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401.
Mapping Invasive Aquatic Vegetation in the Sacramento-San Joaquin Delta using Hyperspectral Imagery 总被引:5,自引:0,他引:5
Underwood EC Mulitsch MJ Greenberg JA Whiting ML Ustin SL Kefauver SC 《Environmental monitoring and assessment》2006,121(1-3):47-64
The ecological and economic impacts associated with invasive species are of critical concern to land managers. The ability to map the extent and severity of invasions would be a valuable contribution to management decisions relating to control and monitoring efforts. We investigated the use of hyperspectral imagery for mapping invasive aquatic plant species in the Sacramento-San Joaquin Delta in the Central Valley of California, at two spatial scales. Sixty-four flightlines of HyMap hyperspectral imagery were acquired over the study region covering an area of 2,139 km2 and field work was conducted to acquire GPS locations of target invasive species. We used spectral mixture analysis to classify two target invasive species; Brazilian waterweed (Egeria densa), a submerged invasive, and water hyacinth (Eichhornia crassipes), a floating emergent invasive. At the relatively fine spatial scale for five sites within the Delta (average size 51 ha) average classification accuracies were 93% for Brazilian waterweed and 73% for water hyacinth. However, at the coarser, Delta-wide scale (177,000 ha) these accuracy results were 29% for Brazilian waterweed and 65% for water hyacinth. The difference in accuracy is likely accounted for by the broad range in water turbidity and tide heights encountered across the Delta. These findings illustrate that hyperspectral imagery is a promising tool for discriminating target invasive species within the Sacramento-San Joaquin Delta waterways although more work is needed to develop classification tools that function under changing environmental conditions. 相似文献
402.
A conceptual model of sustainable forest management is described based on three connected and necessary components: Policy/Strategic Planning, Operational Planning, and EffectivenessMonitoring/Science.Alberta’s proposed Forest Management Planning Standard is described as an example of operational planning. The standard utilizes coarse and fine filter approaches to conserving biodiversity and sets requirements for implementation monitoring.The Alberta Biodiversity Monitoring Program (ABMP) is described as an example of effectiveness monitoring supporting Operational Planning. The ABMP is a rigorous science-based initiative that is being developed to monitor and report on biodiversity status and trends throughout the province of Alberta, Canada. The basic survey design consists of 1656 sites, 20 km apart, evenly spaced on a grid pattern across Alberta. Sites will be sampled over a five-year period at a rate of 350 sites/year. Standardized sampling protocols will be used to cover a broad range of species and habitat elements within terrestrial and aquatic environments, as well as broader landscape-level features.Trends and associations detected by ABMP products will be validated through cause-effect research. ABMP focuses research on critical issues and informs both operational planning and the development of policy and strategic-level plans. The Alberta Forest Management Planning Standard and the ABMP are described as key components to implementing resource planning based on ecosystem management principles. 相似文献
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Public concerns over the toxicity of nanoparticles (NPs) are growing due to the rapid development of nanotechnology. An important mechanism of nanotoxicity is oxidative stress resulting from reactive oxygen species (ROS). In this study, the chemical production of ROS by inorganic NPs oxidizing the mammalian phenolic compound, l-3,4-dihydroxyphenylalanine (l-dopa) was evaluated using a ROS sensitive dye, 2′,7′-diclorodihydrofluorescin (DCFH). CeO2, Fe2O3 and Fe0 NPs enhanced ROS production during the autoxidation of l-dopa by more than four-fold in reactions that were dependent on O2. This is the first report of chemical ROS production due to interaction of phenolic compounds with NPs. Mn2O3 oxidized DCFH in a reaction that did not require O2 or l-dopa, suggesting a direct redox reaction between the Mn2O3 and the dye. CeO2, Mn2O3 and to a lesser extent Fe0 formed clear electron paramagnetic resonance (EPR) signature for hydroxyl radicals when incubated in aerobic aqueous suspensions with spin traps. The results indicate that NPs can generate ROS via chemical reactions with medium components and biomolecules susceptible to oxidation, such as l-dopa. NPs were reactive whereas micron-sized particles were not. The combined assay with l-dopa and DCFH is a method proposed to screen for chemical ROS production by NPs. 相似文献
406.
Trophic ecology and geographic location are crucial factors explaining OC levels in marine vertebrates, but these factors are often difficult to disentangle. To examine their relative influence, we analyzed PCBs, DDTs and stable-nitrogen isotope signatures (δ15N) in the blood of 10 pelagic seabird species across 7 breeding localities from the northeast Atlantic and western Mediterranean. Large scale geographic patterns emerged due to the confined character and greater historical OC inputs in the Mediterranean compared to the Atlantic basin. Spatial patterns also emerged at the regional scale within the Atlantic basin, probably associated with long-range pollutant transport. Trophic ecology, however, was also a major factor explaining OC levels. We found clear and consistent OC differences among species regardless of the sampled locality. However, species δ15N and blood OC levels were not correlated within most breeding localities. Petrel species showed significantly greater OC burdens than most shearwater species but similar trophic positions, as indicated by their similar δ15N signatures. This pattern probably results from Petrel species feeding on mesopelagic fish and squid that migrate close to the sea surface at night, whereas shearwater species mainly feed on epipelagic diurnal prey. In sum, this study illustrates the lasting and unequal influence of past human activities such as PCB and DDT usage across different marine regions. In addition, our results suggest that multi-species designs are powerful tools to monitor geographic patterns of OCs and potentially useful to assess their vertical dynamics in the marine environment. 相似文献
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López Alvarez JV Aguilar Larrucea M Fernández-Carrión Quero S Jiménez del Valle A 《Waste management (New York, N.Y.)》2008,28(2):282-293
This article deals with a methodology for the design of routes for the "bin to bin" (BTB) collection of paper and cardboard waste (PCB) from small businesses, as well as with the new location and calculation of the number of containers needed in the streets for both commercial and non-commercial use due to the large amount of PCB deposited in them. This study was carried out in five shopping areas of the city of Leganés (Community of Madrid, Spain). One of the characteristics of the area is a high density of population and urban traffic. The tool used is the Geographical Information System (GIS-Arc-View). With it we can generate PCB points of high population density in commercial streets based on territorial analysis. We placed the special routes and the new container locations within a distance of 60 m of these collection points (CPT). The system calculates and optimizes six routes according to different urban restrictions. Finally, we provided service to 59% of the shops, which generate almost 82% of the PCB waste, using 160 min per day to collect 1027 kg of high quality PCB. If we compare the system with the system in place previously, we can conclude that the "bin to bin" (BTB) system improves the quality of the PCB in the containers, avoiding overflow and reducing the percentage of rejected material. 相似文献
409.
Occurrence and behavior of per‐ and polyfluoroalkyl substances from aqueous film‐forming foam in groundwater systems
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Per‐ and polyfluoroalkyl substances (PFAS) are fluorinated compounds and the active ingredient in aqueous film‐forming foam (AFFF). AFFF has been identified as a significant source of PFAS contamination in groundwater. PFAS are also present in many other industrial and consumer products and their manufacture and use has led to numerous contaminated sites. Human health risks have been identified with studies linking firefighter cancers to training facilities where AFFF was used. Given the widespread release of these compounds to the environment and their potential health risks, understanding their mobility characteristics is important. This article details the occurrence and behavior of these substances in groundwater systems to help guide the emerging fields of PFAS investigation and remediation. Background is presented on AFFF and PFAS source characteristics, including common industrial and consumer PFAS sources. In addition, chemical properties, sorption and retention parameters, and observed transformation properties of PFAS and related compounds are discussed. Finally, knowledge gaps are identified for future laboratory and field studies. 相似文献
410.
Muñoz-Arnanz J Sáez M Hiraldo F Baos R Pacepavicius G Alaee M Jiménez B 《Environment international》2011,37(7):1164-1168
The occurrence of the emerging chlorinated flame retardant Dechlorane Plus (DP) and three of its possible degradation products was investigated in white stork eggs from two colonies in Spain. The average DP concentrations were 401 pg/g wet weight (w.w.) for the urban/industrial colony and 105 pg/g w.w. for the rural colony. One possible degradation product, anti-[DP-1Cl], was found in approximately 10% of the samples. No significant stereoisomer enrichments were detected in any colony based on the average anti-DP fractional abundances found which agrees with previous studies in herring gulls. The relationship between DP and PBDE contents in both colonies was explored leading to different scenarios, i.e. no correlation was found in the urban colony but they were statistically correlated in the rural colony. To the best of our knowledge, this is the first study to report DP in a species from a terrestrial food web, and also to report a DP degradation product in biota. 相似文献