Integrative molecular biogeochemistry of long-term litter quality and quantity controls on soil organic matter composition and persistence in temperate forests

温带森林土壤有机质组成和持久性长期凋落物质量和数量控制的综合分子生物地球化学

• 批准号: RGPIN-2020-04944
• 负责人: Simpson, Myrna
• 金额: $ 6.85万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=717467
• 关键词: Integrative; molecular; biogeochemistry; long; term

Globally, soils store twice as much carbon as the atmosphere. The cycling of soil carbon is an intricate balance between carbon inputs, from plants and microbes, and removals, from microbial respiration (CO2 flux) and soluble carbon export or translocation through the soil profile. The world's forests store ~45% of terrestrial carbon stocks and contribute to ~50% of the net primary productivity. Recent studies have demonstrated that these forests and their vast carbon reserves are under threat due to anthropogenic climate change which is destabilizing soil carbon and making it susceptible to microbial degradation and export from soil profiles. As such, forest soil carbon is declining globally and this will negatively impact the health of forests and the important ecological services that they provide. It is hypothesized that a major proportion of soil carbon is derived from plant inputs and deposition to soil. Therefore, changes in vegetation type and quantity will also alter soil carbon storage processes. The proposed research program will use an integrative molecular biogeochemistry characterization platform to study the long-term impacts on forest soil carbon with changes in litter deposition and litter quality. As part of an international network of researchers, the applicant and her trainees, will study how long-term litter manipulations govern the quantity and quality of litter deposited to soil and how this subsequently alters soil carbon turnover and biogeochemistry. This program will study five different temperate forests that have undergone 15, 20, and 30 years of litter manipulation. This research program will be the first to study the molecular-level compositional changes of soil organic matter with long-term variation in litter inputs and how this alters soil carbon storage in forests. This research program will provide new knowledge on how soil organic matter and soil carbon are controlled by litter input changes through time and also how these differences are governed by soil and other ecosystem properties. This research program will also measure how changes in soil organic matter alter its ability to be exported or degraded through the solubilization of soil-derived carbon. This molecular-level data is critically needed to develop better management strategies for forests and ensure their long-term sustainability in a changing world. Current environmental policies require more accurate scientific knowledge regarding the sensitivity of soil carbon to potential shifts in litter inputs. Consequently, this proposed research will provide new information that will help shape future environmental mitigation strategies for protecting soil carbon in temperate forests and other sensitive ecosystems around the world.

在全球范围内，土壤存储的碳是大气的两倍。土壤碳的循环是从微生物呼吸（CO2通量）和可溶性碳出口或通过土壤剖面的可溶性碳输出或易位的碳输入之间的复杂平衡。世界森林存储约45％的陆碳库存，占净初级生产力的约50％。最近的研究表明，由于人为的气候变化，这些森林及其巨大的碳储备受到威胁，这使土壤碳稳固，使其容易受到微生物降解并从土壤剖面中出口。因此，森林土壤碳在全球范围内正在下降，这将对森林的健康及其提供的重要生态服务产生负面影响。假设大部分的土壤碳来自植物的输入和土壤沉积。因此，植被类型和数量的变化也将改变土壤碳储存过程。拟议的研究计划将使用综合分子生物地球化学平台来研究对森林土壤碳的长期影响，随着垃圾沉积和垃圾质量的变化。作为国际研究人员网络的一部分，申请人和她的受训者将研究长期垃圾操纵如何控制沉积在土壤中的垃圾的数量和质量，以及随后如何改变土壤碳更换和生物地球化学。该计划将研究经历了15、20和30年的垃圾操纵的五个不同的温带森林。该研究计划将是第一个研究土壤有机物的分子水平组成变化，其中垃圾输入的长期变化以及这如何改变森林中的土壤碳储存。该研究计划将提供有关土壤有机物质和土壤碳如何通过垃圾输入变化以及这些差异如何受土壤和其他生态系统特性控制的新知识。该研究计划还将衡量土壤有机物的变化如何通过土壤来源的碳的溶解来改变其出口或退化的能力。这种分子级别的数据至关重要，以制定更好的森林管理策略，并确保其在不断变化的世界中的长期可持续性。当前的环境政策需要关于土壤碳对垃圾输入潜在转移的敏感性的更准确的科学知识。因此，这项拟议的研究将提供新的信息，以帮助塑造未来的环境缓解策略，以保护温带森林和世界其他敏感生态系统中的土壤碳。