Doctoral Dissertation Research: The Changing Face of the Andean Peatlands: The Effects of Climate and Human Disturbance on Ecosystem Structure and Function

博士论文研究：安第斯泥炭地的变化：气候和人类干扰对生态系统结构和功能的影响

• 批准号: 0826410
• 负责人: Dale Vitt
• 金额: $ 1.2万
• 依托单位: Southern Illinois University at Carbondale
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-01 至 2011-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0826410&HistoricalAwards=false
• 关键词: Doctoral; Dissertation; Research; Changing; Face

Peatlands store nearly thirty percent of global soil carbon, an amount equivalent to twenty-seven years of global carbon emissions. Peatland ecosystems have a positive balance of carbon accumulation under normal conditions, but global warming could turn these ecosystems from net sinks to sources of carbon. Global changes are affecting tropical mountains in the same degree as they are affecting boreal forests. These changes have reduced the extent of the glaciers and pushed the different vegetation types upward, including the tropical alpine region known as paramo. Andean peatlands have been considered to be more affected by local environmental conditions than global changes, but the functional similarity between them and boreal peatlands indicates that Andean peatlands are more susceptible to global changes than previously thought. The function and structure of Andean peatlands are almost unknown and this doctoral dissertation research project aims to locate the Andean peat-forming vegetation in the conceptual framework of boreal peatlands by answering four questions. 1) What is the distribution of the different peat-forming plant communities across elevation, precipitation, and human intervention gradients? 2) What is the relationship between peat-forming vegetation in the Andes and their environmental conditions? 3) Are there observable changes in the carbon balance of the Andean peat-forming vegetation in the last 200 years? 4) Are the changes in species composition observed in the peat related to environmental changes in the last 200 years? Surveys of the peat-forming vegetation will be carried out in twenty-four sites at different elevations, conditions of precipitation, and human activity. Cores taken from each site will show evidence of the changes in peat function and structure during the last 200 years, while the chronology will be controlled using lead-210 radioactive decaying. The relationship between the current peat-forming communities and their environmental conditions provide the framework to identify and recreate recent changes in the Northern-Andean forests climate and environment in the context of human intervention and global change. The research begins with a working hypothesis that Andean peatlands are more connected to boreal peatlands than previously thought. The alpine ecosystems in the Northern Andes, or paramos, have high levels of endemism and provide multiple ecological services to local communities. Peatlands in the Andes regulate water flow used by nearly forty percent of the population in Andean countries; however their fate in the context of climate change and human intervention is unknown. This research will model the extent of these changes and provide basic science for the oncoming amelioration programs. Understanding the high elevation peatlands in the Andes give us the opportunity to project our research beyond the scientific limits and return the knowledge acquired to the local communities, as well as training of local scientists in peatland vegetation science.

泥炭地储存了全球近30%的土壤碳，相当于全球27年的碳排放量。泥炭地生态系统在正常情况下具有碳积累的正平衡，但全球变暖可能使这些生态系统从净汇变为碳源。全球变化对热带山区的影响程度与对北方森林的影响程度相同。这些变化减少了冰川的范围，并推动了不同类型的植被向上生长，包括被称为帕拉莫的热带高山地区。安第斯泥炭地被认为是更多地受到当地环境条件的影响，而不是全球变化，但它们之间的功能和北方泥炭地的相似性表明，安第斯泥炭地更容易受到全球变化比以前认为的。安第斯泥炭地的功能和结构几乎是未知的，这个博士论文研究项目的目的是通过回答四个问题，找到安第斯泥炭形成植被的概念框架的北方泥炭地。1)不同泥炭形成植物群落在海拔、降水和人为干预梯度上的分布情况如何？2)安第斯山脉的泥炭形成植被与其环境条件之间的关系是什么？3)在过去的200年里，安第斯泥炭形成植被的碳平衡是否有可观察到的变化？4)在泥炭中观察到的物种组成的变化是否与过去200年的环境变化有关？将在不同海拔、降水条件和人类活动的24个地点进行泥炭形成植被的调查。从每个地点采集的岩芯将显示过去200年来泥炭功能和结构变化的证据，而年表将使用铅-210放射性衰变进行控制。目前的泥炭形成社区与其环境条件之间的关系提供了一个框架，以确定和重建在人类干预和全球变化的背景下，北安第斯森林气候和环境的最新变化。这项研究从一个工作假设开始，即安第斯泥炭地与北方泥炭地的联系比以前认为的更紧密。北方安第斯山脉的高山生态系统，或称帕拉莫斯，具有高度的特有性，为当地社区提供多种生态服务。安第斯山脉的泥炭地调节着安第斯国家近40%人口的水流量;然而，在气候变化和人类干预的背景下，它们的命运是未知的。这项研究将模拟这些变化的程度，并为即将到来的改善计划提供基础科学。了解安第斯山脉的高海拔泥炭地使我们有机会将我们的研究超越科学限制，并将获得的知识归还给当地社区，以及培训当地科学家进行泥炭地植被科学。