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161.
In this study, we describe a spatially explicit scenario analysis of global change effects on the potential future trade-offs and conflicts between agriculture, energy generation, and grassland and wetland conservation in North Dakota (ND), USA. Integrated scenarios combining global policy, oil security, and climate change were applied to North Dakota using a spatial multi-criteria analysis shell. Spatial data describing climate changes and grassland, wetland, cropland, and energy distributions were used to characterize the geographical environment. The final multi-criteria framework examined the potential trade-offs between climate change, agricultural expansion, and energy generation resulting from global change scenarios on one hand, and the current footprint of wetlands and grasslands for six regions of ND that capture the major climate gradients and differences in land use. The results suggest that the tension between regional climate changes that may limit agricultural expansion, and global changes in food and energy security and commodity prices that favor agricultural expansion, may focus a zone of potential pressure on grasslands and wetland conversion in central ND and the Prairie Pothole Region. The balance between conservation programs, commodity prices, and land parcel productivity may determine grassland conversion, while wetland outcomes may almost totally depend upon regional climate change. 相似文献
162.
In the UK for the period 1994-99, a broad range of environmental projects were given financial support through the European Agriculture Guidance and Guarantee Fund under the Objective 1 and Objective 5b programmes. This paper is concerned with the ex-post evaluation of these projects set within a Sustainable Development framework. The aim was to identify project types or characteristics that offered the greatest return on investment. A classification of six broad project types was adopted. The evaluation revealed that there were significant differences between individual projects with respect to the type and scale, and temporal and social distribution of the benefits they delivered. In particular, as well as delivering environmental and economic benefits, many projects made a significant contribution to the development of human and social capital. The paper concludes that it is possible to improve the basis for future project selection in order to maximise the returns on environmental investments in the context of sustainable development. 相似文献
163.
Impacts of recreation and tourism on plant biodiversity and vegetation in protected areas in Australia 总被引:4,自引:0,他引:4
This paper reviews recent research into the impact of recreation and tourism in protected areas on plant biodiversity and vegetation communities in Australia. Despite the international significance of the Australian flora and increasing visitation to protected areas there has been limited research on recreational and tourism impacts in Australia. As overseas, there are obvious direct impacts of recreation and tourism such as clearing of vegetation for infrastructure or damage from trampling, horse riding, mountain biking and off road vehicles. As well, there are less obvious but potentially more severe indirect impacts. This includes self-propagating impacts associated with the spread of some weeds from trails and roads. It also includes the severe impact on native vegetation, including many rare and threatened plants, from spread of the root rot fungus Phytopthora cinnamomi. This review highlights the need for more recreational ecology research in Australia. 相似文献
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165.
Kevin J. McGraw Jocelyn Hudon Geoffrey E. Hill Robert S. Parker 《Behavioral ecology and sociobiology》2005,57(4):391-397
Animals use several different types of pigments to acquire their colorful ornaments. Knowing the types of pigments that generate animal colors often provides valuable information about the costs of developing bright coloration as well as the benefits of using these signals in social or sexual contexts. It is often assumed that red, orange, and yellow colors in animals are derived from carotenoid pigments, when in fact there are other pigments that confer similar colors on animals. These include the pteridine pigments in a wide range of organisms, hemoglobin in blood-filled sinuses, the psittacofulvins of parrot feathers, and the phaeomelanin pigments in rufous or yellow feathers and fur. In this paper, we describe a quick and easy, two-step chemical method for field biologists to determine if their study species uses carotenoid pigments as integumentary colorants. This laboratory procedure first employs a thermochemical extraction technique, in which acidified pyridine is used under high temperature to free carotenoid pigments from tissue to produce a colorful, pigmented solution. Red, orange, or yellow tissues containing pteridines, hemoglobin, or eumelanins do not release colored pigments into heated pyridine. However, psittacofulvins, and occasionally phaeomelanins, will also solubilize using this method. Thus, a follow-up test is needed, using solvent transfer, to confirm the presence of carotenoids in animal tissues. The use of absorbance spectrophotometry on the colorful solution may also provide information about the predominant carotenoids that bestow color on your study animal. 相似文献
166.
Hill M Stabile C Steffen LK Hill A 《Environmental pollution (Barking, Essex : 1987)》2002,117(2):295-300
Endocrine disrupters are of substantial concern, in large part because effects of these compounds on the growth and development of many aquatic organisms are unknown. We examined toxic effects of three substances (ethylbenzene, nonylphenol, and bisphenol A), that are known to be hormonally active in many animals, on growth and development of two species of freshwater sponge. A common developmental abnormality was observed when sponges were treated with each of these compounds. The three compounds also caused significant reductions in growth rates. Lower concentrations resulted in malformed water vascular systems in several replicates. The utility of freshwater sponge bioassays is discussed as it relates to understanding possible mechanisms of action of endocrine disrupters on aquatic invertebrates. 相似文献
167.
Katherine R. Weeks Scott C. Veenstra David L. Hill Benjamin P. Gregson 《补救:环境净化治理成本、技术与工艺杂志》2003,13(2):131-143
The Army National Guard initiated an Innovative Technology Evaluation (ITE) Program in March 2000 to study potential remedial technologies for the cleanup of explosives‐contaminated soil and groundwater at the Camp Edwards site on the Massachusetts Military Reservation. The soil technologies chosen for the ITE program were: soil washing, chemical oxidation, chemical reduction, thermal desorption/destruction (LTTD), bioslurry, composting, and solid phase bioremediation. The technologies were evaluated based on their ability to treat both washed and untreated soil. A major factor considered was the ability to degrade explosives, such as RDX, found in particulate form in the soils. The heterogeneous nature of explosives in soils dictates that the preferred technology must be able to treat explosives in all forms, including the particulate form. Groundwater remediation technologies considered include: in situ cometabolic reduction, two forms of in situ chemical oxidation, Fenton‐like oxidation and potassium permanganate. This article presents the results of each of the remedial technologies evaluated and discusses which technologies met the established ITE performance goals. © 2003 Wiley Periodicals, Inc. 相似文献
168.
Unnasch RS Sprenger T Katholi CR Cupp EW Hill GE Unnasch TR 《Ecological modelling》2006,192(3-4):425-440
Eastern equine encephalitis virus (EEEV) is one of several arthropod-borne viruses (arboviruses) endemic to the United States. Interactions between arthropod (mosquito) vectors and avian amplification host populations play a significant role in the dynamics of arboviral transmission. Recent data have suggested the hypothesis that an increased rate of successful feeding on young-of-the-year (YOY) birds might play a role in the dynamics of EEEV transmission. To test this hypothesis, we developed a model to explore the effect of the interactions of the vectors and avian host populations on EEEV transmission. Sensitivity analyses conducted using this model revealed eleven parameters that were capable of disproportionately affecting the predicted level of EEEV infection in the vertebrate reservoir and vector populations. Of these, four parameters were related to the interaction of the vector with young-of-the-year birds. Furthermore, adult birds could not substitute for young-of-the-year in initiating and maintaining a predicted enzootic outbreak of EEEV. Taken together, the model predicted that young-of-the-year birds play a key role in establishing and maintaining enzootic outbreaks of EEEV. 相似文献
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