A Hydrogeophysical Study of Northern Raised Bogs: Implications for Generic Models of Peatland Formation, Vegetation Patterning, Pool Formation and Biogenic Gas Generation

为了改善泥炭地管理和预测这些独特的生态系统对气候变化的反应，需要更好地了解泥炭地开发、泥炭地水文和泥炭沼泽内碳气体循环的过程。在这项研究中，我们将采用基于地球物理学的方法来研究泥炭地科学中三个尚未完全解决的当前问题：[1]在泥炭地表面观察到的独特植被结构和模式的原因[1]对许多北部沼泽中遇到的池形成的控制；[3]泥炭地自由相生物气的盆地尺度体积和分布。我们的假设是，我们之前提出的概念模型可以解释从缅因州中部的一个多单元凸起沼泽Caribou Bog中获得的数据，这些数据与缅因州其他综合凸起沼泽的形成、植被模式和碳循环有关，这些沼泽的表面植被和表面水文与Caribou Bog惊人地相似。作为验证这一假设的第一步，我们计划在缅因州以前未开发的1-2个沼泽（取决于遇到的野外条件）收集地球物理数据。我们的分析将集中在这些新数据集是否与我们基于Caribou Bog的概念模型一致。我们选择的泥炭地表现出惊人的相似的地表水文和生态特征。我们利用探地雷达（GPR）和电成像技术进行的地球物理研究将确定这些泥炭地的地下特征是否相应相似，并支持将泥炭地地下特征与地表植被、地表水文和陆地-大气碳交换联系起来的通用模型的存在。我们项目的一个重要的教育倡议是一个研讨会-泥炭地科学家的地球物理学-我们将在2007年夏天运行。本次研讨会的基本目标是提高全球泥炭地科学家对地球物理方法的利用。地球物理方法目前未被泥炭地科学家充分利用，我们认为这不利于我们对泥炭地功能的理解的进步。参与者应获得足够的知识，能够独立地将地面探地雷达和电成像方法应用于自己的实地研究。我们将培训参与者在泥炭地应用地球物理技术，并对所产生的数据集进行独特的解释。我们希望将一群泥炭地科学家带到缅因州来讨论我们的假设和我们迄今为止在文献中提出的概念模型，从而获得协同效益。我们的工作具有全球意义，因为泥炭地目前排放大量的碳气体（全球甲烷总量的25-30%），而这些大型碳库对气候变化的反应是高度不确定的。我们的工作还具有区域意义，因为泥炭地是缅因州重要的生态系统，约占景观的5%。这些系统可能在该州的水文和水质中发挥重要作用，并相应地增强了该州的生物多样性。

The processes of peatland development, peatland hydrology and carbon gas cycling within peat bogs need to be better understood in order to improve peatland management and predict the response of these unique ecosystems to climate change. In this research we will implement a geophysics-based approach to investigate three incompletely resolved, current issues in peatlands science: [1] the causes of the unique vegetation structure and patterning observed at the peatland surface [2] controls on the formation of pools encountered in many northern bogs; [3] the basin-scale volume and distribution of free-phase biogenic gasses in peatlands. Our hypothesis is that conceptual models we previously proposed to explain data obtained from Caribou Bog, a multi-unit raised bog in central Maine, pertain to the formation, vegetation patterning and carbon cycling of other ombotrophic raised bogs of Maine that display a surface vegetation and surface hydrology strikingly similar to Caribou Bog. As a first step in testing this hypothesis we plan to collect geophysical data in 1-2 (depending on field conditions encountered) previously unexplored bog of Maine. Our analysis will focus on whether these new datasets are consistent with our conceptual models based on Caribou Bog. The peatlands we have chosen exhibit strikingly similar surface hydrological and ecological characteristics. Our geophysical research using ground penetrating radar (GPR) and electrical imaging will determine whether the subsurface characteristics of these peatlands are correspondingly similar and support the existence of generic models linking subsurface characteristics of peatlands to surface vegetation, surface hydrology and land-atmosphere carbon exchange.A significant educational initiative of our project is a workshop on -Geophysics for Peatlands Scientists- that we will run in the summer of 2007. The fundamental objective of this workshop is to enhance utilization of geophysical methods by peatland scientists across the globe. Geophysical methods are currently underutilized by peatlands scientists and we believe that this is detrimental to the advancement of our understanding of peatland functions. Participants should gain sufficient knowledge to independently apply surface-based ground penetrating radar and electrical imaging methods to their own field-based research. We will train participants in the application of geophysical technologies in peatlands and in the unique interpretation of datasets produced. We expect to reap synergistic benefits as a result of bringing a group of peatland scientists to Maine to debate our hypotheses and the conceptual models we have so far presented in the literature. Our work has global implications as peatlands currently emit significant amounts of carbon gases (25-30% global total of methane), and the response of these large carbon reservoirs to climatic change is highly uncertain. Our work also has regional implications as peatlands are an important ecosystem in Maine, covering about 5% of the landscape. These systems likely play an important role in the hydrology and water quality of the state and correspondingly enhance the state biodiversity.