Lisboa Sá Nogueira, Macôo Severino, Sitoe Almeida Alberto
Department of Forest Engineering, Faculty of Agronomy and Forest Engineering, Eduardo Mondlane University, P.O. Box 257, Maputo, Mozambique.
N'Lab, Agostinho Neto Avenue, Nitidae, Maputo, Mozambique.
Sci Rep. 2025 Jan 28;15(1):3464. doi: 10.1038/s41598-025-87297-w.
Seasonally dry tropical woodlands are vital for climate change mitigation, yet their full potential in carbon storage remains poorly understood. This is largely due to the lack of species-specific allometric models tailored to these ecosystems. To address this knowledge gap, this study aimed to develop species-specific biomass allometric equations (BAEs) for accurately estimating both above- and below-ground biomass of Colophospermum mopane (J.Kirk ex Benth.) J.Kirk ex J. Léonard, and to assess the feasibility of incorporating total height, estimated using height-diameter (H-D) equations, to improve the accuracy of biomass estimation in Mozambique. We applied a destructive method and felled 120 C. mopane trees in Mabalane and Tambara Districts. We measured breast height diameter (D), total height (H) and biomass of each component (roots, stem, branches and leaves). We fitted three BAE models using Ordinary Least Squares (OLS) regression and fifteen H-D models using nonlinear regression. A validation procedure checked the applicability of all models. We conducted a forest inventory with 78 temporary clusters, each consisting of four 100 m x 20 m plots, to estimate the average AGB and BGB of C. mopane using the best-fitting BAE and H-D model. We also compared the best BAE of C. mopane with existing locally developed species-specific BAEs. The study found that the model including the interaction of D and H, performed better than the model with separate D and H. However, models with D and H performed similarly to models with D alone. The Power model with two parameters and the HossfeldIV model with three parameters exhibited the best performance among the H-D models. Integrating the H from the H-D model into the BAE for AGB estimation can improve the efficiency and reliability of biomass estimation from forest inventory data. This research is timely as there is an urgent need to improve the accuracy of carbon counting to support climate change goals and sustainable management of Mopane woodland given their spatial extent in southern Africa.
季节性干燥热带林地对缓解气候变化至关重要，但其在碳储存方面的全部潜力仍知之甚少。这主要是由于缺乏针对这些生态系统的特定物种异速生长模型。为了填补这一知识空白，本研究旨在开发特定物种的生物量异速生长方程（BAE），以准确估算柯氏苏木（Colophospermum mopane (J.Kirk ex Benth.) J.Kirk ex J. Léonard）地上和地下生物量，并评估纳入使用高度-直径（H-D）方程估算的总高度以提高莫桑比克生物量估算准确性的可行性。我们采用了一种破坏性方法，在马巴兰内和坦巴拉地区砍伐了120棵柯氏苏木树。我们测量了每棵树的胸径（D）、总高度（H）以及各组成部分（根、干、枝和叶）的生物量。我们使用普通最小二乘法（OLS）回归拟合了三个BAE模型，并使用非线性回归拟合了十五个H-D模型。一个验证程序检验了所有模型的适用性。我们进行了一次森林清查，设置了78个临时样地组，每组由四个100米×20米的样地组成，以使用拟合效果最佳的BAE和H-D模型估算柯氏苏木的平均地上生物量（AGB）和地下生物量（BGB）。我们还将柯氏苏木的最佳BAE与现有的本地开发的特定物种BAE进行了比较。研究发现，包含D和H相互作用的模型比单独使用D和H的模型表现更好。然而，包含D和H的模型与仅包含D的模型表现相似。在H-D模型中，双参数幂模型和三参数霍斯费尔德IV模型表现最佳。将H-D模型中的H纳入AGB估算的BAE中，可以提高从森林清查数据估算生物量的效率和可靠性。鉴于柯氏苏木林地在南部非洲的空间范围，迫切需要提高碳核算的准确性以支持气候变化目标和柯氏苏木林地的可持续管理，因此这项研究很及时。
