Climate forcing of an emerging pathogenic fungus across a montane multi-host community

Abstract

Changes in the timings of seasonality as a result of anthropogenic climate change are predicted to occur over the coming decades. While this is expected to have widespread impacts on the dynamics of infectious disease through environmental forcing, empirical data are lacking. Here, we investigated whether seasonality, specifically the timing of spring ice-thaw, affected susceptibility to infection by the emerging pathogenic fungus Batrachochytrium dendrobatidis (Bd) across a montane community of amphibians that are suffering declines and extirpations as a consequence of this infection. We found a robust temporal association between the timing of the spring thaw and Bd infection in two host species, where we show that an early onset of spring forced high prevalences of infection. A third highly susceptible species (the midwife toad, Alytes obstetricans) maintained a high prevalence of infection independent of time of spring thaw. Our data show that perennially overwintering midwife toad larvae may act as a year-round reservoir of infection with variation in time of spring thaw determining the extent to which infection spills over into sympatric species. We used future temperature projections based on global climate models to demonstrate that the timing of spring thaw in this region will advance markedly by the 2050s, indicating that climate change will further force the severity of infection. Our findings on the effect of annual variability on multi-host infection dynamics show that the community-level impact of fungal infectious disease on biodiversity will need to be re-evaluated in the face of climate change.This article is part of the themed issue ‘Tackling emerging fungal threats to animal health, food security and ecosystem resilience’.

Spatiotemporal heterogeneity decouples infection parameters of amphibian chytridiomycosis

“…Thus, the nature and intensity of an amphibian‐parasite interaction will be contingent upon the spatiotemporal patterns of both host and parasite (Hess et al, ). Despite this fact, most studies attempting to elucidate environmental drivers of Bd disease dynamics have focused on the spatial aspects of environmental heterogeneity alone, overlooking the importance of temporal variation (Pounds et al, ; Olson et al, ; Xie, Olson, & Blaustein, ; however, see Clare et al, ). A clearer understanding of the links between environmental parameters, host breeding phenology and the outcomes of ectothermic host–pathogen interactions will provide valuable insights into host–pathogen epidemiology, as well as more fundamental aspects of the ecology and evolution of interspecific interactions (Lambrechts, Chavatte, Snounou, & Koella, ).…”

Climate change accelerates local disease extinction rates in a long‐term wild host–pathogen association

“…The potential for climate change to favour the dynamics of existing, new and emerging diseases thereby threatening global food security (Fisher et al, 2012), human (Altizer, Ostfeld, Johnson, Kutz, & Harvell, 2013;Equihua et al, 2017) and animal (Kalinda, Chimbari, & Mukaratirwa, 2017) health and biodiversity (Clare et al, 2016) has also attracted much attention (Fisher et al, 2012;Kaczmarek et al, 2016). With regard to fungal plant pathogens, concern has focused on the potential for climate change to increasingly favour agricultural pathogens within existing regions of host-pathogen associations (Chakraborty & Newton, 2011;Kaczmarek et al, 2016;Newbery, Qi, & Fitt, 2016) or to promote expansion of the geographic range of such pathogens (Bebber, Ramotowski, & Gurr, 2013;Fisher et al, 2012) into areas from which they are currently excluded by temperature and precipitation regimes.…”

Host–pathogen metapopulation dynamics suggest high elevation refugia for boreal toads

“…, Clare et al. ). Assessing the relative contributions of these factors to host–pathogen dynamics will improve our ability to successfully manage landscapes, species, and populations challenged by chytridiomycosis (Venesky et al.…”

“…The global impacts of chytridiomycosis (Skerratt et al 2007) coupled with local extirpations and differential susceptibility of amphibian populations (Schloegel et al 2006, Murphy et al 2009), make identifying the factors that lead to extinction a conservation priority (Wilber et al 2017). Geographic isolation of populations, host species community richness, variation in climate, and habitat differences across sites have all been suggested to influence amphibian-Bd dynamics (Searle et al 2011, Heard et al 2013, Addis et al 2015, Clare et al 2016. Assessing the relative contributions of these factors to host-pathogen dynamics will improve our ability to successfully manage landscapes, species, and populations challenged by chytridiomycosis (Venesky et al 2014b, Garner et al 2016.…”