A Microcosm Approach to the Detection of the Effects of Herbicide Spray Drift in Plant Communities

It is often difficult to measure and predict the impacts of toxic chemicals, such as herbicides, on natural communities. This is especially true under conditions of spray drift when the amount received by the organisms downwind from the sprayer may be at sub-lethal doses. Laboratory experiments are either artificial, or have not been generally carried out over long enough time periods, to be realistic. Field experiments are often difficult because of the high variability inherent in natural populations. Here an intermediate microcosm approach was used, where standardized artificial communities (eight dicotyledons with and without a grass) were tested. The artifical communities included species typical of British woodland margins, hedgerows and field margins; communities with a high conservation interest, yet potentially under threat from spray drift. The microcosms were placed downwind of a sprayer and exposed to one of the following herbicides: glyphosate, mecoprop and MCPA. This approach ensures that the communities were standardized at the start and have been exposed to realistic doses of herbicide. The experiments reported here were carried out for at least three years with exposures to herbicides repeated each year. The effects of differential herbicide exposure downwind of the sprayer were measured on species yield, flowering performance, seed production, seed viability and invasion by new species. Responses were extremely variable, but all species showed some effects in some years. Some patterns emerged. For example, one group of species appeared to be more successful near to the sprayer. This was particularly true of the grass when exposed to MCPA and mecoprop. The performance of most species was reduced under the sprayer, and there was a general recovery with increasing distance downwind. A few species showed increased performance in the intermediate downwind zone (2–4 m) and this may be due to a hormonal effect on growth processes, or an effect of reduced interference from other community members. Generally, there were few effects on seed production or seed viability. An important result was that most effects were confined within an 8 m zone, as there were few significant differences between plants exposed at 8 m and those untreated. Although damaging effects were found in the immediate downwind zone from the sprayer, the restriction of effects to 8 m suggests that a buffer zone of this size would be adequate to protect sensitive habitats from most deleterious impacts on community processes.     

The feasibility of processing lead-based paint abatement wastes through primary and secondary lead smelters

This study was undertaken to determine the feasibility of processing soil and lead-based paint (LBP) abatement waste through primary and secondary lead smelting facilities. The main objectives were to determine the compatibility of soil and LBP abatement waste with lead smelting circuits; the costs associated with transporting and processing the abatement waste through a smelter; and a review of major environmental laws or regulations which may impact the lead smelting industry's ability to carry out this process. While not all categories of LBP wastes are suited for reclamation through lead smelters, sufficient classes are to make the effort worthwhile. Specifically, lead paint chips, dusts, heatgun sludge, soils and certain blasting abrasives appear metallurgically compatible with the lead smelting circuits. Additionally, there do not appear to be any current regulatory statutes that forbid the process from being carried out, so long as certain permit modifications are obtained. Finally, the estimated smelting costs seem to compare favourably with current treatment and disposal fees at approved landfills. However, despite the promise of these initial findings, a great deal of work remains to be done if the concept of processing lead paint wastes through lead smelters for reclamation is to become a reality.     

Counting of visitors in the Meijendel dunes, The Netherlands

Accurate and sufficiently detailed information about recreation-related use of dune areas is necessary for their management. Long-term monitoring can provide this information. This paper presents the visitor counting programme used in the Meijendel dune area since 1992. The data collected during the first ten years are used to evaluate the method. The combination of mechanical vehicle counts and additional visual counts proved to be reliable and produced an accurate data set. Costs could be reduced through eventually reducing the number of counting locations and limiting the number of visual counts.     

Growth, environment and innovation—a model with production vintages and environmentally oriented research

I develop an innovative environmental new growth model driven by researchers striving for monopoly profits. Skilled labour is allocated between production vintages and two forms of research, ordinary and environmentally oriented. The intermediate sector includes fixed costs and decreasing returns, limiting the number of vintages used. I solve for planner's, laissez-faire, and regulator's solutions, and examine welfare implications and the various distortions in the model (monopoly power, knowledge spillovers, business stealing, environmental externalities). A regulator may wish: (i) to encourage environmentally oriented research; (ii) to concentrate production labour on recent (cleaner) vintages; (iii) to switch labour from production to research. An environmental sales tax may under some circumstances achieve all three—such taxes not only give incentives to reduce pollution, but also shift profits from old vintages to new, thus raising incentives to come up with newer (cleaner) vintages. An environmental tax may even lead to an increase in the rate of production growth.     

LCA comparison of windrow composting of yard wastes with use as alternative daily cover (ADC)

This study compared the environmental impacts of composting yard wastes in windrows with using them in place of soil as alternative daily cover (ADC) in landfills. The Life Cycle Assessment was made using the SimaPro LCA software and showed that the ADC scenario is more beneficial for the environment than windrow composting. ADC use is also a less costly means of disposal of yard wastes. This finding applies only in cases where there are sanitary landfills in the area that are equipped with gas collection systems and can use yard wastes as alternative daily cover. Otherwise, the environmentally preferable method for disposal of source-separated yard wastes is composting rather than landfilling.     

Exploring the possibility of a systematic and generic approach to social sustainability

There is a growing need to understand how existing concepts and tools for sustainability relate to each other and to a robust, trans-disciplinary systems perspective for sustainability. As a response, a group of scientists, including some of the authors, have developed a framework based on backcasting from sustainability principles over the last 20 years – the Framework for Strategic Sustainable Development (FSSD), also known as The Natural Step Framework. The intent of this study is to scrutinize the existing framework as regards its social dimension. The study demonstrates dichotomies and lack of robustness and proposes a way forward to make the social dimension of the FSSD more cohesive as well as operational.     

An approach to assessing sustainability integration in strategic decision systems for product development

This article aims to explore a new approach to assess company decision systems regarding sustainability-related communication and decision support between senior management and product development levels. The assessment approach was developed in theory and its applicability was directly tested in action research in two small and medium-sized companies and two large companies. The results were validated against experiences made by two management consultancies. Our study indicates that successful companies should: (i) integrate sustainability into business goals and plans, backed up by suitable (ii) internal incentives and disincentives and (iii) decision support tools. Our study also indicates that the new assessment approach can be used as a template to assess the current state of sustainability integration in company decision systems.     

Drought planning and water allocation: an assessment of local capacity in Minnesota

Water allocation systems are challenged by hydrologic droughts, which reduce available water supplies and can adversely affect human and environmental systems. To address this problem, drought management mechanisms have been instituted in jurisdictions around the world. Historically, these mechanisms have involved a crisis management or reactive approach. An important trend during the past decade in places such as the United States has been a shift to a more proactive approach, emphasizing drought preparedness and local involvement. Unfortunately, local capacity for drought planning is highly variable, with some local governments and organizations proving to be more capable than others of taking on new responsibilities. This paper reports on a study of drought planning and water allocation in the State of Minnesota. Factors facilitating and constraining local capacity for drought planning were identified using in-depth key informant interviews with state officials and members of two small Minnesota cities, combined with an analysis of pertinent documentation. A key factor contributing to the effectiveness of Minnesota's system is a water allocation system with explicit priorities during shortages, and provisions for restrictions. At the same time, the requirement that water suppliers create Public Water Supply Emergency Conservation Plans (PWSECP) clarifies the roles and responsibilities of key local actors. Unfortunately, the research revealed that mandated PWSECP are not always implemented, and that awareness of drought and drought planning measures in general may be poor at the local level. From the perspective of the two cities evaluated, factors that contributed to local capacity included sound financial and human resources, and (in some cases) effective vertical and horizontal linkages. This analysis of experiences in Minnesota highlights problems that can occur when senior governments establish policy frameworks that increase responsibilities at the local level without also addressing local capacity.     

Spatial Modeling of Harvest Constraints on Wood Supply Versus Wildlife Habitat Objectives

We studied the effects of spatial and temporal timber harvesting constraints on competing objectives of sustaining wildlife habitat supply and meeting timber harvest objectives in a boreal mixedwood forest. A hierarchical modeling approach was taken, where strategic and tactical level models were used to project blocking and scheduling of harvest blocks. Harvest block size and proximity, together with short- and long-term temporal constraints, were adjusted in a factorial manner to allow creation of response–surface models. A new measure of the habitat mosaic was defined to describe the emergent pattern of habitat across the landscape. These models, together with multiple linear regression, were used to provide insight on convergence or divergence between spatial objectives. For example, green-up delay (defined as time required before a harvest block adjacent to a previously logged block can be scheduled for harvest) had an adverse effect on the amount of annual harvest area that could be allocated and blocked spatially, and habitat supply responded in an opposite direction to that of wood supply, where caribou, moose wintering, and marten habitat supply increased when harvest blocks were further apart, maximum block size smaller, and both a green-up delay and mesoscale stratification were applied. Although there was no solution space free of conflicts, the analysis suggests that application of the mesoscale stratification, together with a diversity of harvest block sizes and a between-harvest block proximity of 250 m, will perform relatively well with respect to wood supply objectives, and at the same time create a less fragmented landscape that better reflects natural forest patterns.