The influence of sampling unit size and spatial arrangement patterns on neighborhood-based spatial structure analyses of forest stands.

作   者：Hongxiang Wang, Gongqiao Zhang, Gangying Hui, Yuanfa Li, Yanbo Hu, Zhonghua Zhao
期刊名称：Forest Systems
影响因子：0.761
卷 期 号：25(1)
页     码：
关键词：Stand spatial structure; number of neighboring trees; uniform angle index; mingling; dominance.
论文摘要：
Aim of the study: Neighborhood-based stand spatial structure parameters can quantify and characterize forest spatial structure effectively. How these neighborhood-based structure parameters are influenced by the selection of different numbers of nearestneighbor trees is unclear, and there is some disagreement in the literature regarding the appropriate number of nearest-neighbor trees to sample around reference trees. Understanding how to efficiently characterize forest structure is critical for forest management. Area of study: Multi-species uneven-aged forests of Northern China Material and methods: We simulated stands with different spatial structural characteristics and systematically compared their structure parameters when two to eight neighboring trees were selected. Main results: Results showed that values of uniform angle index calculated in the same stand were different with different sizes of structure unit. When tree species and sizes were completely randomly interspersed, different numbers of neighbors had little influence on mingling and dominance indices. Changes of mingling or dominance indices caused by different numbers of neighbors occurred when the tree species or size classes were not randomly interspersed and their changing characteristics can be detectedaccording to the spatial arrangement patterns of tree species and sizes.Research highlights: The number of neighboring trees selected for analyzing stand spatial structure parameters should be fixed.We proposed that the four-tree structure unit is the best compromise between sampling accuracy and costs for practical forest management.