Nutrient Resorption Strategies of Three Oak Tree Species in Response to Interannual Climate Variability

Abstract

\n Background：Nutrient resorption is critical for plants toward balancing their nutritional requirements and adapting to environmental variabilities, which further impacts litter quality and nutrient cycling. However, the interannual variability of nutrient resorption under climate change remains unclear.Methods: We investigated the five-year nutrient resorption efficiencies (NuRE, %) of 14 elements in three deciduous oak tree species, Quercus aliena var. acuteserrata, Q. glandulifera, and Q. variabilis species in a warm-temperate forest of Central China, and assessed their relationships with interannual climate and soil factors. Results：Nutrient resorption did not differ between species but varied significantly between different years. For each year, nucleic acid-protein elements (N, P, S, and K) were preferentially resorbed in all of the oak species in contrast to photosynthesis-enzymic (C, Mg, and Zn) and structural (Ca, Na, Mn, and Ba) elements, which were to some extent discriminated, and toxic (Al and Fe) elements that were completely excluded. Among the 14 elements, the NuRE of N, P, S, Ca, and Mg was closely associated with interannual climate in the three oak species, showing N and S resorption efficiency were reduced with temperature, while N, P, and S resorption efficiency initially decreased and then increased with precipitation. Moreover, the elemental coefficient variations between different years generally decreased with higher NuREs in all three oak species.Conclusions: Different oak species have analogous nutrient conservation strategies in response to annual climate variability, and interannual climate variations strongly impacted plant nutrient resorption. Deciduous plants may establish a trade-off mechanism to rebalance somatic nutrients for regrowth at the end of growing season.