Anthropogenic impacts drive niche and conservation metrics of a cryptic rattlesnake on the Colorado Plateau of western North America. Issue 4 (April 2016)

• Record Type: Journal Article
• Authors: Douglas, M. R.; Davis, M. A.; Amarello, M.; Smith, J. J.; Schuett, G. W.; Herrmann, H.-W.; Holycross, A. T.; Douglas, M. E.
• Is Part Of: Royal Society open science. Volume 3:Issue 4(2016)
• Publication Date: 2016-04
• Subjects: climate change -- Crotalus cerberus -- drainage vicariance -- environmental niche modelling -- wildfire; Science -- Periodicals; 500
• DOI: 10.1098/rsos.160047
• Languages: English
• ISSNs: 2054-5703

Abstract

Abstract : Ecosystems transition quickly in the Anthropocene, whereas biodiversity adapts more slowly. Here we simulated a shifting woodland ecosystem on the Colorado Plateau of western North America by using as its proxy over space and time the fundamental niche of the Arizona black rattlesnake ( Crotalus cerberus ). We found an expansive (= end-of-Pleistocene) range that contracted sharply (= present), but is blocked topographically by Grand Canyon/Colorado River as it shifts predictably northwestward under moderate climate change (= 2080). Vulnerability to contemporary wildfire was quantified from available records, with forested area reduced more than 27% over 13 years. Both 'ecosystem metrics' underscore how climate and wildfire are rapidly converting the Plateau ecosystem into novel habitat. To gauge potential effects on C. cerberus, we derived a series of relevant 'conservation metrics' (i.e. genetic variability, dispersal capacity, effective population size) by sequencing 118 individuals across 846 bp of mitochondrial (mt)DNA-ATPase8/6. We identified five significantly different clades (net sequence divergence = 2.2%) isolated by drainage/topography, with low dispersal ( F ST = 0.82) and small sizes (2 N ef = 5.2). Our compiled metrics (i.e. small-populations, topographic-isolation, low-dispersal versus conserved-niche, vulnerable-ecosystem, dispersal barriers) underscore the susceptibility of this woodland specialist to a climate and wildfire tandem. We offer adaptive management scenarios that may counterbalance these metrics and avoid the extirpation of this and other highly specialized, relictual woodland clades.