Systems for soil microclimatic manipulation and high frequency monitoring of decomposition rates

土壤微气候操控和分解率高频监测系统

• 批准号: 345847-2007
• 负责人: Risk, David
• 金额: $ 1.75万
• 依托单位: St. Francis Xavier University
• 依托单位国家: 加拿大
• 项目类别: Research Tools and Instruments - Category 1 (<$150,000)
• 财政年份: 2006
• 资助国家: 加拿大
• 起止时间: 2006-01-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=325767
• 关键词: Systems; soil; microclimatic; manipulation; frequency

Field studies are sorely needed to establish the actual, rather than theoretical, in-situ response of soil carbon stocks to climate change.  The major challenge in this area of research is resolution and/or control of variables to hold parameters (e.g. moisture) constant for accurate assessments of driving and limiting factors that contribute to loss or storage of soil organic matter.  Another in-situ challenge in the area of soil carbon research lies in the quantification of decomposition rates among different carbon pools, which is critical since deeper, recalcitrant soil organic matter is thought to hold the majority of long-term sequestration capacity. By using a subsurface, high-temporal resolution monitoring methodology in conjunction with microclimatic manipulation techniques borrowed from contaminant bioremediation studies, it is possible to test new questions in soil carbon stability, namely the effect of the numerous physical parameters other than temperature on soil carbon loss in natural settings.  To date, an in-situ experimental approach has not been used to explicitely test the significance of these physical factors, but it is known that they act in many areas (especially high latitudes) to stabilize soil carbon and protect it from decomposition.  I propose to construct four one-off systems for automated control and high frequency monitoring of soil decomposition rates in response to manipulations of soil physical factors, in particular moisture, oxygenation, and temperature.  In effect, each of these systems constitutes a "field laboratory".  I am requesting four systems to perform manipulative experiments in each of Atlantic Canada's major forest biomes - Boreal, Sub-Boreal, Acadian Forest and Great-Lakes St. Lawrence.

迫切需要实地研究来确定土壤碳储量对气候变化的实际而非理论的原位响应。这一研究领域的主要挑战是解决和/或控制变量，以保持参数（例如湿度）恒定，以便准确评估导致土壤有机质损失或储存的驱动和限制因素。土壤碳研究领域的另一个原位挑战在于不同碳库之间分解速率的量化，这是至关重要的，因为人们认为深层难降解的土壤有机质拥有大部分的长期固存能力。通过使用地下高时间分辨率监测方法，结合从污染物生物修复研究中借鉴的小气候操纵技术，可以测试土壤碳稳定性的新问题，即在自然环境中，温度以外的许多物理参数对土壤碳损失的影响。迄今为止，还没有使用原位实验方法来明确测试这些物理因素的重要性，但已知它们在许多地区（特别是高纬度地区）起作用，以稳定土壤碳并防止其分解。我建议构建四个一次性系统，用于自动控制和高频监测土壤分解率，以响应土壤物理因素的操纵，特别是湿度，氧合和温度。实际上，这些系统中的每一个都构成了一个“现场实验室”。我要求四个系统在加拿大大西洋沿岸的主要森林生物群落-北方森林，亚北方森林，阿卡迪亚森林和大湖区圣劳伦斯进行操控性实验。