Abstract
AbstractAimLarge and ecologically functioning steppe complexes have been lost historically across the globe, but recent land‐use changes may allow the reversal of this trend in some regions. We aimed to develop and map indicators of changing human influence using satellite imagery and historical maps, and to use these indicators to identify areas for broad‐scale steppe rewilding.LocationEurasian steppes of Kazakhstan.MethodsWe mapped decreasing human influence indicated by cropland abandonment, declining grazing pressure and rural outmigration in the steppes of northern Kazakhstan. We did this by processing ~5,500 Landsat scenes to map changes in cropland between 1990 and 2015, and by digitizing Soviet topographic maps and examining recent high‐resolution satellite imagery to assess the degree of abandonment of >2,000 settlements and >1,300 livestock stations. We combined this information into ahuman influence index(HI), mapped changes in HI to highlight where rewilding might take place and assessed how this affected the connectivity of steppe habitat.ResultsAcross our study area, about 6.2 million ha of cropland were abandoned (30.5%), 14% of all settlements were fully and 81% partly abandoned, and 76% of livestock stations were completely dismantled between 1990 and 2015, suggesting substantially decreasing human pressure across vast areas. This resulted in increased connectivity of steppe habitat.Main conclusionsThe steppes of Eurasia are experiencing massively declining human influence, suggesting large‐scale passive rewilding is taking place. Many of these areas are now important for the connectivity of the wider steppe landscape and can provide habitat for endangered megafauna such as the critically endangered saiga antelope. Yet, this window of opportunity may soon close, as recultivation of abandoned cropland is gaining momentum. Our aggregate human influence index captures key components of rewilding and can help to devise strategies for fostering large, connected networks of protected areas in the steppe.
Highlights
Temperate grasslands are among the Earth's most expansive biomes
Focusing on a 38 million ha region of the Eurasian steppe in Kazakhstan, we used a novel approach to map an aggregate measure of changes in human influence, based on changes in cropland extent, grazing pressure and human population density
Our analyses highlight a massive decline in human influence following the collapse of the Soviet Union in 1991, with more than 6 million ha of cropland abandoned
Summary
Temperate grasslands are among the Earth's most expansive biomes. Rich in biodiversity, they provide important ecosystem services such as carbon storage (Dixon, Faber-Langendoen, Josse, Morrison, & Loucks, 2014). This, in turn, may allow the restoration of the ecological integrity of grasslands, with regard to natural disturbance regimes (e.g. fire), increased connectivity of grassland patches and trophic complexity (e.g. large herbivores). Given the current scarcity of natural grasslands in many regions, and the potential multiple benefits of restoring them, identifying places where steppe rewilding could take place is a conservation priority. Both locating candidate areas for grassland rewilding and measuring rewilding progress remain challenging. How has declining human influence affected the connectivity among protected areas in the region?
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call