In the summer of 2012, two wildfires affected Mediterranean ecosystems in the eastern Iberian Peninsula, the Andilla fire and the Cortes fire [1]. The size of these fires (> 20,000 ha each) was at the extreme of the historical variability (megafires sensus [2]). In 2013, we set up 12 plots per fire, covering burned vegetation at different distances from the fire perimeter and unburned vegetation. In each plot, we followed the postfire recovery of arthropods, reptiles (including their ectoparasites), and plants for 2 to 5 years. Here we present the resulting database (POSTDIV) of taxon occurrence and abundance in the burned and unburned areas [3]. Currently, POSTDIV totals 19,906 records for 457 arthropod taxa (113,681 individuals), 12 reptile taxa (503 individuals), 4 reptile parasites (234 individuals), and 518 plant taxa (cover-abundance). We provide examples in the R language to query the database.
The two wildfires occurred simultaneously in Valencia during the 2012 summer (photo: 30 Junio 2012).
POSTDIV database structure. The database is composed of six data tables (blue boxes). For more details, see [3].
In 2021 we described that some lizards can detect wildfires by smelling the smoke, and in this way they can react quickly, e.g., by moving to a safe place [1]. Specifically we performed that study with the mediterranean lizard Psammodromus algirus, from eastern Spain. In a recent paper, we suggest that some lizards are able to recognise wildfires by their sound! [2]. This study was performed with another mediterranean lizard, Sceloporus occidentalis (western fence lizard), from southern California.
Western fence lizard (Sceloporus occidentalis), from southern California.. Photo: L. Álvarez-Ruiz
References
[1] Álvarez-Ruiz L, Belliure J, Pausas JG. 2021. Fire-driven behavioral response to smoke in a Mediterranean lizard. Behavioral Ecology 32: 662–667. [doi | oup | data:dryad | pdf] – blog
[2] Álvarez-Ruiz L, Pausas JG, Blumstein DT, Putmanb BJ. 2023. Lizards’ response to the sound of fire is modified by fire history. Animal Behaviour 196: 91–102. [doi | sciencedirect | pdf]
Early humans and native cultures have used fire for clearing the ground from parasites and diseases, and some agricultural societies use fire to reduce livestock diseases [1,2]. In such cases, fire provide an ecosystem service to humans [2]. We recently asked to what extent this ‘cleaning effect‘ of fire is also observed in the wild, that is, whether wildfires may remove parasites and thus provide some benefits to wildlife [3]. To answer this question, we compared the presence of ecotoparasites (mites,Ophionyssus) in lizard populations of Psammodromus algirus living in recently burned areas with those in adjacent unburned areas, in eastern Spain. Our results suggest that many individuals of P. algirus survive fire (the smoke of the fire acts as a cue for quickly moving to safe microsites [4], e.g., crevices, under rocks, among roots; refugia [5]); and those that survived (and live in the postfire environment) have less ecotparasites (mites) than those living in unburned conditions. That is wildfires produce a ‘cleaning effect’ by reducing lizard ectoparasites in the postfire conditions. Fire, by disrupting the host-parasite interaction, provides a window of opportunity for lizards to avoid the negative effects of ectoparasites. We propose that wildfires likely fulfill a role in controlling vector-borne diseases and pathogens for other species, but this ecological effects have been largely overlooked.
Fig. 1. Probability of lizards infection by mites in relation to lizards’ size (snout-vent length) for recently burned areas (red) and for the corresponding paired unburned (blue). Lines are predicted values (and confidence intervals) from [3].
Fig. 2. Psammodromus algirus enjoying a clean (parasite-free) environment after a fire. Photo: Lola Álvarez-Ruiz
Fig. 3. Pictures of mites (genus Ophionyssus; in different stages) found under the scales of P. algirus, from [3]
Fig. 4. Art work on the paper by Josep Serra, 6/2021
References
[1] Pausas J.G. & Keeley J.E. 2009. A burning story: The role of fire in the history of life. BioScience 59: 593-601 [doi | OUP | pdf]
[2] Pausas J.G. & Keeley J.E. 2019. Wildfires as an ecosystem service. Front. Ecol. Environ. 17: 289-295. [doi | pdf]
[3] Álvarez-Ruiz L, Belliure J, Santos X., Pausas JG. 2021. Fire reduces parasite load in a Mediterranean lizard. Proceed. Royal Soc. B. [doi | pdf] New!
[4] Álvarez-Ruiz L, Belliure J, Pausas JG. 2021. Fire-driven behavioral response to smoke in a Mediterranean lizard. Behav. Ecol. [doi | oup | PDF]
[5] Pausas J.G. 2019. Generalized fire response strategies in plants and animals. Oikos 128: 147-153 [doi | pdf]
The evolutionary role of fire in animals has been poorly explored [1]. We recently conducted an experiment with the mediterranean lizard Psammodromus algirus to evaluate a possible adaptive response to fire [2]. Specifically we tested whether detecting a fire by smoke is adaptive for lizards living in fire-prone ecosystems. To do so we collected lizards from habitats with contrasted fire regimes (fire-prone shrublands vs. non-fire-prone dunes) and exposed them to smoke and to a false smoke (control) in a terrarium. We video-recorded the behavioral reaction to the treatments, and determined whether each individual detected the smoke and the intensity of the reaction. We found that in populations from fire-prone habitats, more lizards reacted to smoke, and their behavioral response was more intense than in lizard populations from non-fire-prone habitats. Our results suggest that the enhanced response to smoke may have been selected as adaptive behavior in fire-prone habitats to increase survival. Smoke has been considered a very important cue for enhancing germination in plants [3]; now we show that is also a cue for fire avoidance in animals. To our knowledge, this is the first evidence of smoke detection by reptiles in wild populations.
Lizards’ behavioral response (seconds of activity in one minute) to the treatments (Control or Smoke) and habitat (Fire-prone or Non Fire-prone). Predicted values (filled symbols with confidence intervals) and data (light colored symbols). Species: Psammodromus algirus. From [2].
References
[1] Pausas JG, Parr CL 2018. Towards an understanding of the evolutionary role of fire in animals. Evol. Ecol. 32: 113–125. [doi | pdf]
[3] Keeley & Pausas 2018. Evolution of ‘smoke’ induced seed germination in pyroendemic plants. S. Afr. J. Bot. 115: 251-255. [doi | pdf]; Moreira & Pausas 2018. Shedding light through the smoke on the germination of Mediterranean Basin flora. S. Afr. J. Bot. 115: 244-250. [doi | pdf]; Tormo et al. 2014. Field evidence of smoke-stimulated seedling emergence and establishment in Mediterranean Basin flora. J. Veget. Sci. 25: 771-777. [doi| pdf]; Moreira et al. 2010. Disentangling the role of heat and smoke as germination cues in Mediterranean Basin flora. Ann. Bot. 105: 627-635. [pdf | doi]
