Human activities, directly and indirectly, impact ecological engineering
activities of subterranean rodents. As engineering activities of burrowing
rodents are affected by, and reciprocally affect vegetation cover via
feeding, burrowing and mound building, human influence such as settlements
and livestock grazing, could have cascading effects on biodiversity and
ecosystem processes such as bioturbation. However, there is limited
understanding of the relationship between human activities and burrowing
rodents. The aim of this study was therefore to understand how human
activities influence the ecological engineering activity of the giant
root-rat (Tachyoryctes macrocephalus), a subterranean rodent species
endemic to the Afroalpine ecosystem of the Bale Mountains of Ethiopia. We
collected data on human impact, burrowing activity and vegetation during
February and March of 2021. Using path analysis, we tested (1) direct
effects of human settlement on the patterns of livestock grazing
intensity, (2) direct and indirect impacts of humans and livestock grazing
intensity on the root-rat burrow density, and (3) whether human settlement
and livestock grazing influence the effects of giant root-rat burrow
density on vegetation and vice versa. We found lower levels of livestock
grazing intensity further from human settlement than in its proximity. We
also found a significantly increased giant root-rat burrow density with
increasing livestock grazing intensity. Seasonal settlement and livestock
grazing intensity had an indirect negative and positive effect on giant
root-rat burrow density, respectively, both via vegetation cover.
Analysing the reciprocal effects of giant root-rat on vegetation, we found
a significantly decreased vegetation cover with increasing density of
giant root-rat burrows, and indirectly with increasing livestock grazing
intensity via giant root-rat burrow density. Our results demonstrate that
giant root-rats play a synanthropic engineering role that affects
vegetation structure and ecosystem processes. This file contains data collected at 216 sample plots established
along 36, 1.5km long transects in the Bale Mountains of Ethiopia. Users
are free to reuse for scientific purposes. File name: GRRData.csv
All variables used in the analysis stored in the file are defined
as follows:
site: 6 sites where data were
collected
transect: 36 transects where plots were
established
plot: sample plots
settype: settlement type
(permanent vs seasonal)
distance: distance of a sample plot from
a settlement area
dung: number of livestock dung counted within
25 x 25m plot
freshholes: number of giant root-rat fresh burrows
counted within 25x25m plot
S: plant species richness recorded
within a plot
vegcvrall: vegetation cover within a plot