Influence of environmental heterogeneity on the distribution and persistence of a subterranean rodent in a highly unstable landscape.
In this study we combine information from landscape characteristics, demographic inference and species distribution modelling to identify environmental factors that shape the genetic distribution of the fossorial rodent Ctenomys. We sequenced the mtDNA control region and amplified 12 microsatellites from 27 populations distributed across the Iberá wetland ecosystem. Hierarchical Bayesian modelling was used to construct phylogenies and estimate divergence times. We developed species distribution models to determine what climatic variables and soil parameters predicted species presence by comparing the current to the historic and predicted future distribution of the species. Finally, we explore the impact of environmental variables on the genetic structure of Ctenomys based on current and past species distributions. The variables that consistently correlated with the predicted distribution of the species and explained the observed genetic differentiation among populations included the distribution of well-drained sandy soils and temperature seasonality. A core region of stable suitable habitat was identified from the Last Interglacial, which is projected to remain stable into the future. This region is also the most genetically diverse and is currently under strong anthropogenic pressure. Results reveal complex demographic dynamics, which have been in constant change in both time and space, and are likely linked to the evolution of the Paraná River. We suggest that any alteration of soil properties (climatic or anthropic) may significantly impact the availability of suitable habitat and consequently the ability of individuals to disperse. The protection of this core stable habitat is of prime importance given the increasing levels of human disturbance across this wetland system and the threat of climate change.
Grupo de Genética y Ecología en Conservación y Biodiversidad (GECOBI), Museo Argentino de Ciencias Naturale "Bernardino Rivadavia", Ciudad de Buenos Aires, Argentina. mjgfernandez@gmail.com.
María Jimena
MJ
Gómez Fernández
Grupo de Genética y Ecología en Conservación y Biodiversidad (GECOBI), Museo Argentino de Ciencias Naturale "Bernardino Rivadavia", Ciudad de Buenos Aires, Argentina.|Quercus, School of Biological Sciences, Queen's University Belfast, Belfast, Northern Ireland, UK.
Emma S M
ES
Boston
Scottish Oceans Institute, University of St Andrews, East Sands, Scotland, UK.
Oscar E
OE
Gaggiotti
Instituto de Investigaciones Marinas y Costeras (IIMyC-CONICET). Departamento de Biología, Universidad Nacional de Mar del Plata, Mar del Plata, Argentina.
Marcelo J
MJ
Kittlein
Grupo de Genética y Ecología en Conservación y Biodiversidad (GECOBI), Museo Argentino de Ciencias Naturale "Bernardino Rivadavia", Ciudad de Buenos Aires, Argentina.
Patricia M
PM
Mirol
D000818:Animals; D004272:DNA, Mitochondrial / Q000235:genetics; D004777:Environment; D014644:Genetic Variation; D015233:Models, Statistical; D010802:Phylogeny; D012377:Rodentia / Q000235:genetics*
D004272:DNA, Mitochondrial
Ctenomys; Habitat fragmentation; Iberá Wetland; Metapopulation; Population genetics; Species distribution modelling