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991.
Spatiotemporal distribution patterns in relation to feeding behavior of herbivorous gastropods have been studied extensively, but still knowledge about small-scale patterns is limited in relation to eutrophication. This experimental study aimed to describe the small-scale distribution of Littorina littorea in nutrient-enriched and nutrient-unenriched mesocosms in a merely atidal region and relate the distribution to food abundance and possible competing organisms, while checking simultaneously for feeding activities. The latter part was accomplished through the “gut fluorescence technique” GFT (which, to our knowledge, has not previously been used for benthic grazers) to estimate per capita grazing rates and the former part through monitoring of spatial heterogeneity of L. littorea and co-variation with sessile organisms (using semivariograms and cross-semivariograms, respectively). After 5 months of nutrient addition, the abundance and biomass of L. littorea had increased in enriched systems, which also had significantly higher total biomass of green algae. Gut pigment content was higher in L. littorea from enriched mesocosms, and gut depletion rate was higher in L. littorea from unenriched mesocosms. Spatial analysis showed that L. littorea exhibited generally random patterns (suggesting feeding activities) but sometimes (often in the morning) spatial patchiness (clumped distribution) in both enriched and unenriched conditions. There was mainly positive co-variation between L. littorea and biofilm, while different nutrient conditions exhibited contrasting co-variation between L. littorea and barnacles (positive co-variation in enriched and negative co-variation in unenriched mesocosms). The study offered insights into how feeding behavior and spatial distribution of a species may interact with community components differently under different nutrient regimes. The applied methodology can be useful for purposes of faster examination of grazing effects among different regions and also to compare grazing intensities and interactions between grazers and the benthic communities in disturbed (including pollution and nutrient enrichment) and non-disturbed systems, as well as in up-welling versus non-upwelling areas.  相似文献   
992.
Taste and odor (T/O) in drinking water often cause consumer complaints and are thus regulated in many countries. However, people in different regions may exhibit different sensitivities toward WO. This study proposed a method to determine the regional drinking water odorant regulation goals (ORGs) based on the odor sensitivity distribution of the local population. The distribution of odor sensitivity to 2-methylisobomeol (2-MIB) by the local population in Beijing, China was revealed by using a normal distribution function/model to describe the odor complaint response to a 2-MIB episode in 2005, and a 2-MIB concentration of 12.9 ng/L and FPA (flavor profile analysis) intensity of 2.5 was found to be the critical point to cause odor complaints. Thus the Beijing ORG for 2-MIB was determined to be 12.9 ng/L. Based on the assumption that the local FPA panel can represent the local population in terms of sensitivity to odor, and that the critical FPA intensity causing odor complaints was 2.5, this study tried to determine the ORGs for seven other cities of China by performing FPA tests using an FPA panel from the corresponding city. ORG values between 12.9 and 31.6 ng/L were determined, showing that a unified ORG may not be suitable for drinking water odor regulations. This study presents a novel approach for setting drinking water odor regulations.  相似文献   
993.
Abstract

The exploitation of mineral resources plays an important role in promoting national economic development. Mining is an essential component of China’s industrial economy. Using grey correlation method to analyze the correlative effect of mineral resources exploitation to relevant industries, using national income method to calculate the pulling effect of mineral resources exploitation to economic growth and using graphs as well as tables to analyze the income distribution effect, the article obtains active economic effect of mineral resources development in Bijie, Guizhou. Moreover, from the view of resources-cored effect, the article analyzes negative effects such as single industrial structure brought by mineral resource development. Through analysis, we find that mineral resources exploitation to some extent brings active effects including gross domestic product growth, local financial revenue growth and relevant industries development; however, its negative effects should not be ignored. The negative effect can be lightened by diversifying industrial structure and prolonging industrial chain.  相似文献   
994.
Abstract

The aim of this article is to develop a structural equation model to assess key factors of residents’ support for hosting mega event based on previous literature. The model consisted of five latent constructs and eight path hypotheses. A survey was conducted in Shanghai before 2010 World Expo. It was found that the support for mega events is affected directly and/or indirectly by four determinants factors: perceived benefits, perceived costs, personal benefits and community attachment, and support relies heavily on perceived benefits rather than costs. This study contributes to the existing body of knowledge in an attempt to understand local residents’ support for a mega event in different economic and cultural settings.  相似文献   
995.
Climate change is one of the main factors that will affect biodiversity in the future and may even cause species extinctions. We suggest a methodology to derive a general relationship between biodiversity change and global warming. In conjunction with other pressure relationships, our relationship can help to assess the combined effect of different pressures to overall biodiversity change and indicate areas that are most at risk. We use a combination of an integrated environmental model (IMAGE) and climate envelope models for European plant species for several climate change scenarios to estimate changes in mean stable area of species and species turnover. We show that if global temperature increases, then both species turnover will increase, and mean stable area of species will decrease in all biomes. The most dramatic changes will occur in Northern Europe, where more than 35% of the species composition in 2100 will be new for that region, and in Southern Europe, where up to 25% of the species now present will have disappeared under the climatic circumstances forecasted for 2100. In Mediterranean scrubland and natural grassland/steppe systems, arctic and tundra systems species turnover is high, indicating major changes in species composition in these ecosystems. The mean stable area of species decreases mostly in Mediterranean scrubland, grassland/steppe systems and warm mixed forests.  相似文献   
996.
Farming in higher latitudes is generally believed to benefit from a warmer climate due to extended growing season, reduced risk of frost, availability of more productive cultivars, and an opening potential of farming in northern locations. We analyzed the impact of climate change on production of cereals in Russia and found that this general perception of beneficiary effect of a warmer climate is unlikely to hold, primarily due to increasing risk of droughts in the most important agricultural areas of the country. Past impacts of droughts on food security throughout the twentieth century suggest that a number of adaptation options are available to mitigate the increasing risks of crop failure. We analyze the effectiveness of these measures in connection with a set of climate change projections, under two contrasting scenarios of interregional grain trade: “Fortress Market” and “Open Market.”  相似文献   
997.
Water resources in Australia are sensitive to changes in rainfall. Ongoing droughts in south-west and south-east Australia are stressing water resources in the major cities and in agricultural regions. Climate change scenarios for Australia include reasonable prospects of long-term drying, which would exacerbate these issues. The dryer scenarios would entail major readjustments and costs on natural and human systems.  相似文献   
998.
Observing the many and varied reactions to the Kyoto Protocol, it becomes clear that different governments find themselves in different contexts that eventually direct them toward taking dissimilar positions on energy issues. This paper, through five integrated studies, investigates whether contextualizing energy issues is (are) relevant to support energy policy formulation and evaluation and provides insights into how to operationalize the contextualization. Instead of considering the most widely accepted tools currently used to assess and evaluate energy policy, this research proposes the utilization of a holistic framework that incorporates social, economic and environmental factors as well as their relations to the energy sector to better contextualize global, regional and national energy issues. This framework, which accounts for feedback loops, delays and non-linearity, is applied to case studies to investigate the longer-term performance of selected energy policies. Results of the study indicate the likely emergence of various unexpected side effects and elements of policy resistance over the medium and longer term due to the interrelations existing between energy and society, economy and environment. Furthermore, while side effects and unintended consequences may arise both within the energy sector and in the other sectors, they simultaneously influence society, economy and environment.  相似文献   
999.
Because ecosystem services are generally not produced and used in the same place, their assessment should consider the flows of services from ecosystems to users. These flows depend on the characteristics and spatial distribution of ecosystems and users, the spatial relationships between them, and the presence of filters or barriers between ecosystems and users. The objective of this paper is to map the ecosystem services provided to the Costa Rican and Nicaraguan hydroelectric sectors, which are crucial sectors for national sustainable development and depend directly on hydrological ecosystem services. The paper presents an approach for modelling the flows of multiple services from diverse ecosystems to diverse users through different kinds of filters in a landscape. The approach uses expert knowledge and fuzzy numbers to handle uncertainties. The analyses for Costa Rica and Nicaragua show how the approach helps identify priority areas for the conservation and restoration of forests for the services they provide to the hydroelectric sector. As such, it is a useful tool for defining spatially targeted policies for the conservation of ecosystem services and for involving the users of ecosystem services in ecosystem management.  相似文献   
1000.
The current state of Mediterranean mountain areas has been driven by two main factors: intense traditional human activity and the dynamics of the ecosystem itself. In this study, we examine land-cover changes in a National Park in the Pyrenees mountains (NE Iberian Peninsula), which was designated a protected area 55 years ago. First, we have analyzed spatio-temporal changes in land-cover pattern and forest dynamics from 1957 to 2005. During this period, land-cover dynamics consisted of two main processes: (i) expansion of the forest area and (ii) increasing cover of forests already present in 1957. To analyze the role of the conservation level of the park, we have also compared the results obtained within the park with those of unprotected, peripheral areas. In the two areas with different protection level, dense forests increased throughout the period because of the reduction in forestry activities. The peripheral area showed a higher rate of forest-cover change from 1957 to 2005 compared to the National Park. This higher increase in forest cover in the peripheral area could be related to a higher proportion in the National Park of screes and rocky areas and to the decline and transformation of forest activities in these peripheral, lower elevation areas.  相似文献   
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