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51.
An evaluation of the degradation of soils can be performed in several ways. Here, one way will be demonstrated beginning with the definition of the objects which are to be evaluated, continued with the definition of protection aims and the derivation of indicators. Objects together with indicators provide the frame within which a multicriteria assessment, has to be performed. Often no deterministic quality function is available, so that the concept of partially ordered sets is suggested. This concept is demonstrated by an example of an evaluation exercise performed for the environmental protection agency in Baden Württemberg. A result is that the use of arbitrarily defined quality functions may lead to erroneous statements. 相似文献
52.
As it is practically impossible in an industrial society to reduce impacts into ecosystems to a level that would preclude any damages, the need for damage valuation arises. One of the available valuation tools is the economic approach. Subsequent publications present this approach using the example of soils. In the first part, soils as part of ecosystems are considered from an ecological and a conventional economic point of view. In the following so-called ecological-economic perspective, more recent developments in economic valuation research are introduced. It is shown how ecological and economic valuation can complement one another. It is emphasized that economic valuations should be restricted to a critical soil structure which, in economic terms, is determined by the non-substitutable services of the ecological asset. 相似文献
53.
The results of the emissions from combustion processes and/or from fire accidents show the risk to man and his environment and thus the need for strict legislation and critical analysis of unwanted compounds. These substances or their thermolysis products are often due to incomplete combustion or may result from the interaction of various substances. In the following we report the formation of octachlorostyrene (OCS) and of high‐toxic substances such as polybrominated dioxins (PBrDD's), dibenzofurans (PBrDF's) by the combustion. In order to determine a possible source of the non‐manufactured compound OCS, we conducted several model experiments in a combustion chamber at various temperatures from 400 °C to 800 °C. The thermolysis of chlorinated solvents like chloroform or of chlorinated aromatice like pentachlorobenzene produced—among other chlorinated substances—OCS as one of the major products. Analogous combustion experiments with polyester plastics containing decabromodiphenylether as flame retardant and antimony trioxide as Synergist led to PBrDD's and PBrDF's. Here antimony trioxide seems to play an important role because in absence of this oxide, PBrDD's and PBrDF's were not found in our experimental conditions. 相似文献
54.
Manuela Baumgarten Rainer Matyssek Christian Huber Hans-Peter Dietrich 《Environmental Sciences Europe》2010,22(5):579-595
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 AOT40phen? 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 AFst>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 AOT40phen and MPOC as well as the flux-based index AFst>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. 相似文献
55.
Villy Christensen Carl J. Walters Robert Ahrens Jacqueline Alder Joe Buszowski Line Bang Christensen William W.L. Cheung John Dunne Rainer Froese Vasiliki Karpouzi Kristin Kaschner Kelly Kearney Sherman Lai Vicki Lam Maria L.D. Palomares Aja Peters-Mason Chiara Piroddi Jorge L. Sarmiento Jeroen Steenbeek Rashid Sumaila Reg Watson Dirk Zeller Daniel Pauly 《Ecological modelling》2009
We present a new methodology for database-driven ecosystem model generation and apply the methodology to the world's 66 currently defined Large Marine Ecosystems. The method relies on a large number of spatial and temporal databases, including FishBase, SeaLifeBase, as well as several other databases developed notably as part of the Sea Around Us project. The models are formulated using the freely available Ecopath with Ecosim (EwE) modeling approach and software. We tune the models by fitting to available time series data, but recognize that the models represent only a first-generation of database-driven ecosystem models. We use the models to obtain a first estimate of fish biomass in the world's LMEs. The biggest hurdles at present to further model development and validation are insufficient time series trend information, and data on spatial fishing effort. 相似文献
56.
57.
Rainer Brüggemann Andreas Kaune Laszlo Zelles Anton Hartmann Christian Steinberg 《Umweltwissenschaften und Schadstoff-Forschung》1995,7(5):265-274
Die ?kotoxikologie mu? sich mit biologischen Systemen und ihren Antworten auf schadstoffinduzierten Stre? auseinandersetzen.
Die hierzu verwendete experimentelle Technik eilt dabei den M?glichkeiten dynamischer, proze?orientierter mathematischer Modellierung
weit voraus.
In dieser methodisch orientierten Arbeit werden Techniken aus der mathematischen Disziplin der Verbandstheorie vorgestellt,
die eine Datenanalyse unter den Aspekten vergleichender Bewertung erlauben. Wichtige Ergebnisse sind dabei
相似文献
– | • Aussagen zur Diversit?t mikrobieller Systeme (soweit durch die hier verwendeten Muster von vier Phospholipidfetts?uren erfa?bar), |
– | • Analysen ordinaler Abh?ngigkeiten sowie |
– | • komprimierte Darstellung komplexer Befunde im Zusammenhang mit der Toxizit?t von Huminstoff-Chemikalien-Systemen. |
58.
59.
Petia S. Nikolova Christian P. Andersen Rainer Matyssek 《Environmental pollution (Barking, Essex : 1987)》2010,158(4):1071-1078
The effects of experimentally elevated O3 on soil respiration rates, standing fine-root biomass, fine-root production and δ13C signature of newly produced fine roots were investigated in an adult European beech/Norway spruce forest in Germany during two subsequent years with contrasting rainfall patterns. During humid 2002, soil respiration rate was enhanced under elevated O3 under beech and spruce, and was related to O3-stimulated fine-root production only in beech. During dry 2003, the stimulating effect of O3 on soil respiration rate vanished under spruce, which was correlated with decreased fine-root production in spruce under drought, irrespective of the O3 regime. δ13C signature of newly formed fine-roots was consistent with the differing gs of beech and spruce, and indicated stomatal limitation by O3 in beech and by drought in spruce. Our study showed that drought can override the stimulating O3 effects on fine-root dynamics and soil respiration in mature beech and spruce forests. 相似文献
60.
Sebastian Pfleiderer Michael Englisch Rainer Reiter 《Environmental geochemistry and health》2012,34(6):665-675
This study presents the current state of heavy metal contents in both urban and forest soils within the city area of Vienna, Austria. Based on a systematic survey of urban soils and on targeted sampling in forest areas, local and regional anomaly thresholds are derived using statistical methods and considering regional distribution patterns. For urban soils, local anomaly thresholds of elements Cu (60?mg/kg), Hg (0.5?mg/kg), Pb (100?mg/kg) and Zn (200?mg/kg) exceed national guideline values for uncontaminated urban soils and according to Austrian legislation fall into the category “anthropogenic contamination present but no damage to plants, animals or humans detectable”. In forest soils within the city, thresholds are very similar to reference values for similar geological settings outside the city, apart from higher concentrations of elements Cr and Ni (threshold values of 107 and 64?mg/kg, respectively). Grouping urban soils according to land use reveals that Cd contents are 25?% higher, Pb contents 36?% higher, in traffic and industrial areas than in parks and like Cu, Hg and Zn, these elements can be shown to be at least partly caused by anthropogenic contamination. A dependency between heavy metal concentrations in soils and underlying geological units is shown within the flysch zone at the western city margin where the contents of elements Co, Cr, Cu, Ni and V are controlled by geology and reveal distinct differences between geological units. In built-up areas, no clear dependency between heavy metal contents in soils and geology is evident as urban soils represent accumulations by anthropogenic activity rather than in situ weathering products of underlying sediments. 相似文献