Soil organic matter at the root of solutions for climate change mitigation and adaptation

土壤有机质是减缓和适应气候变化解决方案的根源

• 批准号: RGPIN-2020-06360
• 负责人: Poirier, Vincent
• 金额: $ 1.82万
• 依托单位: Université du Québec en Abitibi-Témiscamingue
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=741165
• 关键词: Soil; organic; matter; root; solutions

Soil organic matter (SOM) plays a crucial role in mitigating and adapting to climate change. Increasing SOM in agricultural soils is one of the most short-term and viable option to augment carbon (C) storage, limit global warming and reach carbon neutrality by 2050. Plant roots contribute substantially to SOM; living roots release exudates, associate with symbiotic microorganisms and enmesh soil particles to form aggregates, and dead roots serve as a major C and nitrogen (N) input into the soil. However, roots could also destabilize SOM by stimulating its decomposition by soil microorganisms. Moreover, global warming will likely affect plants and belowground processes, but effects on C and N cycling in the soil remain unclear. A quantitative assessment of how roots affect the balance between C and N retention and losses in soil is necessary to develop climate-smart soils and agroecosystems and increase SOM and C storage. Still, few data exists on how roots and microorganisms affect belowground processes. The long-term objectives of the proposed program are: (1) characterize root traits of perennial and annual species used in temperate agroecosystems, (2) evaluate how root traits and climate variables affect SOM processes, and (3) identify root traits that increase storage and limit losses of C and N, in topsoil and subsoil of Eastern Canadian clay soils. The proposed program contains two main themes: (A) How living and decomposing roots of different plant species affect SOM and (B) How climate variables and species diversity affect root traits and SOM. It involves laboratory experiments under controlled conditions (Theme A) and field experiments under natural conditions (Theme B). Morphological, chemical, architectural, and biotic characterisation of specific root traits, together with analyses of C, N, 13C and 15N concentrations in density fractions of the soil, will allow tracing root-derived C and N and studying SOM stabilization mechanisms in topsoil (i.e., 0-20 cm depth) and subsoil (i.e., >20 cm depth). Virtually no data exist to asses the influence of grassland and cropping species, functional groups and communities on C and N stabilization in Eastern Canada, nor there is any information on how roots traits impact soil functioning. This original, hypothesis-driven research program will provide new knowledge on some of the most important issues related to climate change mitigation and adaptation. This research program at the cutting edge of functional ecology and soil science will have a strong impact by creating bridges between these areas and filling gaps in our comprehension of the soil-plant system. With this research program, I will form 1 PhD, 2MSc, 3UG students that will help design and manage climate-smart soils and agroecosystems. Funding through a Discovery Grant represents a significant contribution to the huge efforts Canada must make to fulfill the Paris Agreement engagements and achieve carbon neutrality by 2050.

土壤有机物（SOM）在缓解气候变化和适应气候变化方面起着至关重要的作用。农业土壤中的SOM增加是增加碳（C）储存，限制全球变暖并到2050年到达碳中立性的最短期且可行的选择之一。植物根对SOM有很大贡献。生命的根部释放渗出液，与共生微生物和enmesh土壤颗粒相关，形成聚集体，而死根则是主要的C和氮（N）输入到土壤中。但是，根也可能通过刺激其土壤微生物的分解来破坏SOM的稳定。此外，全球变暖可能会影响植物和地下过程，但对土壤中C和N循环的影响尚不清楚。对根部如何影响C和N保留和土壤损失之间的平衡的定量评估对于发展气候智能土壤和农业生态系统并增加SOM和C存储是必要的。尽管如此，很少有关于根和微生物如何影响地下过程的数据。 The long-term objectives of the proposed program are: (1) characterize root traits of perennial and annual species used in temperate agroecosystems, (2) evaluate how root traits and climate variables affect SOM processes, and (3) identify root traits that increase storage and limit losses of C and N, in topsoil and subsoil of Eastern Canadian clay soils.拟议的程序包含两个主要主题：（a）不同植物物种的生命和分解根部如何影响SOM以及（b）气候变量和物种多样性如何影响根特性和SOM。它涉及在受控条件（主题A）和自然条件下（主题B）下实验实验实验。特定根特征的形态，化学，建筑和生物特征，以及土壤密度分数的C，N，N，13C和15N浓度的分析，将允许追踪根源的C和N，以及研究表层土壤中的SOM稳定机制（即，0-20 cm depth）和下层和下层（即0-20 cm depth）和subsoil（i.ee.ee.e.e.e.e.ee.，> 20 cm，> 20 cm，> 20 cm，几乎没有数据可以评估加拿大东部的草原和种植物种，官能团体和社区对C和N稳定的影响，也没有关于根部特征如何影响土壤功能的任何信息。该原始假设驱动的研究计划将提供有关与气候变化和适应有关的一些最重要问题的新知识。该研究计划在功能生态学和土壤科学的最前沿将产生很大的影响，通过在这些区域之间创建桥梁并填补我们对土壤植物系统的理解中的空白。通过此研究计划，我将组建1个博士学位，2MSC，3个学生，这些学生将帮助设计和管理气候智能的土壤和农业生态系统。通过发现赠款的资金代表了加拿大为实现巴黎协议订婚并在2050年实现碳中立所做的巨大努力做出的重大贡献。