闽楠林土壤-凋落物-叶片碳氮磷生态化学计量对人为干扰的响应

干扰是影响森林生态系统稳定性和功能的重要因子，干扰程度直接影响天然林的生长进而影响其生态系统能量流动和养分循环过程，为此开展干扰对天然林生态系统影响研究，对于揭示干扰对天然林生态系统养分平衡特征机制具有重要意义。以福建两种人为干扰模式下(重度干扰和轻度干扰)闽楠林为研究对象，通过分析“土壤-凋落物-叶片”三个组分化学计量特征，结合养分利用效率、养分再吸收效率、内稳态理论解析干扰对闽楠林养分资源利用策略和生态适应。结果表明：(1)两种干扰模式下，叶片C、N、P含量均显著高于其土壤和凋落物，且三个组分中N和P含量均表现出重度干扰显著高于轻度干扰，但三个组分C/N、C/P和N/P呈现轻度干扰显著高于其重度干扰。(2)闽楠林叶片N、P养分利用效率表现出：重度干扰<轻度干扰，但P再吸收效率则是重度干扰高于轻度干扰，且两种干扰模式下P养分利用效率和再吸收效率显著高于N。(3)随干扰强度的增加，闽楠林叶片N呈现内稳态弱，而叶片P的内稳态强以适应低P环境。(4)凋落物与叶片两组分P、C/P、N/P存在显著正相关关系，土壤C/N分别与叶片P、C/P、N/P以及凋落物P、C/N和C/P存在显著相关关...

Responses of C, N, P ecological stoichiometry of soil, litter, and leaf in the Phoebe bournei forests to human disturbances

Disturbance is an important factor affecting the stability and function of forests ecosystem. The degree of disturbance directly affects the growth of the trees, energy flow and nutrient cycle process in the forest ecosystem. It is significant to study the ecological stoichiometry of the disturbance in natural forest ecosystem, and to reveal the mechanism of disturbance on the characteristics of nutrient balance in the natural ecosystem. Two human disturbances (e.g., severe disturbance and mild disturbance) in the Phoebe bournei forest of Fujian Province were selected. The ecological stoichiometric characteristics of soil, litter, and leaf were analyzed. The ecological adaptation and nutrient utilization strategy of the P. bournei forest responding to the disturbances were estimated by nutrient use efficiency, nutrient resorption efficiency, and the homeostasis. The results showed that:(1) the C, N, and P contents of the leaf were significantly higher than that of the soil and litter under both disturbances, and the N and P contents in the three components of the severe disturbance were significantly higher than those of the mild disturbance, but the ratios of C/N, C/P and N/P in the three components of the mild disturbance were higher than those of the severe disturbance. (2) Leaf N, P nutrient use efficiency of the severe disturbance were lower than that of the mild disturbance, but P resorption efficiency of the severe disturbance were higher than that of the mild disturbance, and P nutrient use efficiency and resorption efficiency were significantly higher than N under both disturbances. (3) With the influence of disturbance, the leaf N had weak stability, but the leaf P had strong stability to adapt to a low P environment. (4) There was a significantly positive correlation between P, C/N, N/P of litter and leaf components. The P, C/N, and N/P of leaf, and P, C/N and C/P of litter were significantly correlated with C/N of soil. The response of stoichiometric characteristics of the P. bournei forest to disturbances showed that disturbance delayed the energy flow and nutrient cycle process of the P. bournei forest ecosystem.