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

<p><span>Foliar </span><span>nitrogen (N) or phosphorus <em>(P)</em> </span><span>status and their </span><span>stoichiometric homeostasis </span><span>are integral parts of the plant nutrient economy </span><span>that determines the success of plant species</span><span> in environments where N or P limits plant growth. </span><span>Despite growing evidence </span><span>for higher predictability of </span><span>stoichiometric </span><span>homeostasis </span><span>of N</span><span> (</span><em><span>H</span></em>_{<span>N</span>}<span>) than that of P (</span><em><span>H</span></em>_{<span>P</span>}<span>) on plant species abundance</span><span> in temperate grasslands</span><span>, no previous studies e</span><span>xplicitly examined how foliar N and P status modulate the relationships between </span><span>stoichiometric </span><span>homeostasis and</span><span> species distribution (regional species abundance)</span><span> of woody plants, especially in P-limited (sub)-tropical ecosystems. W</span><span>e hypothesized that species with a conservative foliar nutrient status but a higher </span><em><span>H</span></em>_{<span>P</span>}<span> (but not</span><span> <em>H</em>_N</span><span>) would be regional abundant in </span><span>P-limited</span><span> forest.</span></p> <p><span>We measured foliar N (LNC) and P (LPC) contents of 54 woody species, community composition and soil N and P </span><span>contents across</span><span> 94 forest plots in Chinese subtropical forests. Then we evaluated the species' levels of N and P </span><span>stoichiometric homeostasis</span><span> and their regional abundance to test our hypotheses.</span></p> <p><span><em><span>H</span></em>_{<span>N</span>}<span> and <em>H</em>_P significantly increased with decreasing LNC and LPC. Foliar nutrient status positively correlated </span><span>with the minimum values of both soil N and P contents, but only negatively associated with the maximum value </span><span>of soil P content, </span><span>indicating that conservative species can occupy a wider range of soil P- than N-based nutrient niche.</span><span> Meanwhile, species abundance negatively correlated with LNC and LPC, and positively correlated with <em><span>H</span></em>_{<span>N</span>}<span> and <em>H</em>_P</span>. However, the structure equation model analysis showed that species abundance increased with decline of LNC but not yet with increased HN. In contrast, species abundance enhanced with increased <span><em>H</em>_P </span>and decreased LPC via <em><span>H</span></em>_{<span>N</span>}, rather than directly with a decline of LPC.</span></span></p> <p><span><strong>Synthesis</strong>.</span><span> 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.</span></p>