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

泥炭地在全球碳循环中发挥着关键作用。它们在大气中储存了大量的二氧化碳，但也会排放甲烷，这两种都是强有力的温室气体。然而，到目前为止，尚不确定碳通量将如何随气候变化而变化。大多数泥炭地呈现微地形，形成了干湿微点（微形态）的格局，每种微形态都有不同的温室气体通量。因此，微形态分布的变化可能对泥炭地碳收支产生重大影响。因此，一个重要的问题是，随着时间的推移，微生物的模式是如何随着气候变化而发展的。这个项目将通过调查古生态泥炭记录来解决这个问题。微形态类型之间的变化将从宏观化石组成中确定，通过放射性碳定年法确定年代，并与过去气候变化的时间有关。在12个泥炭岩心中研究微观形态变化、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。微生物对气候变化的适应能力将通过一种新的方法进行量化，该方法将微生物和泥炭水分指标的变化时间与植物生物标志物同位素特征重建的降水平衡变化进行比较。本研究的结果将阐明对长期微观形态动力学的控制，提高气候变化下泥炭地碳收支预测的准确性。

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.