关键词: 抚育采伐, 森林经营, 功能性状, 功能结构, 谱系结构, 尺度依赖性, 生物多样性

Abstract: [Objective] This paper aims to explore the influences of tending felling on forest structure, biodiversity and ecosystem function, and to provide a better guidance for the management of mixed broadleaf-conifer temperate forest.[Method] In 2011, four 1 hm² stem-mapped plots with different felling intensity were established in Jiaohe, Jilin Province. Six plant traits that have been suggested to have great functional significance for plant growth were measured, including leaf area, specific leaf area, leaf carbon, leaf nitrogen, leaf C/N ratio and maximum tree height. All functional traits were determined for 22 woody species. Traits tree was constructed using the distance matrix of functional traits, meanwhile, phylogenetic tree was obtained based on the distance matrix of phylogeny. Phylogenetic signals of functional traits were detected using the Blomberg's K statistics. Functional structure of forest was represented by the functional diversity index and the nearest neighbor trait distance index. Phylogenetic structure was estimated using the phylogenetic diversity index and the nearest taxon index. The potential effects of tending felling on the functional and phylogenetic structures were examined at three different spatial scales. The influences of felling intensity on radial growth of the residual trees were also assessed.[Result] Five studied traits (specific leaf area, leaf carbon, leaf nitrogen, leaf C/N ratio and maximum tree height) showed significant phylogenetic signal. The variations of functional and phylogenetic structures depended on the studied scales. At the small scale (10 m×10 m), tending felling enhanced the degree of dispersion but reduced the degree of aggregation of community structure. However, at the middle and large scales (20 m×20 m and 50 m×50 m), tending felling enhanced the degree of aggregation but reduced the degree of dispersion. The result showed that the influences of felling intensity on the functional and phylogenetic diversity also have scale-dependency. Low and moderate felling intensity showed significant effects only at small study scale, but high felling intensity at all study scales. The radial growths of residual trees were from top to bottom in the order of moderate felling intensity, high felling intensity, low felling intensity and the controls.[Conclusion] Tending felling with low or moderate intensity could improve forest functional and phylogenetic structure and promote the utilization of resources. However, felling with high intensity is unfavorable to make full use of resources, moreover, felling with high intensity has a significant negative impact on biodiversity conservation. Therefore, from the perspective of forest management, low or moderate felling intensity is the best way to regulate community spatial structure, conserve biodiversity and accelerate the growth of trees.

Key words: tending felling, forest management, functional traits, functional structures, phylogenetic structures, scale dependence, biodiversity