Bernal Blanca, Murray Lara T, Pearson Timothy R H
Winrock International, 2121 Crystal Drive Suite 500, Arlington, VA, 22202, USA.
Carbon Balance Manag. 2018 Nov 20;13(1):22. doi: 10.1186/s13021-018-0110-8.
Forest landscape restoration (FLR) has been adopted by governments and practitioners across the globe to mitigate and adapt to climate change and restore ecological functions across degraded landscapes. However, the extent to which these activities capture CO with associated climate mitigation impacts are poorly known, especially in geographies where data on biomass growth of restored forests are limited or do not exist. To fill this gap, we developed biomass accumulation rates for a set of FLR activities (natural regeneration, planted forests and woodlots, agroforestry, and mangrove restoration) across the globe and global CO removal rates with corresponding confidence intervals, grouped by FLR activity and region/climate.
Planted forests and woodlots were found to have the highest CO removal rates, ranging from 4.5 to 40.7 t CO ha year during the first 20 years of growth. Mangrove tree restoration was the second most efficient FLR at removing CO, with growth rates up to 23.1 t CO ha year the first 20 years post restoration. Natural regeneration removal rates were 9.1-18.8 t CO ha year during the first 20 years of forest regeneration, followed by agroforestry, the FLR category with the lowest and regionally broad removal rates (10.8-15.6 t CO ha year). Biomass growth data was most abundant and widely distributed across the world for planted forests and natural regeneration, representing 45% and 32% of all the data points assessed, respectively. Agroforestry studies, were only found in Africa, Asia, and the Latin America and Caribbean regions.
This study represents the most comprehensive review of published literature on tree growth and CO removals to date, which we operationalized by constructing removal rates for specific FLR activities across the globe. These rates can easily be applied by practitioners and decision-makers seeking to better understand the positive climate mitigation impacts of existing or planned FLR actions, or by countries making restoration pledges under the Bonn Challenge Commitments or fulfilling Nationally Determined Contributions to the UNFCCC, thereby helping boost FLR efforts world-wide.
全球各国政府和从业者已采用森林景观恢复（FLR）来缓解和适应气候变化，并恢复退化景观的生态功能。然而，这些活动吸收二氧化碳以及相关气候缓解影响的程度却鲜为人知，尤其是在恢复森林生物量增长数据有限或不存在的地区。为填补这一空白，我们针对全球一系列森林景观恢复活动（自然更新、人工造林和小片林地、农林业以及红树林恢复）制定了生物量积累率，并给出了相应置信区间的全球二氧化碳清除率，按森林景观恢复活动以及地区/气候进行了分类。
发现人工造林和小片林地的二氧化碳清除率最高，在生长的前20年中，范围为4.5至40.7吨二氧化碳/公顷·年。红树林恢复是第二高效的森林景观恢复活动，在恢复后的前20年中，增长率高达23.1吨二氧化碳/公顷·年。森林自然更新在森林更新的前20年中清除率为9.1 - 18.8吨二氧化碳/公顷·年，其次是农林业，这是森林景观恢复类别中清除率最低且地区差异较大的类别（10.8 - 15.6吨二氧化碳/公顷·年）。人工造林和自然更新的生物量增长数据在全球最为丰富且分布广泛，分别占所有评估数据点的45%和32%。农林业研究仅在非洲、亚洲以及拉丁美洲和加勒比地区被发现。
本研究是迄今为止对已发表的关于树木生长和二氧化碳清除文献的最全面综述，我们通过构建全球特定森林景观恢复活动的清除率来将其付诸实践。这些比率可供从业者和决策者轻松应用，他们希望更好地了解现有或计划中的森林景观恢复行动对气候缓解的积极影响，或者可供根据《波恩挑战承诺》做出恢复承诺或履行对《联合国气候变化框架公约》国家自主贡献的国家应用，从而有助于推动全球森林景观恢复工作。
