Allometric equations are used to estimate biomass and carbon stock of forests. In Ethiopia, despite the presence of large floral diversity, only a few site-specific allometric equations have been developed so far. This study was conducted in the Omo-Gibe woodland of south-western Ethiopia to develop an allometric equation to estimate the Above-ground Biomass (AGB) of the four Acacia species (Senegalia polyacantha, Vachellia seyal, Vachellia etbaica and Vachellia tortilis). Fifty-four (54) Acacia trees were sampled and measured within 35 temporarily established square plots. In each plot, dendrometric variables were measured to derive the models based on combinations of Diameter at Breast Height (DBH), height, and wood density as predictor variables. Model performance was evaluated using goodness-of-fit statistics. The biomass was compared using four allometric biomass models that have been widely used in the tropics. The model containing DBH alone was more accurate to estimate AGB compared to the use of multiple predictor variables. This study, therefore, substantiated the importance of site-specific allometric equations in estimating the AGB of Acacia woodlands. This is because a site-specific allometric equation recognizes the environmental factors, vegetation types and management practices. The results of this study contribute to a better understanding of allometric equations and an accurate estimate of AGB of Acacia woodlands in Ethiopia and similar ecosystems elsewhere.

中文翻译：

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埃塞俄比亚选定的金合欢属（Vachellia 和 Senegalia 属）的异速生长方程

异速生长方程用于估计森林的生物量和碳储量。在埃塞俄比亚，尽管存在大量花卉多样性，但迄今为止仅开发了少数特定地点的异速生长方程。本研究在埃塞俄比亚西南部的 Omo-Gibe 林地进行，目的是开发一个异速生长方程来估计四种金合欢树种（Senegalia polyacantha、Vachellia seyal、Vachellia etbaica 和 Vachellia tortilis）的地上生物量 (AGB)。在 35 个临时建立的方形地块内对五十四 (54) 棵金合欢树进行了采样和测量。在每个图中，测量树状变量以推导出基于乳房高度直径 (DBH)、高度和木材密度组合作为预测变量的模型。使用拟合优度统计评估模型性能。使用在热带地区广泛使用的四种异速生长生物量模型比较了生物量。与使用多个预测变量相比，仅包含 DBH 的模型更准确地估计 AGB。因此，这项研究证实了特定地点的异速生长方程在估计金合欢林地 AGB 中的重要性。这是因为特定地点的异速生长方程可以识别环境因素、植被类型和管理实践。这项研究的结果有助于更好地理解异速生长方程和准确估计埃塞俄比亚金合欢林地和其他地方类似生态系统的 AGB。与使用多个预测变量相比，仅包含 DBH 的模型更准确地估计 AGB。因此，这项研究证实了特定地点的异速生长方程在估计金合欢林地 AGB 中的重要性。这是因为特定地点的异速生长方程可以识别环境因素、植被类型和管理实践。这项研究的结果有助于更好地理解异速生长方程和准确估计埃塞俄比亚金合欢林地和其他地方类似生态系统的 AGB。与使用多个预测变量相比，仅包含 DBH 的模型更准确地估计 AGB。因此，这项研究证实了特定地点的异速生长方程在估计金合欢林地 AGB 中的重要性。这是因为特定地点的异速生长方程可以识别环境因素、植被类型和管理实践。这项研究的结果有助于更好地理解异速生长方程和准确估计埃塞俄比亚金合欢林地和其他地方类似生态系统的 AGB。