Wigley, BJ, Augustine, DJ, Coetsee, C et al. (2 more authors) (2020) Grasses continue to trump trees at soil carbon sequestration following herbivore exclusion in a semiarid African savanna. Ecology, 101 (5). e03008. ISSN 0012-9658
Abstract
Although studies have shown that mammalian herbivores often limit aboveground carbon storage in savannas, their effects on belowground soil carbon storage remain unclear. Using three sets of long‐term, large herbivore exclosures with paired controls, we asked how almost two decades of herbivore removal from a semiarid savanna in Laikipia, Kenya affected aboveground (woody and grass) and belowground soil carbon sequestration, and determined the major source (C3 vs. C4) of belowground carbon sequestered in soils with and without herbivores present. Large herbivore exclusion, which included a diverse community of grazers, browsers, and mixed‐feeding ungulates, resulted in significant increases in grass cover (~22%), woody basal area (~8 m2/ha), and woody canopy cover (31%), translating to a ~8.5 t/ha increase in aboveground carbon over two decades. Herbivore exclusion also led to a 54% increase (20.5 t/ha) in total soil carbon to 30‐cm depth, with ~71% of this derived from C4 grasses (vs. ~76% with herbivores present) despite substantial increases in woody cover. We attribute this continued high contribution of C4 grasses to soil C sequestration to the reduced offtake of grass biomass with herbivore exclusion together with the facilitative influence of open sparse woody canopies (e.g., Acacia spp.) on grass cover and productivity in this semiarid system.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2020 by the Ecological Society of America. This is an author produced version of an article published in Ecology. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | aboveground biomass; browsers; C13 isotopes; grazers; herbivore exclosures; isotopic mixing models |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Biological Sciences (Leeds) > School of Biology (Leeds) |
Funding Information: | Funder Grant number NERC (Natural Environment Research Council) NE/E017436/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 27 Feb 2020 16:31 |
Last Modified: | 05 Jan 2021 09:49 |
Status: | Published |
Publisher: | Ecological Society of America |
Identification Number: | 10.1002/ecy.3008 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:157740 |