A field-based experimental system for the evaluation of the effects of elevated temperature and CO2 on peatlands

提出了一种评价高温和二氧化碳对泥炭地影响的野外实验系统。在两种不同的北方泥炭地类型（贫瘠沼泽和中等沼泽）中，我们将安装一个系统，该系统包括16个透明聚碳酸酯开顶室，一个二氧化碳输送系统，一个地面供暖系统和一个离网电力系统。在此基础上，我们将对包括二氧化碳升高、土壤变暖在内的气候变化因素进行全因子处理，模拟未来气候和土壤条件。透明聚碳酸酯室（~1m直径x 1m高）与0.2米深的刚性项圈将包含每个实验处理。在每个实验室内，将安装一个地面加热系统来模拟长期大气变暖对地表泥炭的影响。将使用精密流量控制器和高压二氧化碳源将实验室内的二氧化碳浓度提高到1000ppm，以模拟未来的大气浓度。这一全球独一无二的基础设施将为六名主要研究人员和他们的研究小组提出有关气候变化对泥炭地生态系统影响的基本问题提供便利。所有研究人员的一个主要目标是减少围绕北方泥炭地储存碳的命运的科学不确定性，以及碳释放回大气的可能性，从而放大未来的气候变化。这种反馈对生态系统和气候模型以及未来“碳经济”中的国民经济福祉具有深远的影响。此外，这些基础设施将使研究人员加深对氮循环、生物多样性和生态系统功能、地下微生物生物地球化学过程以及泥炭地热量和水分转移的物理学的理解，所有这些都与碳循环相关。所有这些数据将直接用于改进预测加拿大泥炭地碳储量轨迹的模型。

A field-based experimental system for the evaluation of the effects of elevated temperature and carbon dioxide on peatlands is proposed. In two different boreal peatland types (poor and intermediate fens) with ~10 years of historical climatological and hydrological monitoring data, we will install a system that comprises 16 clear polycarbonate open-top chambers, a carbon dioxide delivery system, a ground-heating system, and an off-grid power system. With this, we will implement a full factorial treatment of climate change factors, including elevated carbon dioxide, and soil warming, to simulate future climate and soil conditions. Clear polycarbonate chambers (~1m dia x 1m high) with a 0.2m deep rigid collar will contain each experimental treatment. In each of the experimental chambers, a ground-heating system will be installed to simulate the effects of prolonged atmospheric warming on the surface peats. Precision flow-controllers and a high-pressure carbon dioxide source will be used to increase carbon dioxide concentration in experimental chambers to 1000 ppm carbon dioxide to simulate future atmospheric concentrations. This globally unique infrastructure will facilitate the research of six principal investigators and their research groups asking fundamental questions about the effects of a changing climate on peatland ecosystems. A main goal of all investigators is to reduce the scientific uncertainty surrounding the fate of stored carbon in boreal peatlands, and the potential for carbon release back to the atmosphere, amplifying future climate change. This feedback has profound implications for ecosystem and climate modeling, as well as for national economic well-being in a future 'carbon economy'. In addition, the infrastructure will allow the researchers to deepen our understanding of the cycling of nitrogen, biodiversity and ecosystem function, below-ground microbial biogeochemical processes, and the physics of heat and moisture transfer in peatlands, all of which couple to the carbon cycle. All of this data will be used directly to improve models that will be used to forecast the trajectory of Canada's peatland carbon stores.