Using a simple, process-based model to address (and raise) questions about relationships between climate, land-use, and decadal to millennial peatland carbon cycling (Invited)

The Holocene Peat Model simulates peatland coupled carbon and water cycling to estimate long-term peat carbon accumulation driven by climate variability. Recent model developments include incorporation of permafrost/active layer dynamics, radiocarbon labeling, and an empirical representation of tropical peatland hydrology. The model operates at an annual time step and generates a peat profile that includes characterization of depth vs. age, degree of humification, and vegetation composition. This profile can be compared to data from contemporary peat cores. The simulation results also include the peatland development trajectory that generated the contemporary profile - annual net C-balance, water table, plant community composition and productivity. In this way, the model provides a process-based hypothesis for how climate history (or future climate and/or land use) affects the peat profile in ways that potentially can be observed in the field. Here we present an overview of the model, and some recent applications, including climate-warming impacts on high-latitude permafrost peatland systems, and land-use conversion impacts on tropical peat swamp forests.