Conserving threatened riparian ecosystems in the American West: Precipitation gradients and river networks drive genetic connectivity and diversity in a foundation riparian tree (Populus angustifolia).

Autor: Bothwell HM; Environmental Genetics & Genomics Facility, Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA., Cushman SA; Rocky Mountain Research Station, United States Forest Service, Flagstaff, AZ, USA., Woolbright SA; Department of Biology, University of Arkansas, Little Rock, AR, USA., Hersch-Green EI; Department of Biological Sciences, Michigan Technological University, Houghton, MI, USA., Evans LM; Institute for Behavioral Genetics, University of Colorado, Boulder, CO, USA., Whitham TG; Environmental Genetics & Genomics Facility, Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA.; Merriam-Powell Center for Environmental Research, Northern Arizona University, Flagstaff, AZ, USA., Allan GJ; Environmental Genetics & Genomics Facility, Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA.; Merriam-Powell Center for Environmental Research, Northern Arizona University, Flagstaff, AZ, USA.
Jazyk: angličtina
Zdroj: Molecular ecology [Mol Ecol] 2017 Oct; Vol. 26 (19), pp. 5114-5132. Date of Electronic Publication: 2017 Sep 05.
DOI: 10.1111/mec.14281
Abstrakt: Gene flow is an evolutionary process that supports genetic connectivity and contributes to the capacity of species to adapt to environmental change. Yet, for most species, little is known about the specific environmental factors that influence genetic connectivity, or their effects on genetic diversity and differentiation. We used a landscape genetic approach to understand how geography and climate influence genetic connectivity in a foundation riparian tree (Populus angustifolia), and their relationships with specieswide patterns of genetic diversity and differentiation. Using multivariate restricted optimization in a reciprocal causal modelling framework, we quantified the relative contributions of riparian network connectivity, terrestrial upland resistance and climate gradients on genetic connectivity. We found that (i) all riparian corridors, regardless of river order, equally facilitated connectivity, while terrestrial uplands provided 2.5× more resistance to gene flow than riparian corridors. (ii) Cumulative differences in precipitation seasonality and precipitation of the warmest quarter were the primary climatic factors driving genetic differentiation; furthermore, maximum climate resistance was 45× greater than riparian resistance. (iii) Genetic diversity was positively correlated with connectivity (R 2  = 0.3744, p = .0019), illustrating the utility of resistance models for identifying landscape conditions that can support a species' ability to adapt to environmental change. From these results, we present a map highlighting key genetic connectivity corridors across P. angustifolia's range that if disrupted could have long-term ecological and evolutionary consequences. Our findings provide recommendations for conservation and restoration management of threatened riparian ecosystems throughout the western USA and the high biodiversity they support.
(© 2017 John Wiley & Sons Ltd.)
Databáze: MEDLINE
Externí odkaz: