830 resultados para natural environment
Resumo:
El turismo activo en entornos naturales se caracteriza porque la principal motivación del viajero es la posibilidad de practicar algún tipo de actividad física en entornos portadores de incertidumbre requiriendo al participante o participantes una continua adaptación ambiental para disfrutar al margen de una competición oficial o reglada. El objetivo de este artículo es el de ofrecer una herramienta que permita agrupar el conjunto de praxis vinculadas al turismo activo en entornos naturales de forma homogénea de acuerdo a su estructura interna, para facilitar así su estudio y comprensión. Para ello nos hemos propuesto diseñar una clasificación que se ajuste a la realidad de estas praxis de turismo activo en entornos naturales.
Resumo:
El turismo activo en entornos naturales se caracteriza porque la principal motivación del viajero es la posibilidad de practicar algún tipo de actividad física en entornos portadores de incertidumbre requiriendo al participante o participantes una continua adaptación ambiental para disfrutar al margen de una competición oficial o reglada. El objetivo de este artículo es el de ofrecer una herramienta que permita agrupar el conjunto de praxis vinculadas al turismo activo en entornos naturales de forma homogénea de acuerdo a su estructura interna, para facilitar así su estudio y comprensión. Para ello nos hemos propuesto diseñar una clasificación que se ajuste a la realidad de estas praxis de turismo activo en entornos naturales.
Resumo:
El presente artículo plantea la incorporación del cine como argumento válido para la formación del profesorado. Consideramos que el cine incluye suficientes mecanismos para involucrar la educación en artes visuales, la educación en medios, y la educación musical. Entre los directores más relevantes del panorama internacional, proponemos la figura de Hayao Miyazaki. Este creador japonés ha sabido atraer a públicos de todas las edades y culturas a lo largo de su dilatada carrera profesional. La calidad técnica de los trabajos de Miyazaki va acompañada de una serie de valores que resultan muy válidos para incorporar acciones educativas de respeto al medio natural y a las tradiciones culturales. Pensamos que los maestros de educación primaria han de estar preparados para fomentar este tipo de valores entre el alumnado. Tanto la educación artística como el cine son entornos muy atractivos para lograrlo. Hemos observado y analizado a un grupo de estudiantes de grado de Maestro de primaria mientras miraban la película Ponyo en el acantilado. Planteamos un mayor uso del cine como recurso educativo (Ambrós y Breu, 2007; Fedorov, 2010). Animamos al profesorado y al alumnado a realizar nuevas lecturas críticas y personales del cine, indagando más allá del conocimiento del medio como mero entretenimiento (Clarembeaux, 2010; Hernández, 2000; Huerta, 2006)
Resumo:
Aun reconociendo su situación mediadora entre cultura y naturaleza, tanto las disciplinas estéticas como las ciencias sociales suelen reducir el paisaje, o bien a una mera construcción de la mirada que lo abarca o bien al resultado material que la intervención humana deja al "culturizar" su entorno natural. Este ensayo argumenta que, en cambio, tenemos que volver a pensar al paisaje como el proceso que va de la imagen al entorno y viceversa, ensamblando lo humano con lo no-humano. De esta manera, se propone esbozar un marco teórico para historizar el paisaje en la modernidad latinoamericana.
Resumo:
El turismo rural ha sido incorporado por pequeños establecimientos agropecuarios del partido de Cnel. Suárez, provincia de Buenos Aires, Argentina, como actividad alternativa para mejorar la calidad de vida de sus miembros y superar situaciones de crisis agravadas por la marginalidad productiva del SO bonaerense, región a la que pertenecen. Bajo el programa Cambio Rural del INTA (Instituto Nacional de Tecnología Agropecuaria) conforman el Grupo 'Cortaderas II', junto a otros emprendedores interesados en valorar el medio rural. Han avanzado en el proceso de reconocimiento de su identidad y puesta en valor de recursos específicos con anclaje en el territorio. Esta identidad comienza a apreciarse internamente, a raíz de la dinámica grupal lograda y la incipiente articulación con otros actores para la construcción de un partenariado público y privado que genere sinergias y contribuya al desarrollo sustentable del territorio. Sin embargo, aún no es claramente percibida por el turista, cada vez más exigente. Por lo tanto, el presente trabajo persigue proponer indicadores para evaluar el desempeño de un Sistema de Gestión de Calidad con enfoque territorial que, adaptando el modelo europeo 'Marca de Calidad Territorial', sustente una estrategia comercial de diferenciación del servicio y simultáneamente, mida el progreso hacia una mejor calidad de vida y fortalecimiento de vínculos con la cultura local y el entorno físico-natural en el marco del desarrollo sustentable. La investigación se plantea para la micro escala, ya que se trata de un estudio de caso, relevándose información primaria mediante observación directa y entrevistas semi-estructuradas, complementada con información secundaria diagnóstica utilizada por INTA. Las características del grupo y su dinámica de funcionamiento bajo el programa Cambio Rural revelan que es posible adoptar un proceso de certificación participativa propuesto para cuatro pilares de la calidad: de Bienes y Servicios, Institucional, Social y Ambiental. El modelo se integra con indicadores de evaluación de desempeño, agrupados en áreas clave para cada una de las dimensiones de la sustentabilidad, que contemplan el paisaje y la gestión de los recursos naturales; el impacto económico de la actividad, la calidad de la oferta y satisfacción del turista; así como las relaciones sociales internas y los vínculos con otros actores del territorio. Principalmente se encontraron fortalezas en la búsqueda de partenariados y debilidades en aspectos de comunicación y promoción. Se considera que este sistema de herramientas de gestión sustentable permitiría superar las dificultades de una certificación individual, pudiendo aplicarse a emprendimientos con otra ubicación geográfica
Resumo:
Las unidades de producción hortícola del Cinturón Verde del Gran Rosario surgen en un espacio tradicionalmente priorizado para la producción agropecuaria exportable. Presentes desde el siglo XIX en el área, fueron incrementándose en función del crecimiento demográfico hasta aproximadamente mediados de la década de 1970, cuando los precios internacionales pagados por la soja convirtieron a esta leguminosa en una ventajosa competidora por tierra. El incremento de la producción agrícola implicó una presión excesiva sobre el entorno natural de los espacios rurales, como una alteración de las condiciones de trabajo y de vida de las personas vinculadas a este territorio. Este trabajo indaga las modificaciones ocurridas en la estructura social hortícola zonal en los últimos 30 años.
Resumo:
The ubiquitous marine trace gas dimethyl sulfide (DMS) comprises the greatest natural source of sulfur to the atmosphere and is a key player in atmospheric chemistry and climate. We explore the short-term response of DMS production and cycling and that of its algal precursor dimethyl sulfoniopropionate (DMSP) to elevated carbon dioxide (CO2) and ocean acidification (OA) in five 96 h shipboard bioassay experiments. Experiments were performed in June and July 2011, using water collected from contrasting sites in NW European waters (Outer Hebrides, Irish Sea, Bay of Biscay, North Sea). Concentrations of DMS and DMSP, alongside rates of DMSP synthesis and DMS production and consumption, were determined during all experiments for ambient CO2 and three high-CO2 treatments (550, 750, 1000 µatm). In general, the response to OA throughout this region showed little variation, despite encompassing a range of biological and biogeochemical conditions. We observed consistent and marked increases in DMS concentrations relative to ambient controls (110% (28-223%) at 550 µatm, 153% (56-295%) at 750 µatm and 225% (79-413%) at 1000 µatm), and decreases in DMSP concentrations (28% (18-40%) at 550 µatm, 44% (18-64%) at 750 µatm and 52% (24-72%) at 1000 µatm). Significant decreases in DMSP synthesis rate constants (µDMSP /d) and DMSP production rates (nmol/d) were observed in two experiments (7-90% decrease), whilst the response under high CO2 from the remaining experiments was generally indistinguishable from ambient controls. Rates of bacterial DMS gross consumption and production gave weak and inconsistent responses to high CO2. The variables and rates we report increase our understanding of the processes behind the response to OA. This could provide the opportunity to improve upon mesocosm-derived empirical modelling relationships and to move towards a mechanistic approach for predicting future DMS concentrations.
Resumo:
Despite the potential impact of ocean acidification on ecosystems such as coral reefs, surprisingly, there is very limited field data on the relationships between calcification and seawater carbonate chemistry. In this study, contemporaneous in situ datasets of seawater carbonate chemistry and calcification rates from the high-latitude coral reef of Bermuda over annual timescales provide a framework for investigating the present and future potential impact of rising carbon dioxide (CO2) levels and ocean acidification on coral reef ecosystems in their natural environment. A strong correlation was found between the in situ rates of calcification for the major framework building coral species Diploria labyrinthiformis and the seasonal variability of [CO32-] and aragonite saturation state omega aragonite, rather than other environmental factors such as light and temperature. These field observations provide sufficient data to hypothesize that there is a seasonal "Carbonate Chemistry Coral Reef Ecosystem Feedback" (CREF hypothesis) between the primary components of the reef ecosystem (i.e., scleractinian hard corals and macroalgae) and seawater carbonate chemistry. In early summer, strong net autotrophy from benthic components of the reef system enhance [CO32-] and omega aragonite conditions, and rates of coral calcification due to the photosynthetic uptake of CO2. In late summer, rates of coral calcification are suppressed by release of CO2 from reef metabolism during a period of strong net heterotrophy. It is likely that this seasonal CREF mechanism is present in other tropical reefs although attenuated compared to high-latitude reefs such as Bermuda. Due to lower annual mean surface seawater [CO32-] and omega aragonite in Bermuda compared to tropical regions, we anticipate that Bermuda corals will experience seasonal periods of zero net calcification within the next decade at [CO32-] and omega aragonite thresholds of ~184 micro moles kg-1 and 2.65. However, net autotrophy of the reef during winter and spring (as part of the CREF hypothesis) may delay the onset of zero NEC or decalcification going forward by enhancing [CO32-] and omega aragonite. The Bermuda coral reef is one of the first responders to the negative impacts of ocean acidification, and we estimate that calcification rates for D. labyrinthiformis have declined by >50% compared to pre-industrial times.
Resumo:
This study examined the effects of long-term culture under altered conditions on the Antarctic sea urchin, Sterechinus neumayeri. Sterechinus neumayeri was cultured under the combined environmental stressors of lowered pH (-0.3 and -0.5 pH units) and increased temperature (+2 °C) for 2 years. This time-scale covered two full reproductive cycles in this species and analyses included studies on both adult metabolism and larval development. Adults took at least 6-8 months to acclimate to the altered conditions, but beyond this, there was no detectable effect of temperature or pH. Animals were spawned after 6 and 17 months exposure to altered conditions, with markedly different outcomes. At 6 months, the percentage hatching and larval survival rates were greatest in the animals kept at 0 °C under current pH conditions, whilst those under lowered pH and +2 °C performed significantly less well. After 17 months, performance was not significantly different across treatments, including controls. However, under the altered conditions urchins produced larger eggs compared with control animals. These data show that under long-term culture adult S. neumayeri appear to acclimate their metabolic and reproductive physiology to the combined stressors of altered pH and increased temperature, with relatively little measureable effect. They also emphasize the importance of long-term studies in evaluating effects of altered pH, particularly in slow developing marine species with long gonad maturation times, as the effects of altered conditions cannot be accurately evaluated unless gonads have fully matured under the new conditions.
Resumo:
The ongoing oceanic uptake of anthropogenic carbon dioxide (CO2) is significantly altering the carbonate chemistry of seawater, a phenomenon referred to as ocean acidification. Experimental manipulations have been increasingly used to gauge how continued ocean acidification will potentially impact marine ecosystems and their associated biogeochemical cycles in the future; however, results amongst studies, particularly when performed on natural communities, are highly variable, which may reflect community/environment-specific responses or inconsistencies in experimental approach. To investigate the potential for identification of more generic responses and greater experimentally reproducibility, we devised and implemented a series (n = 8) of short-term (2-4 days) multi-level (>=4 conditions) carbonate chemistry/nutrient manipulation experiments on a range of natural microbial communities sampled in Northwest European shelf seas. Carbonate chemistry manipulations and resulting biological responses were found to be highly reproducible within individual experiments and to a lesser extent between geographically separated experiments. Statistically robust reproducible physiological responses of phytoplankton to increasing pCO2, characterised by a suppression of net growth for small-sized cells (<10 µm), were observed in the majority of the experiments, irrespective of natural or manipulated nutrient status. Remaining between-experiment variability was potentially linked to initial community structure and/or other site-specific environmental factors. Analysis of carbon cycling within the experiments revealed the expected increased sensitivity of carbonate chemistry to biological processes at higher pCO2 and hence lower buffer capacity. The results thus emphasise how biogeochemical feedbacks may be altered in the future ocean.
Resumo:
Significant warming and acidification of the oceans is projected to occur by the end of the century. CO2 vents, areas of upwelling and downwelling, and potential leaks from carbon capture and storage facilities may also cause localised environmental changes, enhancing or depressing the effect of global climate change. Cold-water coral ecosystems are threatened by future changes in carbonate chemistry, yet our knowledge of the response of these corals to high temperature and high CO2 conditions is limited. Dimethylsulphoniopropionate (DMSP), and its breakdown product dimethylsulphide (DMS), are putative antioxidants that may be accumulated by invertebrates via their food or symbionts, although recent research suggests that some invertebrates may also be able to synthesise DMSP. This study provides the first information on the impact of high temperature (12 °C) and high CO2 (817 ppm) on intracellular DMSP in the cold-water coral Lophelia pertusa from the Mingulay Reef Complex, Scotland (56°49' N, 07°23' W), where in situ environmental conditions are meditated by tidally induced downwellings. An increase in intracellular DMSP under high CO2 conditions was observed, whilst water column particulate DMS + DMSP was reduced. In both high temperature treatments, intracellular DMSP was similar to the control treatment, whilst dissolved DMSP + DMS was not significantly different between any of the treatments. These results suggest that L. pertusa accumulates DMSP from the surrounding water column; uptake may be up-regulated under high CO2 conditions, but mediated by high temperature. These results provide new insight into the biotic control of deep-sea biogeochemistry and may impact our understanding of the global sulphur cycle, and the survival of cold-water corals under projected global change.
Resumo:
Ocean acidification, caused by rising concentrations of carbon dioxide (CO2), is widely considered to be a major global threat to marine ecosystems. To investigate the potential effects of ocean acidification on the early life stages of a commercially important fish species, European sea bass (Dicentrarchus labrax), 12 000 larvae were incubated from hatch through metamorphosis under a matrix of two temperatures (17 and 19 °C) and two seawater pCO2 levels (ambient and 1,000 µatm) and sampled regularly for 42 days. Calculated daily mortality was significantly affected by both temperature and pCO2, with both increased temperature and elevated pCO2 associated with lower daily mortality and a significant interaction between these two factors. There was no significant pCO2 effect noted on larval morphology during this period but larvae raised at 19 °C possessed significantly larger eyes and lower carbon:nitrogen ratios at the end of the study compared to those raised under 17 °C. Similarly, when the incubation was continued to post-metamorphic (juvenile) animals (day 67-69), fish raised under a combination of 19 °C and 1000 µatm pCO2 were significantly heavier. However, juvenile D. labrax raised under this combination of 19 °C and 1000 µatm pCO2 also exhibited lower aerobic scopes than those incubated at 19 °C and ambient pCO2. Most studies investigating the effects of near-future oceanic conditions on the early life stages of marine fish have used incubations of relatively short durations and suggested that these animals are resilient to ocean acidification. Whilst the increased survival and growth observed in this study supports this view, we conclude that more work is required to investigate whether the differences in juvenile physiology observed in this study manifest as negative impacts in adult fish.