Distribución histórica y actual de la lagartija Liolaemus pictus (Dumeril & Bibron 1837) (Liolaemidae) y nuevo límite continental sur de distribución

Abstract

RESUMENBasado en los registros de la literatura y datos obtenidos de nuestras colectas, discutimos la distribución actual de Liolaemus pictus. La comparación de los resultados indica que esta especie no ha sido detectada en la depresión intermedia de Chile desde 1934. Lo anterior implica que dichas poblaciones se han extinguido, seguramente como consecuencia de la deforestación. Al mismo tiempo, extendemos el límite sur de la distribución conocida de L. pictus hasta los 44 ºS en la Región de Aysén. ABSTRACTBased on literature records and data gathered during our fieldwork, we discuss the current distribution of Liolaemus pictus.

Lizards on Ice: Evidence for Multiple Refugia in Liolaemus pictus (Liolaemidae) during the Last Glacial Maximum in the Southern Andean Beech Forests

“…These divergence levels suggest strong fragmentation, low connectivity and reductions of Ne, especially in clades N1A and N2. Although the effects of the glacial cycles were less prominent in the North, Nothofagus forests are more fragmented and exposed to changes in size because those areas are close to the limits of their distribution [4], [23]. Thus, while the effects of the glaciers in these regions may have been minimal, the marginal conditions of the habitat may have promoted fragmentation, differentiation, and unstable population sizes in L. pictus .…”

“…Despite the exhaustive sampling effort over the entire range of L. pictus [23], no specimen was found in the Longitudinal Valley. The complete loss of native forest, especially of trees of the genus Nothofagus [80], has eliminated suitable habitat for L. pictus in the BioBío and Araucanía regions and almost certainly led to the extinction of L. pictus populations in these regions [81], [82].…”

“…Voucher specimens were catalogued in the Museo de Zoología at Universidad de Concepción (MZUC (UCCC), Chile). No specimen was found in the Chilean “Longitudinal Valley”, very likely due to the almost complete replacement of Nothofagus forests by non-native Pinus dominated agro-forestry systems, which has probably eradicated L. pictus populations from this region [23]. As such, our sampling consists mainly of localities in both the Andean and the Coastal mountain ranges and includes the distributional range of four of the six currently recognized subspecies [37].…”

“…Maxent generates Ecological Niche Models (ENM) using presence-only records, contrasting them with pseudo-absence data sampled from the remainder of the study area. The present-day ENM were developed based on the 123 confirmed occurrence points for L. pictus [23]. The bioclimatic niche of the species was then projected on to past climate layers to predict the potential range of the species during the LGM (∼21,000 ya).…”

“…Ecologically L. pictus ranges from sea level to 1600 m, along over 800 km. Its western distribution covers Chile from the Región del Maule (∼36°S) to the Región de Los Lagos including some islands in the Chiloé archipelago (43°S) while its eastern distribution covers part of the Northern Argentinean Patagonia [23] (Fig. 1).…”