Álvarez-Ruiz L, Belliure J, Santos X, Pausas JG




Wildfires are a natural disturbance in many ecosystems. However, their effect on biotic interactions has been poorly studied. Fire consumes the vegetation
and the litter layer where many parasites spend part of their life cycles. We hypothesize that wildfires reduce habitat availability for parasites
with consequent potential benefits for hosts. We tested this for the lizard Psammodromus algirus and its ectoparasites in a Mediterranean ecosystem.
We predicted that lizards in recently burned areas would have lower parasite load (cleaning effect) than those in unburned areas and that this
phenomenon implies that lizards spending their entire lives in postfire conditions experience a lower level of parasitism than those living in unburned
areas. We compared the ectoparasite load of lizards between eight paired burned/unburned sites, including recent (less than 1 year postfire) and
older fires (2–4 years). We found that lizards’ ectoparasites prevalence was drastically reduced in recently burned areas. Likewise, lizards in older
burned areas showed less evidence of past parasitic infections. Fire disrupted the host–parasite interaction providing the opportunity for lizards
to avoid the negative effects of ectoparasites. Our results suggest that wildfires likely fulfil a role in controlling vector-borne diseases and pathogens
and highlight ecological effects of wildfires that have been overlooked.


Journal: Proceedings of the Royal Society B-Series

DOI: 10.1098/rspb.2021.1230