Landscape heterogeneity in landform and land use provides functional resistance to gene flow in continuous Asian black bear populations.

CONTEXT

Genetic diversity is one of the most important facets of biological diversity, and changes in the spatial pattern of habitats, often modified by human activity, are believed to have affected the genetic diversity of resident natural populations.

OBJECTIVES

We undertook a landscape genetic analysis in order to determine which landscape features influence gene flow within Asian black bear populations and to identify the underlying processes.

METHODS

In our evaluation of gene flow, we estimated four parameters of resistance with regard to landscape elevation: the mean, the difference between the highest and lowest, the standard deviation, and the coefficient of variation of elevation among individuals. We then examined the resistance effect of different land use types.

RESULTS

With the exception of mean elevation, we found that all parameters showed a significant relationship with genetic distance, indicating that unevenness in elevation provides functional resistance to gene flow. Although we found no evidence of landscape barriers (isolation-by-barrier), there was an indication of landscape resistance (isolation-by-resistance). Urban area and farmland are suggested to be the strong factors contributing to the resistance to gene flow, even though isolation-by-distance was also detected. When we examined gene flow for pairs of males and pairs of females, both isolation-by-distance and isolation-by-resistance were stronger in order of female pairs, male pairs, all individual pairs.

CONCLUSIONS

We conclude that landscape resistance was detectable with a high contrast in landscape heterogeneity and they are more influential on females than males.

OPEN PRACTICES

This article has been awarded Open Data badge. All materials and data are publicly accessible via the Open Science Framework at https://doi.org/10.5061/dryad.gn0qf16. Learn more about the Open Practices badges from the Center for Open Science: https://osf.io/tvyxz/wiki.