Study area
The Koksoy river valley is located in Eastern Pamir in Tajikistan
(39°19’15”N 73°13’32”E) at altitudes between 4100 and 4400 m a.s.l. The
valley is ca. 16 km long and up to 1.5 km wide (Fig. 1A) and oriented
west-northwest, with the river flowing along the southern slope. Monthly
averaged air temperatures in the valley are between
-20oC in January and 5oC in July and
August (Kabala et al., 2021). The mean annual precipitation (MAP) in the
nearest meteorological station close to Lake Karakul is ca. 80 mm
(Mischke et al., 2010). Previous research showed that soil development
and plant succession in this area are extremely slow, and organic soil
carbon pools are among the lowest reported in glacier forelands (Kabala
et al., 2021). Marmot burrows are concentrated in two locations: (1) on
the highest out of three river terraces, which has an area of about 1
km2, and on an old alluvial fen adjacent to the
terrace. Burrows are located mainly along the northern edge of the
floodplain between 1 and 3 km from the glacier’s front (the high
cluster, see Fig. 1A) (2) along the northern slope of the valley, at a
length of about 2.6 km, approximately in the middle of the valley,
between 6 and 8.4 km from the glacier terminus. Burrows are located on
flat ground on the lowest river terrace, and on the slope of the valley
(the low cluster, see Fig. 1A). The soil in both locations is very
poorly developed, but there are some differences in the upper layer
(0-10 cm), caused by different ages of the river terraces. The soil on
the highest, oldest terrace has a lower skeleton content and a higher
silt, sand and clay content. It also has a higher total N and P (in
Mehlich-3 extract) content than the soil on the lowest terrace.
Vegetation in the valley is sparse. In the area of the high cluster,
cushion plants and perennial forbs dominate, and the average vegetation
cover is 41.2%. Dwarf shrubs, mainly Krascheninnikovia
ceratoides and cushion plants dominate in the area of the low cluster,
and the average vegetation cover is 21.4% (Kabala et al., 2021). The
long-tailed marmot is a burrow-dwelling rodent that inhabits a large
part of Central Asia. It is a large rodent, typically between 1.5 and
7.3 kg heavy, and is known to occupy a wider range of habitats than
related marmot species, occurring from 600 to 5200 m a.s.l and being
relatively tolerant of aridity (Krystufek & Vohralik, 2013).
Long-tailed marmots consume mainly plants, foraging closely to their
burrows. They hibernate from September to April – May (Blumstein &
Arnold, 1998).