On Thursday, October 16 @ 11am ET, join Cary Institute for a virtual scientific seminar by Dr. Ginger Allington, Cornell University. Mongolian grasslands are crucial for ecosystem services and pastoral livelihoods, but recent studies have found conflicting trends in vegetation that may be scale-dependent. Satellite-based studies indicate regional vegetation growth, but there have also been reports of localized vegetation decline. These discrepancies raise important questions about the underlying drivers of change and how human land-use practices interact with ecological processes.
In this study, we combine multi-year vegetation mapping with household survey data to explore grassland dynamics across the central Mongolian steppe. We developed a cross-scale modeling framework that integrates UAV imagery and Sentinel-2 data to produce annual maps of vegetation volume from 2019 to 2024.
While regional averages suggest a general increase in vegetation over time, local and regional spatial statistics reveal persistent hotspots of vegetation decline, indicating localized degradation. To further investigate the structure of degradation hotspots, we track temporal shifts in the size and fragmentation of vegetation condition. Household surveys conducted in 2023 (188 households) revealed that ~60% of respondents perceived moderate to severe pasture degradation within their region, corroborating our vegetation models.
Beyond perceptions of degradation, we find evidence of declining mobility and reduction in pasture reserves. Perhaps most startlingly, we document increasing interest in fencing of pastures; a practice that was historically rare in Mongolia. These practices may lead to increased grazing pressure on nearby and repeatedly used areas and lead to degradation hotspots. Together, these findings offer new insights into the scale-dependent shifts in vegetation patterns and highlight how pastoral communities both respond to and influence these changes.
Free and open to all. Registration required via Eventbrite.
