Landscape Resistance Models Identify Genetic Connectivity Corridors for a Foundation Riparian Tree (Populus angustifolia)
Presenter(s)
Helen M Bothwell
Abstract
Gene flow is a fundamental evolutionary process that underlies species' ability to adapt to changing environments. Yet, for most species, little is known about the specific factors that facilitate or inhibit dispersal through complex landscapes, and the effects these factors have on patterns of genetic diversity and differentiation. We applied a landscape genetic approach to understand how environment and climate influence the movement of genes in a foundation riparian tree (Populus angustifolia), and their relationships with species-wide patterns of genetic diversity and differentiation. Using multivariate restricted optimization in a reciprocal causal modeling framework, we quantified the relative contributions of river network connectivity, terrestrial uplands, and climate on genetic connectivity. We found that (1) all river orders facilitated gene flow, and terrestrial uplands provided 2.5 times more resistance than riparian corridors. (2) Cumulative differences in precipitation seasonality and precipitation of the warmest quarter were the primary climatic factors driving genetic differentiation. (3) Landscape connectivity was positively correlated with genetic diversity. Comparing our findings with a similar study of P. fremontii suggests that asexual reproduction may be a critical adaptation facilitating P. angustifolia's broader distribution along headwater reaches. Both cottonwoods and other recent studies of shrubs suggest an emerging trend of the general importance of cumulative differences in precipitation gradients in driving spatial patterns of genetic differentiation. Our finding that connectivity was closely related to genetic diversity in P. angustifolia illustrates the utility of landscape resistance models for identifying factors that promote species resiliency in the face of global change.
Topic
Student Presentations
Start Date
6-15-2016 8:20 AM
End Date
6-15-2016 8:35 AM
Room
High Country Conference Center
Recommended Citation
Bothwell, Helen M.; Cushman, Samuel A.; Woolbright, Scott A.; Hersch-Green, Erika I.; Evans, Luke M.; Allan, Gerard J.; and Whitham, Thomas G., "Landscape Resistance Models Identify Genetic Connectivity Corridors for a Foundation Riparian Tree (Populus angustifolia)" (2016). World Conference on Natural Resource Modeling. 3.
https://scholarexchange.furman.edu/rma/all/presentations/3
Landscape Resistance Models Identify Genetic Connectivity Corridors for a Foundation Riparian Tree (Populus angustifolia)
High Country Conference Center
Gene flow is a fundamental evolutionary process that underlies species' ability to adapt to changing environments. Yet, for most species, little is known about the specific factors that facilitate or inhibit dispersal through complex landscapes, and the effects these factors have on patterns of genetic diversity and differentiation. We applied a landscape genetic approach to understand how environment and climate influence the movement of genes in a foundation riparian tree (Populus angustifolia), and their relationships with species-wide patterns of genetic diversity and differentiation. Using multivariate restricted optimization in a reciprocal causal modeling framework, we quantified the relative contributions of river network connectivity, terrestrial uplands, and climate on genetic connectivity. We found that (1) all river orders facilitated gene flow, and terrestrial uplands provided 2.5 times more resistance than riparian corridors. (2) Cumulative differences in precipitation seasonality and precipitation of the warmest quarter were the primary climatic factors driving genetic differentiation. (3) Landscape connectivity was positively correlated with genetic diversity. Comparing our findings with a similar study of P. fremontii suggests that asexual reproduction may be a critical adaptation facilitating P. angustifolia's broader distribution along headwater reaches. Both cottonwoods and other recent studies of shrubs suggest an emerging trend of the general importance of cumulative differences in precipitation gradients in driving spatial patterns of genetic differentiation. Our finding that connectivity was closely related to genetic diversity in P. angustifolia illustrates the utility of landscape resistance models for identifying factors that promote species resiliency in the face of global change.