亚高山针叶林粗木质残体对碎屑食物网结构和多样性的影响

碎屑食物网是森林物质循环和能量流动的重要通道，而粗木质残体特性可能维持着碎屑食物网结构的复杂性和生物多样性，从而控制着生态系统功能和稳定性，但迄今缺乏必要关注。因此，基于“碎屑食物网的复杂性和多样性随着倒木分解而变化，大径级倒木对维持碎屑食物网复杂性和多样性更重要，林分水平的粗木质残体储量决定了碎屑食物网的复杂性和多样性”等假说，拟以前期7年的亚高山森林倒木原位分解实验为基础，采用磷酸脂肪酸、高通量测序和稳定同位素等研究手段，深入研究倒木-土壤界面和倒木表面碎屑食物网结构和多样性随倒木分解和关键时期的变化，粗木质残体径级和分解状态对碎屑食物网结构和多样性的影响，以及粗木质残体储量对碎屑食物网结构和多样性的影响，阐明森林粗木质残体对碎屑食物网结构和多样性的影响机制。研究结果有助于理解粗木质残体对亚高山针叶林生态系统功能和稳定性的维持机理，可为亚高山针叶林永续经营和生物多样性保护提供科学依据。

Detrital food web is a crucial channel for material cycles and energy flow in forest ecosystems, of which complexity and biodiversity might be maintained by coarse woody debris properties, and in turn controls the function and stability of forest ecosystem. However, little attention has been given to the effect of coarse woody debris on detrital food web. Here, we hypothesize that the complexity and biodiversity of detrital food web varies with fallen log decomposition, decaying fallen logs with larger diameter exert more important roles in maintaining the complexity and biodiversity of detrital food web, and coarse woody debris stock determines the complexity and biodiversity of detrital food web at stand level. Therefore, a continued 4-yr in-situ log decomposition experiment will be conduct in the subalpine coniferous forest on the eastern Tibetan Plateau based on the past 7-yr in-situ log decomposition experiment. In combination with the methods of phospholipid fatty acid, high-throughput sequencing and stable isotope technologies, the changes in trophic structure and biodiversity of detrital food web at decaying log-soil interface and on decaying log surface with log decomposition process and critical periods will be deeply studied. Meanwhile, the effects of log diameter class and decay status on the trophic structure and diversity of detrital food web will be investigated in different subalpine forests. Additionally, the effects of coarse woody debris stock on the trophic structure and diversity of plant debris-dwelling food web will be also studied at stand level. The results will be expected to illuminate the effect mechanism of coarse woody debris on the structure and diversity of detrital food web, and to deeply understand the mechanisms of coarse woody debris in maintaining the function and stability of the subalpine forest ecosystem. The findings can provide crucial scientific evidences for sustainable forest management and biodiversity conservation in the subalpine forest.