SUMMARY The European and UK legislation on environmental assessment (EA), as well as requiring assessment of significant ecological effects, also requires development proponents to recommend mitigation measures for adverse impacts. Drawing on a review of proposed ecological mitigation measures in 194 environmental statements (ES) for UK development proposals, this paper highlights problems with the current legislation in ensuring that ecological impacts are mitigated effectively, with a view to sustainable development. The review reveals confusion about the extent to which ecological mitigation is required. First, there is no objective basis for deciding which potentially adverse impacts should be mitigated. Proposed mitigation measures do not always relate directly to the ecological impacts identified in ES and there is a high risk of residual adverse effects. Second, there is no generally accepted method for evaluating the effectiveness of proposed mitigation measures, despite a clear recommendation from the UK's Department of the Environment (DOE, 1989) that an ‘assessment of the likely effectiveness’ of mitigation measures should be included in ES. Methods which can be used to evaluate the likely feasibility, costs and redistributional effects of ecological mitigation measures in EA are needed. Some of the factors which should be taken into account are considered in this paper. 相似文献
The desire to avoid rousing community hostility may encourage firms to behave in an environmentally responsible manner. Firms may engage in corporate social responsibility (CSR) to maintain community support and/or to regain the support of a community where it has been lost. It has been conjectured that such ‘informal regulation’ could effectively replace formal intervention in some settings, and usefully complement it in others. We explore these conjectures with mixed results. Informal regulation is necessarily less efficient than a well-designed formal alternative and the pattern of green behavior induced by the threat of community hostility may increase or decrease welfare. The existence of community pressure may increase or decrease the optimal calibration of a formal intervention (in this case an environmental tax) and may complement or detract from the incentives generated by an optimally calibrated tax. 相似文献
Traditionally, the dynamics of community assembly has been analyzed by means of deterministic models of differential equations. Despite the theoretical advances provided by such models, they are restricted to questions about community-wide features. The individual-based modeling offers an opportunity to link bionomic features to patterns at the community scale, allowing us to understand how trait-based assembly rules can arise by dynamical processes. The present paper introduces an individual-based model of community assembly, and discusses some of the major advantages and drawbacks of this approach. The model was framed to deal with predation among size-structured populations, incorporating allometric constraints to energetic requirements, movement, life-history features and interaction relationships among individuals. A protocol of assembly procedure is proposed, in which a period of intense species introductions is followed by a period without introductions. The resultant communities did not present any pattern of trait over-dispersion, meaning that the multivariate distances of bionomic features among co-occurring species were neither larger nor more regular than expected in a random collection of species. It suggests a weak influence of interspecific interactions in the model environment and individualistic rules of coexistence, driven mainly by the spatial structure. This highlights that trait over-dispersion and resource partitioning should not be considered a necessary condition for coexistence, even in communities entirely structured by internal processes like predation and competition. 相似文献
Networks – structured graphs consisting of sets of nodes connected by edges – provide a rich framework for data visualisation and exploratory analyses. Although rarely used for the visualisation of ecological data, networks are well suited to this purpose, including data that one might not normally think of as a network. We present a simple method for transforming a data matrix into network format, and show how this can be used as the basis for interactive exploratory analyses of ecological data.The method is demonstrated using a database of marine zooplankton samples acquired in the Southern Ocean. The network analyses revealed zooplankton community structures that are in good agreement with previously published results. Variations in community structure were observed to be related to the temporal and spatial pattern of sampling, as well as to physical environmental factors such as sea ice cover. The analyses also revealed a number of errors in the data, including taxon identification errors and instrument failures.The method allows the analyst to generate networks from different combinations of variables in the data set, and to examine the effects of varying parameters such as the scales of spatial, temporal, and taxonomic aggregation. This flexibility allows the analyst to rapidly gain a number of perspectives on the data and provides a powerful mechanism for exploration. 相似文献
Emission allowances are sometimes distributed for free in an early phase of a cap-and-trade scheme to reduce adverse effects on the profitability of firms. This paper investigates whether grandfathering can also be used to avert the relocation of firms to countries with lower carbon prices. We show that under certain conditions, relocation can be averted in the long run, even if the grandfathering scheme is phased out over time and immediate relocation is profitable in its absence. This requires that the permit price triggers sufficient investments into low-carbon technologies or abatement capital that create a lock-in effect which makes relocation unprofitable. 相似文献
A laboratory scale up-flow anaerobic sludge bed (UASB) bioreactor fed with synthetic wastewater was operated with simultaneous methanogenesis and denitrification (SMD) granules for 235 days with a gradient decrease of C/N. Molecular cloning, qRT-PCR and T-RFLP were applied to study the methanogenic community structures in SMD granules and their changes in response to changing influent C/N. The results indicate that when C/N was 20:1, the methane production rate was fastest, and Methanosaetaceae and Methanobacteriaceae were the primary methanogens within the Archaea. The richness and evenness of methanogenic bacteria was best with the highest T-RFLP diversity index of 1.627 in the six granular sludge samples. When C/N was reduced from 20:1 to 5:1, the methanogenic activity of SMD granules decreased gradually, and the relative quantities of methanogens decreased from 36.5% to 10.9%. The abundance of Methanosaetaceae in Archaea increased from 64.5% to 84.2%, while that of Methanobacteriaceae decreased from 18.6% to 11.8%, and the richness and evenness of methanogens decreased along with the T-RFLP diversity index to 1.155, suggesting that the community structure reflected the succession to an unstable condition represented by high nitrate concentrations.
In the past 10 years, both the Wenchuan earthquake (2008, Magnitude?=?8.0) and the Lushan earthquake (2013, Magnitude?=?7.0) struck in the Longmen Shan Fault area, causing extraordinary human and economic losses. After the Wenchuan earthquake, the Chinese government began promoting the Community for Disaster Prevention and Mitigation (CDPM) project nationwide to enhance community-level disaster-resistance capacities. Due to post-earthquake demand, CDPM construction in the Longmen Shan Fault area involved many diverse organisations, each of which had different organisational leadership models, which greatly influenced the CDPM characteristics and mechanisms. From long-term field research in 23 CDPM organisations in Longmen Shan Fault area, four types of CDPM organisations were found, including eight Government-oriented CDPM, six Resident-oriented CDPM, seven NGO-oriented CDPM and two Enterprise-oriented CDPM, forming a multiple organisation-oriented CDPM (M-CDPM) model. As there was only 85?km between the Wenchuan earthquake and the Lushan earthquake epicentres, many of the hardest-hit regions were the same; therefore, most CDPM organisations examined in this study were established after the Wenchuan earthquake and their effectiveness was tested in the Lushan earthquake. Therefore, research on the M-CDPM gives valuable information and provides a practical perspective for community-level disaster risk reduction. 相似文献