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991.
The current paper discusses the topic of marine storm impact along European coastlines, presenting results from two FP7 Projects currently focusing on this topic, one working on the physical aspects of the problem (MICORE) and the other one on the socio-economic implications (ConHaz).The MICORE Project aims to provide on-line predictions of storm-related physical hazards (hydrodynamic as well as morphodynamic). The ConHaz Project addresses the socio-economic implications should these (or other) hazards actually materialize. Together these projects aim to deliver crucial information for emergency response efforts, while realizing the practical limitations for information processing and dissemination during crisis situations.The MICORE Project has developed and demonstrated on-line tools for reliable predictions of the morphological impact of marine storm events in support of civil protection mitigation strategies. The project specifically targeted the development of early warning and information systems to support short term emergency response in case of an extreme storm event. The current paper discusses in detail the outcome of an activity of databasing historical storm data. No clear changes in storminess were observed, except for some storm proxies (e.g. surges) and only at some locations (e.g. northern Adriatic, southern Baltic, etc.).The ConHaz Project undertook a desktop study of the methods normally used for evaluating the impact of marine storms and the associated coastal hazards considering direct costs, costs due to disruption of production processes, indirect costs, intangible costs, and costs of adaptation and mitigation measures. Several methods for cost estimation were reviewed. From the review it emerged that normally end-users only evaluate direct costs after the storms, while the cost of adaptation and mitigation measures is only done strategically in the context of Integrated Coastal Zone Management plans. As there is no standardized method for cost evaluations in this field, it is suggested that clear guidelines should be produced on the basis of simplicity for use by end-users. The integration between historical databases of the physical parameters of storms and detailed cost evaluation information would support the development of a knowledge background in end-users and justify the development of adaptation strategies.  相似文献   
992.
In a context of continued environmental degradation of agricultural landscapes, the concept of Payments for Ecosystem Services (PES) has been attracting growing attention in both academic and policy circles. The main premise of this conservation approach is appealing: land users, who tend to be poorly, if at all, motivated to protect nature on their land, may be encouraged to do so through direct payments from ecosystem service buyers. The theoretical underpinnings of PES emanate from an environmental externality framework, in which market failures are considered the root cause of environmental degradation. While the PES concept is attractive at first sight, this article discusses some weaknesses in its conceptual foundation. It focuses on two important aspects of the market-based PES concept: the hidden political ambiguities of the externality framework and the risk that PES, especially if user-funded, may perpetuate and deepen the regressive financing of global commons by poor local communities.  相似文献   
993.
A methodology for eco-efficiency reporting is proposed with eco-efficiency indicators for climate change, acidification, photo-oxidant formation, human toxicity, freshwater aquatic ecotoxicity, eutrophication, energy consumption and waste generation. The method is applied to emission, consumption and production data of the Flemish industry provided by the Flemish environmental agency for the period 1995–2006. For climate change, acidification, photo-oxidant formation, human toxicity, freshwater aquatic ecotoxicity and eutrophication, the eco-efficiency improved by 39, 55, 41, 58, 72 and 53%, respectively. For each of these impact categories, the total environmental impact decreased despite an increase in production, indicating absolute decoupling of environmental impact from economic growth. The eco-efficiency indicator for energy consumption and waste generation improved by 16 and 14%, respectively. However, due to the increase in production, the total energy consumption and the amount of waste generated increased: for these two environmental themes decoupling from economic growth was relative. Despite the improved eco-efficiency, industry remains one of the main polluters in Flanders. The application of the method to emission, energy consumption and production data of the Flemish industry resulted in a comprehensive and correct source of information for the general public and the government. Moreover, it can serve as a basis for economically and environmentally sound decisions and for the evaluation of the impact of former decisions.  相似文献   
994.
Patterns of coexistence among competing species exhibiting size- and food-dependent growth remain largely unexplored. Here we studied mechanisms behind coexistence and shifts in competitive dominance in a size-structured fish guild, representing sprat and herring stocks in the Baltic Sea, using a physiologically structured model of competing populations. The influence of degree of resource overlap and the possibility of undergoing ontogenetic diet shifts were studied as functions of zooplankton and zoobenthos productivity. By imposing different size-dependent mortalities, we could study the outcome of competition under contrasting environmental regimes representing poor and favorable growth conditions. We found that the identity of the dominant species shifted between low and high productivity. Adding a herring-exclusive benthos resource only provided a competitive advantage over sprat when size-dependent mortality was high enough to allow for rapid growth in the zooplankton niche. Hence, the importance of a bottom-up effect of varying productivity was dependent on a strong top-down effect. Although herring could depress shared resources to lower levels than could sprat and also could access an exclusive resource, the smaller size at maturation of sprat allowed it to coexist with herring and, in some cases, exclude it. Our model system, characterized by interactions among size cohorts, allowed for consumer coexistence even at full resource overlap at intermediate productivities when size-dependent mortality was low. Observed shifts in community patterns were crucially dependent on the explicit consideration of size- and food-dependent growth. Accordingly, we argue that accounting for food-dependent growth and size-dependent interactions is necessary to better predict changes in community structure and dynamics following changes in major ecosystem drivers such as resource productivity and mortality, which are fundamental for our ability to manage exploitation of living resources in, e.g., fisheries.  相似文献   
995.
Wildlife sampling for habitat selection often combines a random background sample with a random sample of used sites, because the background sample could contain too few used sites to be informative for rare species. This approach is referred to as use-availability sampling. Two variants are considered where there is: (1) a random background sample including used and unused sites augmented with a sample of used sites, and (2) a sample of used sites augmented with a contaminated background sample, i.e. use is not recorded. A weighted estimator first proposed by Manski and Lerman (Econometrica 45(8):1977?C1988, 1977) forms the basis for our suggested approach. The weighted estimator has been shown to perform better than the usual unweighted approach with uncontaminated data and mis-specified logit models (Xie and Manski in Sociol Methods Res 17(3):283?C302, 1989). A weighted EM algorithm is developed for use with contaminated background data. We show that the weighted estimator continues to perform well with contaminated data and maintains its robustness to model mis-specification. The weighted estimator has not been previously used for use-availability sampling due to reliance on the assumption that only the intercept is biased, which is valid for a correct logit model. We show that adjusting the intercept may not eliminate the bias with an incorrect logit model. In this case, the weighted estimator is a relatively simple and effective alternative.  相似文献   
996.
Functional gene arrays (FGAs) are a special type of microarrays containing probes for key genes involved in microbial functional processes, such as biogeochemical cycling of carbon, nitrogen, sulfur, phosphorus, and metals, biodegradation of environmental contaminants, energy processing, and stress responses. GeoChips are considered as the most comprehensive FGAs. Experimentally established probe design criteria and a computational pipeline integrating sequence retrieval, probe design and verification, array construction, data analysis, and automatic update are used to develop the GeoChip technology. GeoChip has been systematically evaluated and demonstrated to be a powerful tool for rapid, specific, sensitive, and quantitative analysis of microbial communities in a high-throughput manner. Several generations of GeoChip have been developed and applied to investigate the functional diversity, composition, structure, function, and dynamics of a variety of microbial communities from different habitats, such as water, soil, marine, bioreactor, human microbiome, and extreme ecosystems. GeoChip is able to address fundamental questions related to global change, bioenergy, bioremediation, agricultural operation, land use, human health, environmental restoration, and ecological theories and to link the microbial community structure to environmental factors and ecosystem functioning.  相似文献   
997.
The study uses a rather unusual method, dendrochronology, to investigate the growth and survival of Atriplex portulacoides L. and Artemisia maritima L. on salt marshes at two field sites on the Dutch North Sea barrier islands of Terschelling and Ameland. By providing information on longevity of these typical salt-marsh shrubs, dendrochronology offers an indirect way to investigate the influence of management regime – grazing in this case – on marsh quality and areal extent. Diminishment of salt marshes is a continuing concern in the northern Netherlands. The two shrub species studied here, A. portulacoides and A. maritima, are common to salt marshes. With their extensive roots and branches, they facilitate sedimentation and stabilize salt marshes. Using dendrochronology, this study found that annual growth rings could be identified to determine shrub age and growth. In A. portulacoides these rings took the form of a narrow band of terminal parenchyma. In A. maritima they were made up of unlignified marginal parenchyma together with higher vessel density at the beginning of the growing season. Growth rings indicated that intense grazing was clearly detrimental to the survival of A. portulacoides at the Terschelling site. However, grazing facilitated survival of A. maritima at the Ameland site by reducing light and nutrient competition from grasses. No growth trends could be found, however, as the lifespan for both species is short and many other influences on shrub growth could be identified.  相似文献   
998.
River-bed sediments from the Pangani basin, Tanzania, were characterized for elemental compositions, following contamination risks from rapid expansions of human activities in the area. Samples were collected during two individual seasons and analyzed by high-polarizing beam energy dispersive X-ray fluorescence (EDXRF) for eight major and 14 trace elements. Evaluation of enrichment factors (EFs) was used to investigate the elemental flux and assess the contributions of natural and anthropogenic influences. The abundances of the major elements followed the order Si?>?Al?>?Fe?>?Ca?>?K?>?Ti?>?Mn?>?P, similar to that of the upper earth's crust, and were generally from the weathering of the bed-rock. The high concentrations of typical anthropogenic trace-elements (Cr??1, V??1, Ni??1, Cu??1, La??1) coupled with high EFs (>2) in some locations indicated contamination associated with agricultural and industrial activities. Factor analysis extracted five principal components that contributed to 96.0% of the total observed variance. The results indicated that river-bed sediments of the Pangani basin were influenced to a larger extent by lithogenic sources than anthropogenic impacts.  相似文献   
999.
The distinction between amphibole asbestos fibers and non-asbestos amphibole particles has important implications for assessing potential cancer risks associated with exposure to amphibole asbestos or amphibole-containing products. Exposure to amphibole asbestos fibers can pose a cancer risk due to its ability to reside for long periods of time in the deep lung (i.e., biopersistence). In contrast, non-asbestos amphibole particles are usually cleared rapidly from the lung and do not pose similar respiratory risks even at high doses. Most regulatory and public health agencies, as well as scientific bodies, agree that non-asbestos amphiboles possess reduced biological (e.g., carcinogenic) activity. Although non-asbestos amphibole minerals have been excluded historically from Federal regulations, non-asbestos structures may be counted as asbestos fibers on the basis of dimensional criteria specified in analytical protocols. Given the potential to mischaracterize a non-asbestos structure as a “true” asbestos fiber, our objective was to assess whether exposure to non-asbestos amphiboles that may meet the dimensional criteria for counting as a fiber pose a cancer risk similar to amphibole asbestos. We reviewed analytical methods as well as the mineralogical, epidemiological, and toxicological literature for non-asbestos amphiboles. No evidence of demonstrable cancer effects from exposure to non-asbestos amphiboles that may be counted as fibers, under certain assessment protocols, was found. Data gaps (industrial hygiene data for amphibole-exposed cohorts), inconsistencies (analytical laboratory methods/protocols used to count fibers), and sources of potential bias from misclassification of exposure were identified.  相似文献   
1000.
There is a vast body of knowledge that eutrophication of lakes may cause algal blooms. Among lakes, shallow lakes are peculiar systems in that they typically can be in one of two contrasting (equilibrium) states that are self-stabilizing: a ‘clear’ state with submerged macrophytes or a ‘turbid’ state dominated by phytoplankton. Eutrophication may cause a switch from the clear to the turbid state, if the P loading exceeds a critical value. The ecological processes governing this switch are covered by the ecosystem model PCLake, a dynamic model of nutrient cycling and the biota in shallow lakes. Here we present an extensive analysis of the model, using a three-step procedure. (1) A sensitivity analysis revealed the key parameters for the model output. (2) These parameters were calibrated on the combined data on total phosphorus, chlorophyll-a, macrophytes cover and Secchi depth in over 40 lakes. This was done by a Bayesian procedure, giving a weight to each parameter setting based on its likelihood. (3) These weights were used for an uncertainty analysis, applied to the switchpoints (critical phosphorus loading levels) calculated by the model. The model was most sensitive to changes in water depth, P and N loading, retention time and lake size as external input factors, and to zooplankton growth rate, settling rates and maximum growth rates of phytoplankton and macrophytes as process parameters. The results for the ‘best run’ showed an acceptable agreement between model and data and classified nearly all lakes to which the model was applied correctly as either ‘clear’ (macrophyte-dominated) or ‘turbid’ (phytoplankton-dominated). The critical loading levels for a standard lake showed about a factor two uncertainty due to the variation in the posterior parameter distribution. This study calculates in one coherent analysis uncertainties in critical phosphorus loading, a parameter that is of great importance to water quality managers.  相似文献   
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