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The interplay between local and landscape scales on the density of pond-dwelling anurans in subtropical grasslands

Citation

Iop, Samanta (2020), The interplay between local and landscape scales on the density of pond-dwelling anurans in subtropical grasslands, Dryad, Dataset, https://doi.org/10.5061/dryad.x95x69pf5

Abstract

We investigated the role of local and landscape environmental variables on anurans density classified as habitat specialists and generalists in grassland landscapes, known as South Brazilian grasslands (SBG). In this region, we surveyed 187 ponds distributed over 40 landscape sampling units. For each pond, 31 local environmental variables were measured. Each landscape sampling unit was embedded within a larger regional sampling unit with different landscape properties. For each landscape and regional sampling units, 16 landscape metrics were extracted from a land cover and use map. We recorded 35 species, eleven of which are specialists in the SBG. The specialists were affected by 11 local and 2 landscape environmental variables, while generalists were affected by 14 local and one environmental variable. Thus, specialists and generalists presented different relationships with local and landscape variables, but in general local variables had a greater influence on the density of anurans than the landscape variables. However, the landscape indirectly influenced local variables because higher quality ponds were in landscapes with higher percentages of natural habitat. In conclusion, reproductive sites with higher local quality and located within landscapes with higher percentages of natural grasslands are essential to conserve anurans in this habitat. Effective conservation of such sites would benefit from further studies that assess effects of land use and biotic integrity of ponds, which can help to determine (1) the relative effects of local habitat quality of ponds, and (2) the effectiveness of protecting ponds and their local surroundings for anuran conservation in SBG.

Methods

We surveyed all vocalizing males of anurans in 187 ponds distributed over 40 landscape sampling units in South Brazilian grassland. For each pond, 31 local environmental variables were measured. Each landscape sampling unit was embedded within a larger regional sampling unit with different landscape properties. For each landscape and regional sampling units, 16 landscape metrics were extracted from a land cover and use map. We assessed the relative importance of local environmental and landscape variables on the density of anurans in calling activity with a protocol to select which variables had the greatest additive effects on pooled species counts, using generalized mixed-effect models.

Usage Notes

The data are organized in 3 tables: 1) Abundance of anurans specialist and generalist; 2) Local variables; 3) Landscape variables.

There are 3 scripts: 1) Scrip with principal analyses; 2) Script with functions; 3) Script with plots.

Funding

Fundação de Amparo à Pesquisa do Estado de São Paulo, Award: 2016/16899-0

Conselho Nacional de Desenvolvimento Científico e Tecnológico, Award: 308687/2016-17

Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul, Award: 563271/2010-8

Conselho Nacional de Desenvolvimento Científico e Tecnológico, Award: 308687/201-176

Conselho Nacional de Desenvolvimento Científico e Tecnológico, Award: 309095/2016-6

Conselho Nacional de Desenvolvimento Científico e Tecnológico, Award: 307689/2014-0