# Simulation of the Hydro-ecological Impacts of Climate Change on an Upland Peatland in the Massif Central

## TL;DR

This study uses detailed modeling to assess how climate change will affect peatland ecosystems in the Massif Central, showing wetter winters and drier summers.

## Contribution

The study introduces high-resolution hydro-ecological modeling of climate change impacts on upland peatlands in the Massif Central.

## Key findings

- Annual precipitation increases in 45 of 60 scenarios, with ensemble mean increases of 5–8% under RCP2.6.
- Hydrological conditions supporting mire vegetation decline in 41 of 60 scenarios, especially under higher radiative forcing.
- Stream discharges increase under RCP2.6 but decline under RCP8.5 by the 2080s, with more seasonal flow patterns.

## Abstract

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.

The online version contains supplementary material available at 10.1007/s13157-026-02046-7.