Data from: Comparative landscape genetics of two river frog species occurring at different elevations on Mount Kilimanjaro
Zancolli, Giulia, Washington State University, University of Würzburg
Rödel, Mark-Oliver, Berlin Brandenburg Institute of Advanced Biodiversity Research
Steffan-Dewenter, Ingolf, University of Würzburg
Storfer, Andrew, Washington State University
Published Sep 17, 2014 on Dryad.
Cite this dataset
Zancolli, Giulia; Rödel, Mark-Oliver; Steffan-Dewenter, Ingolf; Storfer, Andrew (2014). Data from: Comparative landscape genetics of two river frog species occurring at different elevations on Mount Kilimanjaro [Dataset]. Dryad. https://doi.org/10.5061/dryad.9pb01
Estimating population connectivity and species’ abilities to disperse across the landscape is crucial for understanding the long-term persistence of species in changing environments. Surprisingly, few landscape genetics studies focused on tropical regions despite the alarming extinction rates within these ecosystems. Here, we compared the influence of landscape features on the distribution of genetic variation of an Afromontane frog, Amietia wittei, with that of its more broadly distributed lowland congener, A. angolensis, on Mt. Kilimanjaro, Tanzania. We predicted high gene flow in the montane species with movements enhanced through terrestrial habitats of the continuous rainforest. In contrast, dispersal might be restricted to aquatic corridors and reduced by anthropogenic disturbance in the lowland species. We found high gene flow in A. wittei relative to other montane amphibians. Nonetheless, gene flow was lower than in the lowland species which showed little population structure. Least-cost path analysis suggested that dispersal is facilitated by stream networks in both species, but different landscape features were identified to influence connectivity among populations. Contrary to a previous study, gene flow in the lowland species was negatively correlated with the presence of human settlements. Also, genetic subdivision in A. wittei did not coincide with specific physical barriers as in other landscape genetics studies, suggesting that factors other than topography may contribute to population divergence. Overall these results highlight the importance of a comparative landscape genetics approach for assessing the influence of the landscape matrix on population connectivity, particularly because non-intuitive results can alter the course of conservation and management.
Amietia wittei and Amietia angolensis tissue samples were collected from sites on the southern slope of Mount Kilimanjaro, Tanzania, in 2011. Total genomic DNA was extracted with the Roche High Pure PCR Template Preparation Kit according to the manufacturer's protocol, except for an extra step after the digestion by proteinase K aiming to discard residual pigments. DNA was digested and fragments were amplified using six primer pair combinations using a modified version of Vos et al. (1995) (Appendix S1, Supporting Information). AFLP fragments were separated in an ABI 3130XL automatic capillary sequencer (Applied Biosystems) with an internal GeneScan 500 ROX size standard at the Department of Human Genetics, Biozentrum, University of Würzburg. AFLP peaks were determined using GeneMapper 4.1 (Applied Biosystems) and the final binary matrices were obtained following thw semi-automated scoring procedure described in Whitlock et al. (2008). The data include presence (1), absence (0), unscored (-1) AFLP fragments (in column) for each study site (rows) for Amietia wittei and Amietia angolensis separately.
LCP distance data
Landscape distances and variables included in each least-cost path (LCP) between study sites of Amietia wittei and Amietia angolensis calculated in ArcGIS 10 (ESRI). For each LCP model between pairs of sites (rows) the following variables (columns) were calculated: topography-corrected route lengths (distance); weighted-average values of compound topographic index (cti), roughness (rough) and slope; proportions of cropland, homegarden, human settlements, erica shrubs, forest, disturbed forest, reforestation and grassland. A 30 x 30 m digital elevation model (DEM) produced by J.A. Ong'injo, C. Lambrechts and A. Help was use for calculating resistance surfaces. Stream network was delineated using the "flow accumulation" tool in ArcGIS 10 (ESRI). The land cover surface was modified from the original produced by T. Appelhans and T. Nauss (unpubl.). Straight-line distances (Euclidean) are also reported and used as null models.
Amietia 16S aligned sequences
Aligned sequences of the 16S mitochondrial rRNA gene from 14 randomly selected individuals (GenBank accession numbers: KJ469265-KJ469278) of Amietia spp on Mt. Kilimanjaro (Tanzania).