Diagnosis del estado de conservación del ensamble de anfibios y reptiles presentes en los ecosistemas de sabanas inundables de la cuenca del río Pauto, Casanare, Colombia

Abstract

ResumenEl propósito de este estudio fue hacer la primera aproximación al conocimiento del ensamble de anfibios y reptiles presente en las sabanas inundables de río Pauto y evaluar los efectos de las transformaciones causadas en él por la introducción de cultivos de arroz y pastos exóticos. Para ello se valoró la riqueza de las especies, así como su abundancia, composición y preferencia de hábitat. Se encontró que la dinámica ecológica de los anfibios y reptiles presentes en las sabanas inundables de río Pauto está determinada por tres factores: (1) la estacionalidad, (2) el pulso de inundación y (3) las coberturas vegetales y su transformación. Así mismo, se concluyó que para la herpetofauna de las sabanas inundables, las coberturas más importantes son los bosques de galería, las vegas y las matas de monte. Finalmente, se evidenció que la actividad humana más nociva y la que más tensión ejerce en los ecosistemas de las sabanas inundables del río Pauto es la de los cultivos transitorios como el arroz.Palabras clave: pulso de inundación, estacionalidad, dinámica ecológica, transformación de coberturas naturales.Diagnosis of the conservation state of the amphibian and reptile ensembles from flooded savannas in the river Pauto basin, Casanare, Colombia AbstractThe main goal of this study was to provide a first approach to the knowledge of the amphibian and reptile ensembles in the flooded savannas of the Pauto River, and to assess the effect derived from the introduction of rice and pasture crops. To do so we first evaluated the richness, abundance, composition and habitat preferences of the species found in the ensemble. We established three factors that determine the ecological dynamics of the ensemble:(1) seasonality, (2) flood pulse and (3) transformations of natural coverts to crops. We concluded that the forest, especially the riparian forest, is the most important natural covert for amphibian and reptile ensembles during the annual climate cycle. Finally, the most harmful and stressful human activity for the flooded savannas of the Pauto River is the practice of transitional crops such as rice.

Tadpoles Inhabiting Natural and Anthropogenic Temporary Water Bodies: Which Are the Environmental Factors that Affect the Diversity of the Assemblages?

“…The Orinoco region has been transformed by livestock, crops, and mining exploitation for more than 50 years (Etter et al, 2008;Angarita-Sierra, 2014). In these landscapes, the vegetation structure and environmental heterogeneity shape the amphibian assemblages that inhabit productive systems (Caceres-Andrade and as well as the seasonality of flood pulses (Angarita-Sierra, 2014;Angarita-Sierra, 2021).…”

“…The Orinoco region has been transformed by livestock, crops, and mining exploitation for more than 50 years (Etter et al, 2008;Angarita-Sierra, 2014). In these landscapes, the vegetation structure and environmental heterogeneity shape the amphibian assemblages that inhabit productive systems (Caceres-Andrade and as well as the seasonality of flood pulses (Angarita-Sierra, 2014;Angarita-Sierra, 2021). Anurans with complex life cycles require a body of water to lay their eggs and allow their tadpoles to develop without parental care, which allows them to colonize anthropogenic cover types (Souza et al, 2008;Suazo Oruño, 2009;Costa et al, 2016).…”

“…In some parts of the Orinoco, anurans preferentially use temporary water bodies to deposit their eggs (Angarita-Sierra, 2014;Angarita-Sierra, 2021). Species that lay eggs in lentic bodies of water immersed in productive systems may experience truncated breeding seasons with shorter hydroperiods and run the risk of ponds drying out before the tadpoles can metamorphose (Guayara-Barragán & Bernal, 2012;Crump, 2015).…”

New record for Colombia, updated distribution map, and comments on the defensive behavior of Thamnodyastes dixoni Bailey & Thomas, 2007 (Serpentes, Dipsadidae, Xenodontinae)

“…The genus has its greatest diversity in Brazil, with 12 species (Costa and Bérnils 2018), while only four species are recorded in Colombia: Thamnodynastes dixoni Bailey & Thomas 2007, T. gambotensis Pérez-Santos & Moreno 1989, T. pallidus (Linnaeus, 1758, and T. para guanae Bailey & Thomas, 2007. Thamnodynastes dixoni is a cis-Andean species inhabiting the Llanos of Venezuela and Colombia (Bailey and Thomas 2007;Rivas et al 2012;Natera et al 2015). This species is known to occur NOTES ON GEOGRAPHIC DISTRIBUTION in gallery forests, shrub lands, and flooded savannahs (Angarita-Sierra 2014;Pedroza-Banda et al 2014;Natera et al 2015). In Colombia, it has been recorded since its description in four localities, which are in the departments of Arauca (Cravo Norte River near the border between Colombia and Venezuela; Bailey and Thomas 2007), and Casanare (ca.…”

“…In Colombia, it has been recorded since its description in four localities, which are in the departments of Arauca (Cravo Norte River near the border between Colombia and Venezuela; Bailey and Thomas 2007), and Casanare (ca. 168 km southwest of Arauca) (Angarita-Sierra 2014;Pedroza-Banda et al 2014;Trujillo 2015;Mora-Fernández 2016). However, information on the natural history and distribution of this species remains poorly known.…”