Impact of future climate on Caithness and Sutherland peatlands

High-latitude boreal peatlands store up to a third of all the terrestrial carbon as peat, partially as decomposed organic matter. And, they act as reservoirs of vast amounts of GHG (Greenhouse gases) such as methane. The balance between being a source, or a sink of GHGs depends on continuation of favourable conditions under which peat is accumulated, or at least maintained through a series of complex feedback mechanisms linking mechanics, ecology and hydrology. Several peatland ecosystems have been disturbed in the past due to land-use change, build-up of roads and other infrastructure, and changing water flow in and out of peatlands. While these disturbances have significantly changed characteristics of many peatlands, they have affected a relatively small area of global peatlands. However, projected climate changes in the future threaten the balance of all global peatland ecosystems.

 

Total rainfall and mean temperature are known to play a significant role in sustaining and expanding blanket bogs – a globally rare type of peatland confined to high latitude regions with year-round cool climate. However, the number of rain days, and length and severity of drought conditions are also important for peatland health. Here, we present projected land use changes and GHG emissions under various RCP climate scenarios along with seasonal weather changes on blanket bogs in Caithness and Sutherland regions of Scotland. Our results show that high precipitation-low temperature climatic regimes necessary for maintaining and restoring peatlands may be changing with the highest contribution from changing rainfall patterns. We highlight how this could impact resilience mechanisms across a range of scales.