Hydric Soils of the Prairie Pothole Region

我的研究计划的主要长期目标是将土壤功能与土地利用和气候变化联系起来。这使我们能够了解土地管理决策如何影响区域土壤生物地球化学过程，并最终影响生态系统的可持续性。具体的长期问题包括：关键的土壤功能，如碳和氮循环与土地利用变化的关系？基于地形的采样能改善我们对营养动态的理解吗？这些关系能否为地方、区域或国家范围的土地管理提供信息？草原坑洼地区（PPR）包括加拿大大草原和美国北方大平原的70多万平方公里。它的特点是数以百万计的湿地被春季融雪填满，但在夏季干燥;每年春季长时间的饱和产生了独特的湿地土壤，我们称之为“含水土壤”。PPR湿地和含氢土壤提供了许多生态系统服务，包括水和养分的保持和循环、洪水衰减、水过滤、地下水补给、碳固存、野生动物栖息地和生物多样性。每年的干湿循环被认为在许多这些服务中发挥着重要作用，但大多数PPR湿地已被排水用于农业生产和郊区发展，而没有完全了解排水对土壤养分动态的长期影响。传统上，PPR的含水土壤已经跨越了学科界限：对土壤科学家来说太湿，对湿地科学家来说太干。在短期内，我的研究计划的目的是确定在PPR湿地管理历史的土壤指标，并研究如何碳和氮动态的土壤水分是由土地利用变化的影响。水成土在水文条件改变后，其水成土的性质能持续多久？我们能否根据湿地的生态系统功能对其进行分类，从而确定哪些湿地最需要保护或恢复？通过提高我们对农业生态系统中的含水土壤的理解，拟议的项目将改善PPR湿地的综合管理，最大限度地提高生态系统服务，同时最大限度地减少生产性土地的损失。

The primary long-term objective of my research program is to link soil function to land use and climate change. This allows us to understand how land management decisions influence regional soil biogeochemical processes and ultimately ecosystem sustainability. Specific long-term questions include: How are key soil functions such as carbon and nitrogen cycling related to land use change? Can landform-based sampling refine our understanding of nutrient dynamics? Can these relationships inform land management at the local, regional, or national scales? The Prairie Pothole Region (PPR) encompasses over 700,000 square kilometres of the Canadian Prairies and northern Great Plains of the U.S. It is characterized by millions of wetlands that are filled by spring snowmelt but dry down during the summer months; the prolonged saturation each spring gives rise to unique wetland soils we refer to as "hydric soils". PPR wetlands and hydric soils provide a number of ecosystem services, including water and nutrient retention and cycling, flood attenuation, water filtration, groundwater recharge, carbon sequestration, wildlife habitat and biodiversity. Annual wet-dry cycles are thought to play an important role in many of these services, but a majority of PPR wetlands have been drained for agriculture production and suburban developments, without complete understanding of the long-term implication of drainage for soil nutrient dynamics. Traditionally, hydric soils of the PPR have fallen through disciplinary boundaries: too wet for soil scientists and too dry for wetland scientists. In the short term, my research program aims to identify soil indicators of wetland management history in the PPR and examine how carbon and nitrogen dynamics of hydric soils are affected by land use change. How long do hydric soils continue to behave as hydric soils following a change to their hydrology? Can we classify wetlands by their ecosystem function and therefore identify those most essential for preservation or restoration? By improving our understanding of hydric soils within agro-ecosystems, the proposed project will improve integrated management of PPR wetlands, maximizing ecosystem services while minimizing loss of productive land.