Fig. 1. The study area in the North-Western part of the Koksoy river
valley. A: Overview of the study area, location of burrows, search area
and sampling sites. B: Part of the aerial image with the location of the
analysed burrows. The green channel is enhanced, so vegetation is
visible. Note, that this is not an exact visualisation of plant
occurrence, as it was not manually corrected and can be biased by
varying lighting conditions in different parts of the image. C: Example
of sampling spots of plant biomass around a burrow with 20 m buffer. D:
Group of 20 m buffers around burrows and the type of relationship
between the distance from the closest burrow entrance and the plant
cover (see Fig. 3). The aerial image is edited like in C. E: Location of
the study area in Tajikistan.
Fig. 2. The distribution of parameters within burrows: a) Mean distance
from the closest burrow entrance of vegetation hexagons and bare soil
hexagons. For clarity, SD is only shown for vegetation hexagons (error
bars) b) Total plant cover in buffers c) Adjusted R2of the linear binomial model of the relationship between the distance
from the closest burrow entrance and plant cover. The number of burrows
is smaller than in other parameters, as models were only done for
burrows with total plant cover above 2%. d) The number of types of
relationship between the distance from the closest burrow entrance and
plant cover, based on the shape of the trend line. For plots a-c, the
values are sorted from smallest to largest. Colours indicate the type of
relationship between the distance from the closest burrow entrance and
plant cover (see Fig. 3)
Fig. 3. Examples of trend lines between the distance from the closest
burrow entrance and plant cover based on binomial linear models,
assigned to different types of relationship.
Fig. 4. The relationship between the distance from the burrow entrance
and parameters of plant samples. Only pairs with significant
relationship are shown. Plant species and Spearman’s rho are given. The
dashed lines in the N:P plot indicate values 14, below which N
limitation can be assumed and 16, above which P limitation can be
assumed. See discussion for details on the constraints of this
inference.
Fig. 5. Stable nitrogen isotope ratios of plants and marmot faeces
collected on each burrow. Asterisks indicate significant differences
between δ15N values of faeces and plant species
sampled from one burrow, based on the Wilcoxon test (p<0.05).
The colour of the asterisk indicates the plant species.
Appendix 1. Comparison of nutrient content and stable isotope ratios
between the low and high cluster within plant species that were sampled
in both clusters. Pairs that are bold differ significantly
(p<0.05). TS – test statistic value, t for t -test, W
for Wilcoxon test. * - Welch’s t -test for unequal variances