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121.
Alister Scott Mike Christie Helen Tench 《Journal of Environmental Planning and Management》2003,46(4):583-604
This paper assesses the efficacy and relevance of visitor payback as a tool for recreation management in the UK. Visitor payback is essentially a voluntary payment made by visitors towards conservation, differing significantly from the compulsory tourist or bed tax practised in other countries. Attention has recently focused on this technique as a means to supplement the limited funds available for conservation work. However, whilst there are several schemes operating in the UK, there is a dearth of published research that has critically reviewed the concept and operationalization of visitor payback. The research reported here utilizes primary and secondary data to include case studies, semi-structured interviews and focus groups. The findings reveal that visitor payback is a complex concept to evaluate, both in theory and practice, involving a range of benefits and disbenefits. Financial benefits appear less prevalent than the more esoteric ‘feel good’ factor, increased awareness about conservation and partnerships that are evident in payback schemes. Support for visitor payback varies considerably with visitors strongly receptive, whilst the tourism business interests are more cautious. It is concluded that visitor payback needs to be re-conceptualized in more positive terms as a ‘visitor investment scheme’ where conservation takes precedence over financial considerations. Further research is required to try and demystify the tourism business resistance to visitor payback as its potential seems somewhat constrained in the present climate. 相似文献
122.
Effects of coral transplantation in sites of varying distances and environmental conditions 总被引:1,自引:0,他引:1
Several scleractinian coral species with different growth forms and life history strategies were studied in terms of colony
growth (expressed as projected linear increment) and survivorship over a range of distances and environmental conditions in
the Philippines. The experimental design consisted of 1 m2 plots grouped within a reef site, to several sites within reef systems separated by a distance of about 340 km. There were
distinct differences among species, with submassive and massive forms displaying slower growth but better survival, confirming
results of other studies. They probably play the role of framework builders of the reef. In contrast, the delicate branching
and foliose species had higher growth rates but poor survivorship. This observation, plus their ease of fragmentation, suggests
they act more as fillers of the reef matrix. There was high variability in colony increment of a species among the square
meter plots, but not among sites within a reef system. Thus, more regular pattern could be observed at this level. In contrast
to growth, survivorship differed significantly among sites, being lowest in the site which harbored the greatest amount of
dead coral. Growth and survival, however, are not sufficient performance measures to evaluate the success of coral transplantation.
Reproduction and subsequent recruitment must also be taken into account. It is recommended that coral transplant and restoration
studies consider the broad environmental context of restoration and seek to develop assembly rules that will allow practitioners
to match coral types and sequence of interventions to each unique context. 相似文献
123.
Stream-bed phosphorus in paired catchments with different agricultural land use intensity 总被引:3,自引:0,他引:3
Elizabeth J. Palmer-Felgate Helen P. Jarvie Paul J.A. Withers Robert J.G. Mortimer Michael D. Krom 《Agriculture, ecosystems & environment》2009,134(1-2):53-66
Stream-bed sediments from three paired catchments, each draining a lower agricultural intensity system and a higher agricultural intensity system, were analysed for (a) total P (TP), (b) bioavailable-P (Resin-P), (c) equilibrium phosphorus concentration (EPC0), and (d) degree of phosphorus saturation (DPS). The influence of agriculture on sediment P was explored within the context of other key variables that may control the sediment P concentrations such as particle size, Fe, Ca and organic matter content, and in terms of potential implications of sediment P to in-stream biota. TP concentrations, EPC0, and the proportion of fine sediment were highest at the sites with the greater agricultural impact. Higher concentrations of bioavailable-P were also found in higher intensity agricultural systems. However, the highest concentrations of bioavailable-P were found at sites with point source inputs. Sites with high Fe concentrations had higher TP concentrations relative to agricultural intensity, but also had lower DPS values, illustrating that the sediment still had the capacity to take up P in a strongly bound form. The results from this study show that higher risk agricultural practices (intensive arable production and dairy and beef production) can lead either directly, or indirectly through increased inputs of fine sediment, to increased sediment TP concentrations. The importance of geochemical and physical controls on the bed sediments’ capacity to mitigate high P inputs in headwater lowland streams, especially under low flows and times of eutrophication risk in spring and summer is illustrated. 相似文献
124.
125.
In this paper, we examined the interactive effects of two contexts—participation and intellectual stimulation, and promotion focus on creativity. On the basis of a multi‐organization sample of 213 employees, we tested and found that although promotion focus was positively related to creativity, the relationship between promotion focus and creativity was most positive when both participation and leader intellectual stimulation were high. We discuss the way contexts in combination influence employee creativity for promotion‐oriented individuals, through increasing decision latitude as well as stimulating and promoting creativity. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
126.
R.?Andrew?HayesEmail author Andrew?M.?Piggott Timothy?E.?Smith Helen?F.?Nahrung 《Chemoecology》2014,24(3):95-103
Plant secondary chemistry mediates the ability of herbivores to locate, accept and survive on potential host plants. We examined the relationship between attack by the cerambycid beetle Phoracantha solida and the chemistry of the secondary phloem (inner bark) of two differentially attacked plantation forestry taxa, Corymbia variegata and its hybrid with C. torelliana. We hypothesised that this differential rate of attack may have to do with differences in secondary chemistry between the taxa. We found differences in the bark chemistry of the taxa, both with respect to phenolic compounds and terpenoids. We could detect no difference between bored and non-bored C. variegata trees (the less preferred, but co-evolved host). Hybrid trees were not different in levels of total polyphenols, flavanols or terpenes according to attack status, but acetone extracts were significantly different between bored and non-bored trees. We propose that variations in the bark chemistry explain the differential attack rate between C. variegata and the hybrid hosts. 相似文献
127.
Helen Y. Chen Clayton C. Hodges Randel L. Dymond 《Journal of the American Water Resources Association》2021,57(1):109-133
Stream ecosystems are increasingly at risk for thermal impairment as urbanization intensifies, resulting in more heated runoff from impervious cover that is less likely to be cooled naturally. While several best management practices, including bioretention filters, have been able to reduce thermal pollution, success has been limited. The extent of thermal mitigation required to prevent ecological damage remains unknown. A calibrated runoff temperature model of a case study watershed in Blacksburg, VA was developed to determine the cumulative treatment volume of bioretention filters required to reduce thermal impacts caused by runoff from development in the watershed to regulated biologically acceptable levels. A future build out scenario of the study watershed was also analyzed. Results from this study established that runoff thermal pollution cannot be fully reduced to goal thresholds during all storms using bioretention filter retrofits. While retrofitting significantly decreased temperatures and heat exports relative to the controls, increasing treatment volumes did not really enhance mitigation. Alternate thermal mitigation methods that actively remove runoff volume should be considered where more thermal mitigation is required. 相似文献
128.
Miguel Azcuna Jortan O. Tun Helen T. Yap Gisela P. Concepcion 《Chemistry and Ecology》2018,34(5):397-411
Marine sponges can produce allelopathic compounds with specific roles in the competition for benthic space. Here we demonstrate that extracts from Callyspongia samarensis (Phylum Porifera) accelerate bleaching in Porites cylindrica (Phylum Cnidaria, Order Scleractinia) and exhibit in vitro anticancer activity. A column chromatography fraction and HPLC fraction, purified from the crude methanol extract of C. samarensis, were incorporated into agar gel cubes at natural concentrations and tested on P. cylindrica corals in a laboratory assay. Statistical analysis of percent bleached area and maximum quantum yield showed that a significant difference existed between P. cylindrica nubbins that were exposed to C. samarensis extracts versus the control group. This suggests that C. samarensis contains allelopathic compounds that can cause bleaching in P. cylindrica, possibly leading to tissue necrosis and death. Furthermore, the aforementioned HPLC fraction exhibited significant growth inhibition of the HCT-116 (human colon cancer) cell line. Understanding the strategies by which sponges exert dominance over other organisms is important because it provides information about the ecological roles of sponge allelopathy and can result in the discovery of compounds with biomedical potential. 相似文献
129.
António O. Soares Danny Haelewaters Olga M. C. C. Ameixa Isabel Borges Peter M. J. Brown Pedro Cardoso Michiel D. de Groot Edward W. Evans Audrey A. Grez Axel Hochkirch Milada Holecová Alois Honěk Ján Kulfan Ana I. Lillebø Zdenka Martinková J. P. Michaud Oldřich Nedvěd Omkar Helen E. Roy Swati Saxena Apoorva Shandilya Arnaud Sentis Jiri Skuhrovec Sandra Viglášová Peter Zach Tania Zaviezo John E. Losey 《Conservation biology》2023,37(1):e13965
Ladybirds (Coleoptera: Coccinellidae) provide services that are critical to food production, and they fulfill an ecological role as a food source for predators. The richness, abundance, and distribution of ladybirds, however, are compromised by many anthropogenic threats. Meanwhile, a lack of knowledge of the conservation status of most species and the factors driving their population dynamics hinders the development and implementation of conservation strategies for ladybirds. We conducted a review of the literature on the ecology, diversity, and conservation of ladybirds to identify their key ecological threats. Ladybird populations are most affected by climate factors, landscape composition, and biological invasions. We suggest mitigating actions for ladybird conservation and recovery. Short-term actions include citizen science programs and education, protective measures for habitat recovery and threatened species, prevention of the introduction of non-native species, and the maintenance and restoration of natural areas and landscape heterogeneity. Mid-term actions involve the analysis of data from monitoring programs and insect collections to disentangle the effect of different threats to ladybird populations, understand habitat use by taxa on which there is limited knowledge, and quantify temporal trends of abundance, diversity, and biomass along a management-intensity gradient. Long-term actions include the development of a worldwide monitoring program based on standardized sampling to fill data gaps, increase explanatory power, streamline analyses, and facilitate global collaborations. 相似文献
130.
Bhattarai Tek Narayan Ghimire Swastik Mainali Bandita Gorjian Shiva Treichel Helen Paudel Shukra Raj 《Environmental science and pollution research international》2023,30(10):25452-25476
Environmental Science and Pollution Research - Energy transformation and sustainability have become a challenge, especially for developing countries, which face broad energy-related issues such as... 相似文献