Format

Send to

Choose Destination
Mol Ecol. 2017 Oct;26(19):4906-4919. doi: 10.1111/mec.14233. Epub 2017 Sep 8.

Landscape genetic analyses reveal fine-scale effects of forest fragmentation in an insular tropical bird.

Author information

1
CNRS, Biogéosciences UMR6282, Université Bourgogne Franche-Comté, Dijon, France.
2
School of Environment and Natural Resources, The Ohio State University, Columbus, OH, USA.
3
CNERA Avifaune Migratrice, Office National de la Chasse et de la Faune Sauvage, Villiers en Bois, France.
4
EPHE, PSL Research University Paris, Dijon, France.

Abstract

Within the framework of landscape genetics, resistance surface modelling is particularly relevant to explicitly test competing hypotheses about landscape effects on gene flow. To investigate how fragmentation of tropical forest affects population connectivity in a forest specialist bird species, we optimized resistance surfaces without a priori specification, using least-cost (LCP) or resistance (IBR) distances. We implemented a two-step procedure in order (i) to objectively define the landscape thematic resolution (level of detail in classification scheme to describe landscape variables) and spatial extent (area within the landscape boundaries) and then (ii) to test the relative role of several landscape features (elevation, roads, land cover) in genetic differentiation in the Plumbeous Warbler (Setophaga plumbea). We detected a small-scale reduction of gene flow mainly driven by land cover, with a negative impact of the nonforest matrix on landscape functional connectivity. However, matrix components did not equally constrain gene flow, as their conductivity increased with increasing structural similarity with forest habitat: urban areas and meadows had the highest resistance values whereas agricultural areas had intermediate resistance values. Our results revealed a higher performance of IBR compared to LCP in explaining gene flow, reflecting suboptimal movements across this human-modified landscape, challenging the common use of LCP to design habitat corridors and advocating for a broader use of circuit theory modelling. Finally, our results emphasize the need for an objective definition of landscape scales (landscape extent and thematic resolution) and highlight potential pitfalls associated with parameterization of resistance surfaces.

KEYWORDS:

gene flow; landscape connectivity; optimization; tropical island

PMID:
28727200
DOI:
10.1111/mec.14233
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Wiley
Loading ...
Support Center