Biochar as a soil amendment in northern forests: ecology, biogeochemistry, and bioenergy tradeoffs

生物碳-生物能源系统最近被誉为少数几项不仅能减少化石燃料使用，还能通过加强碳封存直接缓解人为气候变化的技术之一。尽管前景看好，但对生物碳-生物能源系统的研究还处于初级阶段。这里提出的研究探索加拿大林业部门的生物碳-生物能源系统，以增加利用森林生物质生产可再生能源的环境和经济价值，并提高森林采伐的可持续性。我们之前已经在哈利伯顿森林和野生动物保护区有限公司建立了一个研究规模的热解系统，在受控条件下从木屑和其他磨坊残留物(例如锯末、树皮)中生产生物炭。这一地区的森林磷非常有限，可能是由于长期的氮沉积，也表现出钙的共同限制。在这些土壤条件下，生物炭可提高土壤pH值并增加土壤磷的有效性，可作为一种具有成本效益的森林土壤改良剂，潜在地提高生产力并加强碳封存等环境服务。这项拟议的工作汇集了在森林生态系统动力学、土壤过程、木材分解产品的化学特征和生物多样性评估方面拥有良好记录的科学家。我们将解决有关森林生物质产生的不同类型的生物炭如何影响土壤肥力和碳循环，进而影响植物和林分动态的关键未知问题。还将描述生物碳对地上和地下生物多样性的任何积极或消极影响，并寻求尽量减少影响的解决办法。此外，还将使用生命周期分析来确定生物炭生物能源系统效益的整体碳、能源和经济成本。以前基本上没有关于生物炭作为温带森林土壤改良剂的研究：因此，这里的方法的整合将前所未有地增加这一领域的知识基础。

Biochar-bioenergy systems have recently been heralded as one of the few technologies with substantial promise not only to reduce fossil fuel usage, but also to directly mitigate anthropogenic climate change by enhancing carbon sequestration. While promising, research on biochar-bioenergy systems is in its infancy. The research proposed here explores biochar-bioenergy systems in Canada's forestry sector in order to add environmental and economic value to renewable energy production with forest biomass and to improve the sustainability of forest harvesting. We have previously established a research-scale pyrolysis system at Haliburton Forest and Wildlife Reserve Ltd to produce biochar from wood chips and other mill residues (e.g., sawdust, bark) under controlled conditions. Forests in this region are strongly phosphorus limited, likely as a result of chronic nitrogen deposition, and also show co-limitation bycalcium. Under these soil conditions, biochar, which increases soil pH and increases soil P availability, may act as a cost-effective forest soil amendment that can potentially increase productivity and enhance environmental services such as carbon sequestration. The proposed work brings together scientists with a strong track record in forest ecosystem dynamics, soil processes, chemical characterization of wood breakdown products, and biodiversity assessment. We will address key unknown questions regarding how different types of biochar produced with forest biomass influence soil fertility and carbon cycling and, in turn, influence plant and stand dynamics. Any positive or negative impacts of biochar on above- and below-ground biodiversity will also be characterized and solutions sought to minimize impacts. In addition life cycle analysis will be used to determine the holistic carbon, energy, and economic costs of benefits of biochar bioenergy systems. There are essentially no prior studies on biochar as a soil amendment in temperate forest soils: the integration of approaches here will thus offer an unprecedented increase in the knowledge base in this area.