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41.
Compensatory mitigation of impacted streams and wetlands has increased over the past two decades, with the associated industry spending over US$2.9 billion in aquatic restoration annually. Despite these expenditures, evaluations by the National Research Council and U.S. Government Accountability Office have provided evidence that compensatory mitigation practices are failing to protect aquatic resource functions and services, and vague federal policy and inadequate evaluation of compensatory mitigation projects are to blame. To address these weaknesses, an update to federal regulations on compensatory mitigation was released in 2008. Additionally, the 2012 Reissuance of Nationwide Permits, some of which affects compensatory stream mitigation, was recently published. Current policy, as reflected in these documents, still uses nonspecific language to direct compensatory stream mitigation leaving most implementation decisions to the local U.S. Army Corps of Engineers district. The majority of federal mitigation policy has focused on wetland compensation, with other aquatic resources receiving less attention (e.g., streams). In this article, weaknesses of current policy are discussed, as are suggested policy changes to minimize the loss of stream ecosystem functions and services. Compensatory mitigation policy should clearly define key terms, incorporate adaptive management procedures, and provide guidelines for determining mitigation costs and compensation ratio requirements.  相似文献   
42.
Coastal communities experience a wide array of environmental and social changes to which they must constantly adapt. Further, a community's perception of change and risk has significant implications for a community's willingness and ability to adapt to both current and future changes. As part of a larger study focusing on the adaptive capacity of communities on the Andaman Coast of Thailand, we used Photovoice to open a dialogue with communities about changes in the marine environment and in coastal communities. This article presents the results of two exploratory Photovoice processes and discusses prospects for using the Photovoice method for exploring social and environmental change. Changes examined included a number of broader environmental and social trends as well as ecological specifics and social particularities in each site. Participants also explored the social implications of environmental changes, the impacts of macro-scale processes on local outcomes, and emotive and active responses of individuals and communities to change. Photovoice is deemed a powerful method for: examining social, environmental, and socio-ecological change, triangulating to confirm the results of other scientific methods, revealing novel ecological interactions, and providing input into community processes focusing on natural resource management, community development, and climate change adaptation.  相似文献   
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ABSTRACT. This paper outlines an approach to planning the management of a lake heavily used for recreation and of substantial importance to the tourist economy of Northeastern Wisconsin. A framework, utilizing a three dimensional matrix, is developed to analyze levels of public concern, management alternatives and action agencies. Structural and non-structural alternatives are examined and evaluated on the basis of social and economic criteria, long- and short-term environmental impact and legal-political feasibility. Data requirements which created the necessity for an interdisciplinary approach involving social, physical, and biological sciences are enumerated. The authors examine the role of universities in assisting communities with resource management planning and detail the attributes of academic institutions which desire to successfully attack resource planning problems.  相似文献   
46.
We describe a collection of aquatic and wetland habitats in an inland landscape, and their occurrence within a terrestrial matrix, as a “freshwater ecosystem mosaic” (FEM). Aquatic and wetland habitats in any FEM can vary widely, from permanently ponded lakes, to ephemerally ponded wetlands, to groundwater‐fed springs, to flowing rivers and streams. The terrestrial matrix can also vary, including in its influence on flows of energy, materials, and organisms among ecosystems. Biota occurring in a specific region are adapted to the unique opportunities and challenges presented by spatial and temporal patterns of habitat types inherent to each FEM. To persist in any given landscape, most species move to recolonize habitats and maintain mixtures of genetic materials. Species also connect habitats through time if they possess needed morphological, physiological, or behavioral traits to persist in a habitat through periods of unfavorable environmental conditions. By examining key spatial and temporal patterns underlying FEMs, and species‐specific adaptations to these patterns, a better understanding of the structural and functional connectivity of a landscape can be obtained. Fully including aquatic, wetland, and terrestrial habitats in FEMs facilitates adoption of the next generation of individual‐based models that integrate the principles of population, community, and ecosystem ecology.  相似文献   
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This paper presents a case-study of valuation of public access to a woodland site owned by The Crown Estate in Windsor Forest. It supports the view that contingent valuation is an appropriate technique to use for assessing recreational benefits in the countryside and that consistent and useful results can be obtained. The study found that the recreational benefits far outweighed the costs of access provision, thus giving reassurance to the providers that their efforts are worthwhile.  相似文献   
48.
Summary Anting is a behavior common among passerine birds, yet its function is unknown. The behavior consists of a highly stereotyped set of movements which start when a bird picks up an ant, usually one which sprays formic acid as a defense, and sweeps it with frenzied motions through its feathers. The bird will often also eat the ant. As formic acid is toxic, we have tested the food-preparation hypothesis, that is, that the birds are anting to remove a distasteful or toxic substance from the ant before eating it. In a pair of experiments on starlings, Sturnus vulgaris, we have found evidence in support of this hypothesis. Correspondence to: O.P. Judson  相似文献   
49.
A fatal case of medium-chain acyl-coenzyme A dehydrogenase deficiency is described in a patient who presented with hypoglycaemia and a gross non-ketotic dicarboxylic aciduria. Cultured skin fibroblasts released 14CO2 from [1–14C] octanoic acid at half the normal rate. Prenatal diagnosis was undertaken in a subsequent pregnancy in which cultured amniotic fluid cells revealed a marked reduction in octanoate oxidation indicative of an affected fetus. The pregnancy was terminated and the diagnosis was confirmed by enzyme analysis of skin fibroblasts taken from the fetus. The high residual octanoate oxidation by affected fibroblasts together with the absence of any characteristic abnormality of amniotic fluid organic acids are a potential limitation to the reliability of this type of prenatal diagnosis.  相似文献   
50.
To meet the growing demand for chocolate, cocoa (Theobroma cacao) agriculture is expanding and intensifying. Although this threatens tropical forests, cocoa sustainability initiatives largely overlook biodiversity conservation. To inform these initiatives, we analyzed how cocoa agriculture affects bird diversity at farm and landscape scales with a meta-analysis of 23 studies. We extracted 214 Hedges' g* comparisons of bird diversity and 14 comparisons of community similarity between a forest baseline and 4 farming systems that cover an intensification gradient in landscapes with high and low forest cover, and we summarized 119 correlations between cocoa farm features and bird diversity. Bird diversity declined sharply in low shade cocoa. Cocoa with >30% canopy cover from diverse trees retained bird diversity similar to nearby primary or mature secondary forest but held a different community of birds. Diversity of endemic species, frugivores, and insectivores (agriculture avoiders) declined, whereas diversity of habitat generalists, migrants, nectarivores, and granivores (agriculture associates) increased. As forest decreased on the landscape, the difference in bird community composition between forest and cocoa also decreased, indicating agriculture associates replaced agriculture avoiders in forest patches. Our results emphasize the need to conserve forested landscapes (land sparing) and invest in mixed-shade agroforestry (land sharing) because each strategy benefits a diverse and distinct biological community.  相似文献   
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