Engineering by Cape ground squirrels affects biodiversity in semi-arid grasslands
Loading...
Date
Authors
Ewacha, Michelle V.A.
Roth, James D.
Waterman, Jane M.
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Abstract
Burrowing mammals that disproportionately affect their physical environment, creating habitat and providing resources for other organisms, are considered ecosystem engineers. Such modifications are particularly important in dry grassland environments, where low precipitation and soil nutrients limit plant growth. We tested 5 hypotheses about the impact of Cape ground squirrels (Xerus inauris) on plants and animals in a semi-arid grassland of South Africa. At each burrow cluster and paired control site without burrows, we estimated plant cover, height, and richness using quadrats, and invertebrate and small mammal abundance and richness using pit-fall traps and mark-recapture, respectively. We determined nitrogen concentrations in grasses on and off burrows and measured carbon and nitrogen stable isotopes in plants and squirrel hair to determine squirrel diet. Burrows had greater plant cover and richness, particularly more shrubby vegetation, but plant height and nitrogen concentrations did not differ on and off burrows. Invertebrate and small mammal abundance and richness were greater on burrows. Squirrel disturbances in semi-arid grassland improved conditions for disturbance-dependent shrubs, which were rarely consumed by squirrels but are valuable forage for antelope and provide cover for invertebrates and small mammals. By altering habitat for plants reliant on disturbance, Cape ground squirrels enhance grassland biodiversity.
Description
Keywords
Cape ground squirrel (Xerus inauris), Semi-arid ecosystems, Ecosystem engineer, Semi-fossorial rodents, South Africa (SA), SDG-15: Life on land
Sustainable Development Goals
Citation
Ewacha, M.V.A., Roth, J.D. & Waterman, J.M. 2022, 'Engineering by Cape ground squirrels affects biodiversity in semi-arid grasslands', Journal of Arid Environments
vol. 207, art. 104850, pp. 1-8, doi : 10.1016/j.jaridenv.2022.104850.