Vegetation management with fire modifies peatland soil thermal regime

Area of Science:

• Environmental Science
• Soil Science
• Ecology

Background:

• Prescribed burning is used in UK uplands for red grouse management, altering vegetation on carbon-rich peatlands.
• The impact of prescribed burning on peatland soil thermal regimes in subsequent years remains understudied.

Purpose of the Study:

• To quantify thermal dynamics in peatland soils across a chronosequence of burn ages.
• To develop statistical models predicting soil temperature changes due to vegetation management.

Main Methods:

• Soil thermal regime was monitored for 18 months across 12 burned peatland plots of varying ages (<2 to 15+ years post-fire).
• Generalized least square regression models were developed to predict soil temperatures based on long-term burned plots.
• These models were used to assess deviations in plots of younger burn ages.

Main Results:

• Recently burned plots (<2-4 years) exhibited higher mean, maximum, and range of soil temperatures, with lower minima compared to plots burned 15+ years prior.
• Plots burned less than 2 years showed significant temperature increases: +6.2 °C for daily mean and +19.6 °C for daily maxima.
• Soil temperatures in plots burned 7 years prior showed similarity to those burned 15+ years ago, suggesting recovery.

Conclusions:

• Prescribed peatland vegetation burning significantly alters soil thermal regimes.
• These alterations have implications for carbon cycling, biogeochemistry, and soil hydrology.
• Further research is needed to understand the consequences of altered thermal regimes in peatlands.