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

形成泥炭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储存。但泥炭地也会释放甲烷到大气中。泥炭地作为碳汇和甲烷源的程度在很大程度上取决于生长在那里的植物类型。北极泥炭地所在的远北方地区正在迅速变暖，因此确定其碳储量对已经发生的植被变化的敏感程度是很重要的。众所周知，当泥炭地的主要植物从泥炭藓转变为莎草时，就像许多地区发生的那样，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都不容易预测。很大程度上的不可预测性是因为很难区分泥炭地历史上的主要植物。如果这是可能的，那么就可以对未来做出更好的预测。所以这个项目的主要目标是建立一个数据库，记录北极莎草和其他过去在泥炭地占主导地位的植物的化学特性。该数据库将向公众开放，并将建立起来，以便易于更新和添加。该项目还将继续一项计划，将高中教师从纽约地区带到北极，参加与该项目有关的实地研究。然后，这些教师将开发与高中科学课程有关的教学模块。莎草科（莎草）的成员栖息在不同的环境中，跨越了广泛的水分平衡，pH值和营养物质的可用性。然而，它们是出了名的难以通过泥炭芯中的化石遗骸来识别，甚至是在科的水平上，因为缺乏可识别的植物部分是物种特异性的。但是，虽然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的。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起来。该项目将建立这样一个数据库，并将以其化学成分为特征的植被类型与净碳积累率联系起来。在此过程中，将开发出基于植被变化的泥炭地碳积累的第一个预测模型。这是将泥炭地完全纳入全球气候模型的重要一步，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。

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.