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The Mormon cricket, Anabrus simplex, is one of just a few species of katydids (or bushcrickets, Orthoptera: Tettigoniidae) that, like migratory locusts, appear
to have solitary and migratory morphs. Using radio telemetry we studied movements of individuals of two morphs of this flightless
species. Individuals within each migratory band had similar rates of movements along similar directional headings whereas
solitary individuals moved little and showed little evidence of directionality in movement. Our results also add to other
recent radio-telemetry studies showing that flightless insects of 1–2 g in mass can be tracked successfully using these methods.
Received: 28 February 2000 / Accepted in revised form: 19 June 2000 相似文献
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This paper uses a prediction model of groundwater pollution based on the experiments in the laboratory and in field .The model, which was tested and calibrated by the field observated data ,satisfactorily simulated the field conditions in land treatment system of wastewater . Particularly , the model can provide the reliable pollution prediction of heavy metals , organisms and nitrogen . The model was used to predict the groundwater pollution caused by the land treatment system in the region of North China . The calibration of the model showed that correlation coefficients between the tested and predictive data of Cr6+. As3+, organism and NH4+ could reach 0.990, which proved that the model possessed the realistic instructive significance for design and use of wastewater land treatment systems . 相似文献
326.
This paper describes a method for determining reductions of SO2 emissions from coal- and oil-fired power stations, oil refineries and large industrial units in the UK taking into account their pollution potential. The method is based on the use of two gridded data sets: critical loads, which represent the sensitivity of the environment to acid deposition and modelled estimates of total (wet + dry) sulphur deposition for 646 point sources within the UK. An iterative method is used to identify and subsequently reduce emissions from point sources that contribute most to areas of critical loads exceedance. This paper demonstrates how the method may be used to determine an optimal allocation of emissions across the UK which yields the maximum amount of environmental protection per unit of emission.The paper then goes on to consider the changes that will have to take place within the UK power generation industry in order to meet the revised EC Large Combustion Plant Directive which comes into force on 1 January 2008. Particular emphasis is placed upon proposed emissions trading schemes and the environmental implications of allowing trading between stations with high and low pollution potentials. The paper concludes by suggesting that the emissions trading process should take into account the pollution potential of each source, irrespective of whether the proposed emission is within the plant's agreed emission limit. An approach based entirely on minimizing environmental damage rather than one which takes cost into account, as in current integrated assessment modelling, could provide an interesting approach across the rest of Europe. 相似文献
327.
Sensitized effect of β-cyclodextrin on the fluorescence in the determination of carbaryl 总被引:1,自引:0,他引:1
Based on the significant enhancement of fluorescence intensity of carbaryl in inclusion complex, a spetrofluorimetdc method with high sensitivity was developed for the determination of carbaryl in aqueous solution. Under the optimum conditions, the complex had excitation and emission maxima at 278 nm and 332 nm, respectively. The linear range of the method was 7.0 ng/ml-1500 ng/ml with a detection limit of 1.2 ng/ml. The proposed method was successfully used to determine quantitativelv of carbarvl in cottonseeds. 相似文献
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The possible effects of landscape structure on starling roost distribution were investigated in western France using GIS analysis at different radii (2, 4, 8 and 10 km). Composition (11 land use classes) and configuration (patch size, diversity index) of the landscapes surrounding 97 roost sites used by starlings from 1981 to 2002 and surrounding 50 random points not used as roost sites were compared. Significant results suggested that starling roosts were established preferentially in the centre of an agricultural landscape where large units of pastures and arable land predominated and where natural areas were lacking both in large patches (forests or wetland classes) and in small patches such as woods in the mixed land class. A varied farmland landscape with natural areas and small patches should be promoted to limit the starling damage in wintering regions and also to favour their reproduction in regions where it has declined. 相似文献
330.
社会经济的高速发展,也诱发了新的环境风险可能性的发生,特别是近年来的多种环境风险灾害事故的发生已引起了各国和国际组织的普遍关注。环境风险评价与环境风险管理已成为保护生态环境、维护公众健康的重要内容和制定决策的重要依据。文章结合目前环境风险评价的发展,探讨有关两大类环境风险评价(突发性与非突发性)以及环境风险评价与安全评价的区别,环境风险评价评估标准以及环境风险评价与城市环境管理的一些问题。 相似文献