Data from: Are landscape attributes a useful shortcut for classifying vegetation in the tropics? A case study of La Amistad International Park

Effective vegetation classification schemes identify the processes determining species assemblages and support the management of protected areas. They can also provide a framework for ecological research. In the tropics, elevation-based classifications dominate over alternatives such as river catchments. Given the existence of floristic data for many localities, we ask how useful floristic data are for developing classification schemes in species-rich tropical landscapes and whether floristic data provide support for classification by river catchment. We analyzed the distribution of vascular plant species within 141 plots across an elevation gradient of 130 to 3200 m asl within La Amistad National Park. We tested the hypothesis that river catchment, combined with elevation, explains much of the variation in species composition. We found that annual mean temperature, elevation, and river catchment variables best explained the variation within local species communities. However, only plots in high-elevation oak forest and Páramo were distinct from those in low- and mid-elevation zones. Beta diversity did not significantly differ in plots grouped by elevation zones, except for low-elevation forest, although it did differ between river catchments. None of the analyses identified discrete vegetation assemblages within mid-elevation (700–2600 m asl) plots. Our analysis supports the hypothesis that river catchment can be an alternative means for classifying tropical forest assemblages in conservation settings.高效植被分类方案（vegetation classification schemes）可识别决定物种组合（species assemblages）的生态过程，为保护区（protected areas）管理提供科学支撑，同时亦能为生态学研究构建标准化框架。在热带地区（tropics），基于海拔的分类方案（elevation-based classifications）相较于河流流域（river catchments）等其他分类方式更为常用。鉴于诸多野外样地（plots）已积累植物区系数据（floristic data），我们旨在明确两个核心问题：其一，在物种丰富的热带景观（species-rich tropical landscapes）中，植物区系数据用于构建植被分类方案的实用价值如何；其二，植物区系数据是否能够支撑基于河流流域的分类体系。我们对友谊国家公园（La Amistad National Park）内141个野外样地的维管植物物种（vascular plant species）分布情况展开分析，这些样地的海拔梯度（elevation gradient）覆盖130至3200米海拔（meters above sea level，缩写asl）。本研究验证了如下假说：河流流域与海拔相结合，能够解释物种组成（species composition）的大部分变异。研究结果显示，年平均气温（annual mean temperature）、海拔与河流流域变量可最佳解释当地物种种群的变异特征。然而，仅有高海拔栎林（high-elevation oak forest）与帕拉莫生态系统（Páramo）的样地，与低海拔和中海拔区域（low- and mid-elevation zones）的样地存在显著差异。β多样性（beta diversity）在按海拔区域划分的样地中并无显著差异（低海拔森林样地除外），但不同河流流域的样地间β多样性则存在显著差异。所有分析均未在中海拔（700–2600米海拔）样地中识别出离散植被组合（discrete vegetation assemblages）。本研究结果支持前述假说：在保护实践场景（conservation settings）中，河流流域可作为热带森林植被组合分类的替代方案。