取样面积对森林木本植物空间分布格局分析的影响
摘要
A major objective of ecological research is to infer underlying processes or mechanisms by analyzing the spatial distributions of species. Many studies have shown that spatial distribution patterns vary greatly, even within a species, probably because of the effects of different sampling scales and methods. However, the effects of sampling scale on species spatial distribution patterns have received little research. In this study, we used the relative neighborhood density,<italic>Ω</italic>, based on the average density of conspecific species in a circular neighborhood around each species, to explore the effects of sampling scale on the spatial distribution patterns of woody plants with dbh ≥1 cm and ≥400 individuals in a fully-mapped 25-hm<sup>2</sup> temperate forest plot in Changbai Mountain, Northeast China. Our results showed that: (1) most species were randomly-distributed at sampling scales <1 hm<sup>2</sup>, while the percentage of aggregated species increased with sampling scale; (2) the aggregation intensity of most species increased with sampling scale, but varied greatly among species; (3) the aggregation intensity of most species declined with abundance at sampling scales ≥1 hm<sup>2</sup>, while there was no significant relationship between aggregation intensity and abundance at sampling scales <1 hm<sup>2</sup>. Our study provides further insights into the spatial distribution of species and increases our understanding of underlying ecological processes or mechanisms.