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181.
Population Trends and the Koala Conservation Debate 总被引:1,自引:0,他引:1
Stephen S. Phillips 《Conservation biology》2000,14(3):650-659
Abstract: A critical issue affecting the long-term management of koalas is their perceived conservation status. Koalas still occur in many areas throughout their historical range, but numbers of animals are estimated to vary from <100,000 to at least one order of magnitude higher. Complex factors limit free-ranging koala populations, including food tree preferences, history of disturbance, and Chlamydia infection, all of which make longer-term population trends of many populations difficult to predict. Lack of consensus regarding the size and viability of remaining populations and regarding the extent of and reasons for decline, overabundance or in some instances, hinders the conservation task. A reappraisal of population trends suggests that, notwithstanding localized management issues in Victoria and South Australia, overall the species is "vulnerable" on the basis of current World Conservation Union criteria. Recommendations for more effective conservation of koalas include (1) acknowledging the legitimacy of differing perspectives, (2) recognizing the uncertainty and assumptions inherent in population estimates and trends, (3) applying greater rigor and developing better standards for monitoring population trends, and (4) being cautious in assigning conservation status to national, state, and regional populations. 相似文献
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The effects of ultraviolet radiation (UVR), desiccation and conditions in tidal pools on embryonic survival were examined
for two common pulmonate limpets that lay intertidal benthic egg masses on rocky shores in New Zealand: Benhamina obliquata and Siphonaria australis. Field surveys and manipulative experiments were conducted between December 2006 and September 2007 in the Wellington region
of New Zealand (41°17′S, 174°47′E). Egg mass deposition sites in the field were species-specific: B. obliquata deposited eggs primarily in shaded crevices, whereas S. australis predominantly deposited egg masses in the sun and in tidal pools. For both species, however, embryonic mortality was greater
in egg masses that had been in full sun compared to shade. For S. australis, there was also high mortality in egg masses in tidal pools or desiccated compared to those that remained submerged in flowing
seawater at low tide. In outdoor experiments, embryonic mortality was also always greatest for egg masses exposed to full
sun, and lowest for those in shaded treatments. Mortality was also higher if egg masses were in simulated tidal pools, and
for S. australis, if desiccated, compared to those submerged in flowing seawater. Periods of particularly sunny conditions with high temperatures
also resulted in higher overall mortality. Finally, egg masses of both species that were initially deposited in the shade had greater mortality in response to subsequent
UV exposure compared to egg masses initially deposited in full sun. Results from this study suggest that the egg masses of
these two species are highly vulnerable to UVR, as well as other intertidal stressors. Embryos of both of these species may
be at risk of high mortality particularly during summer when extreme conditions of UV intensity and high temperature coincide
with low tide cycles.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
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Mark Phillips 《Environment, Development and Sustainability》2007,9(3):241-261
In early 1980 an extension agent was assigned to the rural municipality of Bangui, Ilocos Norte, Philippines to work on development
projects – in particular the improvement of the supply of safe water for drinking and sanitation. After many months of visiting
spring sites and meeting with community leaders, a small part of the municipality was selected to build a gravity fed piped
water system. Although the system took many months to plan, identify funding and construct, the 600 community members were
ultimately rewarded with house to house connections that enabled them to achieve per capita water consumption levels above
the minimum levels recommended by the World Health Organization. Of course, money was critical to ensure the project’s success,
but many other factors played an equally critical role. For instance, without the active participation of the community and
the unwavering support of the community leadership the project would not have survived the initial planning stage. Also, the
extension agent played a critical role by acting as a conduit between funding agencies, the Bureau of Public Works and the
community. The primary lesson to be learned from this experience is that the success of rural development projects is largely
driven by the synergy between the community, technical support, financial support, and agents of change such as extension
agents. If any of these ingredients had been lacking, the project result would likely have been far different. 相似文献
187.
Peter G. Flachsbart Susan Phillips 《Journal of the Air & Waste Management Association (1995)》2013,63(7):759-768
This study undertook an empirical Investigation of human response to air quality. Home interviews of 475 respondents living in 22 neighborhoods of Los Angeles County had elicited information on respondent socioeconomic characteristics, behavioral patterns, and measures of human response to air quality. This data base was then augmented with nine measures of actual air quality for six time frames for each neighborhood. An observer-based air quality index (OBAQI) was constructed based upon which combination of air quality variables correlated best with the percentage of neighborhood respondents who perceived “smoggy air.” The best combination (OBAQI 3) consisted of prevailing visibility, O3, and SO2, each measured as the annual number of days that a selected standard had been equalled or exceeded. Subsequently, multiple regression models were constructed using this index as a predictor of aggregated perception of air quality. In addition to a general model for all neighborhoods, separate models were constructed for clusters of neighborhoods of similar micrometeorology as approximated by uniform elevations and/or coastal distances. Zones of homogeneous air quality and micrometeorology were then defined. Within these zones variation in four measures of human response to air quality was associated with respondent socioeconomic characteristics and behavioral patterns. Both the index and model could prove useful in gauging public response to proposed actions of air quality management districts. 相似文献
188.
Eric C. Shepherd Timothy D. Phillips Gary N. Joiner Leon F. Kubena Norman D. Heidelbaugh 《Journal of environmental science and health. Part. B》2013,48(5):557-573
Abstract Penicillic Acid (PA) and Ochratoxin A (OA) are toxic fungal metabolites that are synergistic in combination. This interaction was investigated using mice which were dosed orally as follows: control, none; solvent control, 0.2 ml bicarbonate buffer; PA, 40 mg/kg; OA, 10 mg/kg and combination, 40 mg/kg PA + 10 mg/kg OA. The only significant histopathologic change observed was an acute multifocal toxic tubular nephrosis which appeared most severe in the combination‐treated mice killed on day 10. While the combination group had a death rate of 20% (5/25), no deaths occurred in the other treatment groups. The increased death rate and the extensive nephrotoxic findings in the combination group indicate a toxic interaction between OA and PA at sub‐lethal dose levels and is consistent with a renal site of action. 相似文献
189.
Terry L Tudor Anne C Woolridge Margaret P Bates Paul S Phillips Sharon Butler Keith Jones 《Waste management & research》2008,26(3):233-240
Changes in environmental legislation and standards governing healthcare waste, such as the Hazardous Waste Regulations are expected to have a significant impact on healthcare waste quantities and costs in England and Wales. This paper presents findings from two award winning case study organizations, the Cardiff and Vale NHS Trust and the Cornwall NHS Trust on 'systems' they have employed for minimizing waste. The results suggest the need for the development and implementation of a holistic range of systems in order to develop best practice, including waste minimization strategies, key performance indicators, and staff training and awareness. The implications for the sharing of best practice from the two case studies are also discussed. 相似文献
190.
Tree species and mycorrhizal associations influence the magnitude of rhizosphere effects 总被引:3,自引:0,他引:3
Previous research on the effects of tree species on soil processes has focused primarily on the role of leaf litter inputs. We quantified the extent to which arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) tree species influence soil microbial activity and nutrient availability through rhizosphere effects. Rhizosphere soil, bulk soil, and fine roots were collected from 12 monospecifc plots (six AM and six ECM tree species) planted on a common soil at the Turkey Hill Plantations in Dryden, New York. Rhizosphere effects were estimated by the percentage difference between rhizosphere and bulk soil samples for several assays. Rhizosphere effects on soil microbes and their activities were significant for ECM species but in only a few cases for AM species. In AM tree species, microbial biomass, net N mineralization, and phosphatase enzyme activity in the rhizosphere were 10-12% greater than in bulk soil. In ECM tree species, rhizosphere effects for microbial biomass, C mineralization rates, net N mineralization, and phosphatase activity were 25-30% greater than bulk soil, and significantly greater than AM rhizosphere effects. The magnitude of rhizosphere effects was negatively correlated with the degree of mycorrhizal colonization in AM tree species (r = -0.83) and with fine root biomass (r = -0.88) in ECM tree species, suggesting that different factors influence rhizosphere effects in tree species forming different mycorrhizal associations. Rhizosphere effects on net N mineralization and phosphatase activity were also much greater in soils with pH < 4.3 for both AM and ECM tree species, suggesting that soil pH and its relation to nutrient availability may also influence the magnitude of rhizosphere effects. Our results support the idea that tree roots stimulate nutrient availability in the rhizosphere, and that systematic differences between AM and ECM may result in distinctive rhizosphere effects for C, N, and P cycling between AM and ECM tree species. 相似文献