森林干扰度评价

Evaluation of response extent of forests to disturbances

干扰普遍存在于森林生态系统,是森林群落演替的驱动力之一。干扰对森林生态系统的影响程度,决定于干扰的频率、强度、空间范围等,过度频繁或不合理的干扰,可能导致森林生态系统的毁灭。森林对干扰的响应表现在多方面,其内在联系十分复杂,因此,很难用森林中某个现象或某几个现象反映森林生态系统对干扰的响应。为了准确、科学地评价现有森林生态系统对干扰的响应程度,本文提出应用森林干扰度(REFD)评价现有森林受干扰的程度。森林干扰度是由于干扰的存在造成森林生态系统结构与功能的改变程度,仅反映干扰后现有森林与目标森林(地带性顶极植被或原有森林等)的距离程度(差距),不反映干扰的种类、强度、性质等因素;在对森林干扰度内涵进行详细分析的基础上,确定了评价森林干扰度的原则及不同尺度条件下森林干扰度的评价指标。

Disturbance is one of the driving forces of forest community succession, and of signifi cance in forest ecosystems. The impact extent of disturbances on forest ecosystems was mostly depended on the frequency, intensity, and spatial scale of the disturbances, and, excessive and frequent disturbances may lead to the destruction of forest ecosystems. The response of forest ecosystems to disturbances represents in many aspects, and the internal relationships among these aspects are quite complicated. Therefore, it is difficult to define the response of forest ecosystems to the disturbances from one or several phenomena in a forest ecosystem. Aiming to correctly evaluate the response extent of existing forest ecosystems to the disturbances, the authors considered that the response extent of forests to disturbances （REFD） could be related to the change degrees of forest ecosystem structure and function under the existence of disturbance, which only reflect the extent of the differences between existing forests and objective forests （ zonal climax vegetation or original forest vegetation） after disturbances, but not the types of intensity and property of the disturbances. The concept and connotation of REFD were defined and explored, and the evaluation principles and methods of REFD were also summarized.