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

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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.