东北温带次生林林窗干扰对主要木本植物萌蘖更新过程的影响机制研究

巨量次生林存在生物多样性降低、生态系统服务功能下降等问题，提高次生林主要树种天然更新能力是解决上述问题的根本。萌蘖更新作为一种重要的天然更新方式，在次生林结构与功能恢复中发挥关键作用。林窗干扰是次生林生态系统最重要的小尺度干扰类型，影响着森林结构和更新演替方向，明确林窗干扰对次生林主要树种萌蘖更新过程的影响机制对加速次生林定向恢复具有重要科学和实践意义，但相关研究仍很薄弱。为此，本研究从林窗干扰角度出发，以东北林区森林资源主体—次生林生态系统为对象，采用长期定位监测萌枝存活/生长特征和关键节点定量描述生理特征相结合的方法，探究次生林林窗干扰对主要树种伐桩萌枝形成机制的影响，明确次生林主要树种伐桩萌枝动态变化对林窗干扰的响应规律，阐明不同林窗微环境下主要树种伐桩萌枝最适宜的人工疏伐强度。研究结果对丰富模拟林窗干扰的次生林近自然经营理论，实现东北温带次生林恢复和可持续经营具有重要的科学价值。

A huge amount of secondary forest has some problems such as the decrease of biodiversity and the decline of ecosystem service function, and the key to solve these problems is to improve the natural regeneration ability of dominant tree species. As an important natural regeneration method, sprout regeneration plays a key role in the restoration of structure and function of secondary forest. Forest gap is the most important small-scale disturbance in secondary forest ecosystem, which affects forest structure and the direction of regeneration and succession. It is of great scientific and practical significance to clarify the mechanism of gap disturbance on sprout regeneration process of dominant tree species in secondary forest for accelerating directional restoration of secondary forest, but relevant research is still weak. Therefore, from the perspective of gap disturbance, this study will take the secondary forest ecosystem, the main body of forest resources in Northeast China, as the object, and use a combined method of long-term monitoring of sprout/growth characteristics and quantitative description of physiological characteristics at key points to explore the effect of gap disturbance on the formation mechanism of dominant tree species stump sprouts, to determine the response of dynamic changes of dominant tree species stump sprouts to gap disturbance, and to clarify the optimal artificial thinning intensity of dominant tree species stump sprouts under different within-gap microenvironments. The results of this study have important scientific value for enriching the theory of close-to-natural silviculture of secondary forest by simulating gap disturbance and realizing the restoration and sustainable management of temperate secondary forest in Northeast China.