778 research outputs found

    Preserving Nature

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    To consider the broader environmental significance of protecting species at risk of extinction, we must first consider the roles or functions that species fulfill in nature. Although nature has many definitions, here we define it to mean the end product of ecological and evolutionary processes. That is, within ahabitat, region, or biosphere, the condition of the soil, water, air, and biota reßects the outcome of physical, chemical, ecological, and evolutionary processes. We refer to this combination of abiotic and biotic conditions as nature and to the ecological and evolutionary processes that create it as natural processes. Using these definitions, we propose three approaches in which environmental actions can protect or conserve nature. The first approach is to preserve natural processes by directly managing them or providing suitable substitutions. For example, we can directly manage apolluted watershed to restore its water quality, or we can build expensive water treatment facilities to treat the water (Chichilnisky and Heal1998). The second approach is to protect nature itself, assuming that with adequate protection nature and its natural processes will persist. For example, we can designate marine protected areas that exclude human activities. The third approach is to protect the biotic components of nature that govern the environment. This approach encompasses the intent of the Endangered Species Act (ESA): to protect nature by protecting species. In this chapter, we examine the broader environmental significance of the Endangered Species Act by reviewing the roles species play in natural processes and by examining how natural processes govern our environment, how human activities modify nature, and how the Endangered Species Act can ameliorate the impacts of human activities

    Preserving Nature

    Get PDF
    To consider the broader environmental significance of protecting species at risk of extinction, we must first consider the roles or functions that species fulfill in nature. Although nature has many definitions, here we define it to mean the end product of ecological and evolutionary processes. That is, within ahabitat, region, or biosphere, the condition of the soil, water, air, and biota reßects the outcome of physical, chemical, ecological, and evolutionary processes. We refer to this combination of abiotic and biotic conditions as nature and to the ecological and evolutionary processes that create it as natural processes. Using these definitions, we propose three approaches in which environmental actions can protect or conserve nature. The first approach is to preserve natural processes by directly managing them or providing suitable substitutions. For example, we can directly manage apolluted watershed to restore its water quality, or we can build expensive water treatment facilities to treat the water (Chichilnisky and Heal1998). The second approach is to protect nature itself, assuming that with adequate protection nature and its natural processes will persist. For example, we can designate marine protected areas that exclude human activities. The third approach is to protect the biotic components of nature that govern the environment. This approach encompasses the intent of the Endangered Species Act (ESA): to protect nature by protecting species. In this chapter, we examine the broader environmental significance of the Endangered Species Act by reviewing the roles species play in natural processes and by examining how natural processes govern our environment, how human activities modify nature, and how the Endangered Species Act can ameliorate the impacts of human activities

    Diversification of the Alpine Chipmunk, Tamias alpinus, an alpine endemic of the Sierra Nevada, California

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    BACKGROUND The glaciation cycles that occurred throughout the Pleistocene in western North America caused frequent shifts in species' ranges with important implications for models of species divergence. For example, long periods of allopatry during species' range contractions allowed for the accumulation of differences between separated populations promoting lineage divergence. In contrast, range expansions during interglacial periods may have had homogenizing effects via increased gene flow following secondary contact. These range dynamics are particularly pronounced in the Sierra Nevada, California, given the complex topography and climatic history of the area, thus providing a natural laboratory to examine evolutionary processes that have led to the diversity patterns observed today. RESULTS Here we examined the role of late Pleistocene climate fluctuations on the divergence of the Sierra Nevada endemic Alpine Chipmunk (Tamias alpinus) from its sister taxon, western populations of the Least Chipmunk (T. minimus) from the Great Basin. We used one mitochondrial gene (cytochrome b) and 14 microsatellite loci to examine the evolutionary relationship between these species. Mitochondrial sequence data revealed that T. alpinus and T. minimus populations share mitochondrial haplotypes with no overall geneaological separation, and that diversity at this locus is better explained by geography than by species' boundaries. In contrast, the microsatellite analysis showed that populations of the same species are more similar to each other than they are to members of the other species. Similarly, a morphological analysis of voucher specimens confirmed known differences in morphological characters between species providing no evidence of recent hybridization. Coalescent analysis of the divergence history indicated a late Pleistocene splitting time (~450 ka) and subsequent, though limited, gene flow between the two lineages. CONCLUSIONS Our results suggest that the two species are distinct and there is no contemporary introgression along their geographic boundary. The divergence of T. alpinus during this time period provides additional evidence that Pleistocene glacial cycles played an important role in diversification of species in Sierra Nevada and North America in general.E. M. Rubidge was supported by a National Science & Engineering Research Council (NSERC) PGS-D award, the Museum of Vertebrate Zoology, and the Environmental Science, Policy and Management Department at UC Berkeley, during this research. The project was funded by the Museum of Vertebrate Zoology at UC Berkeley, the Yosemite Fund, the National Geographic Society and the National Science Foundation

    High Genetic Diversity Despite the Potential for Stepping-Stone Colonizations in an Invasive Species of Gecko on Moorea, French Polynesia

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    Invasive species often have reduced genetic diversity, but the opposite can be true if there have been multiple introductions and genetic admixture. Reduced diversity is most likely soon after establishment, in remote locations, when there is lower propagule pressure and with stepping-stone colonizations. The common house gecko (Hemidactylus frenatus) was introduced to Moorea, French Polynesia in the remote eastern Pacific within the last two decades and accordingly is expected to exhibit low diversity. In contrast, we show that H. frenatus on Moorea has exceptionally high genetic diversity, similar to that near the native range in Asia and much higher than reported for other Pacific island reptiles. The high diversity in this recently founded population likely reflects extensive genetic admixture in source population(s) and a life history that promotes retention of diversity. These observations point to the importance of understanding range-wide dynamics of genetic admixture in highly invasive species

    Привлечение иностранного капитала в Украину путем выпуска еврооблигаций

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    In mountain ecosystems, species can be said to respond synchronously to environmental change when the elevation ranges of vegetation types and their associated vertebrates expand or contract in the same direction. Conversely, the response is asynchronous when the elevation ranges of vegetation types and associated vertebrates change in different directions. The capacity of vertebrate species to respond synchronously with change in the elevation ranges of the vegetation that comprises their habitat is likely a function of their ecological traits. Here we combine measures of elevation range shifts in 23 vertebrate species with those of their associated vegetation types across 80 yr, on a large elevation transect in California's Sierra Nevada mountains that encompasses Yosemite National Park. Half the species’ shifts were synchronous with vegetation shifts, ¼ of the species were asynchronous, and the others showed no relationship. Most species that responded synchronously to changes in vegetation elevation ranges expanded their elevation range, and are inhabitants of low and intermediate elevations. In contrast, those species whose range shifts were asynchronous to associated vegetation shifts inhabit high elevations. These species experienced contraction in elevation range even while their associated vegetation types expanded. However, these species were responding synchronously to a subset of their associated vegetation types. Considering trait-based predictors, omnivores were more synchronous than herbivores. Our results on synchronous and asynchronous elevation shifts with vegetation may permit more accurate modeling of future ranges for vertebrates in California's Sierra Nevada. The approach also offers a new method for use in assessment of vertebrate vulnerability in other mountain regions, and can be an important component of assessing their vulnerability to climate change

    State of Wet Tropics Report 2015-2016: ancient, endemic, rare and threatened vertebrates of the wet tropics

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    Each year the Wet Tropics Management Authority prepares a report on the administration of the Act during the year, financial statements for the year, and a report on the state of the Wet Tropics World Heritage Area. This State of Wet Tropics report satisfies the requirements of Queensland's Wet Tropics World Heritage Protection and Management Act 1993 and the Commonwealth's Wet Tropics of Queensland World Heritage Conservation Act 1994
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