Effects of Siberian Marmot Density in an Anthropogenic Eco-System on Habitat Vegetation Modification

Burrowing mammals function as ecosystem engineers by creating spatial heterogeneity in soil structure and vegetation composition, thereby providing microhabitats for a wide range of organisms. These keystone species play a crucial role in maintaining lo-cal ecosystem functions and delivering ecosystem services. However, in Mongolia, where overgrazing has accelerated due to the expansion of a market-based economy, scientific knowledge remains limited regarding the impacts of human activities on such species. In this study, we focused on the Siberian marmot (Marmota sibirica), an ecosystem en-gineer inhabiting typical Mongolian steppe ecosystems. We assessed the relationship between the spatial distribution of marmot burrows and vegetation conditions both inside and outside Hustai National Park. Burrow locations were recorded in the field, and the Normalized Difference Vegetation Index (NDVI) was calculated using Planet Dove satellite imagery (3 m spatial resolution). Through a combination of remote sensing analyses and vegetation surveys, we examined how the presence or absence of anthropogenic disturbance (i.e., livestock grazing) affects the ecological functions of marmots. Our results showed that the distance between active burrows was significantly shorter inside the park (t = –2.68, p = 0.0087), indicating a higher population density. Further-more, a statistical approach using beta regression revealed a significant interaction between burrow type (active, non-active, off-colony area) and region (inside vs. out-side the park) on NDVI (e.g., outside × non-active: z = –5.229, p < 0.001). Notably, in areas with high grazing pressure outside the park, the variance in NDVI differed sig-nificantly depending on the presence or absence of burrows (e.g., July 2023, active vs. off-colony area: F = 133.46, p < 0.001). Combined with vegetation structure data from field surveys, our findings suggest that marmot burrowing activity may contribute to the enhancement of vegetation quality and spatial heterogeneity. These results indicate that the Siberian marmot remains an important component in supporting the diversity and stability of steppe ecosystems, even under intensive grazing pressure. The conservation of this species may thus provide a promising strat-egy for utilizing native ecosystem engineers in sustainable land-use management.