de Oliveira Garcia Wagner, Amann Thorben, Hartmann Jens
Institute for Geology, Center for Earth System Research and Sustainability, Universität Hamburg, Hamburg, Germany.
Sci Rep. 2018 Mar 27;8(1):5280. doi: 10.1038/s41598-018-22728-5.
Energy production from biomass is one of the adopted strategies in different European countries to limit global warming to within the 1.5-2° targets after the 2015 UN climate agreement. This will motivate enhanced forest harvest rates and whole tree harvest to supply the increasing biomass demand. Negative nutrient budgets for certain timberland areas where geogenic nutrient supply cannot cope with harvesting rates will be one consequence. A spatially explicit analysis for a U.S. timberland area of 33,570 km reveals that for a minimum nutrient loss and supply scenario, negative nutrient budgets occur in 17, 20, 16, and almost 94% of the studied areas for Ca, K, Mg, and P, respectively. For a maximum nutrient loss (considering intensive harvesting) and supply assumptions, the affected areas increase to 50, 57, 45 and 96% for Ca, K, Mg, and P, respectively. In general, atmospheric nutrient deposition is of minor importance for the high weathering supply cases. Increasing global woody biomass demand may cause additional pressure on forested ecosystems, enlarging negative nutrient budget areas. If woody biomass demand rises, strategies to counterbalance nutrient gaps might be needed, for example, by preparing harvested areas with rock products, designed to replenish growth limiting nutrients, and/or implementing forest management strategies to minimize nutrient export.
生物质能发电是欧洲不同国家采用的战略之一，旨在根据2015年联合国气候协议将全球变暖限制在1.5 - 2摄氏度目标范围内。这将促使提高森林采伐率和整树采伐量，以满足不断增长的生物质需求。某些林地地区的地质养分供应无法满足采伐率，导致养分预算为负，这将是一个后果。对美国一个面积为33,570平方公里的林地进行的空间明确分析表明，在最低养分损失和供应情景下，钙、钾、镁和磷的负养分预算分别出现在研究区域的17%、20%、16%和近94%。在最大养分损失（考虑高强度采伐）和供应假设下，钙、钾、镁和磷受影响的区域分别增至50%、57%、45%和96%。一般来说，在高风化供应情况下，大气养分沉降的重要性较小。全球对木质生物质需求的增加可能会给森林生态系统带来额外压力，扩大负养分预算区域。如果木质生物质需求增加，可能需要采取平衡养分缺口的策略，例如，用岩石产品处理采伐区，以补充限制生长的养分，和/或实施森林管理策略，以尽量减少养分输出。
