Benchmark Criteria: A Tool for Selecting Appropriate Models in the Field of Water Management

A milestone in the field of European water protection policy is the European Union’s Water Framework Directive (WFD), which came into force in December 2000 and which integrates the management of European waters in many ways. In this study, we start by focusing on management issues connected to the implementation of the WFD and pose a question: “what type of models would be the most suitable for use in the context of the WFD?” With this question in mind, we aim to establish a set of operational and functional selection criteria for (computer) models whose application is intended to support decision-making related to a particular water management issue. These so-called “benchmark criteria” should help water managers and other model users in choosing appropriate models, e.g., for the WFD implementation purposes. We first describe models and their use in general and then propose an approach for setting the benchmark criteria for models, basing it on the concept of uncertainty management, while keeping firmly in mind the important role of citizens and citizen organizations in water management. The suggested benchmark criteria are in the form of 14 questions through which each model can be evaluated. Finally, the process for testing and refining the benchmark criteria is highlighted.     

Body mass dependence of glycogen stores in the anoxia-tolerant crucian carp (<Emphasis Type="Italic">Carassius carassius</Emphasis> L.)

Glycogen is a vital energy substrate for anaerobic organisms, and the size of glycogen stores can be a limiting factor for anoxia tolerance of animals. To this end, glycogen stores in 12 different tissues of the crucian carp (Carassius carassius L.), an anoxia-tolerant fish species, were examined. Glycogen content of different tissues was 2–10 times higher in winter (0.68–18.20% of tissue wet weight) than in summer (0.12–4.23%). In scale, bone and brain glycogen stores were strongly dependent on body mass (range between 0.6 and 785 g), small fish having significantly more glycogen than large fish (p < 0.05). In fin and skin, size dependence was evident in winter, but not in summer, while in other tissues (ventricle, atrium, intestine, liver, muscle, and spleen), no size dependence was found. The liver was much bigger in small than large fish (p < 0.001), and there was a prominent enlargement of the liver in winter irrespective of fish size. As a consequence, the whole body glycogen reserves, measured as a sum of glycogen from different tissues, varied from 6.1% of the body mass in the 1-g fish to 2.0% in the 800-g fish. Since anaerobic metabolic rate scales down with body size, the whole body glycogen reserves could provide energy for approximately 79 and 88 days of anoxia in small and large fish, respectively. There was, however, a drastic difference in tissue distribution of glycogen between large and small fish: in the small fish, the liver was the major glycogen store (68% of the stores), while in the large fish, the white myotomal muscle was the principal deposit of glycogen (57%). Since muscle glycogen is considered to be unavailable for blood glucose regulation, its usefulness in anoxia tolerance of the large crucian carp might be limited, although not excluded. Therefore, mobilization of muscle glycogen under anoxia needs to be rigorously tested.     

Catalytic TiO2 oxidation of ethanethiol for environmentally begnin air pollution control of sulphur compounds

Volatile organic compounds containing reduced sulphur such as thiols and thioethers are released mostly from biological activities and a number of manufacturing processes, such as papermaking and petroleum refining. Environmentally benign and cost-effective air pollution control technology for reduced sulphur compounds is still a topic of research, e.g., in pulp and paper industry. Due to its advantages, photocatalytic oxidation over titanium dioxide presents a potential alternative for the air treatment strategies. The temperature influence on the reaction pathway and kinetics of gas-phase photocatalytic oxidation and thermal catalytic decomposition of ethanethiol over Degussa P25 TiO₂ was established by a continuous flow method in a simple tubular reactor at temperatures from 373 to 453 K. Kinetic parameters for ethanethiol were: adsorption enthalpy −45 kJ mol⁻¹ and activation energy 42 kJ mol⁻¹. Sulphur dioxide, carbon monoxide, carbon dioxide, acetic acid and water were identified as by-products.     

Competition,defense and games between plants

Summary Coexistence of defended and undefended plants may be maintained by herbivory. In the present paper this phenomenon is analyzed by means of evolutionary game theory. The plants in the model play either a defensive or a non-defensive strategy and they interact indirectly: when a plant is grazed its competitive ability decreases, because of this a neighboring plant makes a profit. The solution to the game leads to three qualitatively different cases depending on whether the profit is equal for the two strategies, defended and undefended, or if the profit is higher for one type than for the other. When the results are applied to intea-specific interactions, the model predicts that polymorphic populations should be expected only under certain specific conditions. When the results are applied to inter-specific interactions, the model predicts either stable coexistence, i.e., increased diversity, or a paradoxical situation without increased diversity.Offprint requests to: M. Augner     

Potential biodiversity benefits from international programs to reduce carbon emissions from deforestation

Deforestation is the second largest anthropogenic source of carbon dioxide emissions and options for its reduction are integral to climate policy. In addition to providing potentially low cost and near-term options for reducing global carbon emissions, reducing deforestation also could support biodiversity conservation. However, current understanding of the potential benefits to biodiversity from forest carbon offset programs is limited. We compile spatial data on global forest carbon, biodiversity, deforestation rates, and the opportunity cost of land to examine biodiversity conservation benefits from an international program to reduce carbon emissions from deforestation. Our results indicate limited geographic overlap between the least-cost areas for retaining forest carbon and protecting biodiversity. Therefore, carbon-focused policies will likely generate substantially lower benefits to biodiversity than a more biodiversity-focused policy could achieve. These results highlight the need to systematically consider co-benefits, such as biodiversity in the design and implementation of forest conservation programs to support international climate policy.     

Is biochar or straw-bale construction a better carbon storage from a life cycle perspective?

Biochar has been presented as a key technology for avoiding dangerous climate change. Pyrolysis converts part of the biomass feedstock into a gaseous fraction, which can be used for energy production. The remaining fraction is char, which is highly stable and resistant to biodegradation. When char is added to soil it increases carbon storage, reduces emissions and improves soil quality. Agricultural residues such as straw, stover and hulls are seen as the most accessible raw material. These residues could also be used as insulation in passive energy housing. Straw bale construction is a relatively simple technology, which has been applied for decades. It can store the carbon of the straw material into walls structures and in the process provides energy efficient housing. The climate benefits from improved energy efficiency depend on local conditions and energy production forms. In this study life cycle assessment was used to compare the climate impacts of biochar production and straw bale construction. On a life cycle perspective, straw bale construction results in higher net carbon storage than biochar production (3.3 t CO₂eq vs. 0.9 t CO₂eq/t of straw). However the result was found to be highly dependent on the assumptions on the overall energy efficiency of the replaced building stock.     

Gene expression responses of paper birch (Betula papyrifera) to elevated CO2 and O3 during leaf maturation and senescence

Gene expression responses of paper birch (Betula papyrifera) leaves to elevated concentrations of CO₂ and O₃ were studied with microarray analyses from three time points during the summer of 2004 at Aspen FACE. Microarray data were analyzed with clustering techniques, self-organizing maps, K-means clustering and Sammon's mappings, to detect similar gene expression patterns within sampling times and treatments. Most of the alterations in gene expression were caused by O₃, alone or in combination with CO₂. O₃ induced defensive reactions to oxidative stress and earlier leaf senescence, seen as decreased expression of photosynthesis- and carbon fixation-related genes, and increased expression of senescence-associated genes. The effects of elevated CO₂ reflected surplus of carbon that was directed to synthesis of secondary compounds. The combined CO₂ + O₃ treatment resulted in differential gene expression than with individual gas treatments or in changes similar to O₃ treatment, indicating that CO₂ cannot totally alleviate the harmful effects of O₃.     

Mitigating Human Effects on European Biodiversity through Traditional Animal Husbandry

Abstract: Livestock grazing (without modern fertilizers), mowing, and other traditional methods of animal husbandry are used in Europe for managing human-made habitats such as seminatural grasslands. From a review of essential literature, I hypothesize that traditional animal husbandry partially compensates for the loss of natural processes that have been suppressed by humans. There is indirect evidence that livestock grazing and mowing have made possible the continued existence of many species threatened by the human overkill of megaherbivores and other large herbivores. Many species that were dependent on natural fires and floods may have benefited from grazing and mowing, which also may be effective tools for mitigating the negative effects of eutrophication. As partial surrogates, traditional grazing and mowing have obscured the importance of natural disturbances to European biodiversity. Thus, the end of traditional animal husbandry, together with the suppression of natural disturbances, may cause even more adverse effects to biodiversity than is generally recognized.