Work

Tree species with conservative foliar nutrient status and strong phosphorus homeostasis are regionally abundant in subtropical forests

Year: 2022

Type: article

Abstract: Foliar nitrogen (N) or phosphorus (P) status and their stoichiometric homeostasis are integral parts of the plant nutrient economy that determines the success of plant species in environments where N or P limits plant growth. Despite growing evidence for higher predictability of stoichiometric homeostasis of N ( H N ) than that of P ( H P ) on plant species abundance in temperate grasslands, no previous studies explicitly examined how foliar N and P status modulate the relationships between stoichiometric homeostasis and species distribution (regional species abundance) of woody plants, especially in P‐limited (sub)tropical ecosystems. We hypothesized that species with a conservative foliar nutrient status but a higher H P (but not H N ) would be regional abundant in P‐limited forest. We measured foliar N (LNC) and P (LPC) contents of 54 woody species, community composition and soil N and P contents across 94 forest plots in Chinese subtropical forests. Then we evaluated the species' levels of N and P stoichiometric homeostasis and their regional abundance to test our hypotheses. H N and H P significantly increased with decreasing LNC and LPC. Foliar nutrient status positively correlated with the minimum values of both soil N and P contents, but only negatively associated with the maximum value of soil P content, indicating that conservative species can occupy a wider range of soil P‐ than N‐based nutrient niche. Meanwhile, species abundance negatively correlated with LNC and LPC, and positively correlated with H N and H P . However, the structure equation model analysis showed that species abundance increased with decline of LNC but not yet with increased H N . In contrast, species abundance enhanced with increased H P and decreased LPC via H P , rather than directly with a decline of LPC. Synthesis . This study provides empirical evidence that species with conservative foliar nutrient status are more stable in terms of N and P stoichiometric homeostasis, and foliar N and P economy modulate species abundance distribution in different ways. Our results suggest that maintaining strong stoichiometric homeostasis of leaf P, while maintaining conservative economy of N, is a key physiochemical mechanism for shaping species abundance distribution in P‐limited forests.

Source: Journal of Ecology

DOI: 10.1111/1365-2745.13884