Constraining the Relationship Between Vegetation Change and Net Carbon Sequestration in Arctic and Boreal Peatlands

泥炭形成的生态系统是全球碳循环的关键组成部分，因为它们是大气中二氧化碳的巨大碳库。但泥炭地也会将甲烷释放回大气。泥炭地作为碳汇和甲烷源的程度在很大程度上取决于那里生长的植物的类型。北极泥炭地所在的遥远北部地区正在迅速变暖，因此确定它们的碳储量对已经在进行的植被变化的敏感度是很重要的。众所周知，当主要的泥炭地植物从泥炭苔藓变成莎草时，就像许多地区正在发生的那样，碳储存的速度可能会发生很大变化，但任何特定泥炭地的具体反应并不容易预测。这种不可预测性很大程度上是因为很难区分历史上泥炭地的主要植物。如果这是可能的，那么就可以对未来做出更好的预测。因此，该项目的主要目标是建立一个北极莎草和其他已知过去主导泥炭地植物的化学性质的数据库。该数据库将向公众开放，并进行设置，以便可以轻松地更新和添加。该项目还将继续一项计划，将纽约地区的高中教师带到北极参加与该项目相关的实地考察。然后，这些教师将开发与高中科学课程相关的教学模块。莎草科(莎草科)的成员生活在不同的环境中，跨越了广泛的水分平衡、pH和营养可获得性范围。然而，众所周知，它们很难通过泥炭核心中的化石遗骸来识别，甚至是家庭层面的，因为缺乏物种特有的可识别的植物部分。但是，尽管植物部分本身往往不存在，但它们产生的化学物质几乎总是存在。在产生的数千种化合物中，大多数尚未得到适当的表征并与特定物种联系在一起。该项目将建立这样一个数据库，还将把以化学成分为特征的植被类型与净碳累积率联系起来。在此过程中，将开发出第一个基于植被变化的泥炭地碳积累预测模型。这是朝着将泥炭地完全纳入全球气候模型迈出的重要一步，这将使人们能够更全面地了解气候变化和泥炭地碳积累之间的反馈关系。

Peat-forming ecosystems are key components of the global carbon cycle, as they are tremendous stores of carbon from carbon dioxide in the atmosphere. But peatlands also release methane back to the atmosphere. The degree to which peatlands act as carbon sinks and methane sources largely depends on the types of plants growing there. The far northern areas where Arctic peatlands occur are warming rapidly and so it is important to determine how sensitive their carbon storages are to changes in vegetation that are already underway. It is known that when the main peatland plants change from sphagnum mosses to sedges, as is happening in many areas, the rate of carbon storage may change a lot, but the specific response of any particular peatland is not easy to predict. Much of the unpredictability results from difficulties in telling apart the dominant plants in peatlands through history. If that was possible, then much better predictions into the future could be made. So the main objective of this project is to create a database of the chemical properties of Arctic sedges and other plants known to dominate peatlands in the past. The database will be available to the public and be set up so that it can be easily updated and added to. The project will also continue a program that brings high school teachers from the New York area to the arctic to participate in field studies associated with the project. These teachers will then develop teaching modules connected to high school science curriculums. Members of the Cyperaceae (sedges) inhabit diverse environments, spanning a wide range of moisture balance, pH, and nutrient availability. However, they are notoriously difficult to identify by their fossil remains in peat cores, even to the family level, because of the paucity of identifiable plant parts that are species specific. But while the plant parts themselves are often absent, chemicals they produced are almost always present. Of the thousands of compounds produced, most have yet to be properly characterized and linked to particular species. This project will generate such a database and will also relate vegetation types, as characterized by their chemical constituents, to net carbon accumulation rate. In doing so, the first predictive models of carbon accumulation in peatlands based on vegetation change will be developed. This is an important step towards fully integrating peatlands into global climate models, which will allow a more comprehensive understanding of the feedbacks between climate change and peatland carbon accumulation.