CAREER: Strategies for Understanding the Effects of Global Climate and Environmental Change on Northern Peatlands

我职业生涯规划的主要目标是通过与芒特霍利奥克学院本科生的研究和教育活动相结合，以及与加拿大、美国和芬兰的泥炭地科学家的合作，提高我们对泥炭地生态系统和大气之间的反馈的理解，以应对全球气候变化和大气氮沉积增加。泥炭地拥有全球土壤碳库的三分之一，目前在寒冷、潮湿的条件下，泥炭以泥炭的形式被封存。然而，如果北纬的气候变得更加温暖和干燥，土壤分解速度可能会增加，从而向大气中增加更多的二氧化碳(CO2)和甲烷(CH4)，从而加剧变暖的趋势。或者，可以在更温暖、更干燥的气候下促进植物生长，从而通过增强光合作用从大气中消除更多二氧化碳。大气中氮含量的升高也会刺激植物的生长。总而言之，泥炭地对全球变暖要么是正反馈，要么是负反馈，这取决于植物生长和土壤分解对气候变化和氮沉积的相对反应。我提出了一种级联指导方法，学生从研究助理演变为全面的合作者，以加深我们对三个主要主题的理解：(1)环境控制二氧化碳和甲烷交换的年际和季节变化，重要的温室气体；(2)沿水文和营养梯度的一系列植物群落对气候变化的不同响应；以及(3)氮沉积对碳平衡和植被群落组成的影响。

The main objective of my CAREER plan is to improve our understanding of feedbacks between peatland ecosystems and the atmosphere in response to global climate change and increasing atmospheric nitrogen (N) deposition through a combination of research and educational activities with undergraduate women students at Mount Holyoke College and collaborations with peatland scientists in Canada, U.S. and Finland. Peatlands contain one-third of the global pool of soil carbon, which is currently sequestered as peat under cold, waterlogged conditions. However, if the climate becomes warmer and drier in the northern latitudes, soil decomposition rates could increase, adding more carbon dioxide (CO2) and methane (CH4) to the atmosphere, thus fueling the warming trend. Alternatively, plant growth could be enhanced under a warmer, drier climate, thus removing more CO2 from the atmosphere through enhanced photosynthesis. Elevated levels of atmospheric nitrogen could also stimulate plant growth. In sum, peatlands will either become positive or negative feedbacks to global warming depending on the relative responses of plant growth and soil decomposition to climate change and N deposition. I propose a cascade mentoring approach where students evolve from research assistants to full collaborators in furthering our understanding of three main topics: (1) the environmental controls on interannual and seasonal variability in carbon dioxide and methane exchange, important greenhouse gases, (2) the different responses of a range of plant communities along hydrologic and nutrient gradients to climate variability, and (3) the influence of nitrogen deposition on the carbon balance and vegetation community composition.