Modelling the spatial population dynamics of the green oak leaf roller (Tortrix viridana) using density dependent competitive interactions: Effects of herbivore mortality and varying host-plant quality

Cyclic population dynamics of forest insects with periods of more than two generations have been discussed in relation to a variety of extrinsic and intrinsic forces. In the present study, we employed the selection pressure of density dependent competitive interactions according to Witting's equations (Witting, 2000) as driver for a discrete spatiotemporal model of the green oak leaf roller (Tortrix viridana). The model was successfully parameterised to rebuild the cyclic population dynamics of an empirical data set of a 30-year leaf roller monitoring in Russia. Our analysis focussed on the role of herbivore mortality and host plant food quality, which have a significant effect on T. viridana population dynamics. An additional egg or larvae mortality lowers population density and can lead to selection pressures that favour individuals with higher growth rate. This increased population growth rate can not only compensate the additional mortality, but also can lead to higher average moth abundances in subsequent generations. Furthermore, we analysed the effect of inter- and intraspecific variation in host plant quality on herbivore population dynamics and the spatial distribution of abundance and defoliation patterns. We found significant effects of the qualitative composition of a trees neighbourhood on the herbivore population of the respective tree. Also, the patchy damage patterns observable in reality have been reproduced by the present model. The applicability of the model approach and the putative genetic processes underlying Witting's model are discussed.     

Comparison of external costs between dry tomb and bioreactor landfills: taking intergenerational effects seriously.

Dry tomb and bioreactor landfills were analyzed with respect to their external costs in an intergenerational cost-benefit analysis in a partial framework which enabled a sounder comparison to be carried out between these two technologies from a socio-economic viewpoint. Obviously, this approach was only a first step for building a comprehensive basis of any environmental as well as fiscal policy in the field of waste management. All external costs are identified and evaluated in three different scenarios, corresponding to a worst case, a best guess and a best case. Obviously, discounting is crucial with respect to an intergenerational perspective. Generation-adjusted discounting (GAD) was applied to take into account equity as well as efficiency criteria, in order to deal with three different types of uncertainties that are decisive in waste policy decisions: a physical uncertainty is captured by introducing our three different scenarios; a macroeconomic uncertainty is taken into consideration by calculating present values using different real growth rates; and a microeconomic uncertainty is taken into account by considering individual peculiarities reflected in their subjective time preference rate. The findings show, that whenever there is a low real GDP growth of less than 1%, the bioreactor is generally superior to the dry tomb (lower present values of external costs). This statement becomes more valid as the growth rate decreases. However, whenever there are high positive growth rates, it is the dry tomb technology which is superior to the bioreactor system.     

Management of natural hazards in Europe: The role of spatial planning in selected EU member states

This paper presents the results of an assessment made as a part of the research project, Applied Multi-Risk Mapping of Natural Hazards for Impact Assessment (ARMONIA). The aim was to identify which aspects in the so-called disaster management cycle are covered by spatial planning in planning practice in the European Union's member states of Finland, France, Germany, Greece, Italy, Poland, Spain and the UK. In contrast to the initial hypothesis, the analysis of planning practice has shown that the role of spatial planning in risk assessment and management in many ways has been overestimated. The results have shown that spatial planning is only one of many actors in risk management and that it is, in general, not involved in risk assessment. Further, multi-risk assessment approaches are not used in planning practice, risk indicators are hardly used and vulnerability indicators are not at all used. The paper will interpret these surprising results and will answer the question of the role of spatial planning in natural risk assessment and management.     

Experimente zum Verbleib von Cyanid nach Aufnahme in Pflanzen

Free cyanide (prussic acid) can be degraded by many organisms. Experimental data on the kinetics of degradation by plants, however, are rare. We experimentally determined the mass balance of potassium cyanide in the system nutrient solution/plant/air In the presence of living willows (Salix alba) and light, free cyanide is almost completely eliminated from the nutrient solution, also by a willow cell suspension (> 99%) and even by a dried-out stem (> 80%). The loss is smaller when the willow is autoclaved (30%). Without a willow, the CN can be recovered to more than 89%. The loss depends on light and transpiration. Volatilization and the formation of complexed cyanide are of minor relevance for the elimination of free CN. The most plausible loss process is metabolism by plants. The transfer into the roots and stem does not change with the light/dark-rhythm. The transfer factor (mg CN/kg plant fw/mg CN/l solution) after 24 h, and related to the initial concentration in solution, is between 2 and 3 for roots, 0.1 to 0.6 for leaves and 0.2 for stems. In the roots of willows and elderberries which were growing on the former gas worksite in Holte, Denmark, high concentrations of cyanides were found. In leaves and fruits, concentrations are a factor of 10 to 1000-fold lower and up to as high as that found in non-exposed control plants. Due to these results, a cyanide-polluted site in Denmark has been remediated with poplar trees.     

Heavy-metal ion complexation by particulate matter in the leachate of solid waste: a multi-method approach

The metal ion binding characteristics of particulate matter obtained from column experiments on the anaerobic digestion of solid waste were studied using a titrimetric approach. The experimental set-up allowed us to study the dynamics of particle bound ligand concentrations during digestion processes typically found in landfills.We developed a continuous titration method by simultaneously using a Cd-sensitive and pH electrode and combining metal and acid/base titrations. This technique allows for a more precise determination of pK_a-log K_M pairs for each ligand than metal titrations alone. The results were compared with titration methods using differential pulse anodic stripping voltammetry (DPASV) and atomic absorption spectroscopy (AAS) with longer equilibration times in order to further characterize ligand properties such as reaction kinetics, the electrochemical lability of the respective complex during DPASV, the distinction between metal adsorption to particulate matter and metal complexation by soluble ligands adhered to particles, reversibility of the binding process by competition studies, and resistance against purging with nitrogen gas.The properties of seven major metal binding ligands were identified and assignments to the most likely functional groups were made. The most important ligand properties are for ligand A: pK_a ≈ 9.2, log K_cd ≈ 7.0 fast reaction kinetics (mercapto groups); ligand B: pK_a = 4.8, log K_Cd ≈ 6.0, slow reaction kinetics (chelates with 3 or 4 carboxylic groups); ligand C: pK_a ≈ 6.0, log K_Cd ≈ 13.0, irreversible metal binding at basic pH-values (uptake inside bacterial cells); ligand D: pK_a = 7.7, log K_Cd = 4.0, runs parallel to N content of particulate matter with digestion time (primary amines neighboring oxo groups); ligand E: pK_a ≈ 12.0, log K_Cd = 9.0, runs parallel to P content of particulate matter (phosphate); ligand F:pK_a > 9.0, log K_{Cdf = pKa + 0.4}, runs parallel to N content of particulate matter (primary amines neighboring SH groups); and ligand G: pK_a ≤ 4.8, log K_Pb ≈ 4.3, strong Pb²⁺ ligand, even at low pH-values.Metal ions were found to be irreversibly bound by ligand C at low heavy-metal concentratins, whereas at higher concentrations the binding is reversible and can be predicted using the mass of the digestion process (methanogenic phase). All other ligands have their concentration maximum in the transition phase between acetogenic and methanogenic phase.     

The Spatial Dimension of Landscape Sustainability

Sustainability indicators are mostly derived from parameters which are, in the spatial dimension, more or less distribution-free. In the majority of cases, the indicators are based on statistical data on production, consumption, pollutants emission, land use, etc. This statistical approach is liable to mask sustainability risks which are primarily caused by specific spatial and temporal patterns of landscape and land use structure, such as degradation of soil functions, disturbances in the landscape's water balance, and losses in functional habitat quality.Sustainability risks due to ecologically non-adapted spatial landuse patterns require measures on regional to local scales, based on disaggregated, spatially explicit indicators. Depending on the respective planning and decision level, different levels of spatial aggregation/disaggregation have to be considered.In the concept presented here, a differentiated approach is proposed. For an aggregated assessment of landscape sustainability, long term monitoring of the dynamics of water flow and matter load at the outlet point of river catchments is recommended. A prerequisite for analyzing those measurements in terms of the catchments' land cover and land use pattern, as well as changes thereof, is a Geographic Information System (GIS) holding relevant up-to-date geodata sets. For a spatially more detailed indication of sustainability risks, an approach of GIS-based functional landscape assessment was demonstrated in a regional case study.The results show GIS on regional to local scales together with satellite remote sensing data on land cover and landuse to be a powerful data basis for spatially explicit landscape evaluation, provided that suitable models for assessing specific landscape functions are applied.     

Mainstreaming of climate extreme risk into fiscal and budgetary planning: application of stochastic debt and disaster fund analysis in Austria

While ageing-related costs are perceived as the major drivers of fiscal pressure in the EU, concerns over climate-related public expenditures have received comparatively little attention in securing the EU’s long-term fiscal sustainability. Using the Shared Socioeconomic Pathways (SSPs) scenarios as bridging concept for linking the assessment of public cost of demography- and climate-related expenditures, this study proposes a climate risk mainstreaming methodology. We apply a stochastic debt model and assess the potential flood risk in Austria to the public debt and the national disaster fund. Our results indicate that public debt under no fiscal consolidation is estimated to increase from the current level of 84.5% relative to GDP in 2015 to 92.1% in 2030, with macroeconomic variability adding further risk to the country’s baseline public debt trajectory. The study finds that the estimated public contingent liability due to expected flood risk is small relative to the size of economy. The existing earmarked disaster risk reduction (DRR) funding will likely reduce the risk of frequent-and-low impact floods, yet the current budgetary arrangement may be insufficient to deal with rising risk of extreme floods in the future. This prompts the need for further discussions regarding potential reforms of the disaster fund. As many EU member states are in the early stages of designing climate change policy strategies, the proposed method can support the mainstreaming of climate-related concerns into longer-term fiscal and budgetary planning.

     

Effects of Topographic Heterogeneity on Coarse Resolution Grid-Based Runoff Simulation—Assessment for Three River Basins in Peninsular Malaysia

This paper investigates the effects of topographic heterogeneity on the runoff response simulated by a 0.05 degree (approximately 5.5 km) spatial resolution distributed hydrological model for the Pahang, Kelantan, and Muda river basins (25,600, 11,900, and 4010 km², respectively) in Peninsular Malaysia. Daily simulations were carried out and assessed against observed streamflow for the period 1999–2004. Topographic structure was characterized by means of subgrid terrain slope to guide the decomposition of hydrological parameters over the model grid. The results show improved simulation skill for all three basins compared to a traditional runoff production parameterization scheme that does not take into account the subgrid topographic variability. However, other factors related to morphological heterogeneity and variability in physical terrain conditions should be considered in future work in order to characterize the hydrological heterogeneity. The present methodology may be of potential for further development of large-scale, coarse resolution grid-based hydrological models without adding structural model complexity and without affecting parameter parsimony.     

Effects of experience with access regimes on stewardship behaviors of small-scale fishers

Governance regimes that assign exclusive access to support collective action are increasingly promoted to manage common-pool resources under the premise that they foster environmental stewardship. However, experimental evidence linked to existing policies that support this premise is lacking. Overlapping access policies in small-scale fisheries provide a unique opportunity to test the effects of access regimes on users’ stewardship behaviors. We performed a lab-in-the-field experiment to assess how fishers’ previous experience with access regimes relates to compliance and peer enforcement (n = 120). Fishers’ compliance and peer-enforcement decisions were compared in a common-pool-resource game. Treatments differed in framing to represent exclusive access and pseudo-open access regimes, both of which fishers face in real life. To contrast behavior in the game with real-life observations, we compared fishers’ associations that have shown relatively high and low management performance under exclusive access policies. Compliance and peer enforcement were higher under the exclusive access treatment than under the pseudo-open access treatment only for fishers’ associations with high management performance in real life. Behaviors in the game reflected differences between associations in real life. Our results support previous research on ocean governance by experimentally assessing the role of access regimes in determining users’ stewardship and suggest potential mechanisms for stewardship internalization.