title: Extinction debt from climate change for frogs in the wet tropics.
abstract: The effect of twenty-first-century climate change on biodiversity is commonly forecast based on modelled shifts in species ranges, linked to habitat suitability. These projections have been coupled with species-area relationships (SAR) to infer extinction rates indirectly as a result of the loss of climatically suitable areas and associated habitat. This approach does not model population dynamics explicitly, and so accepts that extinctions might occur after substantial (but unknown) delays-an extinction debt. Here we explicitly couple bioclimatic envelope models of climate and habitat suitability with generic life-history models for 24 species of frogs found in the Australian Wet Tropics (AWT). We show that (i) as many as four species of frogs face imminent extinction by 2080, due primarily to climate change; (ii) three frogs face delayed extinctions; and (iii) this extinction debt will take at least a century to be realized in full. Furthermore, we find congruence between forecast rates of extinction using SARs, and demographic models with an extinction lag of 120 years. We conclude that SAR approaches can provide useful advice to conservation on climate change impacts, provided there is a good understanding of the time lags over which delayed extinctions are likely to occur.
authors.affiliation: The Environment Institute and School of Biological Sciences, University of Adelaide, South Australia 5005, Australia damien.fordham@adelaide.edu.au.
authors.forename: Damien A
authors.identifier: 0000-0003-2137-5592
authors.initials: DA
authors.lastname: Fordham
authors.affiliation: School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, TAS, 7001, Australia.
authors.forename: Barry W
authors.initials: BW
authors.lastname: Brook
authors.affiliation: Centre for Tropical Biodiversity and Climate Change, College of Marine and Environmental Sciences, James Cook University, Townsville, QLD 4811, Australia.
authors.forename: Conrad J
authors.initials: CJ
authors.lastname: Hoskin
authors.affiliation: Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811, Australia.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Pressey
authors.affiliation: Centre for Tropical Biodiversity and Climate Change, College of Marine and Environmental Sciences, James Cook University, Townsville, QLD 4811, Australia.
authors.forename: Jeremy
authors.initials: J
authors.lastname: VanDerWal
authors.affiliation: Centre for Tropical Biodiversity and Climate Change, College of Marine and Environmental Sciences, James Cook University, Townsville, QLD 4811, Australia.
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Williams
mesh_terms: D000818:Animals; D001001:Anura; D001315:Australia; D044822:Biodiversity; D057231:Climate Change; D017753:Ecosystem; D053476:Extinction, Biological; D008954:Models, Biological; D011157:Population Dynamics; D013997:Time Factors
keywords: conservation prioritization; extinction risk; metapopulation; species distribution model; species–area relationship