Biogeophysical controls on soil-atmosphere thermal differences: implications on warming Arctic ecosystems

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Serval ID
serval:BIB_D9CF1F96DB3C
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Biogeophysical controls on soil-atmosphere thermal differences: implications on warming Arctic ecosystems
Journal
Environmental Research Letters
Author(s)
Aalto J., Scherrer D., Lenoir J., Guisan A., Luoto M.
ISSN
1748-9326
Publication state
Published
Issued date
2018
Peer-reviewed
Oui
Volume
13
Number
7
Pages
074003
Language
english
Abstract
Soil temperature (ST) has a key role in Arctic ecosystem functioning and global environmental change. However, soil thermal conditions do not necessarily follow synoptic temperature variations. This is because local biogeophysical processes can lead to a pronounced soil-atmosphere thermal offset (∆T) while altering the coupling (βT) between ST and ambient air temperature (AAT). Here, we aim to uncover the spatiotemporal variation in these parameters and identify their main environmental drivers. By deploying a unique network of 322 temperature loggers and surveying biogeophysical processes across an Arctic landscape, we found that the spatial variation in ∆T during the AAT≤0 period (mean ∆T=-0.6°C, standard deviation ± 1.0°C) was directly and indirectly constrained by local topography controlling snow depth. By contrast, during the AAT>0 period, ∆T was controlled by soil characteristics, vegetation and solar radiation (∆T=6.0°C ± 1.2°C). Importantly, ∆T was not constant throughout the seasons reflecting the influence of βT on the rate of local soil warming being stronger after (mean βT = 0.8 ± 0.1) than before (βT = 0.2 ± 0.2) snowmelt. Our results highlight the need for continuous microclimatic and local environmental monitoring, and suggest a potential for large buffering and non-uniform warming of snow-dominated Arctic ecosystems under projected temperature increase.
Web of science
Open Access
Yes
Create date
30/05/2018 20:38
Last modification date
20/08/2019 15:59
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