<p>Wildfires strongly shape savanna ecosystems through vegetation restructuring, nutrient recycling and abiotic change. Post-fire habitat conditions can progressively redistribute wildlife, with differential responses between functional groups and across vegetation successional stages. Using camera traps and environmental data loggers, we monitored a large landscape (650km<sup>2</sup>) affected by a wildfire in a tree-and-shrub savanna of eastern Namibia to quantify early-phase responses of medium- to large-size mammals across burned areas, adjacent proximal zones and unburned controls. We applied a multi-season, multi-species occupancy model to six months of camera-trap data spanning one month pre-fire and five months post-fire to assess community- and functional group–level dynamics of 31 species. Burned areas experienced higher temperatures, lower humidity, and reduced vegetation growth following the wildfire. Community-level mammal occupancy declined progressively in burned areas (from 0.53 to 0.33), while remaining nearly stable in control areas (from 0.45 to 0.43) and showing small declines in proximal zones (from 0.58 to 0.52). Functional group responses differed in intensity: small carnivores and burrow-associated species showed the strongest fire-driven declines, followed by large carnivores, browsers, and grazers. Proximal areas did not function as refugia and instead showed slight occupancy declines relative to controls, indicating that fire impacts extended beyond the burned perimeter. Our findings demonstrate that drastic habitat change in the first months after a wildfire drives landscape-scale redistribution of savanna mammals, with the strongest effects on small-bodied and specialist species. These results underscore the importance of maintaining large, well-connected habitats to allow adequate space and time for recovery between fire events.</p>

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Early post-fire declines of mammals in a tree-and-shrub savanna

  • Stijn Verschueren,
  • Maria Laura Ruozzi,
  • Laurie Marker,
  • Herwig Leirs,
  • Bogdan Cristescu

摘要

Wildfires strongly shape savanna ecosystems through vegetation restructuring, nutrient recycling and abiotic change. Post-fire habitat conditions can progressively redistribute wildlife, with differential responses between functional groups and across vegetation successional stages. Using camera traps and environmental data loggers, we monitored a large landscape (650km2) affected by a wildfire in a tree-and-shrub savanna of eastern Namibia to quantify early-phase responses of medium- to large-size mammals across burned areas, adjacent proximal zones and unburned controls. We applied a multi-season, multi-species occupancy model to six months of camera-trap data spanning one month pre-fire and five months post-fire to assess community- and functional group–level dynamics of 31 species. Burned areas experienced higher temperatures, lower humidity, and reduced vegetation growth following the wildfire. Community-level mammal occupancy declined progressively in burned areas (from 0.53 to 0.33), while remaining nearly stable in control areas (from 0.45 to 0.43) and showing small declines in proximal zones (from 0.58 to 0.52). Functional group responses differed in intensity: small carnivores and burrow-associated species showed the strongest fire-driven declines, followed by large carnivores, browsers, and grazers. Proximal areas did not function as refugia and instead showed slight occupancy declines relative to controls, indicating that fire impacts extended beyond the burned perimeter. Our findings demonstrate that drastic habitat change in the first months after a wildfire drives landscape-scale redistribution of savanna mammals, with the strongest effects on small-bodied and specialist species. These results underscore the importance of maintaining large, well-connected habitats to allow adequate space and time for recovery between fire events.