High adaptability of Pinus sylvestris var. mongolica to drought-induced soil nutrient deficiency
Jingling Zhang, Guigang Lin, Qiong Zhao, De‐Hui Zeng
Abstract
Abstract Background Drought can exert a profound influence on soil nutrient availability, and understanding whether and how tree species adapt to this change is a critical priority for predicting the consequence of climate change on forest structure and function. The objective of this study was to examine the adaptability of Mongolian pine ( Pinus sylvestris var. mongolica ) to drought-induced changes in soil nutrient availability from the perspective of root functions. Methods We conducted a 7-year precipitation manipulation experiment with three levels of throughfall reduction (0%, 30%, and 50%) to simulate different drought intensities. We measured soil physicochemical properties and fine-root nutrient concentrations and biomass, and calculated the stoichiometric homeostatic regulation coefficient (1/ H ) of fine roots. Results Drought reduced soil organic carbon (C), nitrogen (N), phosphorous (P) and inorganic N concentrations, as well as ratios of total N to total P, and available N to available P in the 0–20 cm soil layer. In contrast, drought had no significant effect on fine-root N and P concentrations, and fine-root biomass in the 0–40 cm soil layer. Fine roots displayed high homeostatic regulation coefficients of N (with 1/ H values of 0.19 and 0) and P (with 1/ H values of 0.33 and 0) concentrations in 0–20 and 20–40 cm soil layers, respectively. Conclusions Our results indicate that drought leads to soil nutrient deficiency and the decoupling between N and P cycling, and provide evidence that Mongolian pine has high adaptability to drought-induced decrease in soil nutrient availability by maintaining great fine-root biomass to ensure sufficient nutrient uptake.