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).