Divergent nitrogen and phosphorus allocation strategies in terrestrial plant leaves and fine roots: A global meta‐analysis

Abstract

1. The quantification of the allocation of nitrogen (N) and phosphorus (P) among plant organs is essential to improve our understanding of plant growth, lifehistory strategies and ecosystem nutrient and energy cycles. However, allocation strategies of N and P between terrestrial plant leaves and fine roots are unclear.2. Here, we compiled a global dataset comprising 807 terrestrial plant species to analyse the stoichiometric scaling of N and P between leaves and fine roots across species, families, plant groups, biomes and locations.3. We found that N and P, and N:P ratios manifest different scaling exponents (α-values) between leaves and fine roots. Specifically, overall α N and α P were >1 and <1, respectively, and α N:P = 1, indicating a higher proportional increase of N to fine roots and P to leaves. However, there were differences in α N , α P and α N:P among major species, families, plant groups, biomes and locations. In addition, α N and α N:P increased with latitude; there was no clear trend for α P . Mean annual temperature accounted for the greatest proportion of variation in α N , whereas soil total P accounted for the greatest proportion of variation in α P and α N:P . 4. Synthesis. Our results demonstrate a divergent N and P allocation strategy between leaves and fine roots in terrestrial plants. This study improves our understanding of the effects of the environment (including changes in global climate and life-history strategies) on nutrient allocation patterns between these two important plant organs.

A ‘Get‐Save‐Return’ process continuum runs on phosphorus economy among subtropical tree species

“…The dual pathways of nitrate assimilation could influence the assessment of root absorption and leaf resorption, and thus obscure their linkages. Third, the N and P allocation strategy diverges between the above‐ and below‐ground plant organs (Wang et al, 2022). More N is allocated to roots than to leaves, and the reverse is the case for P (Wang et al, 2022), possibly because the phloem in roots needs higher levels of N to support the required levels of photosynthate transport (Kerkhoff et al, 2006).…”

“…Third, the N and P allocation strategy diverges between the above‐ and below‐ground plant organs (Wang et al, 2022). More N is allocated to roots than to leaves, and the reverse is the case for P (Wang et al, 2022), possibly because the phloem in roots needs higher levels of N to support the required levels of photosynthate transport (Kerkhoff et al, 2006). Such an N allocation strategy implies that N could be obtained mostly by root absorption rather than leaf resorption, leading to discontinuity in the N economy.…”

Toward a coordinated understanding of hydro‐biogeochemical root functions in tropical forests for application in vegetation models

“…For nutrient aboveground–belowground coordination, a recent global review indicated greater coordination of leaf with root N : P ratios in tropical forests relative to most other biomes, likely related to widespread tropical soil P scarcity and conservation of P in plant tissues (Wang et al ., 2022). A broad‐scale paper linking remotely sense canopy traits in Panama with soil data found that canopy greenness (a surrogate for NPP) corresponded to variations in soil fertility and toxicity (Fisher et al ., 2020).…”

Analysis of nutrient resorption efficiency and homeostasis of four tree species in Kanas natural forest, Xinjiang, China

“…Carbon (C), nitrogen (N), and phosphorus (P) are major macro elements necessary for life (Elser et al, 2000); their cycling in plant leaves-litter-soil systems has substantial effects on the function and stability of ecosystems. Due to the important function of N and P (Wang et al, 2022), previous studies generally pay more attention to the resorption efficiency of N (NRE) and P (PRE).…”