43 resultados para Psychic change


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Rising global temperatures threaten the survival of many plant and animal species. Having already risen at an unprecedented rate in the past century, temperatures are predicted to rise between 0.3 and 7.5C in North America over the next 100 years (Hawkes et al. 2007). Studies have documented the effects of climate warming on phenology (timing of seasonal activities), with observations of early arrival at breeding grounds, earlier ends to the reproductive season, and delayed autumnal migrations (Pike et al. 2006). In addition, for species not suited to the physiological demands of cold winter temperatures, increasing temperatures could shift tolerable habitats to higher latitudes (Hawkes et al. 2007). More directly, climate warming will impact thermally sensitive species like sea turtles, who exhibit temperature-dependent sexual determination. Temperatures in the middle third of the incubation period determine the sex of sea turtle offspring, with higher temperatures resulting in a greater abundance of female offspring. Consequently, increasing temperatures from climate warming would drastically change the offspring sex ratio (Hawkes et al. 2007). Of the seven extant species of sea turtles, three (leatherback, Kemp’s ridley, and hawksbill) are critically endangered, two (olive ridley and green) are endangered, and one (loggerhead) is threatened. Considering the predicted scenarios of climate warming and the already tenuous status of sea turtle populations, it is essential that efforts are made to understand how increasing temperatures may affect sea turtle populations and how these species might adapt in the face of such changes. In this analysis, I seek to identify the impact of changing climate conditions over the next 50 years on the availability of sea turtle nesting habitat in Florida given predicted changes in temperature and precipitation. I predict that future conditions in Florida will be less suitable for sea turtle nesting during the historic nesting season. This may imply that sea turtles will nest at a different time of year, in more northern latitudes, to a lesser extent, or possibly not at all. It seems likely that changes in temperature and precipitation patterns will alter the distribution of sea turtle nesting locations worldwide, provided that beaches where the conditions are suitable for nesting still exist. Hijmans and Graham (2006) evaluate a range of climate envelope models in terms of their ability to predict species distributions under climate change scenarios. Their results suggested that the choice of species distribution model is dependent on the specifics of each individual study. Fuller et al. (2008) used a maximum entropy approach to model the potential distribution of 11 species in the Arctic Coastal Plain of Alaska under a series of projected climate scenarios. Recently, Pike (in press) developed Maxent models to investigate the impacts of climate change on green sea turtle nest distribution and timing. In each of these studies, a set of environmental predictor variables (including climate variables), for which ‘current’ conditions are available and ‘future’ conditions have been projected, is used in conjunction with species occurrence data to map potential species distribution under the projected conditions. In this study, I will take a similar approach in mapping the potential sea turtle nesting habitat in Florida by developing a Maxent model based on environmental and climate data and projecting the model for future climate data. (PDF contains 5 pages)

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There is an unequivocal scientific consensus that increases in greenhouse gases in the atmosphere drive warming temperatures of air and sea, and acidification of the world’s oceans from carbon dioxide absorbed by the oceans. These changes in turn can induce shifts in precipitation patterns, sea level rise, and more frequent and severe extreme weather events (e.g. storms and sea surge). All of these impacts are already being witnessed in the world’s coastal regions and are projected to intensify in years to come. Taken together, these impacts are likely to result in significant alteration of natural habitats and coastal ecosystems, and increased coastal hazards in low-lying areas. They can affect fishers, coastal communities and resource users, recreation and tourism, and coastal infrastructure. Approaches to planned adaptation to these impacts can be drawn from the lessons and good practices from global experience in Integrated Coastal Management (ICM). The recently published USAID Guidebook on Adapting to Coastal Climate Change (USAID 2009) is directed at practitioners, development planners, and coastal management professionals in developing countries. It offers approaches for assessing vulnerability to climate change and climate variability in communities and outlines how to develop and implement adaptation measures at the local and national levels. Six best practices for coastal adaptation are featured in the USAID Guidebook on Adapting to Coastal Climate Change and summarized in the following sections. (PDF contains 3 pages)

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Rural coastal regions across the United States are coping with dramatic social and environmental changes. Historically, these areas relied heavily on fishing and marine commerce and these economic activities defined the character of coastal communities. However, shifting ocean and climate conditions, together with inadequate management strategies, have led to sharp declines in harvestable marine resources. These trends, along with increasing competition from aquaculture and international sources of fish, have led to the steady decline of fishing as the central economic activity in many rural coastal communities. (PDF contains 3 pages)

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This study examines how Thailand’s biodiversity conservation measures affect fishing communities, especially in the marine protected areas (MPAs) on the Andaman Sea coastline. It documents the various efforts of the local fishing communities to protect the resources in the area. Also included are recommendations for government agencies, civil society and the international community. [PDF contains 94 pages]

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The potential importance of marine produetion as a protein ressource for a growing human population can hardly be overestimated. Climatic changes in the marine environment may affect marine production in a significant way. Increasing levels of UV-B may decrease primary production and thus diminish the food base for harvestable marine ressources. Direct effects on early stages of fishes may occur. Temperature changes can lead to additional mortality in the early phase of life histories of fishes. In spite of the potentially negative scenario, actual effects of global change on the ressources have not been detected so far. The marine organisms dispose of a significant level of pre-adaptation to changes of environmental factors both on a seasonal and an interannual scale. Effects on marine life may therefore be less dramatic than those on terrestrial systems, which are more directly linked with the exponentially growing human population.

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The chief objectives of this brief review are to collate and synthesise quantitative information on the temperature requirements of aquatic insects, and to identify species, and groups of species, that could be useful indicators of climate change and predictors of the ecological effects of change. It arose from the first phase of the Terrestrial Initiative in Global Environmental Research (TIGER), a five-year, NERC Community Programme on the role of the terrestrial biosphere in the science of global change. This phase involved the identification of criteria for selecting species suitable for the study of effects of projected climate change in the British Isles. Field and laboratory studies are reviewed, and criteria for selection of species for future research are suggested. The literature survey shows that no species of aquatic insect can be found to meet all three criteria, but information on the British stoneflies and their eggs already satisfies two of them.

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Climate change is amongst the most dreaded problems of the new millennium. Bangladesh is a coastal country bounded by Bay of Bengal on its southern part and here natural disasters are an ongoing part of human life. This paper discusses about the possible impact of climate change through tropical cyclones, storm surges, coastal erosion and sea level rise in the coastal community of Bangladesh and how they cope with these extreme events by the help of mangrove ecosystem. Both qualitative and quantitative discussions are made by collected data from different research work those are conducted in Bangladesh. Mangrove ecosystem provides both goods and services for coastal community, helps to improve livelihood options and protect them from natural disaster by providing variety of environmental support

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Ponds and shallow lakes are likely to be strongly affected by climate change, and by increase in environmental temperature in particular. Hydrological regimes and nutrient cycling may be altered, plant and animal communities may undergo changes in both composition and dynamics, and long-term and difficult to reverse switches between alternative stable equilibria may occur. A thorough understanding of the potential effects of increased temperature on ponds and shallow lakes is desirable because these ecosystems are of immense importance throughout the world as sources of drinking water, and for their amenity and conservation value. This understanding can only come through experimental studies in which the effects of different temperature regimes are compared. This paper reports design details and operating characteristics of a recently constructed experimental facility consisting of 48 aquatic microcosms which mimic the pond and shallow lake environment. Thirty-two of the microcosms can be heated and regulated to simulate climate change scenarios, including those predicted for the UK. The authors also summarise the current and future experimental uses of the microcosms.

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Lough Erne in Northern Ireland has been the subject of much research over the last 30 years by, amongst others, the Department of Agriculture and Rural Development (DARD). In this article, the authors provide a summary of a workshop held on the 16–17th October 2003 in Enniskillen, on the shores of Lough Erne, which gave an opportunity to step back and take a holistic look at the Erne lakes. Ecological change has been driven by many factors, including land use changes and species invasions. The workshop consisted of five sessions which are summarised in this article: Session 1 – Invasive species, nutrients, phytoplankton and macrophytes; Session 2 – Zooplankton, benthic macroinvertebrates and fish; Session 3 – An ecosystem approach – relating the previous sessions; Session 4 – How does Lough Erne fit into lake classifications? Implications of the Water Framework Directive; Session 5 – Using new techniques to examine food webs and species invasions. Identifying a future research programme for Lough Erne.

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This report presents the activities and results of the workshop Envisioning 2050: Climate Change, Aquaculture and Fisheries in West Africa. The objectives of the workshop were to discuss critical issues and uncertainties faced by the fisheries and aquaculture sector in Ghana, Senegal and Mauritania, build sectoral scenarios for 2050 and discuss the implication of these scenarios in the context of climate change for the countries and the region.

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While college students use a wide array of technologies to access information, their skills at determining what is relevant, in a university setting and in life, are poor. Many of these skills have to be taught in college courses. Instruction must be performed by a collaborative team using technologies that effectively reach students. This team must be ready to go into the classroom when needed and be able to address the problem whenever the student needs assistance. The results will be better writing and better research skills that will not only benefit the faculty but will lead to lifelong learning.