Hydro-ecological impacts of 60 climate change scenarios on peat ecosystems of the Dauges National Nature Reserve are assessed using high spatial resolution MIKE SHE / MIKE 11 modelling. Annual precipitation increases for 45 of 60 scenarios (ensemble mean increases: 5–8% for RCP2.6, 1–5% for RCP8.5). Annual potential evapotranspiration increases in all cases (ensemble mean: 2–3% for RCP2.6, 6–12% for RCP8.5). Winters become wetter and summers drier. Mean stream discharges increase in most cases (ensemble means for catchment outlet: 8–9% for RCP2.6, 2–4% (2050s) and − 1–2% (2080s) for RCP8.5). Flows become more seasonal with increasing peaks and declining lows. Winter peat groundwater levels still intercept the surface but declines in summer dominate (> 80% of cases) driving enhanced seasonal ranges and lower mean levels (> 70% of cases). The magnitude of changes increases with higher radiative forcing and into the future (ensemble mean increases in low levels of <1 cm for RCP2.6 in both time slices, declines of 5–7 cm and 12–14 cm for RCP8.5 in the 2050s and 2080s, respectively). The largest declines are concentrated around peatland margins. Hydrological conditions assumed to support mire vegetation decline in extent in most cases (41 of 60 scenarios, more common with higher radiative forcing). Small (< 1%) increases in area are projected by ensemble means for RCP2.6 with declines of 12–13% for RCP8.5 in the 2080s. Sources of uncertainty include shifts in catchment vegetation, changes in peat hydraulic properties and mire vegetation species-specific impacts of hydrological changes.
Thompson et al. (Mon,) studied this question.