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1.
Recreation ecology, the scientific study of visitor impacts and their effective management, has been developed largely in North America, Europe, and more recently in Australia, in response to growing impacts of visitor use to protected area resources. A body of literature has been accumulated that contributes to sustainable visitor management in protected areas. This paper traces the development of recreation ecology research in East Asia and examines the field's relevance to East Asia's protected natural areas which endure both a long history of human utilisation and contemporary recreation and tourism pressure, much of which originates from surrounding densely populated urban areas. The formative, expanding and strengthening stages of recreation ecology research in this region were identified through an extensive review of literature published in English and East Asian languages. Each of these three developmental stages was illustrated with examples and compared with the general state of research during the same period. Key challenges and opportunities for future recreation ecology research in the region are discussed in light of this review.  相似文献   

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This paper investigates impacts of the creation of Marine Protected Areas (MPAs), in both economic and biological perspectives. The economic indicator is defined as the sum of discounted benefits derived from exploitation of the resource in the fishery sector, assumed to be optimally managed. The biological indicator is taken as the stock density of the resource. The basic fishery model (C.W. Clark, Mathematical Bioeconomics: The Optimal Management of Renewable Resources, second ed., John Wiley and Sons, New York, 1990) will serve as a convenient benchmark in comparing results with those that are derived from a model of two patchy populations (cf. R. Hannesson, Marine reserves: what would they accomplish, Mar. Resour. Econ. 13 (1998) 159). In the latter, a crucial characteristic is the migration coefficient with describes biological linkages between protected and unprotected areas. A set of situations where both economic and biological criteria are enhanced, after introducing a MPA, is presented. These results are obtained with the help of numerical simulations.  相似文献   

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The extension of road networks is considered one of the major factors affecting fauna survival. Roadkill has been documented widely and affects all taxonomic groups. Although roadkill is associated mainly with traffic density, some life-history traits of species and the area surrounding roads are expected to modify number of roadkills both taxonomically and geographically. Here we studied the number of roadkills of vertebrates in an extensive region in the northeastern Iberian Peninsula. We surveyed 820?km of 41 roads in two different seasons (spring and autumn), that differ in traffic intensity. In addition, we covered zones with distinct climatic characteristics and levels of protection of the surrounding habitats. Amphibians showed the highest number of roadkills whereas reptiles, birds and mammals had similar rates. General Linear Model tests showed no differences in roadkills by climatic region; however, differences in number of roadkills were linked to protection status, with the highest number of casualties in highly protected areas. Redundancy Analysis demonstrated that the number of amphibians and reptiles killed was associated with roads in highly protected areas whereas that of mammals and birds was linked to unprotected areas. Protected areas often receive many visitors, which in turn may increase wildlife casualties as a result of greater traffic density. We recommend that correction measures be taken to reduce the high number of vertebrate fauna killed along roads that cross protected areas.  相似文献   

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Protection of natural environments sought through management plans varies greatly between countries; characterizing these differences and what motivates them can inform future regional and international conservation efforts. This research builds on previous work addressing the spatial distribution of marine protected areas in the Mediterranean Sea. Particularly, it examines the relationship between a “protection level” (PL) score and a set of variables pertaining to each country's conservation efforts, economic conditions and human impact along the coast using regression analysis. Four sets of models demonstrated country characteristics that correlate with higher protection levels within marine protected areas (MPAs). Certain contextual factors – economic dependence on the marine environment, efforts at terrestrial conservation and greater human impact – were found to be significantly associated with higher PLs among the northern littoral countries of the Mediterranean. Such findings can inform policy makers about where efforts and investments should be directed for marine conservation.  相似文献   

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Recent arguments for conventional fisheries management approaches (CFMAs) and against no-take marine protected areas (NTMPAs) are reviewed, i.e. CFMAs are more effective, density-dependent factors will lead to reduced fish stock production in and around NTMPAs, rights-based approaches in combination with CFMAs will be more effective, and natural refuges from fishing already exist. It is concluded that these are largely valid but only from a fisheries management perspective. The arguments of proponents of NTMPAs and those of proponents of CFMAs are considered as contrasting storylines, the divergences between which are based on two key factors: different objectives and different science. In relation to different objectives, it is concluded that the arguments against NTMPAs based on their lack of fisheries management benefits must be considered as only applying to the secondary resource conservation objectives of such designations and not to the primary marine biodiversity conservation objectives. On this basis it is argued that it is counter-productive for NTMPAs to be ‘sold’ on a win–win basis, including their potential to deliver fisheries management benefits, as this detracts from their marine biodiversity conservation objectives and leaves such calls open to arguments that CFMAs are better able to deliver fisheries management objectives. In relation to different science, it is concluded that criticisms of NTMPAs and support for CFMAs implicitly resist the shift from Mode 1 (reductive, intra-disciplinary) to Mode 2 (holistic, trans-disciplinary) science that is inherent in calls for NTMPAs as part of an ecosystem approach. Mode 2 science attempts to accommodate both uncertainty and wider societal values and preferences, and it is argued that arguments for NTMPAs should be more explicitly focussed on this potential. It is difficult, if not impossible and inappropriate, to extend the reductive approach inherent in CFMA analyses to encompass the broader ethical and scientific concerns for the health of marine ecosystems and their component populations and habitats that arguments for NTMPAs reflect. NTMPA proponents might focus on stressing that arguments against such designations and in favour of CFMAs do not encompass such valid concerns, therefore they tell only half of the story.
P. J. S. JonesEmail:
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There are a variety of ways that environmental changes affect parasites, suggesting that information on parasites can indicate anthropogenic impacts. Parasitism may increase if the impact reduces host resistance or increases the density of intermediate or definitive hosts. Parasitism may decrease if definitive or intermediate host density declines or parasites suffer higher mortality directly (eg. from toxic effects on parasites) or indirectly (infected hosts suffer differentially high mortality). Although these scenarios are opposing, they can provide a rich set of predictions once we understand the true associations between each parasite and impact. In this review, Kevin Lafferty discusses how parasite ecologists have used and can use parasites to assess environmental quality.  相似文献   

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Biased and subjective choices of metrics to be used in ecological studies could lead researchers to reach misleading conclusions regarding patterns of biodiversity response to human disturbances. Nevertheless, little attention has been given to the choices of variables in the majority of studies published to date. Here, we used the literature concerning land use change effects on dung beetles to assess the extent to which variables commonly employed in ecological studies correspond to those deemed to be most important by researchers of the same studies. Specifically, we examined both biodiversity (response) and environmental (explanatory) metrics from a comprehensive literature review and compared their use with their relative importance, according to a survey of the authors of the studies. Our results highlight marked disparities between researchers opinion expressed in our survey and their choice of variables in published papers. We suggest that these disparities are due to the high costs of sampling and processing some variables, logistical constraints and different perceptions of importance amongst researchers. We highlight the importance of these issues for our understanding of the biodiversity consequences of land use change, and highlight some recommendations for alleviating this issue.  相似文献   

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The use of additives such as ractopamine (Rac) in pregnant sows during early-mid pregnancy is an alternative to increase foetal and progeny growth and development. However, Rac supplementation in finishing pigs can lead to behavioural and physiological changes similar to the typical stress responses. The objective of this study was to evaluate the effects of dietary supplementation with Rac in pregnant sows from day 25 to 50 of gestation (pre-hyperplastic stage) on piglet’s vitality, blood parameters, number, diameter and perimeter of muscle fibres in semitendinosus muscle and developmental characteristics of piglets at birth to weaning. Forty-one hybrid sows were divided into three dietary treatments: (1) control diet without Rac (control), (2) addition of 10 mg/kg of Rac (Rac10) and (3) addition of 20 mg/kg of Rac (Rac20). Higher numbers of low-vitality piglets (P<0.05) were observed in Rac-fed sows, regardless of dose, compared with the control group. Very low-density lipoprotein levels were lower in the Rac10 group when compared with the Rac20 group at day 21. Haematocrit was greater, and the mean corpuscular haemoglobin concentration was lower in piglets from Rac-fed sows. No significant statistical differences were detected regarding piglets body weight, average daily gain, blood gasometry, complete blood count and muscle fibre measurements in semitendinosus muscle. The use of Rac in pregnant sows reduced the vitality parameters of piglets but did not improve the performance from birth until weaning and did not negatively influence the haematological parameter and lipid metabolism.  相似文献   

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Veterinary medicines are subject to a rigorous evaluation with regard to safety, efficacy and quality before they are licensed. For drugs used in food producing animals, it is necessary to establish what is referred to as the acceptable daily intake (ADI), this is defined as an estimate of the amount of a substance, expressed on a body weight basis, that can be ingested daily over a lifetime without appreciable risk to human health. It is necessary to determine a toxicological, pharmacological and microbiological ADI. This article describes a recently harmonized guideline that outlines the process for determining the need for a microbiological ADI and discusses the test systems that take into account the complexity of the human intestinal flora. The described process is used to address the effects of antimicrobial drug residues on human intestinal flora for regulatory purposes. The guideline does not recommend any one particular system for use in regulatory decision making but provides recommendations for a harmonized approach to establish a microbiological ADI and offers test options rather than specifying a testing regimen. The process and the challenges of this new guideline are discussed.  相似文献   

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We compared glyphosate, glufosinate and metsulfuron-methyl to control Ambrosia artemisiifolia under non-crop conditions. A laboratory study showed that A. artemisiifolia is an easy-to-wet species and that glufosinate and glyphosate are quickly absorbed by its leaves (nearly 100% in 24 h). Metsulfuron-methyl absorption was slower (about 50% in 24 h) but was strongly promoted by terpenic alcohol and esterified rapeseed oil. In the greenhouse, all three herbicides were efficacious against A. artemisiifolia, with ED50s of <23, 23 and 0.8 g ha(-1) for glufosinate, glyphosate and metsulfuron-methyl, respectively. These results were confirmed on a non-crop area for glufosinate and glyphosate, which at half the registered dose reached high efficacies at both the 4 to 6-node and flowering stages of A. artemisiifolia. By contrast, metsulfuron-methyl showed no efficacy. However, after treatment at the 4- to 6-node stage, new emergence of A. artemisiifolia led to the presence of vigorous plants that bore numerous flowers and produced high levels of pollen. After treatment at the flowering stage, flower production by A. artemisiifolia was not significantly affected, but achene weight was decreased by 60 to 70% and seed viability was only 8 to 13% for the treated plants, as compared to 85% for the control. No significant difference was observed between the two herbicides and between the doses. It is concluded that glufosinate can be an alternative to glyphosate for the chemical control of A. artemisiifolia on non-crop areas. However, with both herbicides, it is difficult to attain the two objectives of reducing seed production and pollen production by means of only one treatment.  相似文献   

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Experimental analyses of causes of patterns of distribution and abundance of intertidal animals and plants on rocky shores have been a major activity for many years. In this review, some of the themes and topics that have emerged from such analyses are briefly discussed to provide an up-date for practitioners and ecologists working in other habitats. Conceptual issues include the widespread occurrence of transphyletic use of the same resources (space and food), theories and experimental analyses of intermediate disturbance in relation to numbers of species, the complex but pervasive nature of indirect interactions among species, relative importance of ‘top-down’ versus ‘bottom-up’ control of assemblages and the importance to rocky intertidal species of ‘supply-side’ influences on densities and interactions. Methodological advances include experimental designs for complex and patchy, interacting sets of species, the importance of controls in experimental manipulations and methods for analyses of hierarchical scales of patterns and processes. Finally, some contributions to social issues (pollution, biodiversity) and some scenarios for future directions are briefly considered.  相似文献   

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Although coral declines have been reported from major reefs of the world, region-specific trends still remain unclear, particularly in areas with high diversity such as the Philippines. We assessed the temporal patterns of the magnitude and trajectory of coral cover change in the Philippines using survey data collected from 317 sites. We examined the rate of change in coral cover in relation to time, effects of bleaching and protection against fishing and assessed the efficacy of marine protected areas (MPAs) using meta-analysis. Results showed an overall increase in coral cover in the Philippines from 1981 to 2010. Protection from fishing contributed to the overall increase in the mean annual rate of change as the coral cover significantly increased within MPAs than outside. The significant differences in the rate of coral cover change through time were influenced by chronic anthropogenic stresses, coinciding with the timing of thermal stress and the establishment of MPAs. The rate of change in coral cover was independent of the level of protection and the age and size of MPA.  相似文献   

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With 76% of its 3063 native species of flora endemic, the New Caledonia biodiversity hotspot has long been recognized as having a high potential for conservation. Under the new IUCN Red List categories, 25% of the endemic plants are at risk (Conservation Dependent, Vulnerable, Endangered, Critically Endangered), and five species are already extinct. A review of their distribution demonstrates that 83% of the threatened species do not occur at all in a conservation area, and only 11% have their conservation status improved by a protected area. The protected area network is geographically and floristically very unbalanced, with the rainforest and high altitude maquis in the south concentrating most of the conservation effort. Conversely, the middle and northern segments of the island, as well as all of the dry west coast, are left without adequate conservation area. Two vegetation types, the sclerophyll forest and the unique low/middle altitude maquis, are virtually totally unprotected. We conclude that the current network of protected areas needs to be considerably expanded, in terms of both geographical/floristic subregions within New Caledonia and vegetation type covered. With only 54% of the conservation area covered by strict mining restrictions, existing reserves need to have their conservation efficiency improved by a more vigorous enforcement of their status, and by extending mining bans to all of them.  相似文献   

16.
《Fungal Biology Reviews》2007,21(2-3):107-124
We have investigated community and ecosystem consequences of endophyte symbiosis with tall fescue over the past 13 y. Lolium arundinaceum is the most abundant plant in the eastern USA, and most is infected by the wild-type KY-31 endophyte Neotyphodium coenophialum. We established two large experimental grasslands (in 1994 and in 2000) with endophyte-infected or endophyte-free seed sown on recently plowed herbaceous vegetation. Other plant species established by seed or vegetative fragments. No other treatments were applied and plots were subject to natural biotic and abiotic variation. A third experiment examined ecological influences on endophyte infection dynamics starting from an intermediate infection frequency. Finally, we synthesized recent literature investigating the impacts of the tall fescue endophyte on the abundance of associated arthropod species. We found wide-ranging consequences of the endophyte from significant effects on soil feedback and decomposition rates, to plant-plant competition, diversity, productivity, invasibility and succession, to plant-herbivore interactions and energy flow through the food web. Further, we found that herbivore pressure caused rapid increases in infection frequency. Our results suggest that endophyte symbiosis in tall fescue can have a transforming effect on ecological systems.  相似文献   

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Psoriatic arthritis (PsA) is a seronegative spondyloarthropathy that commonly appears after the onset of the characteristic cutaneous lesions. This complication affects about 40% of patients with moderate to severe cutaneous disease. Analysis of synovial fluid and tissue in patients with PsA demonstrates a profile of high levels of tumor necrosis factor (TNF) plus other cytokines similar to those seen in patients with rheumatoid arthritis (RA). In the past, medical management of patients with this disease consisted of treatment with nonsteroidal anti-inflammatory agents. Patients with more severe disease have tried a number of different disease-modifying drugs including methotrexate, azathioprine, and gold salts. However, there is no evidence that these agents can arrest the progress of structural joint damage. Infliximab and etanercept are TNF antagonists that have demonstrated significant efficacy and safety in patients with RA. Clinical trials with these two agents in patients with PsA have shown significant improvement in the rheumatologic and cutaneous manifestations of the disease.  相似文献   

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《Palaeoworld》2019,28(4):572-575
Yu et al. (2019) recently described two new species of gastropods from the Cretaceous Burmese amber and attributed them to the marine family Epitoniidae. A close inspection of the images provided by Yu et al. indicates however that the species in question do not belong to that family or any marine gastropod group. In contrast, the two species are attributed here to the terrestrial operculate family Pupinidae (Cyclophoroidea) and tentatively to the genus Pseudopomatias. We briefly review the fossil record of the Cyclophoroidea and Pupinidae and discuss implications of the present revision. After all, Pseudopomatias? lyui (Yu, Wang and Jarzembowski, 2019) and P.? zhuoi (Yu, Wang and Jarzembowski, 2019) belong to the oldest members of the Pupinidae.  相似文献   

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