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Naturschutz – Ökosystemforschung als wichtige Grundlage für Naturschutz – Sachstand und Perspektiven

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Der Artikel enthält folgende Kapitel: Einführung Zur Begriffserklärung Ziele, Schutzgüter und Instrumente des Naturschutzes Inhalte und Anwendungsebenen der Ökosystemforschung In welchen Arbeitsbereichen kann Naturschutz auf Methoden und Ergebnissen der Ökosystemforschung aufbauen? Ausblick Zitierte Literatur Zusammenfassung

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... Aus dem Bereich der Ökosystem-Theorie steht hierfür eine ständig zunehmende Literatur zur Verfügung über Funktionen von Ökosystemen (de Groot, 1992; Fränzle et al., 1993; Müller, 1992; Müller, 1996a; Müller et al., 1997a; Müller et al., 1997b) und deren Fähigkeit zur Selbstorganisation (Breckling & Müller, 1997; Müller et al., 1997a; Müller et al., 1997b). Die Ergebnisse aus diesem Bereich sollen in Zukunft stärkere Berücksichtigung bei der Ableitung von Schutzgütern für nachfolgende Generationen finden (Dierßen, 1999). Der Funktionsbegriff wird aber neben dieser naturwissenschaftlichen Bedeutung auch in einem anthropozentrischen Kontext genutzt, wenn im Zuge der Nachhaltigkeitsdiskussion gefordert wird, in Landschaften die Lebensraum-, Nutz-, Kultur-und Regelungsfunktion zu betrachten (Kirchner-Heßler et al., 1999). ...
... Die bisherigen Ausführungen zeigen, dass innerhalb "der Ökologie" (im weitesten Sinne) heterogene Denk-und Herangehensweisen an den Untersuchungsgegenstand "Natur"schutzfachlicher Probleme wird zunehmend kritisch reflektiert (z.B. Dierßen, 1997; Dierßen, 1999, Trepl, 1999 ). Dabei besteht Konsens, dass Betrachtungsweisen von und Herangehensweisen an Natur im allgemeinen und Ökosysteme im speziellen in unterschiedlichen umweltwissenschaftlichen Disziplinen und Denkrichtungen verankert sind. ...
Article
In jüngerer Zeit wird vor dem Hintergrund systemtheoretischer Prinzipien der Beschreibung komplexer, dynamischer Systeme verstärkt gefordert, die Selbstorganisationsfähigkeit als zentrale Ökosystem-Funktion in ökologische Umweltplanungen zu integrieren. Das Ziel der vorliegenden Arbeit ist es, Grenzen und Möglichkeiten des entsprechenden Kriteriums 'Ökosystem-Funktionen' im Kontext von Nachhaltigkeit aufzuzeigen. Referenzkriterien dieser Überprüfung sind (1) die Forderung der Vereinten Nationen nach Sicherung der Biodiversität und (2) der §1 des Bundesnaturschutzgesetzes. Die Arbeit basiert auf einer Literaturstudie und einer theoretischen Auseinandersetzung mit dem Funktionen- und Ökosystembegriff. Die Ergebnisse wurden (1) einer naturwissenschaftlichen und wissenschaftstheoretischen Analyse und Kritik unterzogen sowie (2) naturschutzfachlichen und ethischen Aspekten der Beschreibung von Natur gegenübergestellt. Ziel der Gegenüberstellung war es zu zeigen, inwieweit das Kriterium 'Ökosystem-Funktionen' geeignet ist, naturschutzfachlichen Anforderung des Nachhaltigkeitsparadigmas gerecht zu werden. Die zentrale Frage nach Grenzen und Möglichkeiten einer Implementierung von Ökosystem-Funktionen in die Operationalisierung von 'ökologischer Nachhaltigkeit' wird auf der Basis der Arbeit folgendermaßen beantwortet: Von einer Operationalisierung über das naturwissenschaftliche Kriterium 'Ökosystem-Funktionen' muss aus naturschutzfachlicher und ethischer Sicht Abstand genommen werden. Als alternativer Weg wird eine Operationalisierung auf der Basis von 'Ökosystem-Funktionen' in einer utilitaristischen Position des Anthroporelativismus vorgeschlagen. Die Implementierung dieser Perspektive auf Natur in die Operationalisierung von Nachhaltigkeit ermöglicht es, über das Kriterium 'Ökosystem-Funktionen' (1) ethische Rahmenbedingungen zu integrieren, (2) sowohl Natur- als auch Kulturwerte in der Landschaft für diese und zukünftige Generationen zu sichern. In recent times, against the background of system-theoretical principles, the description of ecosystems as complex, dynamic systems has been strongly promoted. Therefore the capacity of selforganization of ecosystems is strengthened to be integrated into environmental planning processes. The aim of the following work is to point out the limitations and possibilities given by the scientifically-based criterion 'ecosystem-functioning' in the context of sustainability. The investigations are based on a literature-supported analysis and a theoretical argument about the 'function of ecosystems' in relation to the concept of ecosystems. The results of this argument were submitted (1) to a scientific and science-theoretical analysis and criticism as well as considered in the light of (2) environmental protection issues and ethically relevant aspects of the description and observation of the natural world. The aim of this consideration was to establish to what extent the criterion 'ecosystem functioning' is suitable. The central question about limitations and possibilities of the application of the criterion is answered as follows: The criterion 'ecosystem functioning', formulated via system-theoretical principles of dynamic systems does not meet the requirements of both the natural and ethical issues given by the paradigm of sustainability. A possible alternative is to observe ecosystems and the criterion 'ecosystem-functioning' from a utilitarian position of anthroporelativism. The implementation of this perspective in the world of nature through the criterion 'ecosystem functioning' makes it possible (1) to integrate ethical issues of sustainability and (2) to maintain natural values as well as cultural ones in the countryside for this and future generations.
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We have simulated the dynamics of species evolution in a systems context on a parallel supercomputer. Population dynamics are represented as generalized Lotka-Volterra systems defined as points in a generalized phenotype or character space T. Populations which are closest in T compete most strongly for resources. A variety of systems with varying assumptions, resource distributions, and number of trophic levels were simulated. Starting with a random initial seed proceeding through a complex temporal sequence, most cases converged to essentially the same configuration. The final equilibrium state consisted of a gridwork of localized population clusters in T, representing individual species. The intercluster spacing was roughly equal to the standard deviation of the resource utilization function. Thus the systems self-organize to an array of niches which maximally fills the available volume of resource space while minimizing the overlap of resource utilization functions.The simulations were performed on a Connection Machine (a massively parallel supercomputer) which allowed up to 32 000 distinct points in character space to be modelled in parallel. Simulation allows a more realistic treatment of evolutionary dynamics and greater flexibility in experimental manipulation than previous analytical approaches.We experimented with temporal variations in the resource base. In most cases the niche structure was not affected; species prospered or declined as a function of local resource availability but the niche pattern remained invariant. However, in the case in which each species depends on only one or two resources, increasing randomness in the resource base resulted in a decrease in the number of species.
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Die Arbeit ist angesiedelt an der Schnittstelle zwischen Ökologie und Umweltplanung und geht der Frage nach, welche wissenschaftstheoretischen Voraussetzungen denjenigen ökologischen Modellvorstellungen und Betrachtungsperspektiven zugrunde liegen, die im Kontext von Landschafts- und Umweltplanung Anwendung finden. Theoretische Basis der Arbeit ist die "Allgemeine Modelltheorie" Stachowiaks, nach der alle Wahrnehmung und Erkenntnis als modellhaft aufgefaßt werden kann. Dieses Modellkonzept wird für die Analyse und Reflexion der Modellbildung von Natur und Umwelt im Hinblick auf Landschafts- und Umweltplanung nutzbar gemacht. Im Zentrum der Arbeit steht eine systematische Darstellung der theoretischen Einflüsse und Aspekte, die der wissenschaftlichen Betrachtung von Natur und Umwelt zugrunde liegen und damit die Modellvorstellungen der Ökologie bestimmen. Diese Einflußfaktoren sind - angelehnt an Kant - die zentralen Kategorien der Erkenntnis, d.h. Substanz, Raum, Zeit und Relation. Von Bedeutung sind weiterhin die nomothetische und die idiographische Wissenschaftsauffassung, als zwei unterschiedliche Intentionen wissenschaftlicher Betrachtung von Natur und Umwelt, sowie der Holismus, der Reduktionismus und das Systemdenken, die als unterschiedliche Forschungsstrategien die theoretische Einordnung beobachteter Erscheinungen bestimmen. Die ökologische Modellierungsperspektive und das dahinter stehende Ökologieverständnis wird als ein übergreifender Einflußfaktor betrachtet und in seine Kernelemente Organismus, Beziehung und Umwelt differenziert und die Interpretation dieser drei Komponenten analysiert. Die systematische Zusammenstellung der theoretischen Einflüsse ökologischer Modellvorstellungen von Natur und Umwelt liefert eine Plattform für eine wissenschaftstheoretische und methodische Reflexion ökologischer Modellbildung und erleichtert damit den notwendigen Dialog über eine angemessene Erfassung und Abbildung von Natur und Umwelt in umweltpolitischen Planungs-, Entscheidungs- und Handlungsprozessen. Die Einflüsse dieser unterschiedlichen Faktoren werden am Beispiel des Ökosystemkonzeptes nachgezeichnet und damit die Vielfalt der existierenden Ökosystemverständnisse aufgehellt und nachvollziehbar gemacht.
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Ecologists are making increasing use of computer methods in analyzing ecological data on plant and animal communities. Ecological problems naturally involve numerous variables and numerous individuals or samples. Multivariate techniques permit the summary of large, complex sets of data and provide the means to tackle many problems that cannot be investigated experimentally because of practical restraints. Ecologists are thus enabled to group similar species and similar sample sites together, and to generate hypotheses about environmental and historical factors that affect the communities. This timely book presents a full critical description of three methodologies - direct gradient analysis, ordination, and classification - from both theoretical and practical viewpoints. Both traditional and new methods are presented. Using a wide range of illustrative examples, Hugh Gauch provides an up-to-date synthesis of this field, which will be of interest to advanced students and ecologists. These mathematical tools are also used in a wide variety of other areas, from natural resource management and agronomy to the social and political sciences.
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This volume is based on a workshop on "Effects of accumulation of air pollutants in forest ecosystems'; held in GOttingen, Federal Republic of Germany, from May 16-18, 1982. This work'shop was initiated and sponsored by the Environmental Agency of the Federal Republic of Germany (project officer: Dr. J. Pankrath) as part of a research contract (project leader: Dr. B. Ulrich). THE PROBLEM SEEN UNDER THE ASPECT OF ADMINISTRATION The problem of forest damage caused by air pollution is not new in Europe. Already in 1983 a comprehensive report from Schroeder and Reuss about vegetation damages by fume in the Harz mountains was published. In 1923, Prof. Dr. Julius Stocklasa of the Bohemian Technical Highschool in Prague was concerned with research of toxical effects of sulphur dioxide in his publication "The damage of vegetation by flue gas and exhalations of facili­ ties". This comprehensive and instructive work concludes with the sentence: "It is already high time for the governments of all cultural states to take legal, police and private measures in order to prevent damage by flue gases". In the neighbourhood of industries with high gaseous and dust emissions damages have been shown to occur for a long timei these deleterious effects have influenced the growth of trees and in extreme cases have even caused their early death.
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Increased atmospheric nitrogen deposition and changes in the management of heathlands have caused a significant change in the species composition of the NW-European heathlands. This change from ericaceous towards gramineous dominance is analysed in detail in Heathlands: Patterns and Processes in a Changing Environment. Special emphasis is put on the effects of increased atmospheric nutrient input on nutrient cycling, competition between plant species and plant--herbivore interactions. The possibilities for the long-term conservation of heathlands are discussed by considering regeneration from seed and the usefulness of mathematical management models. The book provides a synthesis of pure and applied plant ecology. It is vital reading for plant ecologists, biological conservationists, heathland managers and government decision makers.
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Für die Erfassung, Bewertung und Lösung komplexer Umweltprobleme ist eine interdisziplinäre Ausrichtung von Forschung und Lehre unerlässlich. Gemeint sind fachübergreifende Kommunikation und Kooperation von Natur- und Sozialwissenschaften, von Ingenieur- und Geisteswissenschaften. In den Beiträgen des Bandes werden hierzu moderne und innovative Methoden, Ansätze und Sichtweisen vorgestellt. In Grundlagen- und angewandter Forschung, aber auch in der universitären Lehre gibt es verstärkt Ansätze, bei denen die Notwendigkeit eines fachübergreifenden Diskurses erkannt und umgesetzt wird. Es fällt auf, daß im Rahmen der hier vorgestellten Ansätze Wissenschafts-Kooperationen verwirklicht werden, die noch vor wenigen Jahren in der Umweltforschung undenkbar gewesen wären. Die wachsende Durchlässigkeit der Grenzen zwischen den Disziplinen wird hier anhand von Themen wie Klimafolgen-, Katastrophen- und Technikfolgenforschung, globaler Wandel, nachhaltige Umweltpolitik und modernes Umweltrecht verdeutlicht.
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Klimawirkungsforschung untersucht die Auswirkungen von Klimaänderungen hinsichtlich ökologischer und zivilisatorischer Effekte auf den Menschen und seine Umwelt durch Erarbeitung von Handlungsstrategien. Dieser Statusbericht vermittelt einen Einblick ins Treibhaus aus verschiedenen Blickwinkeln: auf den globalen und regionalen Wandel, als Blick zurück in das geologische Archiv sowie auf die Klimaauswirkungen, auf die Hydro-Morphodynamik und Küstensicherheit, auf die Flora und Fauna, auf Ökosysteme und Stoffkreisläufe sowie auf sozio-ökonomischer Ebene am Beispiel der südlichen Nord- und Ostsee. Küsteningenieure, Geographen und Raumplaner, Geologen, Biologen, Klima-, Sozial- und Wirtschaftsforscher sowie Verantwortliche in den Küstenverwaltungen erhalten einen bisher nicht verfügbaren Überblick über die Zusammenhänge des globalen Wandels an diesem konkreten Raumbeispiel.
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1st Lecture Prologue: Science and Responsibility.- 2nd Lecture The Motivation of Science.- 3rd Lecture The Scientific Approach (1): Terminology and Language.- 4th Lecture The Scientific Approach (2): Data, Hypotheses, and Theories.- 5th Lecture The Scientific Approach (3): Laws, Prediction, Explanation.- 6th Lecture The Principle of Causality.- 7th Lecture The Structure of Teleological Action.- 8th Lecture Physics and Biology: The Problem of Reduction.- 9th Lecture Physiology and Comparative Biology.- 10th Lecture Tradition and Progress in Science: The Notion of Paradigms.- 11th Lecture The Ethics of Science.- 12th Lecture Science and Technology.- 13th Lecture The Crisis of Science.- 14th Lecture Science and Values.- 15th Lecture Epilogue: Epistemology and Evolution.- References.
Chapter
In dem Artikel soll am Beispiel von Ökologie und Jurisprudenz die These vom unüberbrückbaren Unterschied zwischen Naturwissenschaften und Sozialwissenschaften widerlegt werden. Die hierzu entwickelte Argumentation basiert auf der - an Luhmanns Analyse der ökologischen Kommunikation angelehnten - Ausgangsthese, wonach Bildung und Erziehung wichtige Grundlagen für eine die gesellschaftlichen Teilsysteme übergreifende, integrative ökologische Kommunikation schaffen können. In Forschung und Lehre sind Rechtswissenschaften und Ökologie besonders gefragt, einen solchen Brückenschlag zu versuchen.
Chapter
In this chapter I will try to answer the following questions: How should we apply thermodynamic methods and concepts to ecology; how can we describe the ecosystem’s behavior in the terms of physics (and particularly, thermodynamics); and what kind of physical criteria can be used for the estimation of anthropogenic impacts on ecosystems? From the viewpoint of thermodynamics, any ecosystem is an open system far from thermodynamic equilibrium, in which the entropy production is balanced by the outflow of entropy to the environment. I suggest the “entropy pump” hypothesis: that climatic, hydrological, soil and other environmental conditions are organized in such a way that only a natural ecosystem which is specific for these conditions can be in the dynamic equilibrium (steady state). In the framework of this hypothesis I can calculate the entropy production for an ecosystem under anthropogenic stress. By considering systems far from thermodynamic equilibrium, we can prove that the so-called exergy is a functional of a dissipative function, which is undertaken along the trajectory going from a thermodynamic equilibrium to a dynamic one. It was shown there is a close connection between the measure of an additional information (Kullback measure) and the exergy. And finally I try to show the deep internal connection between Lyapunov functions which are the main instruments of the stability theory and basic thermodynamic concepts, especially in applications to ecology.
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This study reports on small‐scale changes in the distribution of plant species in a 2.5 m ² plot of grazed, species‐rich Veronica spicata ‐ Avenula pratensis grassland on shallow, dry, nutrient‐poor soil in the Great Alvar area (Stora Alvaret) of southern Öland, southeastern Sweden. Multivari‐ate analysis of 0.001 m ² and 0.25 m ² quadrats within the plot showed that there is little floristic variation without any trend in the plot. Average species richness varied little throughout the study period from 1986 to 1991 with 1986 averages of 7.0 on 0.001m ² , 16.3 on 0.01 m ² , and 26.1 on 0.25 m ² . On 0.001 m ² the highest species number found was 12, on 0.01 m ² , 27. However, cumulative species richness, i.e. species number in the first year plus new species appearing in later years (averaged over 40 quadrats) increased over the same period, on 0.001 m ² from 7.0 in 1986 to 14.9 in 1991, and on 0.01 m ² from 16.3 to 24.1. Cumulative frequency, i.e. number of quadrats out of 40 where a species occurred in the first year or/and in later years, increased as well; the number of cumulatively highly frequent (> 80%) species increased from 5 in 1986 to 18 in 1991. Species mobility on the scale of the small quadrats used implies both appearance and disappearance from these quadrats. Using six examples, species mobility is shown to vary individualistically, both in rate and degree. We postulate that in homogeneous, grazed, nutrient‐ and water‐deficient environments many species can reach virtually all microsites within the plot, which we express through the idea of the ‘carousel model’. We also question the usefulness of the niche concept and re‐interpret it by stating that all species of this plant community have the same habitat niche, while most of them are short‐lived and have the same regeneration niche. The essential variation amongst the species is their individual ability to establish or re‐establish by making use of favourable conditions appearing in microsites in an unknown, complex spatio‐temporal pattern.
Article
Presents 31 papers grouped under six headings. An introductory chapter provides an overview of acidification research in Sweden in respect to national and international perspectives. Three papers follow looking at air pollution levels and deposition. Eight papers are then presented on soils and soil processes, with respect to acidification. Six papers than review the effect of acid deposition and tropospheric ozone on Swedish trees and forests. Five contributions then look at the effect on flora and fauna. The last section presents six integrated studies, some with a modelling component. Twenty papers are individually abstracted in Geographical Abstracts: Physical Geography, in addition to six in Ecological Abstracts. -S.R.Harris
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Models with periodically changing environments are investigated. It is demonstrated that an arbitrary number of competitors for a single limited resource can coexist. Trade-off conditions for growth or mortality parameters, which enable temporal organization of the competing species within the environmental period, are necessary to coexistence. No limit for similarity is observed in the models. An attempt is made to formulate a general coexistence principle for similar species in periodically changing environments.
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The ecosystem theories of the Odum school are based on the premise that the observed order in ecosystems is unlikely to arise by chance from Darwinian struggles for existence. However, Hairston et al. (1960; HSS) showed, a quarter of a century ago, that such emergence of order from exploitative interactions, guided by short-term maximization of individual fitness, is not at all unlikely. The original HSS hypothesis conflicts with well-documented cases of resource limitation in herbivorous populations and with the recurring strong impacts exerted by these populations on the vegetation, but this conflict is only apparent. HSS explained why the world is green and why there can be an abundance of forage that is not consumed. This observation does not refer to steppe and tundra environments, which are green for only a few weeks and where there is an obvious shortage of forage during the unfavorable season. The limitation of grazers by resource depletion in such environments and the strong impacts of herbivory on the vegetation are straightforward consequences of the exploitation view in HSS, applied to relatively unproductive ecosystems. The same reasoning, applied to still more barren environments, predicts that these should be passively harsh, with grazers limited by resource shortage but having only marginal impact on the vegetation. -from Author
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A group of Nordic experts has tried to draw conclusions on critical loads for sulphur and nitrogen. The critical load is defined as “The highest load that will not cause chemical changes leading to long-term harmful effects on most sensitive ecological systems”. Most soils, shallow groundwaters and surface waters would probably not be significantly changed by a load of 10–20 keq H+·km2·yr−1 in areas with a low content of base cations in the deposition. The total deposition of hydrogen ions in southwestern Scandinavia is in the order of 100 keq ·km−2·yr−1. The long-term critical load for nitrogen is in the range of 10–20 kg N·ha·1-yr−1 in most forest ecosystems. In high productive sites it might be as high as 20–45 kg N·ha− yr−1 in southern Sweden, and amounts to 30–40 kg·ha−1·yr−1 and even more over large areas in central Europe. The current deposition of sulphur and nitrogen must be substantially reduced to keep the long-term changes in sensitive ecosystems within acceptable limits.
Article
Untersucht wurde die Dynamik verschiedener Größen des Stickstoffhaushalts eines Agrarökosystems bei aufeinanderfolgendem Anbau von Mais, Hafer und Futterrübe auf einer sandigen Braunerde im Östlichen Hügelland Schleswig‐Holsteins. Dabei wurden die Stickstoffeinträge über Stallmistausbringung, anorganische Düngerformen und die atmosphärische Deposition, bei der organischen Düngung einmalig auch die Ammoniakverluste erfaßt. Die Dynamik der Nettomineralisation, der Nmin⁻ Mengen, der in der Bodenlösung vorliegenden Stickstoffmengen und der Tiefensickerung wurde durch regelmäßige Messungen und außerdem auf Grundlage eines prozessorientierten Modells (WAS‐MOD&STOMOD) auch über Simulationsrechnungen ermittelt und Abweichungen zu den Meßergebnissen diskutiert. Mit dem für gebietsbezogene Berechnungen des Wasser‐ und Stickstoffhaushalts entwickelten Modell lassen sich diese Größen in guter Annäherung prognostizieren. Dabei ist die ermittelte Tiefensickerung von etwa 100 kg N ha⁻¹ a⁻¹ durch die gedüngten Stickstoffmengen des betrachteten Jahres aber nur teilweise zu erklären. Das Modell ermöglicht die Einbindung des Prozeßgeflechtes von Mineralisation, Pflanzenaufnahme und Stickstoffrückführung über Ernterückstände. Während Messungen in der Regel nur Einzelpunkte zu bestimmten Zeitpunkten repräsentieren, besteht durch den Flächenbezug des Modellansatzes eine Möglichkeit, die Stoffdynamik kontinuierlich flächenhaft abzuschätzen. Damit wird die Voraussetzung geschaffen, um die Wirkung unterschiedlicher Bewirtschaftung zu prognostizieren und prozessbezogene Planungsgrundlagen für eine effizientere Ausnutzung des Stickstoffs in der Landbewirtschaftung zu entwickeln.
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Article
A spatially explicit, climate‐sensitive vegetation model is presented to simulate both present and future distribution of potential natural vegetation types in Switzerland at the level of zonal forest communities. The model has two versions: (1) a ‘basic’ version using geographical region, aspect, bedrock (represented by soil pH), and elevation, and (2) a ‘climate‐sensitive’ version obtained by replacing elevation (complex environmental gradient) with temperature (climatic factor). Version 2 is used to predict vegetation response under different (today's and projected) climatic conditions. Two regional climate scenarios are applied: (1) assuming an annual mean temperature increase of 1.1 — 1.4 °C, and (2) assuming an increase of 2.2 — 2.75 °C. Both scenarios result in significant changes of the spatial vegetation patterns as compared with today's climatic conditions. In scenario 1, ca. 33 % of the sample points remain unchanged in terms of the simulated zonal forest community; in scenario 2, virtually all sample points change. The most noticeable changes occur on the Swiss Plateau with Carpinion forests (zonal vegetation of present colline belt) expanding to areas that are occupied today by submontane and low‐montane Fagus forests. To estimate the reliability of the simulation, quantitative (comparison with field mapping) and qualitative (comparison with climate types in the Alpine region) tests are performed and the main limitations of the approach are evaluated.
Article
Wet meadows of the Calthion type are strongly endangered ecosystems in Northern Germany due to agricultural intensification and abandonment. Empirical data of biocoenotic structures, hydrologic parameters, nutrient budgets and soil structure are used for an integrated evaluation of differently degenerated wet grasslands on peat soils (mesotrophic and eutrophic Calthion, Lolio-Potentillion, abandoned wet meadows) with respect to their functions in the landscape. Based on the evaluation of the investigated ecosystems two specific management targets are derived: (1) the maintenance and restoration of Calthion systems from degenerated states to re-establish high biocoenotic diversity and to avoid high nutrient leakages; (2) The restoration of the systems functioning as nutrient sinks. The potentials and prerequisites for the development of the investigated systems and suitable management measures concerning these two targets are described, focussing on groundwater dynamics, phytomass production, nutrient losses and the re-establishment of typical plant species. Our results illustrate that referring to target 1 none of the management measures discussed are suitable to restore strongly degenerated Lolio-Potentillion systems to Calthion systems completely. The limited restoration success is caused by partially irreversible changes of the biotic and abiotic properties of the Lolio-Potentillion sites. A re-development of the mesotrophic Calthion from eutrophic Calthion sites or abandoned wet meadows seems to be impossible. From this point of view restoration efforts should mainly focus on the preservation and maintenance of near-natural Calthion ecosystems. Nevertheless, referring to the high portion of Lolio-Potentillion in the landscape of Northern Germany, it is essential to reduce their ecological function as a nutrient source. This could be achieved by moderate rewetting and harvesting. For strongly degenerated grasslands, which can hardly be restored according to target 1, the establishment of eutrophic swamps is a desired development target (target 2). A suitable measure for this target is the drastic rising of the groundwater level. But we must take into account that the current knowledge about the nutrient retention function, resulting from this management measure, is not sufficient to predict this function in detail for former intensively used fen ecosystems. The presented interrelationships and management alternatives are integrated into a knowledge based modelling system to support decision making.
Article
Air pollution can cause a decline in species through eutrophication of the habitat. In the Netherlands eutrophication largely results from atmospheric nitrogen deposition. A simulation model has been developed for evaluation of the impacts of atmospheric nitrogen deposition on dry heathlands. The model has been applied to three deposition scenarios. The results of the model show that atmospheric nitrogen is the trigger for the change of heatland into grassland. Moreover, the results implicate that a further transition of heathlands into grasslands will be ineviable in the Netherlands under scenario 1 (an average deposition of 2200 eq N·ha−1·yr−1). Scenario 2 (1400 eq N·ha−1·yr−1) meets the target that Calluna will be the (co)-dominant species 25 years after sod cutting for 14 out of 17 areas in the Netherlands. Scenario 3 (1230 eq N·ha−1·yr−1) meets this target for all areas. It is argued that uncertainties of the model are little, because the model outcomes are sufficiently supported by quantified data. It is concluded that the process of decline of heathlands can only be reversed if eutrophication is reversed.
Article
We describe an approach to investigating and understanding the interactions between vegetation structure and ecosystem processes that uses simulation models as a framework for comparison and synthesis across ecosystems arrayed along environmental gradients. The models are individual-based vegetation simulators and compartment models of nutrient cycling and soil water relations. Applications focus on interactions and feedbacks between vegetation structure (species composition, size structure) and ecosystem processes (water balance, nutrient cycling), and how these relationships vary across environmental gradients. Preliminary results indicate that life-history traits of plants have a profound influence on system-level behaviors, and that differences between grasslands and forests can be attributed largely to contrasting traits of grasses and trees. Experiments with linked vegetation-ecosystem process models diverge from simulations with either model run independently, suggesting the importance of feedbacks between details of vegetation pattern and ecosystem processes. The development of a fully coupled vegetation-ecosystem process model that is sufficiently general to simulate systems dominated by multiple lifeforms presents several conceptual, logistical, and scaling challenges, but also provides for new opportunities in ecosystem theory.
Article
This paper attempts to characterize the development, the recent state, and some future problems of ecosystem theory. As a fundamental for the evaluation of the discipline's potentials and limitations, the general tasks and features of theories are discussed in the introduction part of the text. These characteristics from the philosophy of science are applied to ecosystem theory, and on that basis the general objective of the text is defined: Does ecosystem theory cope with the general tasks of theories? What are the potentials and where are the problems? To find an answer to these questions, the different scientific roots of ecosystem theories are briefly presented, whereby a focus is put on systems analytical sources, such as cybernetics, control theory, information theory, network theory, thermodynamics, the theory of self-organization and emergence, and hierarchy theory. After these approaches have been characterized, some unifying and integrating concepts are proposed. Finally, the present problems and the future tasks of ecosystem theory are discussed.
Conference Paper
The problem of uncertainty often appear in modelling of ecosystems, in particular uncertainty of data and even uncertainty in relations between system components. To solve these problems and the problems of subjectivity in evalation of ecological paramaters a fuzzy logic approach has been proposed. The paper shows some first results obtained by investigation into this problems.
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N2O‐Emissionen und Denitrifikationsabgaben von Böden einer Jungmoränenlandschaft in Schleswig‐Holstein
  • B. Mogge
Expertensysteme in der biozönologischen Modellierung: Ein Beratungssystem zum Feuchtwiesenmanagement
  • Asshoff M.
Biologische Daten zur Bewertung von Eingriffen in Natur und Landschaft und zur Bemessung einer Ausgleichsabgabe
  • Auhagen A.
Kleine Anleitung zum ökologischen Machiavellismus. In: Die feindlose Demokratie
  • U. Beck
Methodische Einbindung von Leitbildern und naturschutzfachlichen Zielvorstellungen im Rahmen planerischer Beurteilungen
  • Jessel B.
Modeling in ecotoxicology
  • S.E. Jørgensen
Selbstorganisation – Aspekte einer wissenschaftlichen Revolution
  • U. Maturana
Natur und Moral – Ethik in der Biologie. Dimensionen der modernen Biologie 4
  • H. Mohr
Nutrients and the species composition of heathlands
  • G. W. Heil