Quantifying trace gas emissions from composite landscapes: A mass-budget approach with aircraft measurements

Quantifying trace gas emissions and the influence of surface exchange processes on the atmosphere is a necessary step towards the control of global greenhouse gas emissions and reliability of air quality models. This paper proposes a procedure based on the mass balance method and implemented on highly resolved aircraft data. It allows one to estimate surface exchanges on areas of several km² and heterogeneous features exploiting the characteristics of convective boundary layer during steady state conditions that permit the estimation of emission/absorption terms as functions of advective fluxes only. A nonparametric approach is adopted and the fluxes on the surface of a virtual box surrounding the area of interest are reconstructed on the basis of scalar densities and wind vectors using Shepard functions. Two different techniques are also proposed to face lack of data on the top surface of the box. The method has been applied to experimental data coming from measurement campaigns on two different sites. It provides realistic estimates of the CO₂ emission/absorption in the considered areas that are in good agreement with CO₂ fluxes evaluated by Airborne Eddy Covariance and confirm the suitability of the proposed approach for the assessment of turbulent exchange of trace gases by composite landscapes. Uncertainties on the estimated emissions due to both propagation of the experimental error and interpolation have been quantified by bootstrap analysis as 6%.     

Phenotypic variation and adaptive reaction to the presence of predator in two Daphnia species (Daphniiformes, <Emphasis Type="Italic">Daphnia</Emphasis>) in Lake Baikal

The effect of invertebrate predation pressure by the cladoceran Leptodora kindti on the population structure of Daphnia galeata and D. hyalina has been estimated by analyzing the occurrence frequency of the normal and spined morphotypes in Lake Baikal. It is shown that the growth of L. kindti population density leads to an increase in the proportion of the spined morphotype, while that of that of the normal morphotype decreases.     

Simulation of biological uptake of uranium and radium in an industrially polluted area

Distribution of ²³⁸U and ²²⁶Ra in soils and plants of an industrially polluted area are considered. The dependence between the biological uptake coefficients (BUCs) for the plant species studied and the radionuclide concentrations in soil can be approximated by a decreasing power function. Species differences in radionuclide uptake are demonstrated.     

Characteristics of the contact zone of three chromosome races of the common shrew <Emphasis Type="Italic">Sorex araneus</Emphasis> L. (Mammalia) as indices of interpopulation competition

The distribution of three chromosome races (Moscow, Western Dvina, and Seliger) of the common shrew Sorex araneus L. in the zone of contact between their ranges in the Valdai Heights (32°00′ E, 57°00′ N) is discussed. The area co-inhabited by all the three races is extremely small. Representatives of all the three races have been captured on only one trap line, although there are no obstacles to the expansion of shrews. The extremely small area co-inhabited by the three races, as well as the strictly parapatric distribution of the Moscow and Western Dvina races, may be related with competition forms such as avoidance of contacts and separation of ecological niches.     

Long-Term Community Dynamics of Small Landbirds with and Without Exposure to Extensive Disturbance from Military Training Activities

Military training activities are known to impact individual species, yet our understanding of how such activities influence animal communities is limited. In this study, we used long-term data in a case study approach to examine the extent to which the local small landbird community differed between a site in northeast Kansas that experienced intensive disturbance from military training activities (Ft. Riley Military Installation) and a similar, nearby site that experienced minimal human disturbance (Konza Prairie Biological Station). In addition, we characterized how the regional pool of potential colonizers influenced local community dynamics using Breeding Bird Survey data. From 1991 to 2001, most species of small terrestrial landbirds (73%) recorded during breeding surveys were found at both sites and the mean annual richness at Ft. Riley (39.0 ± 2.86 [SD]) was very similar to that of Konza Prairie (39.4 ± 2.01). Richness was maintained at relatively constant levels despite compositional changes because colonizations compensated local extinctions at both sites. These dynamics were driven primarily by woodland species that exhibited stochastic losses and gains and were present at a low local and regional abundance. Our results suggest that military training activities may mimic natural disturbances for some species in this area because the small landbird community did not differ markedly between sites with and sites without extensive human disturbance. Although our results suggest that military training is not associated with large changes in the avian community, additional studies are needed to determine if this pattern is found in other ecological communities.     

Integrating Environmental and Socio-Economic Indicators of a Linked Catchment–Coastal System Using Variable Environmental Intensity

Can we develop land use policy that balances the conflicting views of stakeholders in a catchment while moving toward long term sustainability? Adaptive management provides a strategy for this whereby measures of catchment performance are compared against performance goals in order to progressively improve policy. However, the feedback loop of adaptive management is often slow and irreversible impacts may result before policy has been adapted. In contrast, integrated modelling of future land use policy provides rapid feedback and potentially improves the chance of avoiding unwanted collapse events. Replacing measures of catchment performance with modelled catchment performance has usually required the dynamic linking of many models, both biophysical and socio-economic—and this requires much effort in software development. As an alternative, we propose the use of variable environmental intensity (defined as the ratio of environmental impact over economic output) in a loose coupling of models to provide a sufficient level of integration while avoiding significant effort required for software development. This model construct was applied to the Motueka Catchment of New Zealand where several biophysical (riverine water quantity, sediment, E. coli faecal bacteria, trout numbers, nitrogen transport, marine productivity) models, a socio-economic (gross output, gross margin, job numbers) model, and an agent-based model were linked. An extreme set of land use scenarios (historic, present, and intensive) were applied to this modelling framework. Results suggest that the catchment is presently in a near optimal land use configuration that is unlikely to benefit from further intensification. This would quickly put stress on water quantity (at low flow) and water quality (E. coli). To date, this model evaluation is based on a theoretical test that explores the logical implications of intensification at an unlikely extreme in order to assess the implications of likely growth trajectories from present use. While this has largely been a desktop exercise, it would also be possible to use this framework to model and explore the biophysical and economic impacts of individual or collective catchment visions. We are currently investigating the use of the model in this type of application.     

Relation between management's behavioural intentions toward the environment and environmental actions

Drawing on Ajzen's Theory of Planned Behaviour, this paper analyses whether there is a relation between management's behavioural intentions toward an environmental problem and the company's specific actions in this area, and also considers the impact of the company size on these actions. For the data, a questionnaire was sent to 184 managers employed in industrial companies located in Spain which belonged to the automobile industry. The empirical analysis produces positive and significant regression coefficients and provides support for the hypotheses proposed. Specifically, the results show that the environmental actions carried out in the company respond at least in part to management's behavioural intentions toward these issues and the size of the firm.     

Analytical Solutions to the Linearized Boussinesq Equation for Assessing the Effects of Recharge on Aquifer Discharge1

Boggs, Kevin G., Robert W. Van Kirk, Gary S. Johnson, Jerry P. Fairley, and P. Steve Porter, 2010. Analytical Solutions to the Linearized Boussinesq Equation for Assessing the Effects of Recharge on Aquifer Discharge. Journal of the American Water Resources Association (JAWRA) 46(6):1116–1132. DOI: 10.1111/j.1752-1688.2010.00479.x Abstract: There is a need to develop a general understanding of how variations in aquifer recharge are reflected in discharge. Analytical solutions to the linearized Boussinesq equation governing flow in an unconfined aquifer provide a unified mathematical framework to quantify relationships among lag time, attenuation and distance between aquifer recharge and discharge and the effect of an up-gradient no-flow boundary. We applied this framework to three types of recharge: (1) instantaneous, (2) periodic, and (3) constant rate for a finite duration. When the temporal scale of recharge exceeds the diffusive aquifer time scale, recharge will be reflected in discharge quickly and with little attenuation. When aquifer time scale is large, most recharge events are shorter in scale than that of the aquifer, resulting in large attenuation. Attenuation is more sensitive to boundary effects than lag time, and boundary effects increase as recharge time scale increases. Boundary effects can often be ignored when the recharge source is farther than 1/3 of the domain length away from the no-flow boundary. We illustrate analytical results with application to the economically critical Eastern Snake River Plain Aquifer in Idaho. In this aquifer, detectable annual and decadal cycles in discharge can result from recharge no farther than 20 and 60 km away from the discharge point, respectively. The effects of more distant, long-term recharge can be detected only after a time lag of several decades.     

Lateral movement of soil fumigants 1,3-dichloropropene and chloropicrin from treated agricultural fields

The soil fumigants 1,3-dichloropropene (1,3-D) and chloropicrin (CP) are often used for controlling soil-borne plant pathogens and parasitic nematodes before reestablishing new vineyards and orchards. To evaluate crop safety and environmental risks with the replant fumigation, four field experiments were performed over 2 yr to examine 1,3-D and CP lateral movement away from the treated fields. Shank injection with or without a virtually impermeable film (V1F) was used in two vineyard fumigation experiments, and spot drip application without tarp cover was used in two orchard experiments. Results showed that 1,3-D and CP gases moved laterally to 6 m from the treated fields when the fumigants were applied by shank injection. The maximum 1,3-D or CP soil gas concentration at 6 m was approximately 10 ng cm(-3) when the fumigated plot was not cover with a tarp. With VIF, the measured maximum concentration increased to approximately 100 ng cm(-3). In the spot drip application, maximum 1,3-D and CP gas concentrations reached approximately 100 ng cm(-3) but at 1.5 m radial distance from the point of fumigant injection.