Faculdade de Tecnologia, Departamento de Engenharia Florestal, Universidade de Brasília, Campus Darcy Ribeiro Asa Norte, Brasília, DF, 70910-900, Brazil.
Faculdade de Tecnologia, Departamento de Engenharia Florestal, Universidade de Brasília, Campus Darcy Ribeiro Asa Norte, Brasília, DF, 70910-900, Brazil.
J Environ Manage. 2024 Jan 15;350:119593. doi: 10.1016/j.jenvman.2023.119593. Epub 2023 Nov 27.
The Amazon has a range of species with high potential for sustainable timber harvesting, but for them to be utilized globally, the merchantable wood volume must be accurately quantified. However, since the 1950s, inadequate methods for estimating merchantable timber volumes have been employed in the Amazon, and Brazilian Government agencies still require some of them. The natural variability of the Amazon Forest provides an abundance of species of different sizes and shapes, conferring several peculiarities, which makes it necessary to use up-to-date and precise methods for timber quantification in Amazon Forest management. Given the employment of insufficient estimation methods for wood volume, this study scrutinizes the disparities between the actual harvested merchantable wood volume and the volume estimated by the forest inventory during the harvesting phase across five distinct public forest areas operating under sustainable forest management concessions. We used mixed-effect models to evaluate the relationships between inventory and harvested volume for genera and forest regions. We performed an equivalence test to assess the similarity between the volumes obtained during the pre-and post-harvest phases. We calculated root mean square error and percentage bias for merchantable volume as accuracy metrics. There was a strong tendency for the 100% forest inventory to overestimate merchantable wood volume, regardless of genus and managed area. There was a significant discrepancy between the volumes inventoried and harvested in different regions intended for sustainable forest management, in which only 22% of the groups evaluated were equivalent. The methods currently practiced by forest companies for determining pre-harvest merchantable volume are inaccurate enough to support sustainable forest management in the Amazon. They may even facilitate the region's illegal timber extraction and organized crime.
亚马逊地区拥有多种具有可持续木材采伐潜力的物种，但要实现全球利用，就必须准确量化其可商业采伐木材的蓄积量。然而，自 20 世纪 50 年代以来，亚马逊地区一直采用不充分的方法来估计可商业采伐木材的蓄积量，巴西政府机构仍然需要其中的一些方法。亚马逊森林的自然变异性提供了丰富的不同大小和形状的物种，赋予了它多种独特性，这使得在亚马逊森林管理中，必须采用最新和精确的木材量化方法。鉴于木材蓄积量的估计方法不足，本研究详细研究了在五个不同的公共林区进行可持续森林管理特许权经营期间，采伐阶段的实际采伐可商业采伐木材蓄积量与森林清查估计蓄积量之间的差异。我们使用混合效应模型来评估清查和收获蓄积量之间的关系。我们进行了等效性检验，以评估收获前后两个阶段的体积之间的相似性。我们计算了可商业采伐木材体积的均方根误差和百分比偏差作为准确性指标。无论属和管理区如何，100%的森林清查都存在高估可商业采伐木材蓄积量的强烈趋势。在不同的可持续森林管理区，清查和收获的蓄积量之间存在显著差异，在所评估的群体中，只有 22%是等效的。森林公司目前用于确定收获前可商业采伐木材蓄积量的方法不够准确，不足以支持亚马逊地区的可持续森林管理。它们甚至可能助长该地区的非法木材采伐和有组织犯罪。
