Shedding light on the increased carbon uptake by a boreal forest under diffuse solar radiation across multiple scales

Neimane‐Šroma, Santa ORCID: https://orcid.org/0000-0002-3207-6048 , Durand, Maxime ORCID: https://orcid.org/0000-0002-8991-3601 , Lintunen, Anna ORCID: https://orcid.org/0000-0002-1077-0784 , Aalto, Juho ORCID: https://orcid.org/0000-0002-5686-1366 and Robson, Matthew ORCID: https://orcid.org/0000-0002-8631-796X (2024) Shedding light on the increased carbon uptake by a boreal forest under diffuse solar radiation across multiple scales. Global Change Biology, 30 (4). e17275.

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Abstract

Solar radiation is scattered by cloud cover, aerosols and other particles in the atmosphere, all of which are affected by global changes. Furthermore, the diffuse fraction of solar radiation is increased by more frequent forest fires and likewise would be if climate interventions such as stratospheric aerosol injection were adopted. Forest ecosystem studies predict that an increase in diffuse radiation would result in higher productivity, but ecophysiological data are required to identify the processes responsible within the forest canopy. In our study, the response of a boreal forest to direct, diffuse and heterogeneous solar radiation conditions was examined during the daytime in the growing season to determine how carbon uptake is affected by radiation conditions at different scales. A 10‐year data set of ecosystem, shoot and forest floor vegetation carbon and water‐flux data was examined. Ecosystem‐level carbon assimilation was higher under diffuse radiation conditions in comparison with direct radiation conditions at equivalent total photosynthetically active radiation (PAR). This was driven by both an increase in shoot and forest floor vegetation photosynthetic rate. Most notably, ecosystem‐scale productivity was strongly related to the absolute amount of diffuse PAR, since it integrates both changes in total PAR and diffuse fraction. This finding provides a gateway to explore the processes by which absolute diffuse PAR enhances productivity, and the long‐term persistence of this effect under scenarios of higher global diffuse radiation.

Item Type:	Article
Journal / Publication Title:	Global Change Biology
Publisher:	Wiley
ISSN:	1365-2486
Departments:	Institute of Science and Environment > Forestry and Conservation
Additional Information:	This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Depositing User:	Insight Administrator
SWORD Depositor:	Insight Administrator
Date Deposited:	17 Apr 2024 20:09
Last Modified:	17 Apr 2024 20:15
URI:	https://insight.cumbria.ac.uk/id/eprint/7646

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