庐山森林景观空间分布格局及多尺度特征

森林景观是区域整体景观的重要组成部分,研究其空间分布格局对于优化区域景观整体结构和发挥生态经济效益具有重要意义。基于庐山2010年植被斑块数据,将森林景观划分为常绿阔叶林、落叶阔叶林、松类、杉类和竹类等5类景观,从森林景观的不同发育阶段和林分类型角度出发,运用点格局分析法分析5类森林景观空间分布格局特征。最邻近距离分析表明:5类森林景观空间分布类型均服从集聚分布但聚集强弱有变化;不同发育阶段的森林景观空间分布类型以集聚分布为主,随机分布为辅,尤其幼龄林比较显著,中龄林和老龄林次之;5类森林景观的天然林均服从集聚分布,人工林大多趋于随机分布,只有松类和杉类呈显著集聚分布。Ripley's K函数揭示了不同发育阶段和林分类型的森林景观的多尺度集聚特征,即在小尺度范围内服从随机分布,随着空间距离的增大,以空间特征尺度为分界线,空间聚集强度先逐渐增强,随后不断减弱。总体来看,庐山森林景观的发育阶段主要处于幼年时期,原始植被遭到人类大肆破坏,幼龄林大片分布,属于典型的恢复性植被,未来要重点保护好天然林,减少人为干扰,实现森林景观适度集聚。研究庐山森林景观的空间分布和多尺度特征可以为生态环境保护和实现森林可持续经营提供理论指导。

Spatial distribution patterns and multi-scale features of the Lushan forest landscape

The forest landscape is an important part of the overall landscape, and therefore studying the spatial distribution pattern of regional landscapes will play an important role in optimizing the overall landscape structure for ecological and economic benefits. Based on vegetation patch data obtained from the Lushan forest in 2010, point-pattern analysis was used to examine the spatial distribution patterns of five forest landscape features with respect to developmental stage and forest type. Nearest-neighbor analysis showed that the five types of forest landscape were consistent with a clustered distribution, but the strength of the distribution varied; the nearest-neighbor indices for each type were all less than 1, but the overall forest landscape was consistent with a random distribution. The spatial distribution of various developmental stages mainly showed a clustered distribution pattern, but random and uniform distributions also occurred, especially in young forests, followed by middle-aged and mature forests. This distribution pattern was closely related to the number of patches: greater patch numbers were associated with a more clustered distribution, and smaller patch numbers were associated with random and uniform distributions. Natural forests of the five landscape types were all consistent with a clustered distribution, and the extent of clustering was variable. Only pine and fir demonstrated significantly clustered distributions among the plantation forests, and others were subject to a random distribution. Ripley''s K-function analysis showed strong scale-dependence of the distribution pattern of landscapes. Different spatial scales showed different distribution patterns, but different developmental stages and forest types exhibited generally consistent distributions, i.e., random distributions on a small scale, a more clustered distribution as the spatial distances increased, and became weakening beyond of the dividing lines, which were defined as the spatial characteristics lines. Overall, the developmental stage of the Lushan forest landscape was in its infancy, and is characterized by a typical pattern of vegetation recovery; during this phase, it is critical to protect the natural forest rather than damage it. Therefore, the task of closing hillsides to facilitate afforestation is tough. Further study and research on various developmental stages and forest types and their associated landscape spatial distribution patterns and multi-scale features can provide theoretical guidance for ecological and environmental protection and sustainable forest management.