Browsing by Author "Fuentes, Norka"

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    COMPOSITION, DIVERSITY AND SIZE OF DIATOMS CONSUMED BY THE ANDEAN FLAMINGO (PHOENICOPARRUS ANDINUS) IN SALAR DE PUNTA NEGRA, ANTOFAGASTA REGION, NORTHERN CHILE
    (2012) Tobar, Claudio; Rau, Jaime R.; Iriarte, Agustin; Villalobos, Rodrigo; Lagos, Nicolas; Cursach, Jaime; Diaz, Carolina; Fuentes, Norka; Gantz, Alberto
    In April 2009, at the Salar de Punta Negra (24 degrees 35'S, 68 degrees 58'W) in the Antofagasta Region of northern Chile, we quantified the composition, diversity, and size of diatoms, the only consumed prey by both adults and nestlings of Andean Flamingos (Phoenicoparrus andinus). We identified a total of 39 species, 34 in the faeces of nestlings and 25 in adult faeces. The most abundant species in both was Surirella se//a and Denticula thermal/s. The most frequent diatoms observed in the nestlings' faeces were S. se/la, D. thermalis, Pinnularia sp. and Haloroundia speciosa, whereas in the adult faeces they were Denticula thermalis, Surirella se//a, Pinnularia sp. and Haloroundia speciosa. There was no statistically significant difference in diatoms consumed by adults and nestlings. The dietary similarity between adults and nestlings was 0.644. The nestlings consumed a greater diversity of diatoms than adults. The most consumed diatom by adults (S. sea) was sized between 58 and 140 mu m, with a greater frequency for organisms between 70 and 100 mu m. The size of the diatoms consumed by nestlings was between 40 and 120 mu m with a greater frequency of organisms between 60 and 90 pm. Comparing the sizes of the consumed diatoms, we found that adults preferred individuals of greater size than nestlings. Accepted 18 June 2012.
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    Multiscale spatial analysis of headwater vulnerability in South-Central Chile reveals a high threat due to deforestation and climate change
    (2022) Alaniz, Alberto J.; Smith-Ramirez, Cecilia; Rendon-Funes, Adriana; Hidalgo-Corrotea, Claudia; Carvajal, Mario A.; Vergara, Pablo M.; Fuentes, Norka
    Headwaters represent an essential component of hydrological, ecological, and socioeconomical systems, by providing constant water streams to the complete basin. However, despite the high importance of headwaters, there is a lack of vulnerability assessments worldwide. Identifying headwaters and their vulnerability in a spatially explicit manner can enable restauration and conservation programs. In this study, we assess the vulnerability of headwaters in South -Central Chile (38.4 to 43.2 degrees S) considering multiple degradation factors related to climate change and land cover change. We analyzed 2292 headwaters, characterizing multiple factors at five spatial scales by using remote sensing data related to Land Use and Cover Change (LUCC), human disturbances, vegetation cover, climate change, potential water demand, and physiography. We then generated an index of vulnerability by integrating all the analyzed vari-ables, which allowed us to map the spatial distribution of headwater vulnerability. Finally, to estimate the main drivers of degradation, we performed a Principal Components Analysis with an Agglomerative Hierarchical Clustering, that allowed us to group headwaters according to the analyzed factors. The largest proportion of most vulnerable headwa-ters are located in the north of our study area with 48.1 %, 62.1 %, and 28.1 % of headwaters classified as highly vul-nerable at 0, 10, and 30 m scale, respectively. The largest proportion of headwaters are affected by Climate Change (63.66 %) and LUCC (23.02 %) on average across all scales. However, we identified three clusters, in which the north-ern cluster is mainly affected by LUCC, while the Andean and Coastal clusters are mainly affected by climate change. Our results and methods present an informative picture of the current state of headwater vulnerability, identifying spa-tial patterns and drivers at multiple scales. We believe that the approach developed in this study could be useful for new studies in other zones of the world and can also promote Chilean headwater conservation.