秦岭暖温性落叶阔叶林植食作用及其对幼苗更新的影响

植食作用是影响森林幼苗更新的关键过程之一，但其效应会因研究地微环境条件、邻体树种密度和动物类群等因素的不同而存在明显差异。以往研究大多仅考虑单一因素的影响，而综合考虑上述因素的研究十分匮乏。为此，本项目拟以秦岭暖温性落叶阔叶林为研究对象，沿海拔梯度对幼苗虫损及动物啃食进行调查，并结合微环境和邻体同种大树密度等数据，探究不同海拔梯度下植食动物对幼苗更新的影响，阐明影响植食作用强度的关键因素。此外，本项目还将在低、中、高三个海拔设置不同孔径的围栏实验，旨在研究大、小型动物和昆虫等对幼苗更新的影响，以及各植食作用类型在不同微环境和邻体树种密度下的差异。项目结果将揭示秦岭暖温性落叶阔叶林植食动物对幼苗更新的影响，理清动物类群、微环境条件和邻体同种大树密度等对植食作用强度的相对重要性，阐明动植物关系及其对植物多样性维持的作用，为秦岭生物多样性保护和森林生态系统恢复提供科学依据。

Herbivory is one of the critical processes in regulating seedling recruitment in forests. The impacts of herbivores vary considerably across micro-environmental conditions, neighboring tree densities and types of herbivores. Still, their relative importance remains largely unknown, as previous work has generally targeted one single aspect. This project will be conducted in a warm-temperate deciduous broad-leaved forest in Qinling Mountains. To investigate the impacts of herbivores on seedling recruitment and the essential drivers of the strength of herbivory, we will survey the herbivory rates along altitude gradients with distinct micro-environmental conditions and conspecific neighboring adult tree densities. Further, three levels of exclosures will be established to test the relative importance of large vertebrates, small vertebrates and insects on seedling recruitment. Meanwhile, we will show how do their impacts vary with micro-environmental conditions and conspecific tree densities by settling pairs of exclosures at low (1300-1350 m), medium (1600-1650 m) and high (1900-1950 m) elevations. Overall, this project aims to reveal the impacts of herbivores on tree seedling recruitment in warm-temperate deciduous broad-leaved forests in Qinling Mountains. Importantly, we will clarify the relative importance of micro-environmental conditions, neighboring tree densities and types of herbivores in regulating the strength of herbivory. The results are expected to deepen our understanding of the herbivore-plant interactions and the effects of herbivory in maintaining plant diversity. The project also provides scientific basis for biodiversity conservation and ecosystem restoration in forest ecosystems.