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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.

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Manganese (Mn 2+ ) toxicity or UV-B radiation and their individual effects on plants have been documented previously. However, no study about the combined effect of these stresses is available. We evaluated the individual and combined effects of excess Mn 2+ and UV-B radiation on physiological and biochemical parameters in two highbush blueberry (Vaccinium corymbosum L.) cultivars differing in resistance to Mn toxicity (Brigitta (resistant) and Bluegold (sensitive)). Plants grown in Hoagland nutrient solution were subjected to the following treatments: 2 mM MnCl 2 (control), 500 mM MnCl 2 (toxic Mn 2+ ), UV-B radiation (a daily dose of 94.4 kJ m -2 ), and the combined treatment (toxic Mn 2+ + UV-B) for 30 days. In both cultivars, the Mn 2+ + UV-B treatment caused a more negative effect on net photosynthesis (P n ), stomatal conductance (g s ), the photochemical parameters of PSII and the chl a/b ratio than the treatments with toxic Mn 2+ or UV-B alone. However, Brigitta showed also a better acclimation response in P n and g s than Bluegold at the end of the experiment. The Mn 2+ + UV-B treatment inhibited growth, enhanced radical scavenging activity and superoxide dismutase activity, and increased the concentration of total UV-absorbing compounds, phenols and anthocyanins, mainly in Bluegold. In conclusion, Mn-resistant Brigitta showed a better acclimation response and greater resistance to the combined stress of Mn 2+ toxicity and UV-B exposure than the Mn-sensitive Bluegold. An increased concentration of photoprotective compounds and enhanced resistance to oxidative stress in Brigitta could underpin increased resistance to the combined stress.(pH water between 4.5 to 5.5); however, there is a serious risk of Mn 2+ and aluminum (Al 3+ ) toxicity affecting plant metabolic processes and productivity (Horst 1988;Mora et al. 2004;Ducic and Polle 2005;Reyes-Díaz et al. 2010). In addition, an expansion of the hole in the ozone layer over Antarctica results in higher UV-B radiation doses in southern Chile, particularly in spring and

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Ulex europaeus (gorse) is an invasive shrub deemed as one of the most invasive species in the world. U. europaeus is widely distributed in the south-central area of Chile, which is considered a world hotspot for biodiversity conservation. In addition to its negative effects on the biodiversity of natural ecosystems, U. europaeus is one of the most severe pests for agriculture and forestry. Despite its importance as an invasive species, U. europaeus has been little studied. Although information exists on the potential distribution of the species, the interaction of the invasion process with the spatial dynamic of the landscape and the landscape-scale factors that control the presence or absence of the species is still lacking. We studied the spatial and temporal dynamics of the landscape and how these relate to U. europaeus invasion in south-central Chile. We used supervised classification of satellite images to determine the spatial distribution of the species and other land covers for the years 1986 and 2003, analysing the transitions between the different land covers. We used logistic regression for modelling the increase, decrease and permanence of U. europaeus invasion considering landscape variables. Results showed that the species covers only around 1 % of the study area and showed a 42 % reduction in area for the studied period. However, U. europaeus was the cover type which presented the greatest dynamism in the landscape. We found a strong relationship between changes in land cover and the invasion process, especially connected with forest plantations of exotic species, which promotes the displacement of U. europaeus. The model of gorse cover increase presented the best performance, and the most important predictors were distance to seed source and landscape complexity index. Our model predicted high spread potential of U. europaeus in areas of high conservation value. We conclude that proper management for this invasive species must take into account the spatial dynamics of the landscape within the invaded area in order to address containment, control or mitigation of the invasion.