Regional assessment of climate change impacts on maize productivity and associated production risk in Switzerland

A simple model of yield was used along with climate scenarios to assess the impact of climate change on grain maize productivity and associated economic risk in Switzerland. In a first application, changes in the precipitation regime alone were shown to affect the distribution of yield considerably, with shifts not only in the mean but also in the standard deviation and the skewness. Production risk was found to respond more markedly to changes in the long-term mean than in the inter-annual variability of seasonal precipitation amounts. In a further application, yield projections were generated with respect to a full climate scenario, with the emission pathway as specified in the IPCC A2 scenario. Anticipation of the sowing date was found to reduce the negative impact of climate change on yield stability, but was not sufficient to ensure average productivity levels comparable to those observed at present. We argued that this was caused by the reduction in the duration of the growing season, which had a stronger impact than suggested by previous studies. Assuming no change in price relations, the results also revealed a strong increase in production risk with climate change, with more than a doubling in the probability of yield falling short of a critical threshold as compared to today’s situation.     

Waste Management in the European Union: National Self-Sufficiency and Harmonization at the Expense of Economic Efficiency?

/ Since 1975, the European Union (EU) has developed an impressive body of waste management legislation, although, according to the principle of subsidiarity, responsibilities belong to the most local level at which the tasks can be carried out effectively. Using economic theory, this paper examines several factors that influence the efficient distribution of regulatory authority among the EU and the member states. We specifically analyze the role of harmonization that, in our opinion, will often lead to an overcentralization. Within this context, a second issue is becoming more important, as ongoing discussions show. If no consensus can be reached about harmonization, should member states be allowed to stop cross-border shipments of waste, or should the EU strive for a common market for waste? We take the position that most objections against waste shipments are not convincing, especially if the member states implement minimum standards for landfills and waste processing facilities and common information and control systems. Competition between different national regulations within adequate constraints that, e.g., control transboundary externalities leads to more efficient waste management structures in Europe than national self-sufficiency or centralized decision-making at the EU level. KEY WORDS: Waste management; European Union; Subsidiarity; Institutional competition; Harmonization; Cross-border shipments of waste     

Grazing regulates the spatial variability of periphyton biomass

The presence of consumers not only alters the mean biomass of the prey assemblage, but also affects the spatial heterogeneity of biomass distribution. Whereas the mean prey biomass is generally reduced by consumer presence, the effect on spatial heterogeneity is less clear-cut. A meta-analysis of almost 600 field experiments manipulating the presence of benthic invertebrate or vertebrate grazers was conducted to analyze the effect of grazers on both the absolute spatial variability of periphyton biomass and the relative variability, which was standardized to the mean. Effects on absolute variability were measured as the log response ratio of the standard deviation of biomass (LR-SD), whereas effects on relative variability were measured as the log response ratio of the coefficient of variation of biomass (LR-CV). The overall magnitude and range of LR-SD and LR-CV indicated that grazers not only reduced periphyton biomass, but also substantially altered their spatial distribution. However, grazer effects differed strongly for absolute and relative variability. On average, grazers reduced the absolute spatial variability in prey biomass by 50% (average LR-SD = -0.68) but increased the relative variability by 24% (average LR-CV = 0.22). The magnitude of LR-SD strongly depended on the efficiency of grazing, with strong biomass removal leading to strong homogenization. Moreover, LR-CV and LR-SD were significantly affected by habitat type (freshwater vs. coastal) and substrata. Given the importance of spatial heterogeneity for resource uptake, competition and the maintenance of diversity, grazer presence has potentially strong indirect effects on the interactions within prey assemblages.     

Multiple functions increase the importance of biodiversity for overall ecosystem functioning

Biodiversity is proposed to be important for the rate of ecosystem functions. Most biodiversity-ecosystem function studies, however, consider only one response variable at a time, and even when multiple variables are examined they are analyzed separately. This means that a very important aspect of biodiversity is overlooked: the possibility for different species to carry out different functions at any one time. We propose a conceptual model to explore the effects of species loss on overall ecosystem functioning, where overall functioning is defined as the joint effect of many ecosystem functions. We show that, due to multifunctional complementarity among species, overall functioning is more susceptible to species loss than are single functions. Modeled relationships between species richness and overall ecosystem functioning using five empirical data sets on monocultures reflected the range of effects of species loss on multiple functions predicted by the model. Furthermore, an exploration of the correlations across functions and the degree of redundancy within functions revealed that multifunctional redundancy was generally lower than single-function redundancy in these empirical data sets. We suggest that by shifting the focus to the variety of functions maintained by a diversity of species, the full importance of biodiversity for the functioning of ecosystems can be uncovered. Our results are thus important for conservation and management of biota and ecosystem services.     

DEMAND SIDE MANAGEMENT OF WATER IN ONTARIO MUNICIPALITIES: STATUS,PROGRESS, AND OPPORTUNITIES1

ABSTRACT: Demand side management is being used increasingly by Ontario municipalities as a way to improve the efficiency of water use, defer the costs associated with constructing new water treatment works, and minimize the environmental impacts associated with supplying water. A comprehensive survey of 153 Ontario municipalities was completed in mid‐1998. These ranged in size from small rural townships (with populations as low as 500 people) to the province's largest urban center, Metropolitan Toronto, with a population of approximately 2.5 million people. The questionnaire measured the use of six broad types of demand side measures, including water pricing and metering; municipal by‐laws (ordinances) that promote water conservation; operational and maintenance measures to reduce water losses and consumption; water‐saving plumbing fixtures and devices; public participation programs that encourage water conservation; and other measures, such as water audits. Additionally, the survey collected data on implementation barriers and opportunities. Since the last comprehensive Ontario survey, conducted in 1987 by Kreutzwiser and Fea‐gan (1989), there has been an increase in the use of basic tools such as metering and pricing, plumbing fixtures, and public participation programs. Additionally, new initiatives, such as water audits and computerized monitoring equipment, are being used. However, in many areas opportunities exist to make better use of demand side measures. Unfortunately, municipal capacity to do so often is constrained by (among other factors) limited finances, lack of political will, and public resistance. Demonstration of real cost savings to consumers, and the development of specific goals and objectives for demand side management programs, are two important steps needed to overcome these challenges.