Comportamiento térmico en ríos mediterráneos andinos de la zona centro-sur de Chile

Abstract

Thermal behavior of Mediterranean Andean streams in South-Central ChileDespite of the importance of temperature in the fluvial ecosystems, the knowledge of its spatial and temporal variability in Andean rivers is limited, thus it is necessary to clarify the relative importance of site-specific factors in controlling the temperature of rivers. The aim of this research was to characterize the thermal regime of five Andean streams through an altitudinal gradient. The results show that there is a spatial and temporal variability in water temperature with a relatively rapid rise in temperature in mid-December, being stable in January and February, and a rapid decrease at the beginning of March and April. The thermal heterogeneity recorded in the high Andean zone of the Biobio River Basin makes it clear that geomorphology characteristics of each site are important in regulating water temperature, associated mainly with the altitude and shade; this latter mainly generated by high mountains and in some cases by the timberline. It is known that thermal variability, mainly the maximum and minimum mean temperatures; causing severe stress on stenotherm organisms. Therefore, a deeper knowledge of the river temperature is essential for the management and future protection of the Andean freshwater ecosystems to mitigate the impacts associated to the global warming.

Climate change can disproportionately reduce habitats of stream fishes with restricted ranges in southern South America

“…This method is useful to develop spatiotemporal regressions affected by parametric instability, providing adequate results to generate maps adjusted to different scales in cases of variables that vary spatially 71 . Specifically, we used Worldclim v2.1 72 with a resolution of 1 km as the response variable, which was locally corrected by the GWR method using a series of meteorological data from the Dirección de Aguas de Chile (DGA) (See Supplementary material), and Pedreros et al 73 . As predictor, we used the digital elevation model DEM (SRTM of 30 m resolution resampled at a resolution of 1 km and 15 m. The spatial coefficients obtained through the GWR were interpolated using ORDINARY KRIGING with automatic variogram.…”

Critical swimming speed at different temperatures for small-bodied freshwater native riverine fish species

“…Tests were performed at 10, 15 and 20°C, based on the temperature ranges observed in the two rivers (Monsalve et al 2012;Pedreros et al 2013). Fish were acclimated to the test temperature for at least 15 days before the trial.…”

Climate change can disproportionately reduce habitats of stream fishes with restricted ranges

“…This method is useful to develop spatiotemporal regressions affected by parametric instability, providing adequate results to generate maps adjusted to different scales in cases of variables that vary spatially 69 . Speci cally, we used Worldclim v2.1 70 with a resolution of 1 km as the response variable, which was locally corrected by the GWR method using a series of meteorological data from the Dirección de Aguas de Chile (DGA) (See Supplementary material), and Pedreros et al 71 . As predictor, we used the digital elevation model DEM (SRTM of 30 m resolution resampled at a resolution of 1 km and 15 m. The spatial coe cients obtained through the GWR were interpolated using ORDINARY KRIGING with automatic variogram.…”