National University of Comahue

About: National University of Comahue is a education organization based out in Neuquén, Argentina. It is known for research contribution in the topics: Population & Species richness. The organization has 2242 authors who have published 4498 publications receiving 87157 citations. The organization is also known as: UNCOMA & UNCo.

Habitat distribution modeling reveals vegetation flammability and land use as drivers of wildfire in SW Patagonia

Abstract: Despite important recent advances in modeling current and future global fire activity in relation to biophysical predictors there remain important uncertainties about finer-scale spatial heterogeneity of fire and especially about human influences which are typically assessed at coarse-spatial resolutions. The purpose of the current study is to quantify the influence of biophysical and anthropogenic variables on the spatial distribution of wildfire activity between 1984 and 2010 over an extensive southern Patagonian-Andean region from ca. 43° to 53° S extending from coastal rainforests to xeric woodland and steppe. We used satellite imagery to map all detectable fires >5 ha from 1984 to 2010 in four study areas (each of 13,100 to 36,635 km 2 ) and field checked 65 of these burns for accuracy of burned vegetation class and fire perimeters. Then, we used the MaxEnt modeling technique to assess the relationships of wildfire distributions to biophysical and human environmental variables in each of the four regions. The 232 fires >5 ha mapped in the four study areas accounted for an area of 1,314 km 2 indicating that at least 1.8% of the total area burned between 1984 and 2010. In general, areas with intermediate productivity levels (e.g., shrublands) have higher fire probability compared with areas of low and high productivity levels, such as steppe and wet forests, respectively. There is a marked contrast in the flammability of broad vegetation classes in determining fire activity at a regional scale, as well as a strong spatial relationship of wildfires to anthropogenic variables. The juxtaposition of fire-resistant tall forests with fire-prone shrublands and woodlands creates the potential for positive feedbacks from human-set fires to gradually increase the flammability of extensive landscapes through repeated burning. Distance to roads and settlements were also strong predictors, suggesting that fire in all regions is ignition-limited. However, these anthropogenic predictors influenced probability of fire differently among study regions depending on their main land-use practices and their past and present socioeconomic contexts.

Impacts to agriculture and critical infrastructure in Argentina after ashfall from the 2011 eruption of the Cordón Caulle volcanic complex: an assessment of published damage and function thresholds

Abstract: The 2011 Cordon Caulle (Chile) was a large silicic eruption that dispersed ashfall over 75,000 km2 of land in Central Argentina, affecting large parts of the Neuquen, Rio Negro, and Chubut provinces, including the urban areas of Villa la Angostura, Bariloche and Jacobacci. These regions all received damage and disruption to critical infrastructure and agriculture due to the ashfall. We describe these impacts and classify them according to published damage/disruption states (DDS). DDS for infrastructure and agriculture were also assigned to each area using the tephra thickness thresholds suggested by previous studies reported in the volcanological literature. The objective of this study was to evaluate whether the impacts were as expected based on the DDS suggested thresholds, and to determine whether other factors, apart from ashfall thickness, played a part. DDS thresholds based on tephra thickness were a good predictor of the impacts that occurred in the semi-arid steppe area around Jacobacci. This was unexpected as the more severe impacts were related to the challenging environmental conditions (low precipitation levels, high levels of wind erosion) and the daily wind remobilisation of ash that occurred, rather than the ashfall thicknesses received. The temperate region, including Villa la Angostura and Bariloche, performed better than the DDS assigned by ashfall thickness suggested. Despite deposits as thick as 300 mm, full recovery occurred within months of the ashfall event. The DDS scales need to incorporate a wider range of system characteristics, and environmental and vulnerability factors, as we propose here.

Vulnerability to climate warming of four genera of New World iguanians based on their thermal ecology

Abstract: Climate change and rising global temperatures pose a serious threat to biodiversity. We assessed the vulnerability to global warming of four genera of iguanian lizards whose distributions include a broad range of environments from the Peninsula of Yucatan to southern Patagonia. Original data on body temperatures (Tb), operative temperatures (Te, ‘null temperatures’ for non-regulating animals), thermoregulatory set-point range (preferred body temperatures, Tset) and quantitative indices of temperature regulation and quality of the thermal environment (db, de and E) for Tropidurus species were compared to published data for Anolis, Liolaemus and Sceloporus. Our results suggest that thermoregulatory behavior typically increases with latitude and altitude (except for two southernmost liolaemids), and that tropical and lowland lizards generally behave as thermoconformers. In a warming scenario, thermoconformity or poor thermoregulation in environments where large proportions of Tb and Te exceed the population's Tset will cause a reduction in the hours of activity and a higher risk of overheating. These results identify tropical populations as the most vulnerable to rising temperatures, especially the ones inhabiting open and low elevation sites. This indicates that protection of these environments should be a conservation priority. In contrast, Patagonia and montane environments represent potential future thermal refuges for many equator-ward or lowland lizards that, if capable of dispersion, would eventually be forced to retreat to these environments.