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

作者：Ci, Hang; Guo, Chao; Tuo, Bin; Zheng, Li-Ting; Xu, Ming-Shan; Sai, Bi-Le; Yang, Bai-Yu; Yang, Yong-Chuan; You, Wen-Hui^*; Yan, En-Rong^*; Cornelissen, Johannes H. C.

来源：Journal of Ecology, 2022, 110(7): 1497-1507.

DOI：10.1111/1365-2745.13884

• Foliar nutrient status
• N
• P ratio
• nutrient limitation
• plant nutrient economy
• soil nutrient gradient
• species abundance
• stoichiometric homeostasis

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.

• 单位
  重庆大学