Aridity influences the recovery of vegetation and shrubland birds after wildfire

Abstract

Wildfires play a determining role in the composition and structure of many plant and animal communities. On the other hand, climate change is considered to be a major driver of current and future fire regime changes. Despite increases in drought in many areas of the world, the effects of aridity on post-fire colonization by animals have been rarely addressed. This study aims to analyse how a regional aridity gradient affects post-fire recovery of vegetation, bird species richness and the numbers of four early to middle-successional warbler species associated with the shrub cover. The database contains bird relative abundance and environmental variables from 3072 censuses in 695 transects located in 70 recently burnt areas (1 to 11 years after wildfire) in Catalonia (Spain), which were sampled between 2006 and 2013. Generalized linear mixed models (GLMMs) showed that plant cover was affected by time since fire, aridity and forest management. However, only the highest vegetation height layer (>100 cm) recovered slower in arid areas after fire. Time since fire positively influenced bird species richness and the relative abundance of the four focal species. The post-fire recovery of Melodious (Hippolais polyglotta) and Subalpine warblers (Sylvia cantillans) was hampered by aridity. Although this was not demonstrated for Dartford (S. undata) and Sardinian warblers (S. melanocephala), their occurrence was low in the driest areas during the first three years after fire. Overall, this study suggests that future increases in aridity can affect plant regeneration after fire and slow down the recovery of animal populations that depend on understorey and shrublands. Given the recently highlighted increases in aridity and fire frequency in Mediterranean-climate regions, improved knowledge on how aridity affects ecological succession is especially necessary.

Modeling variability in the fire response of an endangered bird to improve fire‐management

“…Elevation and gypsum content did not change across a broad geographic gradient, as changes in other environmental variables often do (e.g., mean annual rainfall; Barry and Elith , Puig‐Gironès et al. , Kenny et al. ).…”

“…Elevation and gypsum content did not change across a broad geographic gradient, as changes in other environmental variables often do (e.g., mean annual rainfall; Barry and Elith 2006, Puig-Giron es et al 2017, Kenny et al 2018). Furthermore, variability in the Mallee Emu-wren fire response was not associated with differences in vegetation type, as other authors have found (Gosper et al 2012, 2013, Janion-Scheepers et al 2016.…”

“…Using a single fire-response curve to determine the time since fire at which to burn to regenerate habitat implicitly assumes that for most areas of habitat, species occurrence declines at a similar time since fire to the mean time-since-fire response across the species' range , Akresh et al 2015. For species with variation in their fire response, using the mean to determine the time since fire at which to burn may create a situation where fire management aiming to promote a species, drives the landscape toward a post-fire vegetation class that is actually detrimental for that species (Pons and Clavero 2010, Pons et al 2012, Puig-Giron es et al 2017, Theimer et al 2018. The negative effects of such planned burning could be catastrophic for endangered species are exacerbated (Guisan et al 2013, Theimer et al 2018.…”

Anthropogenic disturbance and rainfall variation threaten the stability of plant–ant interactions in the Brazilian Caatinga

“…Puig-Gironès et al (2017) reported rainfall effects on the post-fire recovery patterns of plant and bird populations in a Mediterranean region. the effective number of plant species visited by ant species or specialization at the ant level).…”

“…In these areas, it is essential to understand how CAD may harm ecosystem stability, and consequently, compromise the future use of these ecosystem resources by humans. Moreover, aridity may interact with disturbance to intensify ecosystem instability (Pulla et al 2015, Puig-Gironès et al 2017. Consequently, ecosystem stability would be lower in more disturbed areas than in relatively undisturbed areas.…”