Effects of sampling scale on patterns of habitat association in tropical trees
Effects of sampling scale on patterns of habitat association in tropical trees
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DOI：
10.1111/jvs.12090
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发表时间：
2014-03-01
影响因子：
2.8
通讯作者：
Olff, Han
中科院分区：
文献类型：
--
作者：
Garzon-Lopez, Carol X.;Jansen, Patrick A.;Olff, Han
问题生态位分化是热带森林中众多树种共存和分布模式的核心解释，但导致中性动态的功能等同性已被提出作为替代解释。对树种分布与环境因素之间关联性的研究得出的高度可变的结果加剧了这种利基与中立的争论，其中一些研究发现了很强的关联性，但另一些则没有。在这里，我们询问研究之间的采样规模差异如何导致这种变化。地点巴罗科罗拉多岛，巴拿马。方法使用树冠高度个体的分布图，我们评估了巴罗科罗拉多岛五种热带树种在各种采样规模（从 50 到 1600 公顷）内的栖息地关联模式。我们使用点模式分析研究了物种丛集模式（Ripley's K）的尺度依赖性以及物种分布与重要环境变量（森林年龄、地形和地质构造）的关联。结果丛集大小和丛集密度在空间尺度内和空间尺度之间具有很大差异。在所有五个物种中都发现了显着的栖息地关联，栖息地关联的数量通常随着采样规模的增加而增加。忽略分散限制会夸大重要栖息地关联的数量。结论我们发现栖息地关联的模式（以及因此关于生态位与中性过程的重要性的结论）受到采样规模和位置的选择的强烈影响。明确纳入空间尺度的影响对于研究栖息地关联和构建热带树木群落的主要过程至关重要。
QuestionsNiche differentiation is a central explanation for the co-existence and distribution patterns of numerous tree species in tropical forests, but functional equivalence leading to neutral dynamics has been proposed as an alternative explanation. This niche vs neutral debate is fuelled by the highly variable results yielded by studies of the association between tree species distributions and environmental factors, where some studies find strong associations but others do not. Here, we ask how differences in sampling scale between studies contribute to this variation.LocationBarro Colorado Island, Panama.MethodsUsing distribution maps of canopy-statured individuals, we evaluated patterns of habitat association in five tropical tree species on Barro Colorado Island across a wide range of sampling scales (from 50 to 1600ha). We investigated the scale-dependency of species clumping patterns (Ripley's K) and the association of species distributions with important environmental variables (forest age, topography and geological formation) using point pattern analyses.ResultsClump size and clump density had high variances within and among spatial scales. Significant habitat associations were found in all five species, with the number of habitat associations generally increasing with the sampling scale. Ignoring dispersal constraints inflated the number of significant habitat associations.ConclusionsWe found that patterns of habitat association (and hence conclusions on the importance of niche vs neutral processes) are strongly affected by the choice of sampling scale and location. Explicit inclusion of the effect of spatial scale is critical for studies of habitat association and the main processes that structure communities of tropical trees.