moreover, with increasing latitude, both αN and αP significantly decreased from > 1 at low latitude (23.2°N) to < 1 at high latitude (50.9°N), and this trend was consistent among the different forest types (i.e., tropical, temperate and boreal forests) across the study area. These results suggested that, as plant nutrient concentration increased, plants at low latitudes showed a faster increase in twig nutrient concentration, whereas plants at high latitudes presented a faster increase in leaf nutrient concentration. Such shifts in nutrient allocation strategy from low to high latitudes may be controlled by temperature. Overall, our findings provide a new approach to explore plant nutrient allocation strategies by analysing the stoichiometric scaling of nutrients among organs, which could broaden our understanding of the interactions between plants and their environments.