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351.
Fish and seafood are important contributions to a healthy diet, but also contain persistent organic pollutants (POPs) like polybrominated diphenylethers (PBDEs) and polychlorinated biphenyls (PCBs). Discrepancies have been found between intake and accumulated levels of POPs, where fish consumers have had similar levels of POPs to the general population. Similarly fish oil consumption has been found to reduce accumulation of POPs. This study examined the accumulation of BDE47 or PCB153 in mice fed diets with different nutritional composition, using female mice with pre-weanling pups exposed through gestation and lactation. A fish-based diet was compared to a standard casein-based rodent diet. All diets had low background levels of environmental contaminants and were spiked with BDE47 or PCB153 to levels representing a realistic (∼0.004 μmol kgbw−1 d) or a high dietary exposure (∼1.3 μmol kgbw−1 d). Accumulation of BDE47 or PCB153 in offspring tissues after 18 d lactation reflected the maternal exposure levels. However, the pups of dams fed a fish-based diet had consistently lower BDE47 accumulation in liver, fat and stomach than pups from casein-fed dams. Similarly the pups of dams fed a high dose of PCB153 in a fish diet also accumulated less PCB153 than pups of the dams fed a casein diet, although not significant. In conclusion, the fish based diets seemed to reduce transfer of BDE47 and PCB153 from dams to pups. The study highlights that in-depth knowledge about nutritional impact on toxicokinetics is of great interest to vulnerable consumers. 相似文献
352.
353.
This study evaluated the impact of small boat traffic on reaction distances of Marbled Murrelets (Brachyramphus marmoratus), in the marine waters of Pacific Rim National Park Reserve, British Columbia, Canada. Observers on moving boats recorded the minimum distance the boat came to murrelets on the water, and any disturbance reaction (fly, dive, no reaction). Out of the 7500 interactions 11.7% flew, 30.8% dove and 58.1% exhibited no flushing reaction. Using a product-limit analysis, we developed curves for the proportion of Marbled Murrelets flushing (dive or flight) as a function of reaction distance. Overall, the majority of Marbled Murrelets waited until boats were within 40 m before reacting, with 25% of the population reacting at 29.2m. A stepwise Cox regression indicated that age, boat speed, and boat density (loaded in that order), significantly affected flushing response. More juveniles flushed than adults (70.1 versus 51.7%), but at closer distances. Faster boats caused a greater proportion of birds to flush, and at further distances (25% of birds flushed at 40 m at speeds > 29 kph versus 28m at speeds <12kph). A stepwise logistic regression on diving and flight responses indicated that birds tended to fly completely out of feeding areas at the approach of boats travelling >28.8 kph and later in the season (July and August). Other secondary variables included; boat density and time of day. Discussion focused on possible management actions such as the application of speed limits, set back distances, and exclusion of boat traffic to protect Marbled Murrelets. 相似文献
354.
Hemlock Woolly Adelgid (Adelges tsugae) is spreading across forests in eastern North America, causing mortality of eastern hemlock (Tsuga canadensis [L.] Carr.) and Carolina hemlock (Tsuga caroliniana Engelm.). The loss of hemlock from riparian forests in Great Smoky Mountains National Park (GSMNP) may result in significant
physical, chemical, and biological alterations to stream environments. To assess the influence of riparian hemlock stands
on stream conditions and estimate possible impacts from hemlock loss in GSMNP, we paired hardwood- and hemlock-dominated streams
to examine differences in water temperature, nitrate concentrations, pH, discharge, and available photosynthetic light. We
used a Geographic Information System (GIS) to identify stream pairs that were similar in topography, geology, land use, and
disturbance history in order to isolate forest type as a variable. Differences between hemlock- and hardwood-dominated streams
could not be explained by dominant forest type alone as forest type yields no consistent signal on measured conditions of
headwater streams in GSMNP. The variability in the results indicate that other landscape variables, such as the influence
of understory Rhododendron species, may exert more control on stream conditions than canopy composition. The results of this study suggest that the
replacement of hemlock overstory with hardwood species will have minimal impact on long-term stream conditions, however disturbance
during the transition is likely to have significant impacts. Management of riparian forests undergoing hemlock decline should,
therefore, focus on facilitating a faster transition to hardwood-dominated stands to minimize long-term effects on water quality. 相似文献
355.
Management effectiveness evaluation has been recognized as an important mechanism for both reporting on and improving protected
area management. The Convention on Biological Diversity’s program of work on protected areas calls on all countries to implement
such systems. In 2004, the first whole of system assessment of park management effectiveness, based on the IUCN-WCPA Management
Effectiveness Evaluation Framework, was undertaken in New South Wales, Australia as part of a State of the Parks reporting
requirement. This article describes the development of the State of the Parks assessment tool, its elements, and how it addresses
the management effectiveness difficulties associated with assessments conducted across an extensive and diverse range of park
types. The importance of engaging staff, at all levels, throughout the process is highlighted, as well as the adjustments
made to the assessment tool based on staff feedback. While some results are presented, the main purpose of the article is
to identify and discuss important procedural and methodological considerations. These include balancing quantitative and qualitative
assessment approaches, achieving a comprehensive understanding of the management processes, and responding to any problems
associated with assessments. 相似文献
356.
Xiaojiang Tang Yang Bai Anh Duong Martyn T. Smith Laiyu Li Luoping Zhang 《Environment international》2009,35(8):1210-1224
Formaldehyde, an economically important chemical, is classified as a human carcinogen that causes nasopharyngeal cancer and probably leukemia. As China is the largest producer and consumer of formaldehyde in the world, the Chinese population is potentially at increased risk for cancer and other associated health effects. In this paper we review formaldehyde production, consumption, exposure, and health effects in China. We collected and analyzed over 200 Chinese and English documents from scientific journals, selected newspapers, government publications, and websites pertaining to formaldehyde and its subsequent health effects.Over the last 20 years, China's formaldehyde industry has experienced unprecedented growth, and now produces and consumes one-third of the world's formaldehyde. More than 65% of the Chinese formaldehyde output is used to produce resins mainly found in wood products — the major source of indoor pollution in China. Although the Chinese government has issued a series of standards to regulate formaldehyde exposure, concentrations in homes, office buildings, workshops, public places, and food often exceed the national standards. In addition, there have been numerous reports of formaldehyde-induced health problems, including poisoning and cancer. The lack of quality epidemiological studies and basic data on exposed populations emphasizes the need for more extensive studies on formaldehyde and its related health effects in China. 相似文献
357.
Visitor perceptions of rural landscapes: a case study in the Peak District National Park, England 总被引:1,自引:0,他引:1
Maintaining national parks is an integral policy tool to conserve rare habitats. However, because national parks are funded by taxpayers, they must also serve the needs of the general public. Increasingly, and thanks to today's diverse society, there is evidence that this creates challenges for park managers who are pulled in two opposing directions: to conserve nature on the one hand and to meet different visitor expectations on the other. This tension was explored in the Peak District National Park, a rural landscape dominated by heather moorland and sheep farming in Northern England where research was conducted to determine how social class and ethnicity shaped perceptions of the park. Results uncovered that social class played a very strong role in shaping perceptions of this region with 'middle class' respondents reacting far more favourably to the park than people from more working class backgrounds. We observed ethnicity playing a similar role, though our results are less significantly different. 相似文献
358.
On the decline of ground lichen forests in the Swedish boreal landscape: Implications for reindeer husbandry and sustainable forest management 总被引:1,自引:0,他引:1
Per Sandström Neil Cory Johan Svensson Henrik Hedenås Leif Jougda Nanna Borchert 《Ambio》2016,45(4):415-429
Lichens are a bottleneck resource for circumpolar populations of reindeer, and as such, for reindeer husbandry as an indigenous Sami land-use tradition in northern Sweden. This study uses ground lichen data and forest information collected within the Swedish National Forest Inventory since 1953, on the scale of northern Sweden. We found a 71 % decline in the area of lichen-abundant forests over the last 60 years. A decline was observed in all regions and age classes and especially coincided with a decrease of >60 year old, open pine forests, which was the primary explanatory factor in our model. The effects of reindeer numbers were inconclusive in explaining the decrease in lichen-abundant forest. The role that forestry has played in causing this decline can be debated, but forestry can have a significant role in reversing the trend and improving ground lichen conditions.
Electronic supplementary material
The online version of this article (doi:10.1007/s13280-015-0759-0) contains supplementary material, which is available to authorized users. 相似文献359.
旅游资源经济价值的量化能促进资源的合理开发和保护利用,对旅游资源价值的评估是监测旅游资源的保护与可持续开发利用效果的理论基础。以甘肃国家级自然保护区为研究对象,运用游憩费用法对甘肃国家级自然保护区旅游资源的游憩价值进行了评估,计算出其游憩总价值。这些结果可为甘肃国家级自然保护区的旅游资源管理决策和旅游资源补偿提供一定的参考。 相似文献
360.
E Amodio R Turci MF Massenti F Di Gaudio C Minoia F Vitale A Firenze G Calamusa 《Chemosphere》2012,89(8):970-974