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1

First observations of Boeckella michaelseni Mrazek 1901 in and optical properties of a central patagonian lake

100%
De los Ríos-Escalante P., Acevedo P.
Polish Journal of Environmental Studies
|
2016
|
tom 25
|
nr 4
The Patagonian lakes have a glacial origin and some of these are associated with glaciers that generate specific optical properties, such as water colorations due to glacier sediments. These lakes also are oligotrophic with a low crustacean zooplankton species number. The aim of the present study was to analyze potential associations between optical properties and zooplankton communities in General Carrera Lake (46°S). The results revealed inverse associations in reflectance of bands 1, 5, and 7 of LANDSAT TM+with calanoid copepodites, between band 7 with conductivity, and band 7 with B. michaelseni abundance. Also, we observed direct associations between bands 1-5 with total dissolved solids, meaning that this zooplankton assemblage is similar to north Patagonian oligotrophic lakes. These results would agree with a few reports for other similar Patagonian lakes of glacial origins as reported for Argentinean and Chilean Patagonia. Nevertheless, more studies are necessary for finding potential associations between limnological characters and optical properties.
2

First observations on zooplankton and optical properties in a glacial North Patagonian lake (Tagua Tagua Lake, 41°S Chile)

100%
De los Rios-Escalante P., Acevedo P.
Polish Journal of Environmental Studies
|
2016
|
tom 25
|
nr 1
The Patagonian lakes are of glacial origin and some of these are associated with glaciers that generate specific optical properties such as water colorations due to glacier sediments. These lakes also are oligotrophic with a low crustacean zooplankton species number. The aim of the present study was to analyze potential associations between optical properties and zooplankton communities in Tagua Tagua Lake (41°S). The results revealed inverse associations in reflectance of bands 3 and 7 of LANDSAT TM+ with Daphnia ambigua, Mesocyclops araucanus, and nauplius, and direct Neobosmina chilensis and Cyclopoids copepodites, whereas it was inverse relations between bands 5 and 2 with B. gracilipes and calanoid copepodites that make this zooplankton assemblage similar to Nord Patagonian oligomesotrophic lakes. These results would agree with few reports for other similar Patagonian lakes of glacial origin reported for Argentinean and Chilean Patagonia. Nevertheless, it is necessary for more studies to find potential associations between limnological characters and optical properties.
3

Survival of Ceriodaphnia dubia [Crustacea, Cladocera] exposed to different screens against natural ultraviolet radiation

81%
De L. R. P., Acevedo P., Verdugo K.
Polish Journal of Environmental Studies
|
2007
|
tom 16
|
nr 3
481-485
The current increase of penetration of natural ultraviolet radiation (UVR ) in southern South America affects water bodies because the UVR can penetrate the water column. In this scenario, the zooplankton develops photoprotective strategies such as vertical migrations against UVR or synthesis of photoprotective substances. The present study was done using a population of Ceriodaphnia dubia. that was collected from small shallow wetland near Temuco, Chile. The specimens were exposed for 7 to 9 hours to natural ultraviolet radiation, and with different colored nylon as protection against UVR , the experiment was done during the southern summer of 2006. The results revealed that in the presence of protection against UVR provided by colored nylon, the mortality was low, whereas under exposure to UVR and covering by transparent nylon total mortality was observed. The relation between mortality and the dose of UV that can penetrate the different colored nylon is represented by LC₅₀ in UV (280-400 nm) and UVB (280-320 nm), within intensities of 234.82 and 14.96 kJ/m², respectively.
4

Spectral property observations in lakes surrounding a chilean volcano

81%
De los Ríos Escalante P., Castro M., Esse C., Acevedo P.
Polish Journal of Environmental Studies
|
2017
|
tom 26
|
nr 2
Northern Chilean Patagonia has numerous pristine lakes associated with Nothofagus and Araucaria araucana forests. The present study consists of a study of optical properties in visible, close, and medium infrared wavelengths in mountain lakes surrounding Llaima Volcano – lakes that have associated Nothofagus and Araucaria araucana native forests with volcanic origins. The results revealed high reflectance values in Arcoiris Lagoon that has volcanic stones in its bottom, whereas the other lakes and lagoons have low reflectance values. These differences in spite of oligotrophy would be associated with surrounding vegetation and geological characteristics of studied sites.
5

Satellite spectral property observations in Chilean lakes

81%
De los Ríos Escalante P., Castro M., Esse C., Acevedo P.
Polish Journal of Environmental Studies
|
2017
|
tom 26
|
nr 3
Northern Chilean Patagonia has numerous pristine lakes associated with Nothofagus and Araucaria araucana forests. The present study looks at optical properties in visible, close, and medium infrared wavelengths in mountain lakes located in Huerquehue National Park. These lakes have associated Nothofagus and Araucaria araucana native forests with glacial origin. The satellite results revealed high reflectance values in Los Patos Lagoon to B5, B6, and B7 Landsat-8 satellite bands. This lagoon is the most ephemeral pool located within A. araucana forest, whereas Tinquilco Lake has B5, B6, and B7 low reflectance values, which would be due to the presence of Nothofagus forest and probable human intervention in its surrounding basin. Whereas Angelica, Del Sacrificio, Chico, Los Condores, Las Mercedes, Olvidada, Toro, and San Manuel lagoons have low B3, B4, B5, B6, and B7 reflectance values, which would be because of the presence of native forest in their surrounding basin, and that all of these ecosystems are permanent. These differences, in spite of the oligotrophy, would be associated with surrounding vegetation and geological characteristics of studied sites.
6

Spectral properties observations in lakes of a Chilean National Park

81%
De los Ríos Escalante P., Castro M., Acevedo P., Esse C.
Polish Journal of Environmental Studies
|
2017
|
tom 26
|
nr 1
Northern Chilean Patagonia has numerous pristine lakes associated with perennial native forests. The present study looks at optical properties in visible, close, and medium infrared wavelengths in mountain lakes of Alerce Andino National Park (41°S). These lakes have associated Nothofagus and Fitzroya cupressoides native forests of glacial origins. The results revealed high reflectance values for B1 and B3 for Chaiquenes, Triangulo, and Sargazo lakes located within Nothofagus and F. cupressoides native forest; Precipicio Lagoon has high B3, B4, B5, B6, and B7 reflectance values, perhaps due to granite surroundings; and the remaining 18 lagoons have relative low reflectance values for all bands, probably due to the predominance of Cupressaceae forest and mountains that make access difficult. These differences are associated with surrounding vegetation and geological characteristics of the studied sites.
7

Spectral properties observations: a first comparison of bulgarian and chilean mountain lakes

81%
De los Rios Escalante P., Acevedo P., Pandourski I.
Polish Journal of Environmental Studies
|
2016
|
tom 25
|
nr 6
While Bulgaria has oligotrophic lakes in mountain zones with Pinus mugus shrubs associated with mountains with Fagus forests, northern Chilean Patagonia has numerous pristine lakes associated with Nothofagus forests. The present study consists of an optical properties description of mountain lakes from Bulgaria with Chilean mountain lakes (Huerquehue and Alerce Andino National Parks) with Nothofagus forest, in visible, close, and medium infrared wavelengths. The results revealed that Bulgarian lakes have different optical properties than Chilean lakes, in spite of the oligotrophy associated with surrounding vegetation and geological characteristics of both groups of studied sites.
8

Factors affecting wild boar abundance across an environmental gradient in Spain

81%
Acevedo P., Escudero M. A., Munoz R., Gortazar C.
Acta Theriologica
|
2006
|
tom 51
|
nr 3
327-336
The recent Europe-wide increase in wild boarSus scrofa, Linnaeus, 1758 abundance is undoubtedly due to many different factors, the relative importance of which differs from region to region. In Aragón (northeastern Spain), wild boar enlarged its distribution area eight times in the 1990s as compared with the century before, occupying the whole region. We studied wild boar abundance along an environmental gradient in Aragón to determine which factors are most responsible for its variation. Relative abundance of wild boars was estimated by catch-effort methods in 134 hunting estates (sampling units) for 5 consecutive hunting seasons. To characterise the environmental conditions, we quantified landscape composition and structure, topographical factors and climatic factors. Hunting pressure indices were also calculated for our sampling units. The average wild boar catch per hunting activity and per 100 km2 ranged from 0.72 to 16.31. Our results suggest thatwild boar abundances are affected by landscape structure, mainly by landscape diversity. In addition, lowland arid agrosystems (characterized by high temperatures and open juniper woodlands with little food availability) constrain the abundance of wild boar populations in spite of their wide plasticity to colonize new habitats.
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