Through Collapse to Restoration: The Nonstationary Dynamics of the Rodent Community in a New Cycle of Desertification in Kalmykia

The grazing ecosystems of Kalmykia are extremely dynamic, this being associated with the high variability of grazing pressure in the region: a drastic reduction in the number of livestock in the 1990s led to the restoration of pastures and the transition of their functioning from the “desert” to the “steppe” regime. Since the late 2000s, new desertification processes have been gaining momentum, these being caused by increased grazing pressure and droughts. The vegetation cover of pastures quite quickly began to respond to the increase in livestock numbers by reducing the percentage cover, while the species composition of plants sharply changed to “desert” only a few years later. With increasing desertification, the rodent community first collapsed and then recovered. Apparently, the collapse is a delayed reaction to the steppification of pastures that preceded desertification, this leading to a decline in numbers of desert species and a depauperated community, thereby slowing down its recovery during a new cycle of desertification. Thus, both the vegetation cover and the rodent community demonstrated nonstationary dynamics with changing regimes and a delayed response (inertia) to landscape desertification.