The activity of a subterranean small mammal alters Afroalpine vegetation patterns and is positively affected by livestock grazing

Subterranean rodents can act as ecosystem engineers by shaping the landscape due to soil perturbation and herbivory. At the same time, their burrow density is affected by environmental conditions, vegetation and anthropogenic factors. Disentangling this complex interplay between subterranean rodents and their environment remains challenging. In our study, we analysed the interplay of abiotic conditions, vegetation patterns and human land-use and the burrow density of the giant root-rat (GRR; Tachyoryctes macrocephalus), a subterranean rodent endemic to the Afroalpine ecosystem of the Bale Mountains in south-east Ethiopia. Specifically, we examined the effects of GRR on plant species richness and vegetation cover and vice-versa, and how these reciprocal effects might be modulated by temperature, habitat wetness and grazing. Our results showed that increasing GRR burrow density led to decreased vegetation cover, and that effects of GRR on vegetation cover were slightly stronger than vice -versa. Considering the reciprocal causation models, we found that increasing plant species richness led to increased GRR burrow density, while GRR burrow density decreased as vegetation cover increased. Increases in habitat wetness and livestock grazing intensity also directly led to increased GRR burrow density. Our results stress the importance of subterranean ecosys-tem engineers on vegetation and highlight the vulnerability of these complex interactions to human activity.(c) 2022 The Author(s). Published by Elsevier GmbH on behalf of Gesellschaft fur Okologie. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Automated summary

Subterranean rodents can shape the landscape through soil perturbation and herbivory, and their burrow density is influenced by environmental conditions, vegetation, and human land-use. This study examined the interplay between the giant root-rat and its environment in the Bale Mountains of Ethiopia. The results showed that increasing burrow density of the giant root-rat led to decreased vegetation cover, while increasing plant species richness also influenced the burrow density.