Ökologische Kriterien der Technik- und Stoffbewertung: Integration des Vorsorgeprinzips

The development of criteria for the comparative assessment of technologies and substances beyond the toxicological approach and the development of an integrated pattern of criteria is still at the beginning. The criteria presented here for integrating the precautionary principle into the substance and technology assessment have to be further operationalised and completed, in the same way as the criteria which have been discussed and developed within the framework of

- the poisoning and pollutant paradigm

- the equilibrium paradigm

- the sustainability and “Mitwelt” paradigm

- the energy and the general technology assessment debate.

The resolution of the criteria has to be improved and their range (which is certainly limited) has to be explored more precisely. The application of the criteria should never occur mechanically. Technology assessment and substance assessment are not only scientific, but essentially social and, hence, discursive processes. It is not so much the assessment of individual substances which should be in the center of the debate, but rather the comparative assessment of competing techniques, substances and substancerelated development pathways (see vonGleich andRubik, 1966 as a first approach to assess the environmental effects of old and new materials). According to the example of the energy strategies, only the development of competing strategies in the substance field could create the necessary prerequisites for a broad public discourse and thus for a democratisation of the basic substancerelated policy decisions. This discourse is a duty which science and economy have toward society.     

Ökologische Aspekte des Phosphor-Kreislaufs

In contrast to the complex N-cycle with its high number of reactive compounds, the global P-cycle is uncomplicated. There is only one reactive compound (PO₄ ^3?), and the atmosphere is practically not involved. Nevertheless, severe ecological imbalances may be induced by anthropogenic perturbations of the P-cycle, especially in aquatic ecosystems. The present knowledge on the global P-cycle (reservoirs, fluxes, residence times) is summarized and the ecological dimension of increased phosphorus inputs into surface waters is discussed in detail. Exemplary for Germany, the role of agriculture is described in this context. The fact that the rock phosphate resources are principally limited and not renewable is of a high ecological and economical relevance. The expected lifetime of the P-reserves is calculated for different estimate-scenarios concerning the magnitude of reserves and consumption. Measures to reduce the P-surplus in agriculture, to increase the efficiency of P-fertilization, and to recycle P more consequently are therefore highly required.     

Raumgliederung für die Ökologische Umweltbeobachtung des Bundes und der Länder

Ecoregionalizations are important for the evaluation of monitoring networks. In this article a method is decribed concerning how to define Germany’s ecoregions by using ecological data on soil, vegetation, climate and elevation through the aid of classification and regression trees. The resulting ecoregions can be linked to metadata (parameters, methods, quality control and assurance measures) from thousands of Germany’s environmental monitoring sites. Together with GIS procedures, multivariate statistics and geostatistics, ecoregions are useful for integrating data of environmental measurements according to ecological and spatial criteria.     

Ökologische Situation der Region Leipzig-Halle

Air pollution in the region Leipzig-Halle was investigated using two-year-old pine needles (Pinus sylvestris L.) at 39 sites of a biomonitoring net covering an area of ca. 7 500 km². The concentration values of Al, Ca, Cr, Fe, K, Mg, Mn, Pb and V characterize the immission patterns of the period 1990/91. The method is less suited for Cu, Ni and Zn due to the transfer route soil-pine, and for Cd due to the small total content. There are significant spatial and element-specific variations which require distinct evaluation of the pollution situation. The city of Leipzig itself is a significant source for Pb, Cr, Fe and V emission. Mainly as far as the centre of the region is concerned, the Pb concentration values are beyond those of heavily contaminated reference sites. The bioindication system is also applicable for comparable regions in Eastern Europe where the pine is the dominating conifer type. Immission trends can be monitored over ecologically relevant periods of time.     

Ökologische Situation der Region Leipzig-Halle

The deposition of heavy metals bound to air dust and their ecological effects depend, to a large degree, on particle size, which influences the transport processes in the environment. To estimate the size range of the particles mainly taken up by the pine needles, concentration gradients along a sector leeward of Leipzig were modelled according toGauss plume calculations. The results show that the aerodynamic size is between 1 and 10 μm. Particles of this size range can be taken up by lungs and, thus, have a particular toxicological relevance.     

Kosovo-Konflikt: Ökologische Auswirkungen

10 years ago, the WWF (World Wide Fund for Nature) began to support the work of environmental protection in the countries of Eastern Europe. A main topic is the Danube-Carpathian Program. With the beginning of the bombardements, connected with great amounts of chemicals released directly and as clouds from the fires and explosions, the question raises: What are the consequences for mankind and nature? Is there a risk for the Danube-Carpathian Program? The WWF feels responsible for reporting about these consequences. In July 1999, a group of two Oil Experts and two scientists (each a chemist and a toxicologist) visited Belgrad, Pan?evo and Novi Sad, took samples of soil and water, and estimated the contents of dangerous substances. The first findings and the first consequences for nature and human health are described.     

Ökologische Optimierungspotenziale der energetischen Nutzung von Palmöl

Aim and Background The use of palm oil for bioenergy has become increasingly important for Europe in the last years because of its favourable proportion of yield to area under cultivation. Thus, palm oil presents a low-priced alternative to other energy sources, e.?g. rapeseed oil. Currently, however, palm oil gets a bad press due to new studies about the negative environmental consequences of cultivation practices. Due to the high demand for palm oil, land is becoming scarce. This results in the clearing of primary forests and consequently in the loss of biodiversity and in an increase of greenhouse gas emissions. To reduce the latter, not only the process of oil palm cultivation has to be optimised but also the practice of establishing new plantations by clearing natural forests has to be questioned. The aim of this article is to disclose potentials for greenhouse gas reductions in existing as well as in newly-planned oil palm plantations. Results and Discussion For existing oil palm plantations, two main fields for possible optimisation can be identified: one is improving the plantation management, the other is increasing the efficiency of the utilisation of waste products such as fibres and husks or oil mill effluents. For newly-planned oil palm plantations alternative land use scenarios have to be considered. The results show a big potential for optimisation. Thus, the greenhouse gas balance improves slightly if plantations are run more efficiently. If the waste products are used to generate energy, there are significantly positive effects on the greenhouse gas balance, especially through the reduction of methane emissions. By running a plantation in a professional best-practice way, 4.8 t of greenhouse gases can be saved annually per hectare cultivation area, expressed as CO₂ equivalents. If newly-planned oil palm plantations are established on fallow land, greenhouse gas emissions can be further reduced by an additional 4.8 t of CO₂ equivalents per hectare and year. From an economic perspective, this may be more costly than clearing primary forest but it is advantageous for both the greenhouse gas balance and the biodiversity of the concerned areas. All in all, exploiting the whole potential for optimisation could result in the saving of 10.2 t CO₂ equivalents per hectare and year more than it is the case in the existing mode of cultivation. Conclusions and Perspectives Due to the high demand of palm oil by the world market, cultivation areas for oil palms are becoming increasingly scarce. Thus, it is vital to exploit the full potential of oil palm cultivation in an environmentally and economically sustainable way. The management of plantations has to be optimised and a generally valid waste management system must be implemented in existing and future plantations. New plantations should preferably be established on fallow land, not by the clearing of primary forests. It is essential for a sustainable palm oil production to tap the full potential for optimisation. This, however, is currently not happening due to the high start-up investments. It is thus recommended to introduce an internationally valid certification system which may provide an incentive for more sustainable and effective production methods.     

Integration der monetären Kosten in Ökobilanzen

For assessing product system sustainability, ecological as well as economical and social criteria have to be considered. These are very different criteria and individual valuation plays an important role when they are being compared. This paper shows how the most important economic parameter, i.e. monetary cost, can be integrated into the ecobalances of product systems without individual valuation. To do this, the less costly of two different product systems is improved until it reaches the cost of the other. The two product systems are not compared on an equal technical basis (as is notmally the case), but on the basis of equal cost. The procedure can be explained using windows as an example, assessing their production, service life (with maintenance and heating) and recycling/disposal. Standard windows with good insulating properties made of PVC, wood and aluminium are taken as the starting point. When they are compared, the ecobalances of PVC and wood windows differ only slightly, with a little greater difference for aluminium windows. The ecobalance of the aluminium window, on the other hand, is significantly different from those of PVC and wood windows. The cost of the PVC window is much lower than that of the other two systems. Because of this, PVC windows are technically improved by introducing a more expensive but better insulating glass pane, leaving the PVC window system still cheaper than the other two systems, but with drastically improved ecobalance results. If product systems with different monetary costs are to be compared using ecobalances, we propose that this be performed on an equal economical rather than an equal technical basis. Monetary cost can thus be integrated into ecobalance studies.     

Beurteilung des Ozonrisikos für die Waldregionen Bayerns am Beispiel des Jahres 2002 und des Extremtrockenjahres 2003 auf der Basis der externen Ozonexposition und der internen Ozonaufnahme

Background, aim, and scope Increasing background concentrations of ground-level tropospheric ozone and more frequent and prolonged summer drought incidences due to climate change are supposed to increase the stress on Bavarian forests. For such scenarios growth reduction and yield losses are predicted. Sustainable forest management in Bavaria aims to significantly increase the proportion of beech (Fagus sylvatica L.) because of its broad ecological amplitude. In our regional study different approaches for calculating ozone impact were used to estimate the risks for Bavarian forests in the average climatic, rather moist year 2002 and the extremely dry year 2003.Materials and methods Measurements were conducted for eleven forest ecosystem sites and two forest research sites representing typical Bavarian forest stands under different climatic conditions and situated in different altitudes. For risk assessment currently used approaches were applied either based on the calculation of the cumulative ozone exposure (external dose; MPOC maximal permitted ozone concentration; critical level AOT40_phen? accumulated ozone exposure over a threshold of 40 nl [O₃] l^–1, for the effective phenolgy of beech) or based on the calculation of the phytomedically relevant ozone flux into the stomata (internal dose, critical level AF_st>1,6, accumulated stomatal flux above a flux threshold of 1.6 nmol O₃?m^–2 PLA; PLA = projected leaf area). For calculations continuously recorded ozone concentrations and meteorological and phenological data from nearby rural open field background measuring stations from the national air pollution control and from forested sites were used. Additionally ozone induced leaf symptoms were assessed.Results The exposure-based indices AOT40_phen and MPOC as well as the flux-based index AF_st>1.6suggest that Bavarian forests are at risk from O₃ during a rather moist average year concerning climate conditions (2002) as well as in an extreme dry year (2003). Thus, growth reductions of 5?% are predicted when thresholds are exceeded. Threshold exceedance occurred in both years at all plots, mostly already at the beginning of the growing season and often even many times over. Ozone induced leaf symptoms could be detected only on a few plots in a very slight occurrence.Discussion The results for the applied critical level indices differed depending on climatic conditions during the growing seasons: Regarding exposure-based indices, the highest degree of threshold exceedance occurred in the dry year of 2003 at all plots; the flux-based approach indicated the highest stomatal ozone uptake and thus an increased risk at moist sites or during humid years, whereas the risk was decreasing at dry sites with prolonged water limitation. Hence, soil and accordingly plant water availability was the decisive factor for the flux-modelled internal ozone uptake via stomata. Drought and increased ozone impact can generate synergistic, but also antagonistic effects for forest trees. At water limited rather dry forest sites restricted transpiration and thus production, but concurrently lower ozone uptake and reduced risk for damage can be expected.Conclusions, recommendations, and perspectives For realistic site-specific risk assessment in forest stands the determination of the internal ozone dose via modeling flux based internal stomatal ozone uptake is more appropriate than the calculation of the external ozone dose. The predicted 5?% growth reductions are in discrepancy with the frequently observed increment increase during the last decades in forest stands. Comprehensive and significant statistical verification for ozone induced forest growth reduction as well as the systematic validation of thresholds for ozone in the field is still lacking. However, a multiplicity of different specific new and retrospective growth analysis data should allow closing the gap. Moreover, the determination of canopy transpiration with sap flow measurements is a novel approach to provide cause-effect related, site specific results for the effective internal ozone dose as well as for canopy water supply and consecutively for regional risk estimation. A further future objective is the refinement of O₃ flux modelling by further consideration of soil/water budget characteristics and the above mentioned improved estimations of crown and canopy transpiration. Further, the introduction of threshold ranges for forest trees in view of their specific regional climatic conditions and their validation in real forest stands is necessary for developing meaningful ozone risk predictions for forests.     

Die Rolle von Stressproteinen bei der Anpassung an Umweltbedingungen: Ökophysiologische, ökotoxikologische und evolutionsbiologische Implikationen

Introduction Stress proteins are ubiquitous and inducible by a vast number of stressors. Their relevance for ecological and microevolutionary adaptations has been investigated since the early 1990s. Stress proteins: function and induction Stress proteins are categorized in different families of which most data have been recorded for Hsp70, Hsp60, and Hsp90. These cytoplasmatic proteins play a central role in protein folding, the trans-membrane passage of proteins, and the stabilization of signal transduction pathways. Hsp70 is induced by elevated concentrations of unfolded or malfolded intracellular proteins and hence indicates proteotoxicity. Modulation of the stress protein level by internal factors During certain developmental stages, stress protein levels are modified by internal factors. This has been particularly shown for the early ontogeny, for the formation of quiescent stages, and for the reproductive phase. Adaptation to external stressors in the laboratory Laboratory studies on the effects of ecophysiologically relevant stressors have revealed short-term physiological adaptation to heat or environmental chemicals to involve an elevation of stress protein levels. Extreme stressor impact disrupts this responsive mechanism. Adaptation to field situations Also in the field, physiological responses to temperature fluctuations or contamination usually involve the induction of stress proteins which can be used as a biomarker of proteotoxic effect. Implications for evolutionary biology In long-term contaminated sites, however, phenotypes displaying low stress protein levels appear to be evolutionarily favored. Whether different stress response strategies may entail different degrees of phenotypic variation even under natural conditions – via Hsp action on developmental canalization – is a matter of hot debate.     

Raumbezug und Repräsentativität in der Ökologischen Flächenstichprobe

The quality of regionalizations can only be evaluated with regard to its specific purposes. In environmental monitoring, regionalizations, besides being an analysis tool, has a great importance on the selection of monitoring sites. The article describes the relationship between regionalization, selection procedure and representativeness using the example of Ecological Area Sampling (EAS) and presents the regionalization which was tested in an EAS pilot study.