Context Agricultural land abandonment across the steppe belt of Eurasia has provided an opportunity for the restoration of steppe landscapes in recent decades. However, global food demands are about to revert this trajectory and put restored steppe landscapes at risk. Objectives We analysed steppe development in southern Russia in the last 40 years, assessed its spatial patterns and drivers of change for several periods. Methods Using Landsat imagery, we mapped the permanent steppe and steppe restoration from 1990 to 2018. Based on regression tree models, we evaluate and explain its dynamics. Results were compared with district-level trends in land-use intensities of cropland. Results We found 70% of the steppe in 2018 represented permanent steppe and 30% of former cropland dominantly abandoned in the postsocialism (1990–2000). The permanent steppe and steppe restored in the postsocialism (1990–2000) were located far from settlements, on rough terrain and in districts of the Virgin Land Campaign (1954–1963). In recent decades, the patterns of steppe restoration (2000–2018) were mostly determined by unfavourable agroclimatic conditions and distance from grain storage facilities. The restoration pattern reflects regional differences in land-use intensities, e.g., isolated steppe patches mostly appeared in areas of intensive agricultural land-use. Conclusions Steppe restoration has appeared in areas marginal for agricultural production, with poor natural conditions and little human footprint. Consequently, the permanent steppe became less fragmented and a more continuous steppe landscape resulted. The remaining isolated steppe patches require attention in restoration programs as they are mostly located in areas of intensive agricultural land-use.

Over the 20th century, the Eurasian steppes underwent drastic land-cover changes.Much progress was made studying cropland expansion and the post-1990 (i.e., post-Soviet) agricultural land abandonment in Eurasia. However, the alteration of steppe landscapes may include other disturbances, such as oil and gas development, formal and informal roads and garbage dumps, which were not systematically documented.Considering the example of the steppe Orenburg Province in Russia, we reconstructed agricultural land-cover change dynamics using Landsat and Sentinel-2 imagery from 1990 to 2018. Furthermore, we used very high-resolution imagery and assessed the patterns and determinants of other steppe landscape anthropogenic disturbances. Our study showed that, despite steppe recovery due to widespread cropland abandonment from 1990 to 2018, the steppes, including the recovered steppe patches, underwent fragmentation due to informal roads, oil and gas development, shrub encroachment, garbage dumps and quarries, as well as abandonment of settlements and buildings. Only 6.4% of the sampled 7859 1Â1 km blocks in 2018 showing grassland extent had no documented disturbances. The mapped disturbances occurred primarily near settlements and roads, while some disturbances occurred in remote areas. Given the accessibility of steppes, our study calls for a urgent need to systematically document alternatives to agricultural land uses in the steppes of Eurasia and other parts of the global grassland biome.

Modern climatic resources of model regions (Orenburg oblast and Altai Krai) were identified and their agricultural assessment was made to explain scientifically development and implementation of approaches of rational environmental management to agricultural use of farming lands in the post-virgin land regions of Ural and West Siberia. Open access special data on climatic research have served as a source of meteorological information. Commonly accepted methods of the statistical analysis were used to process digital content. It was ascertained that under a total aridity within the studied regions their modern climatic resources had a line of special features. Altai Krai is characterized by more favorable conditions for spring crops vegetation due to predominant precipitation during the summer months and less favorable conditions for winter crops, especially against the background of cooling during the winter months. In Orenburg oblast, increasing aridity of the summer months may prevent complete actualization of productive potential of spring crops and formation of full-grown shoots of winter crops. Introduction of nature-similar technologies in landscape-adaptive systems of agriculture was considered as the principal way to use effectively climatic resources.

For the development of fundamental bases of strategy of rational steppe land use and its realization we analyzed the most significant steppe megaprojects - "Stalin's plan to transform the nature of forest steppe and steppe", the Virgin Lands Campaign of 1954-1963, Agrarian Reform of the 1990s. Both specific consequences of each project and their cumulative impact determining the modern appearance of steppe landscapes and their agro-ecological problems are established. The Altai Territory, primarily the Kulunda steppe, is considered a special arena of megaprojects in the steppes of Siberia, bearing all the features of the old-developed region, where the most positive effect of these projects was achieved. The interrelation between the main problems of modern steppe land use and the results of the considered megaprojects has been presented. The main problems of agrarian steppe land use have been revealed. Taking into account modern tendencies of development of agrarian and industrial complex three most probable scenarios of development of steppe agriculture landscapes are considered. They are neo-wildland, stagnation, and optimization scenario with adaptation of agricultural lands structure to natural-climatic conditions and requirements of market conditions, with concentration of intensive agriculture on the best lands and transformation of low-productive lands into long-term managed steppe fodder lands of adaptive animal husbandry.