Predictive mapping of tree species assemblages in an African montane rainforest

Conservation of mountain ecosystems can benefit from knowledge of habitats and their distribution patterns. This benefit is particularly true for diverse ecosystems with high conservation values such as the “Afromontane” rainforests. We mapped the vegetation of one such forest: the rugged Bwindi Impenetrable Forest, Uganda—a World Heritage Site known for its many restricted-range plants and animal taxa including several iconic species. Given variation in elevation, terrain and human impacts across Bwindi, we hypothesised that these factors influence the composition and distribution of tree species. To test this, detailed surveys were carried out using stratified random sampling. We established 289 georeferenced sample sites (each with 15 trees ≥20 cm dbh) ranging from 1,320 to 2,467 m a.s.l. and measured 4,335 trees comprising 89 species that occurred in four or more sample sites. These data were analysed against twenty-one digitally mapped biophysical variables using various analytical..., Study design
To account for the different environmental conditions, we employed a stratified random sampling approach. The park was divided into five strata based on geological formations visible on the Digital Elevation Model (DEM) of Bwindi and the starting points on the boundary of the DEM in each stratum were selected randomly with the random point function within ArcGIS (version 10.5; ESRI, Redlands, CA, USA). Line transects were drawn on the DEM in each stratum from the random starting points to traverse the topographic positions of the ridges (Figure 1; Table 1). The number and length of the transects selected varied with area, accessibility and shape of the strata. We then superimposed the transect drawings on high-resolution (0.5m) true color, digital aerial photographs of Bwindi. The aerial photos were visually interpreted along the transects by drawing polygons around areas perceived to be of uniform tree community structure based on differences in tone and texture. This allo..., , # Predictive mapping of tree species assemblages in an African montane rainforest

Predictive mapping of tree species assemblages in an African montane rainforest

Babaasa, Dennis, Mbarara University,
Finn, John T., University of Massachusetts
Schweik, Charles M., University of Massachusetts
Fuller, Todd K., University of Massachusetts
Sheil, Douglas, Wageningen University

Research facility: Institute of Tropical Forest Conservation
Published January …., 2024 on Dryad.

Cite this dataset:
Babaasa, Dennis, Finn, John T., Schweik, Charles M., Fuller, Todd K., Sheil, Douglas (2024). Predictive mapping of tree species assemblages in an African montane rainforest. [Dataset] Dryad.

### Abstract

In this study, Bwindi Impenetrable National Park, Uganda, was divided into five strata based on geological formations visible on the Digital Elevation Model (DEM) of the study area. Random transects were established with the starting points on the boundary of the DEM in each stratum. The aeri...

山地生态系统的保护可借助栖息地及其分布格局的研究成果获得显著裨益，对于以极高保护价值为特征的多样态生态系统而言更是如此，例如"非洲山地（Afromontane）"雨林。本研究针对其中一处此类森林——地处乌干达的崎岖布温迪难以穿越森林（Bwindi Impenetrable Forest）——开展植被制图工作，该区域为世界遗产地（World Heritage Site），以众多狭域分布的动、植物类群（含多种标志性物种）而享誉学界。

鉴于布温迪地区在海拔、地形与人类活动影响方面存在显著差异，我们提出假设：上述因素会对树木物种的组成与分布格局产生影响。为验证该假设，研究团队采用分层随机抽样（stratified random sampling）法开展了详细野外调查。我们共设立289个地理参考样地（georeferenced sample sites），每个样地内调查15株胸径（dbh, diameter at breast height）≥20厘米的树木，样地分布海拔范围为1320至2467米（a.s.l.，即海拔以上），共测量4335株树木，涵盖89个物种，且每个物种至少在4个及以上样地中出现。研究人员利用21个数字化测绘的生物物理变量结合多种分析方法对上述数据开展了分析……

## 研究设计
为兼顾不同环境条件，本研究采用分层随机抽样方案。基于研究区域数字高程模型（DEM, Digital Elevation Model）中可见的地质构造，将该公园划分为5个分层单元。在每个分层单元的DEM边界处，利用ArcGIS（10.5版本；ESRI，美国加利福尼亚州雷德兰兹）的随机点工具随机选取样线起始点。在每个分层单元的DEM上，从随机起始点出发绘制样线，以穿越山脊的地形位置（见图1、表1）。样线的数量与长度根据分层单元的面积、可达性与形状进行调整。随后，我们将样线叠加至布温迪地区0.5米分辨率的高分辨率真彩色数字航空影像上。研究人员沿样线对航空影像进行目视解译，根据色调与纹理差异，在具有均一树群落结构的区域周围绘制多边形。此部分内容……

# 非洲山地雨林树木物种组合的预测制图
非洲山地雨林树木物种组合的预测制图

作者：Babaasa, Dennis（姆巴拉拉大学）、Finn, John T.（马萨诸塞大学）、Schweik, Charles M.（马萨诸塞大学）、Fuller, Todd K.（马萨诸塞大学）、Sheil, Douglas（瓦赫宁根大学）

研究机构：热带森林保护研究所
2024年1月发布于Dryad数据平台。

数据集引用方式：
Babaasa, Dennis, Finn, John T., Schweik, Charles M., Fuller, Todd K., Sheil, Douglas (2024). 非洲山地雨林树木物种组合的预测制图. [数据集] Dryad.

### 摘要
本研究以乌干达布温迪禁猎国家公园为研究对象，基于研究区域数字高程模型（DEM）中可见的地质构造，将公园划分为5个分层单元。在每个分层单元的DEM边界处随机选取样线起始点。航空影像……