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41.
Monitoring is essential to track the long-term recovery of endangered species. Greater emphasis on habitat monitoring is especially important for taxa whose populations may be difficult to quantify (e.g., insects) or when true recovery (delisting) requires continuous species-specific habitat management. In this paper, we outline and implement a standardized framework to facilitate the integration of habitat monitoring with species recovery efforts. The framework has five parts: (1) identify appropriate sample units, (2) select measurable indicators of habitat requirements, (3) determine rating categories for these indicators, (4) design and implement appropriate data collection protocols, and (5) synthesize the ratings into an overall measure of habitat potential. Following these steps, we developed a set of recovery criteria to estimate habitat potential and initially assess restoration activities in the context of recovering an endangered insect, the Karner blue butterfly (Lycaeides melissa samuelis). We recommend basing the habitat potential grading scheme on recovery plan criteria, the latest information on species biology, and working hypotheses as needed. The habitat-based assessment framework helps to identify which recovery areas and habitat patches are worth investing in and what type of site-specific restoration work is needed. We propose that the transparency and decision-making process in endangered insect recovery efforts could be improved through adaptive management that explicitly identifies and tracks progress toward habitat objectives and ultimate population recovery.  相似文献   
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A detailed lithostratigraphic analysis already exists for salt marsh sediments of the Severn Estuary, which provides an ideal background for an investigation of phase associations of trace elements within sediment depth profiles. The first stages of a detailed investigation are reported in which phase associations of Cu, Pb and Zn are related to early diagenetic processes.Reading University PRIS Contribution No. 044.  相似文献   
43.
Species employ diverse strategies to cope with natural disturbance, but the importance of these strategies for maintaining tree species diversity in forests has been debated. Mechanisms that have the potential to promote tree species coexistence in the context of repeated disturbance include life history trade-offs in colonization and competitive ability or in species' ability to survive at low resource conditions and exploit the temporary resource-rich conditions often generated in the wake of disturbance (successional niche). Quantifying these trade-offs requires long-term forest monitoring and modeling. We developed a hierarchical Bayes model to investigate the strategies tree species employ to withstand and recover from hurricane disturbance and the life history trade-offs that may facilitate species coexistence in forests subject to repeated hurricane disturbance. Unlike previous approaches, our model accommodates temporal variation in process error and observations from multiple sources. We parameterized the model using growth and mortality data from four censuses of a 16-ha plot taken every five years (1990-2005), together with damage data collected after two hurricanes and annual seed production data (1992-2005). Species' susceptibilities to hurricane damage as reflected by changes in diameter growth and fecundity immediately following a storm were weak, highly variable, and unpredictable using traditional life history groupings. The lower crowding conditions (e.g., high light) generated in the wake of storms, however, led to greater gains in growth and fecundity for pioneer and secondary-forest species than for shade-tolerant species, in accordance with expectation of life history. We found moderate trade-offs between survival in high crowding conditions, a metric of competitive ability, and long-distance colonization. We also uncovered a strong trade-off between mean species fecundity in low crowding conditions, a metric of recovery potential, and competitive ability. Trade-offs in competitive and colonization ability, in addition to successional niche processes, are likely to contribute to species persistence in these hurricane-impacted forests. The strategies species employ to cope with hurricane damage depend on the degree to which species rely on sprouting, repair of adult damage, changes in demographic rates in response to enhanced resource availability after storms, or long-distance dispersal as recovery mechanisms.  相似文献   
44.
This paper explores issues of governance and decision-making structures associated with the problem of hexachlorobenzene (HCB) waste at Botany in New South Wales. From a government perspective, the problem is ‘downstream’ of a well-known national controversy over whether Australia should have a high-temperature incinerator (HTI) to ‘dispose’ of such scheduled wastes. The 1992 decision not to proceed with HTI followed an extensive process of public consultation, which, against the expectations of industry and government, saw the emergence of Australia-wide community opposition. Alternative national management plans were formulated for the treatment of several types of organochlorine waste, with the scheme of these plans first approved in 1993 by the Australian and New Zealand Environment and Conservation Council (ANZECC). The HCB Management Plan is one of three such plans (the others being for PCBs and organochlorine pesticides). With this, ANZECC established the Scheduled Waste Management Group comprising government officials, and the National Advisory Body (NAB) made up of stakeholders. Officially the NAB had oversight of the HCB problem until 2002 when it was disbanded. As a result of the HTI experience, new community consultation protocols were introduced in association with the alternative management plans. For HCBs, which are confined almost entirely to Orica's Botany site in southeastern Sydney, this led to the establishment of the Community Participation and Review Committee (CPRC), a representative body with review and advisory functions. This paper draws conclusions from this history about government processes of decision making, the role of individual and institutional actors, the central importance of trust, and the democratisation of risk management. Using concepts delineated by McDonell [1991. Toxic waste management in Australia: why did policy reform fail? Environment 33(6), 11–13, 33–39; 1997. Scientific and everyday knowledge: trust and the politics of environmental initiatives. Social Studies of Science 27, 819–863.] we identify swings towards, then away from institutionalised trust. Across two decades, government and industry have placed faith in centrally controlled mechanisms for public participation, hoping to garner trust and legitimate privileged technological solutions. On the ‘backswings’, these processes have seen public trust dissipate in the face of government misunderstanding of the opportunities for effective bureaucratic interventions.  相似文献   
45.
The C-Lock system was developed to address the need for an improved method of quantifying and certifying project-level carbon emission reduction credits (CERC). It was designed to enable individual landowners to efficiently quantify, certify, pool, market and trade CERCs generated by agricultural management practices. We provide a general overview of the C-Lock system as it has been implemented for the USA State of South Dakota. C-Lock is comprised of four linked components: a web interface, a client database, a Geographic Information System (GIS) database of soil, climate and generalized land use history parameters, and the CENTURY soil carbon model. The user-friendly interface elicits generalized land-use and crop history information from the client from 1900 through 1989, then explicit annual information from 1990 onward. A climate-zone level landuse and crop management database is used to fill in gaps in the client-provided data. These data are used to drive the CENTURY model, which estimates annual changes in soil carbon stocks. Monte Carlo simulation is used to estimate uncertainty bounds, and these are applied to the CENTURY outputs in order to provide probabilistic estimates of accrued CERCs in a manner that is transparent and verifiable. In a demonstration application, CERCs are estimated for three different land-use scenarios on a representative field in eastern South Dakota: reduced tillage or conservation (no-till) management of a corn (maize)/wheat/soybean rotation, and enrollment in the Conservation Reserve Program, which entails establishing permanent grass cover. The credits are based on a business-asusual scenario of conventional tillage.  相似文献   
46.
Low levels (ng/g) of musk ketone (MK),used as a fragrance additive in the formulation of personal care products,are frequently detected in the water and other environment.Thus,aquatic organisms can be continuously exposed to MK.In this study,kinetics and dose-response assessments of 2-amino-MK (AMK) metabolite,bound to cysteine-hemoglobin (Hb) in rainbow trout,formed by enzymatic nitro-reduction of MK have been demonstrated.Trout were exposed to a single exposure of 0.010,0.030,0.10,and 0.30 mg MK/g fish...  相似文献   
47.
If a municipal solid waste (MSW) landfill is used as the foundation for a construction site, the change in the loading conditions may cause considerable compression of the landfill. Therefore, reinforcement to compensate for the loose compression nature of a MSW landfill is a very important design factor for geotechnical engineers when considering the end-use of the landfill. In this study, we discuss a possible technique for stabilizing MSW landfills through the codisposal of municipal solid waste and fly ash. To estimate the stabilization based on the compression characteristics of the codisposed landfill, we performed tests using a large compression set and experimental cells. According to the test results, if the proportion of fly ash is increased, initial and long-term compression could be reduced.  相似文献   
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