Can degraded trees serve as sustainable feedstock for forest bioenergy production?

由于对气候的潜在负面影响，使用整棵树生产生物能源引起了争议;这使得一些政策制定者考虑禁止它们作为生物能源原料。整个树木的一个特殊情况是边缘纤维质量的树木，如有缺陷的，腐烂或垂死的树木，在这里统称为退化树木。该计划的长期重点是提高对加拿大森林生物质原料动态的基础知识，以优化利用森林生物能源，为大气提供最大的好处。在接下来的五年里，该计划将重点关注传统木材产品行业不需要的退化树木，因为它们的纤维质量低。 它旨在测试退化的树木在多大程度上可以成为可持续调动森林资源以减缓气候变化的一部分。该计划一方面将研究生态系统中的生物质碳动态，另一方面将生物质碳回收到技术系统中的能源产品中，确定森林立地过程中退化树木含量的命运和生物质到生物能源的转换。这些成果将被纳入森林生物能源系统和更大的森林管理系统。短期目标是：1-评估森林地点退化树木随时间的碳动态（生态系统）; 2-评估生物能源转化潜力和从退化树木的木材中回收碳转化为能源产品（技术系统）; 3-评估退化树木作为生物能源系统原料的碳平衡和减缓气候变化的潜力，作为更大的森林管理系统的一部分。拟议的项目将着重于加拿大东部森林中典型的两种退化树木，由于纤维质量低，目前很少或根本没有用于传统木材产品：一）魁北克北部地区被云杉芽虫落叶的香脂冷杉; ii）美国山毛榉在魁北克南部和西部受到山毛榉树皮病的袭击。我的研究项目涉及21世纪世纪两个主要的相互关联的挑战，能源转型和减缓气候变化。该计划的三个项目旨在为生态和技术系统中木质材料的碳循环以及这些系统与大气之间的关系做出重要贡献。它还将为加拿大利益攸关方提供信息，这些利益攸关方需要最好的数据来评估真正有助于减少温室气体排放和减缓气候变化的能源生产情景。该计划将允许以跨学科的思维方式培训几名HQP，为新一代的专业人士和科学家做出贡献，这些专业人士和科学家可以全面解决气候变化和能源转型等社会问题。

The use of whole trees for bioenergy production stirs controversy due to potential negative impacts on climate; this has brought some policymakers to consider banning them as a bioenergy feedstock. A special case of whole trees is trees of marginal fibre quality, such as defective, decaying or dying trees, together referred here as degraded trees.The long-term focus of the program is to improve fundamental knowledge about dynamics of forest biomass feedstocks from Canadian forests for an optimized utilisation of forest bioenergy providing the greatest benefits to the atmosphere. Over the next five years, the program will focus on degraded trees that are unwanted by conventional wood product industries due to their low fibre quality. It aims to test to what extent degraded trees can be part of a sustainable mobilisation of forest resources for climate change mitigation. The program will study biomass carbon dynamics in ecological systems on one hand, and biomass carbon recovery into energy products in technological systems on the other hand, determining the fate of the content of degraded trees during forest site processes and biomass-to-bioenergy conversion. These results will then be integrated within forest bioenergy systems and larger forest management systems. The short-term objectives are to: 1- assess the carbon dynamics of degraded trees through time as found on forest sites (ecological systems); 2- assess the bioenergy conversion potential and carbon recovery into energy products of wood from degraded trees (technological systems); 3- assess the carbon balance and climate change mitigation potential of degraded trees as feedstocks for bioenergy systems, as part of larger forest management systems. The proposed project will focus on two species of degraded trees typical of Canadian eastern forests:, and which currently have little or no use for conventional wood products due to low fibre quality : i) balsam fir defoliated by the spruce budworm in boreal regions of Quebec; ii) American beech attacked by the beech bark disease in south and western Quebec.My research program addresses two major and interlinked challenges of the 21st century, energy transition and climate change mitigation. The three projects of this program are designed to significantly contribute to fundamental knowledge on carbon cycling of woody material in ecological and in technological systems, and relationships between these systems and the atmosphere. It will also provide info to Canadian stakeholders who need the best data possible to appraise energy production scenarios that truly contribute to GHG emissions reduction and climate change mitigation. This program will allow the training of several HQPs in an interdisciplinary mindset, contributing to a new generation of professionals and scientists that can holistically address societal issues such as climate change and energy transition.