The crucial role of blue light as a driver of litter photodegradation in terrestrial ecosystems

Wang, Qing-Wei, Pieristè, Marta, Kotilainen, Titta K., Forey, Estelle, Chauvat, Matthieu, Kurokawa, Hiroko, Robson, Matthew ORCID logo ORCID: and Jones, Alan G. (2023) The crucial role of blue light as a driver of litter photodegradation in terrestrial ecosystems. Plant and Soil, 488 (1-2). pp. 23-38.

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Background and aim: Wherever sunlight reaches litter, there is potential for photodegradation to contribute to decomposition. Although recent studies have weighed the contribution of short wavelength visible and ultraviolet (UV) radiation as drivers of photodegradation, the relative importance of each spectral region across biomes and plant communities remains uncertain.

Methods: We performed a systematic meta-analysis of studies that assessed photodegradation through spectrally selective attenuation of solar radiation, by synthesizing 30 published studies using field incubations of leaf litter from 110 plant species under ambient sunlight.

Results: Globally, the full spectrum of sunlight significantly increased litter mass loss by 15.3% ± 1% across all studies compared to darkness. Blue light alone was responsible for most of this increase in mass loss (13.8% ± 1%), whereas neither UV radiation nor its individual constituents UV-B and UV-A radiation had significant effects at the global scale, being only important in specific environments. These waveband-dependent effects were modulated by climate and ecosystem type. Among initial litter traits, carbon content, lignin content, lignin to nitrogen ratio and SLA positively correlated with the rate of photodegradation. Global coverage of biomes and spectral regions was uneven across the meta-analysis potentially biasing the results, but also indicating where research in lacking.

Conclusions: Across studies attenuating spectral regions of sunlight, our meta-analysis confirms that photodegradation is a significant driver of decomposition, but this effect is highly dependent on the spectral region considered. Blue light was the predominant driver of photodegradation across biomes rather than UV radiation.

Item Type: Article
Journal / Publication Title: Plant and Soil
Publisher: Springer
ISSN: 0032-079X
Departments: Institute of Science and Environment > Forestry and Conservation
Additional Information: T. Matthew Robson, National Forestry School, University of Cumbria, Ambleside, UK. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made.
Depositing User: Anna Lupton
Date Deposited: 02 Aug 2022 07:43
Last Modified: 13 Jan 2024 15:15


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