Shrub expansion in the Arctic may induce large-scale carbon losses due to changes in plant-soil interactions


Parker TC, Thurston AM, Raundrup K, Subke J, Wookey PA & Hartley IP (2021) Shrub expansion in the Arctic may induce large-scale carbon losses due to changes in plant-soil interactions. Plant and Soil, 463 (1-2), pp. 643-651.

Background Tall deciduous shrubs are increasing in range, size and cover across much of the Arctic, a process commonly assumed to increase carbon (C) storage. Major advances in remote sensing have increased our ability to monitor changes aboveground, improving quantification and understanding of arctic greening. However, the vast majority of C in the Arctic is stored in soils, where changes are more uncertain. Scope We present pilot data to argue that shrub expansion will cause changes in rhizosphere processes, including the development of new mycorrhizal associations that have the potential to promote soil C losses that substantially exceed C gains in plant biomass. However, current observations are limited in their spatial extent, and mechanistic understanding is still developing. Extending measurements across different regions and tundra types would greatly increase our ability to predict the biogeochemical consequences of arctic vegetation change, and we present a simple method that would allow such data to be collected. Conclusions Shrub expansion in the Arctic could promote substantial soil C losses that are unlikely to be offset by increases in plant biomass. However, confidence in this prediction is limited by a lack of information on how soil C stocks vary between contrasting Arctic vegetation communities; this needs to be addressed urgently.

Shrub expansion; Arctic; Soil; Rhizosphere; Carbon cycle; Climate change

Plant and Soil: Volume 463, Issue 1-2

FundersNERC Natural Environment Research Council, NERC Natural Environment Research Council and European Commission (Horizon 2020)
Publication date30/06/2021
Publication date online21/03/2021
Date accepted by journal10/03/2021
PublisherSpringer Science and Business Media LLC