Shifting patterns? Understanding peatland resilience from shifts in small scale microform patterns (SPURT)

转变模式？

• 批准号: 423373829
• 负责人: Dr. Paul Mathijssen
• 金额: --
• 依托单位: Lamont-Doherty Earth Observatory
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/423373829?language=en
• 关键词: Shifting; patterns; Understanding; peatland; resilience

Peatlands play a key role in the global carbon cycle. They store large amounts of atmospheric carbon dioxide, but also emit methane, both potent greenhouse gases. However, to date it is uncertain how carbon fluxes will change in response to climate change. Most peatlands exhibit microtopography, creating a pattern of wet and dry microsites (microforms), and each microform has different greenhouse gas fluxes. Thus, a shift in microform distribution may have large consequences for the peatland carbon budget. An important remaining question is therefore how patterns of microforms develop over time in response to climate change. This project will address this question by investigating paleo-ecological peat records. Shifts between microform types will be identified from macrofossil composition, dated through radiocarbon dating, and related to the timing of past climate changes. The relation between microform shifts, hydraulic properties, decomposition, and carbon accumulation will be studied in twelve peat cores, capturing spatial variation across the peatland. Microform resilience to climate change will be quantified using a novel method comparing the timing of shifts in microforms and peat moisture indicators with changes in precipitation balance reconstructed from isotopic signatures of plant biomarkers. The results of this study will clarify the controls on long-term microform dynamics, increasing the accuracy of predictions of peatland carbon budgets under a changing climate.

泥炭地在全球碳循环中扮演着关键角色。它们储存了大量的大气二氧化碳，但也排放了甲烷，这两种气体都是强有力的温室气体。然而，到目前为止，还不确定碳通量将如何变化以应对气候变化。大多数泥炭地表现出微地形，形成了干湿微相(微相)的模式，每种微相都有不同的温室气体通量。因此，微相分布的变化可能会对泥炭地的碳收支产生重大影响。因此，一个重要的遗留问题是缩微胶片的模式如何随着时间的推移而发展，以应对气候变化。这个项目将通过研究古生态泥炭记录来解决这个问题。显微形态类型之间的转换将从宏观化石成分中识别出来，通过放射性碳测年确定日期，并与过去气候变化的时间相关。将在12个泥炭岩芯中研究泥炭微相迁移、水力特性、分解和碳积累之间的关系，捕捉泥炭地的空间变化。微相对气候变化的恢复力将使用一种新的方法来量化，该方法将微相和泥炭水分指标的变化时间与根据植物生物标志物的同位素特征重建的降水平衡的变化进行比较。这项研究的结果将阐明对长期微相动态的控制，提高气候变化下泥炭地碳收支预测的准确性。