Wildfire and the ecological niche: Diminishing habitat suitability for an indicator species within semi‐arid ecosystems. (9th September 2020)

• Record Type: Journal Article
• Authors: O'Neil, Shawn T.; Coates, Peter S.; Brussee, Brianne E.; Ricca, Mark A.; Espinosa, Shawn P.; Gardner, Scott C.; Delehanty, David J.
• Is Part Of: Global change biology. Volume 26:Number 11(2020)
• Page Start: 6296
• Page End: 6312
• Publication Date: 2020-09-09
• Subjects: annual grass -- Bromus tectorum -- Centrocercus urophasianus -- ecological trap -- global change -- greater sage‐grouse -- maladaptive habitat selection -- nest survival -- source–sink -- wildfire‐grass cycle; Climatic changes -- Environmental aspects -- Periodicals; Troposphere -- Environmental aspects -- Periodicals; Biodiversity conservation -- Periodicals; Eutrophication -- Periodicals; 551.5
• DOI: 10.1111/gcb.15300
• Languages: English
• ISSNs: 1354-1013

Abstract

Abstract: Globally accelerating frequency and extent of wildfire threatens the persistence of specialist wildlife species through direct loss of habitat and indirect facilitation of exotic invasive species. Habitat specialists may be especially prone to rapidly changing environmental conditions because their ability to adapt lags behind the rate of habitat alteration. As a result, these populations may become increasingly susceptible to ecological traps by returning to suboptimal breeding habitats that were dramatically altered by disturbance. We demonstrate a multistage modeling approach that integrates habitat selection and survival during the key nesting life‐stage of a bird species of high conservation concern, the greater sage‐grouse ( Centrocercus urophasianus ; hereafter, sage‐grouse). We applied these spatially explicit models to a spatiotemporally robust dataset of sage‐grouse nest locations and fates across wildfire‐altered sagebrush ecosystems of the Great Basin ecoregion, western United States. Female sage‐grouse exhibited intricate habitat selection patterns that varied across regional gradients of ecological productivity among sagebrush communities, but often selected nest sites that disproportionately resulted in nest failure. For example, 23% of nests occurred in wildfire‐affected habitats characterized by reduced sagebrush cover and greater composition of invasive annual grasses. We found survival of nests was negatively associated with wildfire‐affected areas, but positively associated with higher elevations with increased ruggedness and overall shrub cover. Strong site fidelity likely drove sage‐grouse to continue nesting in habitats degraded by wildfire. Hence, increasing frequency and extent of wildfire may contribute disproportionately to reduced reproductive success by creating ecological traps that act as population sinks. Identifying such habitat mismatches between selection and survival facilitates deeper understanding of the mechanisms driving reduced geographic niche space and population decline at broad spatiotemporal scales, while guiding management actions to areas that would be most beneficial to the species. Abstract : Wildfire frequency and severity has increased within Great Basin sagebrush ecosystems. Non‐native annual grasses invade burned areas, providing new fuels and promoting additional fire through a positive feedback cycle. Greater sage‐grouse can become "trapped" in the wildfire‐invasive grass feedback loop, due to strong breeding and nest site fidelity to areas where sagebrush cover and subsequent nest success becomes reduced following wildfire. Landscape modeling of nest site selection and nest survival suggests that long‐term losses in sagebrush and permanent transitions to annual grassland facilitate maladaptive breeding habitat selection and ecological niche loss.