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

Purpose Leaf elemental stoichiometry is indicative of plant nutrient limitation, community composition, ecosystem function. Understanding the variations of leaf carbon (C), nitrogen (N), and phosphorus (P) stoichiometry at genus-level across large geographic regions and identifying their driving factors are important to predict the response and adaptation of the deciduous Quercus species affected by climate change. Methods Here, we determined the patterns of leaf concentrations ([]) and ratios ( /) of C, N, P of five deciduous Quercus species across China covering similar to 20 latitude (similar to 21-41 degrees N) and longitude (similar to 99-119 degrees E) degrees, and detected their relationships with climatic and edaphic variables. Results Leaf [C], [N] and N/P, C/P significantly increased, while leaf [P] and C/N decreased with increasing latitude. Leaf stoichiometry except for leaf [C] had no significant trends along the longitude. Climatic variables, i.e., mean annual temperature, mean annual precipitation, aridity index, and the potential evapotranspiration as well as the edaphic factors, i.e., the concentration of soil organic matter, soil P, and soil pH were the determinants of the geographic patterns of leaf C, N, P stoichiometry of the deciduous Quercus species at the broad geographic range. The studied deciduous Quercus species growing in cold, dry and infertile environments tended to increase leaf [P] and C/N but to decrease leaf [C], [N], C/P and N/P, implying positive regulation on nutrient strategies to adapt to different environments. Conclusions Both climatic and edaphic variables have important effects on leaf C, N, P stoichiometry of the studied deciduous Quercus species across large geographic scales. The ongoing climate change might alter nutrient strategies and potentially shift the distribution range of this eurytopic species.

Automated summary

Leaf elemental stoichiometry of Quercus species varies at genus-level across China and is influenced by both climatic and edaphic factors. Climate change may alter nutrient strategies and potentially shift the distribution range of these species.