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The wildland–urban interface (WUI) is the region where development meets and intermingles with wildlands. The WUI has an elevated fire risk due to the proximity of development and residents to wildlands with natural wildfire regimes. Existing methods of delineating WUI are typically applied over a large region, use proxies for risk, and do not consider site-specific fire hazard drivers. While these models are appropriate for federal and provincial risk management, municipal managers require models intended for smaller regions. The model developed here uses the Burn-P3 fire behavior model to model WUI from local fire susceptibility (FS) in two study communities. Forest fuel code (FFC) maps for the study communities were modified using remote sensing data to produce detailed forest edges, including ladder fuels, update data currency, and add buildings and roads. The modified FFC maps used in Burn-P3 produced bimodal FS distributions for each community. The WUI in these communities was delineated as areas within community bounds where FS was greater than or equal to ?1 SD from the mean FS value ( ${\text{WUI}} = {\text{FS}} \geqslant - 1 \, [\bar \chi - \sigma ]$ ), which fell in the trough of the bimodal distribution. The WUI so delineated conformed to the definition of WUI. This model extends WUI modeling for broader risk management initiatives for municipal management of risk, as it (a) considers site-specific drivers of fire behavior; (b) models risk, represented by WUI, specific to a community; and, (c) does not use proxies for risk.  相似文献   
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Provisioning weaned young is an important part of the cooperative rearing system of marmosets and tamarins (family: Callitrichidae). Juvenile callitrichids receive a substantial proportion of their diet from all adult group members, whereas juveniles of most other primate species only receive food from the mother infrequently via scrounging. We conducted a longitudinal study of provisioning to 21 young wild golden lion tamarins through their first year of life in two Brazilian reserves. Juveniles were predicted to experience higher provisioning rates at the site with mature forest (the presumed ancestral habitat) and in territories that contained a higher proportion of preferred habitat within the mature forest reserve. Key measures of provisioning did not differ substantially between habitat types. The rates at which juveniles begged for food were very similar across habitats, while the influence of habitat on the rates at which juveniles received food was small and varied across age groups. The most pronounced differences between the reserves were: adult resistance to food-transfer attempts was less frequent, food-offering calls before food transfer were more frequent, and the proportion of prey provisioned was higher in the reserve in which earlier successional-stage forest predominated. Within the mature forest reserve, begging success of young juveniles covaried positively with preferred habitat. Rather than overt caretaker–offspring conflict, an information–feedback loop between juveniles and adults appears to drive provisioning changes as juveniles mature. Direct measures of resource abundance are needed to help clarify the mechanisms by which forest successional stage influences provisioning.  相似文献   
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Computerized methodologies for the quantification of total PCBs, PCB in Aroclor mixtures and individual PCB congeners in environmental samples are presented. The method for total PCBs is based on a multiple-linear regression analysis using data from capillary gas chromatography of Arocolor standards. PCB congeners were identified and their weight percentages determined in Aroclor mixtures by GC/MS. PCB congeners and total PCBs were accurately quantified in predetermined test data and environmental samples.  相似文献   
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Regional Environmental Change - Climate change and a growing population around the Mediterranean Rim are increasing the need for water and, consequently, the pressure on resources in terms of both...  相似文献   
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The objective of this study is to assess how local planning can influence the acidity in the upper forest soil layer. Exceedance of soil acidity was determined by a steady-state mass balance model approach in relation to both present and future deposition. Future deposition scenarios were derived for Stockholm County based on transportation planning. Europe-wide scenarios were derived using the RAINS (Regional Air Pollution Information and Simulation) model. The deposition changes were assessed in relation to two different types of forest harvesting practices: whole-tree harvesting; and stem harvesting. The results demonstrate that local emission reductions combined with tree stem harvesting give the greatest remediation of soil acidity. This implies that forest soil acidity can be introduced as an indicator in local environmental planning.  相似文献   
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In this paper, we develop a framework for (a) the study of sustainability of dynamic bioeconomic systems and (b) the definition of recovery paths from unsustainable situations. We assume that the system follows a sustainable trajectory if it evolves over time within a set of multidimensional constraints. We use the mathematical concept of viability to characterize sustainability. Recovery paths are studied with regards to their duration and their acceptability. This general framework is applied to the issue of recovering sustainable fisheries. We define sustainability in a fishery as the requirement that a set of economic, ecological, and social constraints is satisfied at all times. Recovery paths are characterized by the time required to obtain sustainable exploitation conditions in the fishery and by the acceptable recovery costs for fishermen. In particular, we identify the recovery path which minimizes the time of crisis under a minimum transition profit constraint. We then describe the trade-off between speed and accepted costs of recovery paths, by comparing “Hare”-like high-speed–high-cost strategies to “Tortoise”-like low-speed–low-cost strategies. We illustrate our results by means of a numerical analysis of the Bay of Biscay Nephrops fishery.  相似文献   
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Measurement of untransformed (p,p'- and o,p'-) DDT in rain, snow, and peat indicates that input of “new” DDT continues over a large portion of eastern North America. Peat cores obtained from ombrotrophic bogs indicate that current atmospherically derived fluxes are about 10–20% of those which occurred during peak DDT usage (~1960). Since DDT has been banned in North America and considering the magnitude of present fluxes, these residues must result from atmospheric transboundary transport. It is suggested that “new” DDT is being transported from neighboring areas where current use is substantial, Mexico and Central America.  相似文献   
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