School of Biological Sciences, Washington State University, Pullman, Washington, USA.
Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA.
Ecology. 2022 Jun;103(6):e3681. doi: 10.1002/ecy.3681. Epub 2022 Apr 20.
The study of community spatial structure is central to understanding diversity patterns over space and species co-occurrence at local scales. Although most analytical approaches consider horizontal and vertical dimensions separately, in this study we introduce a three-dimensional spatial analysis that simultaneously includes horizontal and vertical species associations. Using tree census data (2000-2016) and allometries from the Luquillo forest plot in Puerto Rico, we show that spatial organization becomes less random over time as the forest recovered from land-use legacy effects and hurricane disturbance. Tree species vertical segregation is predominant in the forest with almost all species that co-occur in the horizontal plane avoiding each other in the vertical dimension. Horizontal segregation is less common than vertical, whereas three-dimensional aggregation (a proxy for direct tree competition) is the least frequent type of spatial association. Furthermore, dominant species are involved in more non-random spatial associations, implying that species co-occurrence is facilitated by species segregation in space. This novel three-dimensional analysis allowed us to identify and quantify tree species spatial distributions, how interspecific competition was reduced through forest structure, and how it changed over time after disturbance, in ways not detectable from two-dimensional analyses alone.
研究群落空间结构是理解空间多样性模式和局部尺度物种共存的核心。尽管大多数分析方法分别考虑水平和垂直维度，但在本研究中，我们引入了一种同时包含水平和垂直物种关联的三维空间分析。利用波多黎各卢奎洛森林观测站的树木普查数据（2000-2016 年）和种间关系，我们表明，随着森林从土地利用遗留效应和飓风干扰中恢复，空间组织的随机性随着时间的推移而降低。树木物种的垂直隔离在森林中占主导地位，几乎所有在水平面上共存的物种都避免在垂直方向上相互竞争。水平隔离比垂直隔离少见，而三维聚集（直接树木竞争的代理）是最不常见的空间关联类型。此外，优势物种参与了更多非随机的空间关联，这意味着物种在空间上的隔离促进了物种共存。这种新颖的三维分析使我们能够识别和量化树木物种的空间分布，以及种间竞争如何通过森林结构得到减少，以及在干扰后随时间的变化，而这些是二维分析无法检测到的。
