873 resultados para Homo-ecological zoning


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Alpine meadow and shrub are the main pasture types on the Tibetan Plateau, and they cover about 35% of the total land area. In order to understand the structural and functional aspects of the alpine ecosystem and to promote a sustainable animal production system, the Haibei Alpine Meadow Research Station was established in 1976. A series of intensive studies on ecosystem structure and function, including the energy flow and nutrient cycling of the ecosystem, were the main tasks during the first 10 years. Meanwhile, studies with 5 different grazing intensities on both summer and winter pasture have been conducted. In the early years of the 1990s, the research station started to focus its research work on global warming, biodiversity and sustainable animal production systems in pastoral areas. Various methods for improving degraded pasturelands have been developed in the region.

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Benefits and costs of dispersal and philopatry of the social plateau pika (Ochotona curzoniae) were studied on the Tibetan plateau for 3 years. Although short-lived, plateau pikas live in cohesive family groups that occupy burrow systems in sedge meadow habitat Most (57.8%) plateau pikas were philopatric, and dispersal movements were extremely restricted. No juvenile females or adult pikas moved more than two family ranges between years; the greatest observed dispersal distances were by two juvenile males that moved five family ranges from the family of their birth. Traversing unfamiliar habitat was not a cost of pika dispersal because most dispersers settled in families that they could easily visit before dispersal. Dispersal movements appeared to result in equalization of density among pika families, an expected result if competition for environmental resources influenced dispersal. Males did not disperse to gain advantages in competition for mates, as evidenced by their moving to families with significantly fewer females. Females, however, moved to families with significantly more males. Males provide abundant paternal care, and significantly more offspring per female survived to become adults from families with more adult males per adult female. Evidence concerning the influence of inbreeding avoidance on natal dispersal was indirect. Some males exhibited natal philopatry; thus some families had opportunity for close inbreeding. Males and females that dispersed had no opposite-sex relatives in their new families. Philopatric pikas may have benefited by remaining in families that exhibited low local densities, and philopatric females might have benefited from social cooperation with relatives.

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J. Keppens and Q. Shen. Granularity and disaggregation in compositional modelling with applications to ecological systems. Applied Intelligence, 25(3):269-292, 2006.

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Joern Fischer, David B. Lindermayer, and Ioan Fazey (2004). Appreciating Ecological Complexity: Habitat Contours as a Conceptual Landscape Model. Conservation Biology, 18 (5)pp.1245-1253 RAE2008

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Warren, J. and James, P. (2006). The ecological effects of exotic disease resistance genes introgressed into British gooseberries. Oecologia 147(1),69-75. RAE2008

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Ioan Fazey, John A. Fazey, Joern Fischer, Kate Sherren, John Warren, Reed F. Noss, Stephen R. Dovers (2007) Adaptive capacity and learning to learn as leverage for social?ecological resilience. Frontiers in Ecology and the Environment 5(7),375-380. RAE2008

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Africa faces problems of ecological devastation caused by economic exploitation, rapid population growth, and poverty. Capitalism, residual colonialism, and corruption undermine Africa's efforts to forge a better future. The dissertation describes how in Africa the mounting ecological crisis has religious, political, and economic roots that enable and promote social and environmental harm. It presents the thesis that religious traditions, including their ethical expressions, can effectively address the crisis, ameliorate its impacts, and advocate for social and environmental betterment, now and in the future. First, it examines African traditional religion and Christian teaching, which together provide the foundation for African Christianity. Critical examination of both religious worldviews uncovers their complementary emphases on human responsibility toward planet Earth and future generations. Second, an analysis of the Gwembe Tonga of Chief Simamba explores the interconnectedness of all elements of the universe in African cosmologies. In Africa, an interdependent, participatory relationship exists between the world of animals, the world of humans, and the Creator. In discussing the annual lwiindi (rain calling) ceremony of Simamba, the study explores ecological overtones of African religions. Such rituals illustrate the involvement of ancestors and high gods in maintaining ecological integrity. Third, the foundation of the African morality of abundant life is explored. Across Sub-Saharan Africa, ancestors' teachings are the foundation of morality; ancestors are guardians of the land. A complementary teaching that Christ is the ecological ancestor of all life can direct ethical responses to the ecological crisis. Fourth, the eco-social implications of ubuntu (what it means to be fully human) are examined. Some aspects of ubuntu are criticized in light of economic inequalities and corruption in Africa. However, ubuntu can be transformed to advocate for eco-social liberation. Fifth, the study recognizes that in some cases conflicts exist between ecological values and religious teachings. This conflict is examined in terms of the contrast between awareness of socioeconomic problems caused by population growth, on the one hand, and advocacy of a traditional African morality of abundant children, on the other hand. A change in the latter religious view is needed since overpopulation threatens sustainable living and the future of Earth. The dissertation concludes that the identification of Jesus with African ancestors and theological recognition of Jesus as the ecological ancestor, woven together with ubuntu, an ethic of interconnectedness, should characterize African consciousness and promote resolution of the socio-ecological crisis.

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Ecological concern prompts poor and indigenous people of India to consider how a society can ensure both protection of nature and their rightful claim for a just and sustainable future. Previous discussions defended the environment while ignoring the struggles of the poor for sustenance and their religious traditions and ethical values. Mohandas Karamchand Gandhi addressed similar socio-ecological concerns by adopting and adapting traditional religious and ethical notions to develop strategies for constructive, engaged resistance. The dissertation research and analysis verifies the continued relevance of the Gandhian understanding of dharma (ethics) in contemporary India as a basis for developing eco-dharma (eco-ethics) to link closely development, ecology, and religious values. The method of this study is interpretive, analytical, and critical. Françoise Houtart’s social analytical method is used to make visible and to suggest how to overcome social tensions from the perspective of marginalized and exploited peoples in India. The Indian government's development initiatives create a nexus between the eco-crisis and economic injustice, and communities’ responses. The Chipko movement seeks to protect the Himalayan forests from commercial logging. The Narmada Bachao Andolan strives to preserve the Narmada River and its forests and communities, where dam construction causes displacement. The use of Gandhian approaches by these movements provides a framework for integrating ecological concerns with people's struggles for survival. For Gandhi, dharma is a harmony of satya (truth), ahimsa (nonviolence), and sarvodaya (welfare of all). Eco-dharma is an integral, communitarian, and ecologically sensitive ethical paradigm. The study demonstrates that the Gandhian notion of dharma, implemented through nonviolent satyagraha (firmness in promoting truth), can direct community action that promotes responsible economic structures and the well-being of the biotic community and the environment. Eco-dharma calls for solidarity, constructive resistance, and ecologically and economically viable communities. The dissertation recommends that for a sustainable future, India must combine indigenous, appropriate, and small- or medium-scale industries as an alternative model of development in order to help reduce systemic poverty while enhancing ecological well-being.

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This dissertation sets out to provide immanent critique and deconstruction of ecological modernisation or ecomodernism.It does so, from a critical social theory approach, in order to correctly address the essential issues at the heart of the environmental crisis that ecomodernism purports to address. This critical approach argues that the solution to the environmental crisis can only be concretely achieved by recognising its root cause as being foremost the issue of material interaction between classes in society, and not simply between society and nature in any structurally meaningful way. Based on a metaphysic of false dualism, ecological modernisation attributes a materiality of exchange value relations to issues of society, while simultaneously offering a non- material ontology to issues of nature. Thus ecomodernism serves asymmetrical relations of power whereby, as a polysemic policy discourse, it serves the material interests of those who have the power to impose abstract interpretations on the materiality of actual phenomena. The research of this dissertation is conducted by the critical evaluation of the empirical data from two exemplary Irish case studies. Discovery of the causal processes of the various public issues in the case studies and thereafter the revelation of the meaning structures under- pinning such causal processes, is a theoretically- driven task requiring analysis of those social practices found in the cognitive, cultural and structural constitutions respectively of actors, mediations and systems.Therefore, the imminent critique of the case study paradigms serves as a research strategy for comprehending Ireland’s nature- society relations as influenced essentially by a systems (techno- corporatist) ecomodernist discourse. Moreover, the deconstruction of this systems ideological discourse serves not only to demonstrate how weak ecomodernism practically undermines its declared ecological objectives, but also indicates how such objectives intervene as systemic contradictions at the cultural heart of Ireland’s late modernisation.

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'The ecological emergency’ describes both our emergence into, and the way we relate within, a set of globally urgent circumstances, brought about through anthropogenic impact. I identify two phases to this emergency. Firstly, there is the anthropogenic impact itself, interpreted through various conceptual models. Secondly, however, is the increasingly entrenched commitment to divergent conceptual positions, that leads to a growing disparateness in attitudes, and a concurrent difficulty with finding any grounds for convergence in response. I begin by reviewing the environmental ethics literature in order to clarify which components of the implicit narratives and beliefs of different positions create the foundations for such disparateness of views. I identify the conceptual frameworks through which moral agency and human responsibility are viewed, and that justify an ethical response to the ecological emergency. In particular, I focus on Paul Taylor's thesis of 'respect for nature' as a framework for revising both the idea that we are ‘moral’ and the idea that we are ‘agents’ in this unique way, and I open to question the idea that any response to the ecological emergency need be couched in ethical terms. This revision leads me to formulate an alternative conceptual model that makes use of Timothy Morton’s idea of enmeshment. I propose that we dramatically revise our idea of moral agency using the idea of enmeshment as a starting point. I develop an alternative framework that locates our capacity for responsibility within our capacity for realisation, both in the sense of understanding, and of making real, sets of conditions within our enmeshment. I draw parallels between this idea of ‘realisation as agency’ and the work of Dōgen and other non-dualists. I then propose a revised understanding of ‘the good’ of systems from a biophysical perspective, and compare this with certain features of Asian traditions of thought. I consider the practical implications of these revisions, and I conclude that the act of paying close attention, or realising, contains our agency, as does the attitude, or manner, with which we focus. This gives us the basis for a convergent response to the ecological emergency: the way of our engagement that is the key to responding to the ecological emergency

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During ecological speciation, divergent natural selection drives evolution of ecological specialization and genetic differentiation of populations on alternate environments. Populations diverging onto the same alternate environments may be geographically widespread, so that divergence may occur at an array of locations simultaneously. Spatial variation in the process of divergence may produce a pattern of differences in divergence among locations called the Geographic Mosaic of Divergence. Diverging populations may vary in their degree of genetic differentiation and ecological specialization among locations. My dissertation examines the pattern and evolutionary processes of divergence in pea aphids (Acyrthosiphon pisum) on alfalfa (Medicago sativa) and clover (Trifolium pretense). In Chapter One, I examined differences among North American aphid populations in genetic differentiation at nuclear, sequence-based markers and in ecological specialization, measured as aphid fecundity on each host plant. In the East, aphids showed high host-plant associated ecological specialization and high genetic differentiation. In the West, aphids from clover were genetically indistinguishable from aphids on alfalfa, and aphids from clover were less specialized. Thus, the pattern of divergence differed among locations, suggesting a Geographic Mosaic of Divergence. In Chapter Two, I examined genomic heterogeneity in divergence in aphids on alfalfa and clover across North America using amplified fragment length polymorphisms (AFLPs). The degree of genetic differentiation varied greatly among markers, suggesting that divergent natural selection drives aphid divergence in all geographic locations. Three of the same genetic markers were identified as evolving under divergent selection in the eastern and western regions, and additional divergent markers were identified in the East. In Chapter Three, I investigated population structure of aphids in North America, France, and Sweden using AFLPs. Aphids on the same host plant were genetically similar across many parts of their range, so the evolution of host plant specialization does not appear to have occurred independently in every location. While aphids on alfalfa and clover were genetically differentiated in most locations, aphids from alfalfa and clover were genetically similar in both western North America and Sweden. High gene flow from alfalfa onto clover may constrain divergence in these locations.

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Atlantic croaker Micropogonias undulatus is a commercially and ecologically important bottom-associated fish that occurs in marine and estuarine systems from Cape Cod, MA to Mexico. I documented the temporal and spatial variability in the diet of Atlantic croaker in Chesapeake Bay and found that in the summer fish, particularly bay anchovies Anchoa mitchilli, make up at least 20% of the diet of croaker by weight. The use of a pelagic food source seems unusual for a bottom-associated fish such as croaker, but appears to be a crepuscular feeding habit that has not been previously detected. Thus, I investigated the bioenergetic consequences of secondary piscivory to the distribution of croaker, to the condition of individuals within the population and to the ecosystem. Generalized additive models revealed that the biomass of anchovy explained some of the variability in croaker occurrence and abundance in Chesapeake Bay. However, physical factors, specifically temperature, salinity, and seasonal dynamics were stronger determinants of croaker distribution than potential prey availability. To better understand the bioenergetic consequences of diet variability at the individual level, I tested the hypothesis that croaker feeding on anchovies would be in better condition than those feeding on polychaetes using a variety of condition measures that operate on multiple time scales, including RNA:DNA, Fulton's condition factor (K), relative weight (Wr), energy density, hepatosomatic index (HSI), and gonadosomatic index (GSI). Of these condition measures, several morphometric measures were significantly positively correlated with each other and with the percentage (by weight) of anchovy in croaker diets, suggesting that the type of prey eaten is important in improving the overall condition of individual croaker. To estimate the bioenergetic consequences of diet variability on growth and consumption in croaker, I developed and validated a bioenergetic model for Atlantic croaker in the laboratory. The application of this model suggested that croaker could be an important competitor with weakfish and striped bass for food resources during the spring and summer when population abundances of these three fishes are high in Chesapeake Bay. Even though anchovies made up a relatively small portion of croaker diet and only at certain times of the year, croaker consumed more anchovy at the population level than striped bass in all simulated years and nearly as much anchovy as weakfish. This indicates that weak trophic interactions between species are important in understanding ecosystem processes and should be considered in ecosystem-based management.

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Limb, trunk, and body weight measurements were obtained for growth series of Milne-Edwards's diademed sifaka, Propithecus diadema edwardsi, and the golden-crowned sifaka, Propithecus tattersalli. Similar measures were obtained also for primarily adults of two subspecies of the western sifaka: Propithecus verreauxi coquereli, Coquerel's sifaka, and Propithecus verreauxi verreauxi, Verreaux's sifaka. Ontogenetic series for the larger-bodied P. d. edwardsi and the smaller-bodied P. tattersalli were compared to evaluate whether species-level differences in body proportions result from the differential extension of common patterns of relative growth. In bivariate plots, both subspecies of P. verreauxi were included to examine whether these taxa also lie along a growth trajectory common to all sifakas. Analyses of the data indicate that postcranial proportions for sifakas are ontogenetically scaled, much as demonstrated previously with cranial dimensions for all three species (Ravosa, 1992). As such, P. d. edwardsi apparently develops larger overall size primarily by growing at a faster rate, but not for a longer duration of time, than P. tattersalli and P. verreauxi; this is similar to results based on cranial data. A consideration of Malagasy lemur ecology suggests that regional differences in forage quality and resource availability have strongly influenced the evolutionary development of body-size variation in sifakas. On one hand, the rainforest environment of P. d. edwardsi imposes greater selective pressures for larger body size than the dry-forest environment of P. tattersalli and P. v. coquereli, or the semi-arid climate of P. v. verreauxi. On the other hand, as progressively smaller-bodied adult sifakas are located in the east, west, and northwest, this apparently supports suggestions that adult body size is set by dry-season constraints on food quality and distribution (i.e., smaller taxa are located in more seasonal habitats such as the west and northeast). Moreover, the fact that body-size differentiation occurs primarily via differences in growth rate is also due apparently to differences in resource seasonality (and juvenile mortality risk in turn) between the eastern rainforest and the more temperate northeast and west. Most scaling coefficients for both arm and leg growth range from slight negative allometry to slight positive allometry. Given the low intermembral index for sifakas, which is also an adaptation for propulsive hindlimb-dominated jumping, this suggests that differences in adult limb proportions are largely set prenatally rather than being achieved via higher rates of postnatal hindlimb growth.(ABSTRACT TRUNCATED AT 400 WORDS)