【摘要】 【目的】探讨基于空间结构的森林稳定性维持机制,提出森林"随机体-稳定性"假说,为改善我国人工林稳定性提供科学参考。【方法】以我国不同气候带典型天然林为研究对象,利用林分空间结构参数——角尺度精细解译林木点格局,根据参照树及其最近4株相邻木构成的结构单元中相邻木的分布形式定义结构体,分析典型天然林结构体类型构成,揭示稳定性高的天然林普适性结构规律。【结果】天然林中的林木主要由随机木组成,其林木株数频率达55%,断面积占比高达50%以上;随机木构成天然林的主体,既与天然林地域分布和森林类型无关,也与天然林树种组成和格局类型无关。【结论】随机木是天然林稳定的基石,其在天然林中的主体构成是促使森林稳定性的关键。林分中随机体的架构形式使得随机木具有两面受光的邻体微环境,相较于均匀体,其中心木受相邻木的竞争压力更小,而相较于聚集体,随机木的相邻木之间挤压程度则更小,随机木及其邻体(随机体)相对来说承受的生存压力较小,在自然演替过程中能够获得更大的存活几率;随机体数量越多,森林群落越稳定。更多还原

【Abstract】 【Objective】The mechanism of forest stability maintenance based on spatial structure was discussed and the forest "random structural framework-stability " hypothesis was also put forward, to provide scientific reference for improving the stability of plantation in China.【Method】Taking the typical natural forests in different climatic zones in China as the research objects,the stand spatial structure parameters of uniform angle index were used to interpret the pattern of tree points. The structural unit was defined according to the distribution form of the nearest four adjacent trees around the reference tree. The composition of typical natural forest structural unit was analyzed and the universal structure law of natural forest with high stability was revealed.【Result】The trees in the natural forest are mainly composed of random trees,whose tree number frequency is as high as 55%,and the basal area accounts for more than 50%; random trees constitute the main body of natural forests,which haven’t corretation with the geographical distribution and forest types of natural forests,and don’t correlate with the tree species composition and pattern types of natural forests either.【Conclusion】Random tree is the cornerstone of natural forest stability,and its main composition in natural forest is the key to promote forest stability. The random structural unit in the stand makes the random trees have the neighborhood microenvironment with light on both sides,compared with the regular unit,the reference tree has less competitive pressure from its neighbors. Compared with the clumped unit,the degree of extrusion between the neighbors of random trees is smaller,so the survival pressure of random trees and their neighbors (random structural unit) is relatively small,and they can obtain a greater survival probability in the process of natural succession. The more the number of random structural unit is,the more stable the forest community might be.更多还原