Fueling the discussion: are fire-fuel clearings impacting mammal activity at Jasper Ridge Biological Preserve, California, USA

Vegetation is crucial for mammals by providing food, shelter, and predator protection. However, increasing wildfire frequency in California has promoted fire-fuel clearings that aim to reduce flammable vegetation and fire risks. These practices may inadvertently diminish habitat quality and foraging opportunities for mammals, especially mid-sized species. This study assesses the effects of fire-fuel clearings on vegetation condition and mammal activity in Jasper Ridge Biological Preserve ('Ootchamin 'Ooyakma) (JRBP) in San Mateo County, California, using ten years of satellite-derived NDVI and camera trap records. We calculated NDVI from Landsat 8 imagery to track vegetation condition (viz., greenness and canopy density) in areas around JRBP with varying fire-fuel clearing practices and analyzed camera trap data for ten mid-sized and large mammal species to evaluate activity patterns. NDVI trends revealed spatial and temporal fluctuations in vegetation conditions, particularly after major wildfires. Areas surrounding JRBP with more fire-fuel clearing exhibited lower NDVI values. We observed non-significant correlations between vegetation condition and mammal activity at JRBP. However, two opportunistic species—Mephitis mephitis and Didelphis virginiana—showed strong interspecific activity associations, consistent with co-occurrence or commensalism, suggesting interactions beyond vegetation change. We uncovered that while fire-fuel clearings impact vegetation structure and underpin fire prevention, their immediate effect on mammal activity at JRBP is limited within the study’s timeframe. Our findings underscore the need for multi-scalar ecological monitoring to assess their overall impact on mammals in suburban preserves and to inform fire management strategies that balance wildfire mitigation with biodiversity conservation.