Disturbance impacts on thermal hotspots and hot moments at the peatland-atmosphere interface

Soil-surface temperature acts as a master variable driving non-linear terrestrial ecohydrological, biogeochemical and micrometeorological processes, inducing short-lived or spatially isolated extremes across heterogeneous landscape surfaces. However, sub-canopy soil-surface temperatures have been, to date, characterised through isolated, spatially discrete measurements. Using spatially complex forested northern peatlands as an exemplar ecosystem, we explore the high resolution spatiotemporal thermal behaviour of this critical interface and its response to disturbances by using Fibre-Optic Distributed Temperature Sensing. Soil-surface thermal patterning was identified from 1.9 million temperature measurements under undisturbed, trees removed and vascular sub-canopy removed conditions. Removing layers of the structurally diverse vegetation canopy not only increased mean temperatures but it shifted the spatial and temporal distribution, range and longevity of thermal hotspots and hot-moments. We argue that linking hotspots and/or hotmoments with spatially variable ecosystem processes and feedbacks is key for predicting ecosystem function and resilience.