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461.
Partitioning behavior of the antifouling booster biocide, Irgarol-1051 (2-methythio-4-tert-butylamino-6-cyclopropylamino-s-triazine), its production by-product, M3, and its environmental transformation products, M1 and M2, were studied. Octanol-water partition coefficients, log K(OW), and organic matter-water partition coefficients, log K(OC), of these s-triazines were measured by reversed-phase HPLC and a triphasic SPME equilibrium model, respectively. The average log K(OW) (+/-SD) of the four s-triazine species were: 4.39+/-0.07 (M3); 3.38+/-0.12 (Irgarol-1051); 2.92+/-0.12 (M2) and 2.54+/-0.11 (M1), while mean log K(OC) (+/-SD) of these species were: 2.47+/-0.03 (M3); 2.16+/-0.03 (Irgarol-1051); 1.97+/-0.03 (M2) and 1.79+/-0.04 (M1). These results were compared to reported physicochemical parameters of Irgarol-1051 in the literature. Partitioning behavior of these s-triazine species in the coastal environment revealed by their K(OW) and K(OC) were also discussed. 相似文献
462.
Ole Mertz Kenneth Grogan Dirk Pflugmacher Guillaume Lestrelin Jean-Christophe Castella Thoumthone Vongvisouk 《Journal of Land Use Science》2018,13(1-2):1-15
Forest reference levels (FRLs) provide a benchmark for assessing reduced emissions from deforestation and forest degradation (REDD+), and they are central to demonstrate additionality of REDD+. Attaining realistic FRLs, however, is challenging, especially in complex mosaic landscapes. We established FRLs in northern Laos for different reference periods and tested them against actual carbon stock changes. Annual time series of Landsat satellite images were used to capture the subtle changes in carbon stocks in complex landscapes characterized by shifting cultivation. We found that FRLs differ considerably depending on the reference period chosen. Abrupt land-use changes occurred when hybrid maize replaced traditional shifting cultivation and forests, and this invalidated carbon stock trends that would have been predicted had the FRL been projected into the future. We conclude that demonstrating additionality of REDD+ in fast developing areas is difficult and that payment systems rewarding potential emission reductions against hypothetical extrapolation of FRLs are unlikely to be a cost-effective strategy. 相似文献
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464.
Extinction in a hyperdiverse endemic Hawaiian land snail family and implications for the underestimation of invertebrate extinction
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Claire Régnier Philippe Bouchet Kenneth A. Hayes Norine W. Yeung Carl C. Christensen Daniel J. D. Chung Benoît Fontaine Robert H. Cowie 《Conservation biology》2015,29(6):1715-1723
The International Union for Conservation of Nature (IUCN) Red List includes 832 species listed as extinct since 1600, a minuscule fraction of total biodiversity. This extinction rate is of the same order of magnitude as the background rate and has been used to downplay the biodiversity crisis. Invertebrates comprise 99% of biodiversity, yet the status of a negligible number has been assessed. We assessed extinction in the Hawaiian land snail family Amastridae (325 species, IUCN lists 33 as extinct). We did not use the stringent IUCN criteria, by which most invertebrates would be considered data deficient, but a more realistic approach comparing historical collections with modern surveys and expert knowledge. Of the 325 Amastridae species, 43 were originally described as fossil or subfossil and were assumed to be extinct. Of the remaining 282, we evaluated 88 as extinct and 15 as extant and determined that 179 species had insufficient evidence of extinction (though most are probably extinct). Results of statistical assessment of extinction probabilities were consistent with our expert evaluations of levels of extinction. Modeling various extinction scenarios yielded extinction rates of 0.4‐14.0% of the amastrid fauna per decade. The true rate of amastrid extinction has not been constant; generally, it has increased over time. We estimated a realistic average extinction rate as approximately 5%/decade since the first half of the nineteenth century. In general, oceanic island biotas are especially susceptible to extinction and global rate generalizations do not reflect this. Our approach could be used for other invertebrates, especially those with restricted ranges (e.g., islands), and such an approach may be the only way to evaluate invertebrates rapidly enough to keep up with ongoing extinction. 相似文献
465.
Saunders JR Hough C Knopper LD Koch I Reimer KJ 《Journal of environmental monitoring : JEM》2011,13(6):1784-1792
Arsenic in terrestrial contaminated sites has the potential to cause harm to residential wildlife. The aim of this study was to determine the arsenic species in wild rodents living in arsenic contaminated habitats, specifically deer mice from Yellowknife, NT and meadow voles from Seal Harbour, NS, along with co-located plants. Methanol : water (1 : 1) extractions were used to optimize the extraction of methylated arsenic(v) species. Total arsenic concentrations were substantially higher in the Yellowknife deer mice (1.7-3.2 μg kg(-1) wet weight in livers) and Seal Harbour meadow voles (0.67-0.97 μg kg(-1) wet weight in livers) living on the contaminated sites with respect to the surrounding background locations (0.12-0.34 μg kg(-1) wet weight in livers). Around 50% of arsenic could be identified in Yellowknife deer mouse tissues, but only <10% was identified in Seal Harbour vole tissues; inorganic arsenic (iii and v) and dimethylarsinic acid were all found. Monomethylarsonic acid was only detected in both the mice and voles living in the contaminated sites. In the Yellowknife food chain, methyl arsenic (v) proportions increased from plants to mouse inner organs, but the trend was not for clear as the Seal Harbour food chain. Seal Harbour voles may be sequestering arsenic in a less mobile form, rather than transforming it. 相似文献
466.
Municipal solid waste generation in Kathmandu, Nepal 总被引:1,自引:0,他引:1
Dangi MB Pretz CR Urynowicz MA Gerow KG Reddy JM 《Journal of environmental management》2011,92(1):240-249
Waste stream characteristics must be understood to tackle waste management problems in Kathmandu Metropolitan City (KMC), Nepal. Three-stage stratified cluster sampling was used to evaluate solid waste data collected from 336 households in KMC. This information was combined with data collected regarding waste from restaurants, hotels, schools and streets. The study found that 497.3 g capita(-1) day(-1) of solid waste was generated from households and 48.5, 113.3 and 26.1 kg facility(-1) day(-1) of waste was generated from restaurants, hotels and schools, respectively. Street litter measured 69.3 metric tons day(-1). The average municipal solid waste generation rate was 523.8 metric tons day(-1) or 0.66 kg capita(-1) day(-1) as compared to the 320 metric tons day(-1) reported by the city. The coefficient of correlation between the number of people and the amount of waste produced was 0.94. Key household waste constituents included 71% organic wastes, 12% plastics, 7.5% paper and paper products, 5% dirt and construction debris and 1% hazardous wastes. Although the waste composition varied depending on the source, the composition analysis of waste from restaurants, hotels, schools and streets showed a high percentage of organic wastes. These numbers suggest a greater potential for recovery of organic wastes via composting and there is an opportunity for recycling. Because there is no previous inquiry of this scale in reporting comprehensive municipal solid waste generation in Nepal, this study can be treated as a baseline for other Nepalese municipalities. 相似文献
467.
Environmental planners and managers face unique challenges understanding and documenting the effectiveness of programs that
rely on voluntary actions by private landowners. Programs, such as those aimed at reducing nonpoint source pollution or improving
habitat, intend to reach those goals by persuading landowners to adopt behaviors and management practices consistent with
environmental restoration and protection. Our purpose with this paper is to identify barriers for improving voluntary environmental
management programs and ways to overcome them. We first draw upon insights regarding data, learning, and adaptation from the
adaptive management and performance management literatures, describing three key issues: overcoming information constraints,
structural limitations, and organizational culture. Although these lessons are applicable to a variety of voluntary environmental
management programs, we then present the issues in the context of on-going research for nonpoint source water quality pollution.
We end the discussion by highlighting important elements for advancing voluntary program efforts. 相似文献
468.
469.
引言 当蒸发损失的水分大于补充的淡水时,盐浓度将超过正常海水浓度(大约35psu),就出现了高盐度的情况,处于高盐胁迫下的活组织遭受严重的水胁迫、渗透压压迫及干燥的威胁[1~5].长期的盐胁迫作用,形成了这些生物系统中的特定的生物区系[1~5]. 相似文献
470.