Abstract
Badgers
(Meles meles) inhabiting Central European forests may be a leading
factor driving changes in plant species community and diversity. The
digging activity of badgers may shape plant species communities in
important ways, especially in managed forests where natural events on
the forest floor (e.g. soil disturbance due to tree uprooting) are
largely eliminated by silviculture. We tested the following hypotheses
in our study: that badger burrows act as focal sites which allow many
bryophyte species to occur and complete their reproductive cycle; that
the effect of burrows as focal sites of bryophyte diversity is more
pronounced in mesotrophic forests than in fertile forests; and that the
bryophyte communities of badger burrows differ quantitatively and
qualitatively from those of their near vicinity. The study was done in
2013 in the Kampinos Forest, one of the largest (ca. 385 km2) lowland
forest complexes in central Poland. We distinguished two types of
research sites: badger burrows (main setts) and paired reference plots.
The pairs of plots were divided into two groups depending on habitat
fertility (C/N ratio): lower-fertility plots (N = 20) and
higher-fertility plots (N = 20). All data were collected from circular
plots (5.64 m radius); the burrow plots were centered on the badger
burrows and were paired with same-size reference plots. We recorded 55
bryophyte species in the survey, 26 of them exclusively on burrows. The
beta diversity of the bryophyte assemblages, expressed as total
dissimilarity, turnover and nestedness, was similar for the burrows and
the reference plots. The mean number of bryophyte species and their
Shannon H' diversity index were significantly higher for burrow plots
than for undisturbed reference plots. Neither the number of species nor
the species diversity of bryophytes were affected by the interaction of
habitat fertility. We observed no relation between the profile of
bryophyte groups on the burrows and specific substrate, acidity or life
history. Only epiphytic bryophytes were overrepresented in burrow plots.
The spatial scale and range of disturbance caused by badger digging
suggest that badger setts contribute to the diversity of bryophyte
species in managed and protected forests in Central Europe. The
burrowing activity of badgers seems to be an important factor boosting
the diversity of bryophyte species in managed forests, especially where
natural topsoil disturbances are limited by silviculture practices. In
forest ecosystems, badger activity creates a patch distribution of
microhabitats for vascular plants - and also for bryophytes, as shown
here.
