Agricultural abandonment across the Eurasian steppe: effect on fires, vegetation succession and habitat quality for rare waterfowl species

The Eurasian steppe were converted to an agricultural landscape in the middle of the 20th century and then abandoned after the collapse of the Soviet Union in 1991. These rapid changes have numerous consequences such as rewilding of former fields, burned area increase, vegetation succession and changes in habitat structure affecting steppe inhabitants and migratory wildlife. Remote sensing data provide a unique opportunity to study spatiotemporal land cover changes while bird GPS tracking and in-the-field data collection with drones allow to evaluate ecological response to land cover changes.

The overall goal of my proposed research is to study the effects of agricultural abandonment in the Eurasian steppe on fires, vegetation successions, and habitat use by rare migratory geese. Specifically, I will: 1) evaluate fire dynamics since the late Soviet period in unplowed steppes and abandoned fields and identify relationships between fires and land use changes; 2) describe vegetation succession due to fires in unplowed steppe and on abandoned fields; and 3) analyze habitat use by rare waterfowl species, the spatial-temporal variability of their stopover sites, and the role of land cover changes in this variability in order to model bird distributions in the Eurasian steppe during migrations.

I will use my already developed land cover maps to extract the necessary information (unplowed steppe, abandonment, active agriculture and water bodies) for my proposed research. For the first objective I will create annual fire maps using all available Landsat images from 1986 to 2020 complemented by MODIS if necessary. For each year, I will evaluate the amount of fires, their mean areas, and the proportion of burned and unburned areas in steppe and abandonment. Then I will evaluate differences in fire regime between steppe and abandonment, across various ecoregions, and if there is a specific fuel accumulation period on abandoned fields for fires to emerge. For the second objective, I will conduct massive fieldwork in Kazakhstan and collect botanical data in unburned and regularly burned areas. I will assess fire effect on vegetation structure and plant biodiversity and test if there is a positive feedback loop in that fires foster successional pathways in favor of more flammable communities, resulting in even more fires. For the third objective, I selected three model species (Taiga been goose; Red-breasted goose; and Bewick’s Swan) that are species of conservation concern. I will map their migration stopover sites (using birds GPS data), compare them with the land cover maps and estimate what environmental factors are more important for waterfowl habitat selection. Then I will utilize these data to model distribution of these species in the Eurasian steppe during their migrations.

Results of my research will provide new insights into grassland ecology, relationships of different processes (fires, vegetation successions) in open landscapes and waterfowl biology. Practically, the results will be helpful for fire and animal population management, improving protection of rare species and high conservation value landscapes, hunting regulations and creating protected areas. Results will reveal human triggered land cover changes and their environmental consequences, so could serve as a basis for to predicts the effects of climate change or human landscape transformations elsewhere.