scholarly journals The impact of a strong natural hypoxic event on the toadfish Aphos porosus in Coliumo Bay, south-central Chile

2012 ◽  
Vol 47 (3) ◽  
pp. 475-487 ◽  
Author(s):  
Eduardo Hernández-Miranda ◽  
Renato A Quiñones ◽  
Gustavo Aedo ◽  
Ernesto Díaz-Cabrera ◽  
José Cisterna
Mammalia ◽  
2019 ◽  
Vol 83 (2) ◽  
pp. 115-124
Author(s):  
Sandra P. Escudero-Páez ◽  
Esteban Botero-Delgadillo ◽  
Cristián F. Estades

Abstract Information on how wildlife is affected by pine plantation clearcutting is relevant for designing management strategies to promote biodiversity conservation in productive systems. By comparing the number of records of carnivores in a mosaic of pine plantations and native forest remnants before and after pine harvesting, we assessed the effect of plantation clearcutting on carnivore presence in ten sampling areas in Central Chile. We also included a number of covariates to account for their potential confounding effects, for example, the distance between each site and the nearesting human settlement and vegetation cover. A total of 10 species were observed, but no negative effect of clearcutting on carnivore presence was detected. Only the culpeo fox (Lycalopex culpaeus) responded positively to the harvesting of pine plantations. The threatened kodkod (Leopardus guigna) was absent in clearcut areas and the number of records increased in forests or plantations with a dense understorey. The domestic dog (Canis lupus familiaris) responded positively to human settlements and seems to prefer more open areas. The number of records for the Puma (Puma concolor) and the domestic cat (Felis silvestris catus) was too few, and hence, we could not make any inference regarding these two species. The other species recorded showed different responses to one or more of the included covariates. Although our results showed that the recording of some species could change in the short term after pine harvesting, future studies should assess the impact of clearcutting at a much higher scale, both in terms of space and time.


Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1828
Author(s):  
Guillermo Barrientos ◽  
Albert Herrero ◽  
Andrés Iroumé ◽  
Oscar Mardones ◽  
Ramon J. Batalla

This study analyses the changes in the runoff of forested experimental catchments in south-central Chile, to determine to what extent observed trends can be attributed to effects of intensive forestry and/or climate change. For this, we applied the distributed TETIS® model to eight catchments (7.1−413.6 ha) representative of the land uses and forestry activities in this geographical area. Rainfall and runoff data collected between 2008 and 2015 were used for modelling calibration and validation. Simulation of three land uses (current cover, partial harvest and native forest) and 25 combinations of climatic scenarios (percentage increases or decreases of up to 20% of rainfall and evapotranspiration relative to the no-change scenario applied to input series) were used in each calibration. We found that changes in land use and climate had contrasting effects on runoff. Smaller catchments affected by the driest climatic scenarios experienced higher runoff when the forest cover was lower than under full forest cover (plantations or native forests). In contrast, larger catchments under all climatic scenarios yielded higher runoff below the full forest cover than under partial harvest and native forest. This suggests that runoff can be influenced, to a great extent, by rainfall decrease and evapotranspiration increase, with the model predicting up to a 60% decrease in runoff yield for the dry’s climatic scenario. This study proves to be relevant to inform ongoing discussions related to forest management in Chile, and is intended to minimize the impact of forest cover on runoff yield under uncertain climatic scenarios.


Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 344
Author(s):  
Rémy Lapere ◽  
Sylvain Mailler ◽  
Laurent Menut

In January 2017, historic forest fires occurred in south-central Chile. Although their causes and consequences on health and ecosystems were studied, little is known about their atmospheric effects. Based on chemistry-transport modeling with WRF-CHIMERE, the impact of the 2017 Chilean mega-fires on regional atmospheric composition, and the associated meteorological feedback, are investigated. Fire emissions are found to increase pollutants surface concentration in the capital city, Santiago, by +150% (+30 µg/m3) for PM2.5 and +50% (+200 ppb) for CO on average during the event. Satellite observations show an intense plume extending over 2000 km, well reproduced by the simulations, with Aerosol Optical Depth at 550 nm as high as 4 on average during the days of fire activity, as well as dense columns of CO and O3. In addition to affecting atmospheric composition, meteorology is also modified through aerosol direct and indirect effects, with a decrease in surface radiation by up to 100 W/m2 on average, leading to reductions in surface temperatures by 1 K and mixing layer heights over land by 100 m, and a significant increase in cloud optical depth along the plume. Large deposition fluxes of pollutants over land, the Pacific ocean and the Andes cordillera are found, signaling potential damages to remote ecosystems.


Author(s):  
Jaime Vásquez-Gómez ◽  
Nelson Gatica Salas ◽  
Pedro Jiménez Villarroel ◽  
Luis Rojas-Araya ◽  
Cesar Faundez-Casanova ◽  
...  

Cardiorespiratory fitness (CRF) provides oxygen to the exercising muscles and is related to body adiposity, with cardiometabolic variables. The aim was to develop reference values and a predictive model of CRF in Chilean adolescents. A total of 741 adolescents of both genders (15.7 years old) participated in a basic anthropometry, performance in the six-minute walk test (SMWT), and in Course Navette was measured. Percentiles were determined for the SMWT, for the V̇O2max, and an equation was developed to estimate it. The validity of the equation was checked using distribution assumptions and the Bland–Altman diagram. The STATA v.14 program was used (p < 0.05). The 50th percentile values for males and females in the SMWT and in the V̇O2max of Course Navette were, respectively, from 607 to 690 and from 630 to 641 m, and from 43.9 to 45 and from 37.5 to 31.5 mlO2·kg·min−1, for the range of 13 to 17 years. For its part, the model to predict V̇O2max incorporated gender, heart rate, height, waist-to-height ratio (WHR), and distance in the SMWT (R2 = 0.62; estimation error = 0.38 LO2·min−1; p <0.001). Reference values can guide physical fitness in Chilean adolescents, and V̇O2max was possible to predict from morphofunctional variables.


2004 ◽  
Vol 25 (1) ◽  
pp. 71-89 ◽  
Author(s):  
Mariano Lastra ◽  
Eduardo Jaramillo ◽  
Jesus Lopez ◽  
Heraldo Contreras ◽  
Cristian Duarte ◽  
...  

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