Collin Alexandre, Thiffault Evelyne, Tremblay Stéphane, Doyon Frédérik, Nolet Philippe
Institut des Sciences de la Forêt tempérée (ISFORT), Université du Québec en Outaouais, Québec, Canada.
Département des sciences du bois et de la forêt, Centre de Recherche sur les Matériaux Renouvelables (CRMR), Université Laval, Québec, Canada.
Ecol Appl. 2025 Apr;35(3):e70050. doi: 10.1002/eap.70050.
Understanding carbon dynamics in managed forest ecosystems is increasingly crucial for formulating informed recommendations in the context of climate change. Silviculture significantly impacts forest carbon pools, though these effects can vary depending on the type of treatment applied. In recent decades, partial cuttings have been proposed as an alternative to more intensive treatments like clearcutting to mitigate negative impacts on forest function and enhance carbon sequestration. In this study, we conducted a meta-analysis comparing the effects of clearcutting and partial cuttings across North America on six forest carbon pools: live trees, snags, understory vegetation, coarse woody debris, forest floor, and soil mineral horizons. The analysis was based on a database of 558 carbon observations from temperate and boreal forests in eastern North America. Our findings indicate a -30% difference in total carbon post-harvesting, predominantly influenced by changes in the overstory carbon pool. Only the live tree carbon pool was significantly affected by cutting intensity, with clearcutting resulting in lower total carbon values (-78% relative to the reference) compared to partial cuttings (-45%). However, after 30-40 years, live tree carbon levels were similar between clearcutting and partial cuttings. The primary factor influencing differences in deadwood carbon pools was the time since treatment, while soil carbon pools showed minimal variation with no significant differences compared to unmanaged forests. This meta-analysis suggests that using partial cuttings instead of clearcutting to mitigate the effects of forest management on carbon pools may be more complex than previously thought and will depend on site conditions and allowing sufficient time for the forest to recover. Further studies are needed to identify suitable forest stands for partial cuttings and evaluate tree selection strategies that optimize forest productivity and carbon sequestration.
了解人工管理的森林生态系统中的碳动态对于在气候变化背景下制定明智的建议变得越来越重要。造林活动对森林碳库有重大影响，不过这些影响会因所采用的处理方式而异。近几十年来，已有人提出采用部分砍伐作为皆伐等更集约处理方式的替代方案，以减轻对森林功能的负面影响并增强碳固存。在本研究中，我们进行了一项荟萃分析，比较了北美地区皆伐和部分砍伐对六个森林碳库的影响：活立木、枯立木、林下植被、粗木质残体、森林地表和土壤矿质层。该分析基于北美东部温带和寒温带森林的558个碳观测数据组成的数据库。我们的研究结果表明，采伐后总碳量存在30%的差异，主要受上层碳库变化的影响。只有活立木碳库受砍伐强度的显著影响，与部分砍伐（-45%）相比，皆伐导致的总碳值更低（相对于参考值为-78%）。然而，30 - 40年后，皆伐和部分砍伐的活立木碳水平相似。影响枯木碳库差异的主要因素是处理后的时间，而土壤碳库变化最小，与未管理的森林相比无显著差异。这项荟萃分析表明，使用部分砍伐而非皆伐来减轻森林管理对碳库的影响可能比之前认为的更为复杂，这将取决于立地条件，并需要给森林留出足够的恢复时间。需要进一步研究以确定适合进行部分砍伐的林分，并评估优化森林生产力和碳固存的树木选择策略。
