Data from: The potential importance of unburned islands as refugia for the persistence of wildlife species in fire-prone ecosystems
Steenvoorden, Jasper et al. (2019), Data from: The potential importance of unburned islands as refugia for the persistence of wildlife species in fire-prone ecosystems, Dryad, Dataset, https://doi.org/10.5061/dryad.30jh437
The persistence of wildlife species in fire-prone ecosystems is under increasing pressure from global change, including alterations in fire regimes caused by climate change. However, unburned islands might act to mitigate negative effects of fire on wildlife populations by providing habitat in which species can survive and recolonize burned areas. Nevertheless, the characteristics of unburned islands and their role as potential refugia for the post-fire population dynamics of wildlife species remain poorly understood. We used a newly developed unburned island database of the north-western United States from 1984–2014 to assess the post-fire response of the greater sage-grouse (Centrocercus urophasianus), a large gallinaceous bird inhabiting the sagebrush ecosystems of North America, in which wildfires are common. Specifically, we tested whether pre- and post-fire male attendance trends at mating locations (leks) differed between burned and unburned areas, and to what extent post-fire habitat composition at multiple scales could explain such trends. Using time-series of male counts at leks together with spatially-explicit fire history information, we modelled whether male attendance was negatively affected by fire events. Results revealed that burned leks often exhibit sustained decline in male attendance, whereas leks within unburned islands or >1.5 km away from fire perimeters tend to show stable or increasing trends. Analyses of post-fire habitat composition further revealed that sagebrush vegetation height within 0.8 km around leks, as well elevation within 0.8km, 6.4km, and 18 km around leks, had a positive effect on male attendance trends. Moreover, the proportion of the landscape with cheatgrass (Bromus tectorum) cover >8% had negative effects on male attendance trends within 0.8 km, 6.4 km, and 18 km of leks, respectively. Our results indicate that maintaining areas of unburned vegetation within and outside fire perimeters may be crucial for sustaining sage-grouse populations following wildfire, and requires more attention in wildlife management.