Hypothetical Question Modes and Real Willingness to Pay

In the literature there are many, more or less well founded, reasons for favoring dichotomous choice over any other question modes that exist. One area that merits closer attention is which hypothetical question mode best approximates a real willingness to pay. In this paper a hypothetical dichotomous choice question is compared to a hypothetical open-ended question, and these are then compared to responses from a real valuation institution. This is done through controlled economic experiments using a private good. Contrary to most earlier studies, no difference between the two hypothetical question formats is found. The results may be regarded as support of the survey technique.     

Modeling surface water critical loads with PROFILE: possibilities and challenges

The critical load concept has become a valuable tool for policymakers in the European negotiations on emission reductions. Despite the international acceptance, ongoing validation of critical load methodology is of the utmost importance to avoid a situation where the calculation results are difficult to defend. In this paper we explore the potential of using the steady state soil chemistry model PROFILE as an alternative to the Steady State Water Chemistry (SSWC) method for calculating critical loads of acidity. The hypothesis is that the uncertainty in prediction of preindustrial leaching of base cations is reduced when soil properties instead of lake chemistry are used as input data. Paleolimnological reconstructions of preindustrial lake chemistry are used to test PROFILE. As PROFILE requires soil data that are not generally available on a catchment level, we used distributions of crucial parameters from soil survey data within the vicinity of five lakes for which paleoecological pH reconstructions were available. An important concern is the characterization of catchment hydrology. A calibration of the "effective" soil depth, needed to give PROFILE predictions that coincided with paleolimnology, suggested that approximately 0.6 m of the total soil depth was hydrologically active in supplying acid neutralizing capacity (ANC) to runoff through weathering. At present, there is insufficient evidence to either recommend or reject the PROFILE model for surface water critical loads. Before such a judgement can be made, the approach presented here has to be tested for other regions, and the definition of catchment hydrology needs to be investigated further.     

Effects of Acidification and its Mitigation with Lime and Wood Ash on Forest Soil Processes in Southern Sweden. A Joint Multidisciplinary Study

A joint multidisciplinary investigation was undertaken to studythe effects of lime and wood ash applications on two Norway spruce forest Spodosolic soils. The two sites, typical for southern Sweden, were treated in 1994 with either 3.25 t ha^-1 dolomite or 4.28 t ha^-1 wood ash (Horröd site) or in 1984 with either 3.45 or 8.75 t ha^-1 dolomite (Hasslöv site). Both sites show signs of acidification by atmospheric anthropogenic deposition and possessed low soil pH(4.3) and high concentrations of inorganic Al (35 M) in theupper illuvial soil solution. The prevailing soil conditions indicated perturbed soil processes. Following treatment with lime or wood ash, the soil conditions were dramatically altered. Cation exchange capacity (CEC) and base saturation (BS) was considerable increased after addition. Four years after application most of the added Ca and Mg was still present in the mor layer. Fifteen years after application,Mg in particular, became integrated deeper in the soil profile with a greater proportion lost by leaching incomparison to Ca. The concentrations of these ions were greatestin the mor layer soil solutions and Mg had higher mobility givinghigher concentrations also deeper in the profile. Four years after treatment, the application of wood ash and limeresulted in lower pH values and higher inorganic Al in mineral subsoil solutions compared to the untreated soil. We hypothesize that this was probably due to an increased flow of hydrogen ionsfrom the upper soil as a result of displacement by Ca and Mg ionsin the enlarged exchangeable pool. In contrast, fifteen years after lime and wood ash application, the mineral subsoil horizonspossessed a higher pH and lower soil solution Al content than theuntreated plots.Liming promoted soil microbial activity increasing soil respiration 10 to 36%. This is in the same range as net carbon exchange for forests in northern Sweden and could potentially have a climatological impact. The turnover of low molecularweight organic acids (LMWOA) by the soil microbial biomass werecalculated to contribute 6 to 20% to this CO₂ evolution.At Horröd, citrate and fumarate were the predominant LMWOAs with lowest concentrations found in the treated areas. In contrast, at the Hasslöv site, propionate and malonate were the most abundant LMWOAs. Higher microbial activity in the upper soil horizons was also theprobable cause of the considerably higher DOC concentrations observed in the soil solution of ash and lime treated areas. Thelime-induced increase in DOC levels at Hasslöv could be attributed to increases in the 3–10 kDa hydrophobic size fraction. Liming also promoted nitrification with high liming doses leading to extreme concentrations of NO₃ ^- (1 mM) in soil solution.At Hasslöv the community of mycorrhizal fungi was dramatically changed by the addition of lime, with only four of 24 species recorded being common to both control and treated areas.Many of the observed effects of lime and ash treatment can be viewed as negative in terms of forest sustainability. After fouryears of treatment, there was a decrease in the pH of the soil solution and higher concentrations of inorganic Al and DOC. Increased organic matter turnover, nitrification and NO₃ ^-leakage were found at Hasslöv. Considering that the weathering rate and the mineral nutrient uptake by trees is mostprobably governed by mycorrhizal hyphae etchingmineral grains in the soil, it is important to maintain this ability of the mycorrhizal fungi. The lime and ash-induced changed mycorrhizal community structure may significantly affect this capability. In light of this investigation and others, as reviewed by Lundström et al. (2003), the implications ofliming on forest health are multifaceted with complex relationships occurring over both space and time.     

A qualitative analysis of the stability of the root-microorganism soil system II. Combined effect of several factors

This is the second part of a study aimed at achieving some qualitative understanding of the stability properties of the root-microorganism soil system. The first part concentrated on the effect on this stability of different patterns of either nitrogen- or energy-limiting conditions. To this end, a mathematical model has been developed. The model, the theory and some results of the first part are extended here to more complex situations.A factor is first defined to measure the likelihood of the danger of extinction of the roots. It is found that this danger is increased with increasing specific mortality rates, decreasing nitrogen input and/or increasing periods of time during which decomposers are nitrogen-limited. It is also found that the danger of extinction is not directly proportional to absolute nitrogen losses from the system. Some possible explanations in terms of compensatory mechanisms of the roots are discussed.     

Future bioenergy trade in the EU: modelling trading options from a cost-effectiveness perspective

The purpose of this paper is to analyse under what conditions, with respect to CO₂ emission-reduction and biofuels-for-transport targets, the trading in the EU of CO₂ credits and solid and/or liquid biofuels is cost-effective from the perspective of an optimisation energy systems model. We use the PEEP model covering the EU27 (except Bulgaria, Malta, and Cyprus) to generate insights about the cost-effectiveness of different options under different policy scenarios. Trade in CO₂ credits is a cost-effective option, in all relevant policy scenarios. Trade in some biofuels (mainly from central and eastern European countries to the EU15) is cost-effective in all assessed scenarios. In the case of CO₂ targets (whether national or at the EU level) there is trade in solid biofuels. When biofuels-for-transport targets are also implemented, trading both solid and liquid biofuels is cost-effective.     

National Inventory of Landscapes in Sweden (NILS)��scope, design, and experiences from establishing a multiscale biodiversity monitoring system

The landscape-level and multiscale biodiversity monitoring program National Inventory of Landscapes in Sweden (NILS) was launched in 2003. NILS is conducted as a sample-based stratified inventory that acquires data across several spatial scales, which is accomplished by combining aerial photo interpretation with field inventory. A total of 631 sample units are distributed across the land base of Sweden, of which 20% are surveyed each year. By 2007 NILS completed the first 5-year inventory phase. As the reinventory in the second 5-year phase (2008?C2012) proceeds, experiences and insights accumulate and reflections are made on the setup and accomplishment of the monitoring scheme. In this article, the emphasis is placed on background, scope, objectives, design, and experiences of the NILS program. The main objective to collect data for and perform analyses of natural landscape changes, degree of anthropogenic impact, prerequisites for natural biological diversity and ecological processes at landscape scale. Different environmental conditions that can have direct or indirect effects on biological diversity are monitored. The program provides data for national and international policy and offers an infrastructure for other monitoring program and research projects. NILS has attracted significant national and international interest during its relatively short time of existence; the number of stakeholders and cooperation partners steadily increases. This is constructive and strengthens the incentive for the multiscale monitoring approach.     

Greenhouse gas emissions and energy balance of sunflower biodiesel: Identification of its key factors in the supply chain

The production of first generation biofuels, such as sunflower-based biodiesel, is potentially an option for diversifying the energy matrix in several South American countries. However, biofuels present environmental challenges, especially concerning the reduction of greenhouse gas (GHG) emissions. This study, using a life-cycle approach, evaluates the GHG emissions and energy balance of the future nationwide production of sunflower-based biodiesel in Chile. Direct land use change is included in the analysis. The overall findings indicate that sunflower biodiesel, under the most likely production conditions, will have better environmental performance than fossil diesel in terms of both indicators. The agricultural stage is associated to key factors such as land use change, and nitrogen fertilizers. These factors contribute significantly to GHG emissions or energy demand in the biodiesel life cycle. The sensitivity analysis shows that no GHG emission saving could occur if nitrogen fertilizers rate exceeds 330 kg N/ha. In order to reduce the environmental impacts of this biofuel, improvement measures are suggested.     

Dealing with uncertainty: a case study of controlling insect populations in natural ecosystems

This paper analyses the political process for handling an outbreak of an insect causing human allergic reactions. In the southern part of the Swedish island Gotland in the Baltic Sea, an outbreak of the northern pine processionary moth, Thaumetopoea pinivora, has occurred. With regard to the human nuisance and long-term effects on the tourist industry, demands have been raised for intervention to reduce and control the insect population. At the same time, there have been warnings against treating the insect population because there are knowledge gaps concerning the wider ecological consequences, including effects on biodiversity. This paper analyses the political process and its problem-solving efforts. Of particular interest is how it dealt with the issue of uncertainty. It was found that the uncertainty associated with the issue hindered the development of a shared understanding of the problem and a possible solution. There seems to be a growing need in society to develop the institutional capacity to handle complex issues that cross different sectors, regulatory frameworks and policy targets.     

Urban Metal Flows – A Case Study of Stockholm. Review and Conclusions

Metals have rapidly accumulated in the anthroposphere, especiallyin urban areas, indicating possible environmental and resource problems. Here, Stockholm City was chosen for a case study of urban metal flows, i.e. metal inflow to, metals in the stock of,and metal outflow from the anthroposphere to the biosphere. Themetal stock of Stockholm is large and still growing. The large amounts of metals in the solid waste fraction totally dominatethe outflow from the city. For major parts of the stock, the emissions from goods in use are negligible. There are, however,goods applications corresponding to significant emissions: e.g. the traffic sector (Cu, Zn, Cr, Ni, Pb), the tapwater system (Cu), roofs/fronts or other metal surfaces (Cu, Zn). Today's known metal flows from the anthroposphere of Stockholm to the biosphere and sewage sludge are quantitatively dominated by Zn(34 ton y^-1) and Cu (14 ton y^-1). Historical and present emissions have resulted in high metal concentrations insediments (especially Cd, Hg and Pb, but also Cu and Zn), groundwater (Cu, Hg) and in soils (Hg, Cu, Pb). At present theannual median concentrations are below the Swedish limits for metals in sewage sludge, even if the safety margins aresmall for Cd, Hg and to some extent Cu. The flows of Cu and Zn to Stockholm soils are high with a significant accumulationindicating an environmental impact in a longer time perspective.High levels of metals in surface sediments in the waterenvironments reflects an ongoing input where these metals aretransported from known (Cu, Zn) and or partly unknown (Cd, Hg, Pb) sources. In future urban areas, monitoring of metal flows must be performed both in the anthroposphere and the biospherein order to have a pro active approach to urban environmentalproblems and to get prompt answers to measures taken.