Climatic rather than edaphic variables determine leaf C, N, P stoichiometry of deciduous Quercus species

Abstract

Purpose Leaf stoichiometry of carbon (C), nitrogen (N) and phosphorus (P) is indicative of plant nutrient limitation, community composition, ecosystem function. Understanding leaf stoichiometry patterns of C, N, P of eurytopic species at genus-level across large-scale geographic regions and identifying their driven factors are of great importance to assess and to predict species’ distribution range shifts affected by climate change. Methods Here, we determined the patterns of leaf C, N, P stoichiometry of five deciduous oaks species ( Quercus) across China covering ~ 20 latitude (~ 21–41˚ N) and longitude (~ 99–119˚ E) degrees, and detected their relationships with climatic, edaphic variables. Results We found that the concentrations ([ ]) of leaf C, N and the ratios ( / ) of N: P, C: P significantly increased, while leaf [P] and C/N decreased with the increasing latitude. However, leaf stoichiometry had no significant trends along the longitudinal gradient with an exception of leaf [C] which decreased with increasing longitude. The climatic variables, i.e. mean annual temperature precipitation (MAP), the max temperature of the warmest month (Tmax), temperature seasonality (TS), aridity index (AI) were the determinants on the geographic patterns of leaf C, N, P stoichiometry. The studied deciduous Quercus species growing in warm and wet environments tended to increase leaf [C], [N], C/P, and N/P, but to decrease leaf [P] and C/N, which maybe their nutritional strategies to improve adaptability. Conclusion The adaptative mechanisms of leaf stoichiometry should be further studied to assess the fate of deciduous Quercus species affected by climate change.