Objective This study aimed to explore the effects of tree species mixing on stoichiometric characteristics, nutrient resorption efficiency, and homeostasis of leaves, litter, and soil in Pinus tabuliformis plantations in mountainous areas of Beijing, northern China to provide a scientific basis for sustainable management of P. tabuliformis plantations.
Method Pure P. tabuliformis plantation, P. tabuliformis + Tilia mandshurica mixed plantation (PT), P. tabuliformis + Quercus mongolica mixed plantation (PQ), and P. tabuliformis + Prunus davidiana + Prunus sibirica mixed plantation (PR) were measured for C, N, and P contents and stoichiometry in leaves, litter and soil. Nutrient resorption efficiency and homeostasis were assessed using allometric growth and resorption efficiency models.
Result The PQ plantation showed optimal nutrient status, with significantly higher leaf N content and N∶P, as well as elevated soil C, N, C∶P and N∶P. The PT plantation had the highest leaf C∶N and C∶P, indicating a conservative nutrient strategy. Tree species mixing generally had higher litter C, N and N∶P than pure stands, suggesting enhanced decomposition and nutrient release potential. PQ and PT exhibited the highest N and P resorption efficiency, respectively, both exceeding pure P. tabuliformis stand. All four stands maintained strong P homeostasis, with leaf P content unaffected by soil P variation.
Conclusion Compared with pure stand, tree species mixing, particularly the PQ plantations significantly enhance nutrient status, soil fertility and resorption efficiency, providing an optimal model for transforming low-efficiency plantations in Beijing mountainous areas. Prioritizing ecologically complementary species in mixing is recommended to improve nutrient cycling and ecosystem stability.
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