The identification of inputs and outputs is the first and probably most important step in testing and analyzing complex systems. Following accepted natural laws such as the conservation of mass and the principle of electroneutrality, the input/output analysis of the system, be it steady or in connection with perturbations will reveal the status dynamic, will identify whether changes are reversible or irreversible and whether changing the input will cause a hysteresis response. Moreover, measurements ofinput and output fluxes can indicate the storage capacity ofa system, its resilience to buffer or amplify variations of the external input, and it can identify structural changes. Therefore, to a certain extent, the input/output analysis can facilitate predictions about the ecosystem stability. The measurement of fluxes and the determination of inputs and outputs of eco­ systems are, in many aspects, analogous to measurements done by engineers when testing an electronic apparatus. The first step is the measurement ofthe input/output properties of the instrument as a whole, or ofvarious circuit boards, and the compari· son ofthese with the expected variations of the original design. Varying input and out· put can give valuable information about the stability and the regulatory properties of the device. Nevertheless, only the circuit as an entity has specific properties which cannot be anticipated if the individual components are investigated regardless oftheir position. Also, the instrument as a whole will have different input/output properties than its subcircuits.

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to the Problem of Ecosystem Analysis.- to the Problem of Ecosystem Analysis.- 1 Input/Output Analysis of Ecosystems.- Preface.- A. Stability, Elasticity, and Resilience of Terrestrial Ecosystems with Respect to Matter Balance.- I. Introduction.- II. Definition of a Terrestrial Ecosystem with Respect to Ion Cycling.- III. Steady State and Elasticity.- IV. Ecosystems as Open Systems in Steady State.- V. Possible De-Couplings of the Matter Cycle.- VI. The Acid-Buffering Properties of Soils.- VII. The Role of Acid Stress in Ecosystems.- VIII. Stability and Resilience from the Point of View of Matter Balance.- IX. Conclusions.- References.- B. Water and Carbon Fluxes in Ecosystems.- I. Introduction.- II. What Is an Ecosystem with Respect to Carbon and Water Fluxes.- III. The Study of Ecosystems.- IV. Analysis of Ecosystem Functioning.- V. Prediction of Ecosystem Functioning.- VI. Conclusions.- References.- C. Environmental Transfer of Some Organic Micropollutants.- I. Introduction.- II. Study Area, Sampling Procedures, and Analytical Methods.- III. Behavior of Organic Micropollutants in the Atmospheric Boundary Layer.- IV. Movement of Organic Micropollutants in Soil- and Groundwater.- V. Movement of Organic Micropollutants in a River.- VI. Distribution of Organic Micropollutants in the Food Web 89.- VII Equilibrium Distribution and Fluxes of Organic Micropollutants.- VIII. Conclusions. Potentials and Limits of Determining Environmental Chemodynamics of Organic Micropollutants.- References.- D. Simple and Diversified Crop Rotations - Approach and Insight into Agroecosystems.- I. Introduction.- II. Agroecosystems and Natural Ecosystems - a Comparison in View of Their Historical Development.- III. Farm Management and Production Systems.- IV. Common Differences Between Agroecosystems and Natural Ecosystems.- V. Conclusions.- References.- 2 Processes and Functions at the Primary Producer Level.- Preface.- A. Plant Specialization to Environments of Different Resource Availability.- I. Introduction.- II. Plant Growth as a Regulated System of Resource Use.- III. Plant Organization.- IV. Plant Specialization to Specific Habitats.- V. Ecosystem Implications.- VI. Conclusions.- References.- B. Control of Leaf Carbon Assimilation - Input of Chemical Energy into Ecosystems.- I. Introduction.- II. Photosynthetic Performance of Plants Under Natural Conditions.- III. The Types of External and Internai Factors Which Determine Leaf Carbon Gain.- IV. Carbon Dioxide Exchange of Thallophytes.- V. Carbon Dioxide Exchange of Leaves of Higher Plants.- VI. Conclusions.- References.- C. Plant Architecture and Resource Competition.- I. Introduction.- II. Traits of a Competitive Plant.- III. Competition for Light.- IV. Morphological Flexibility and the Light Environment.- V. Competition Below Ground.- VI. Concluding Remarks.- References.- D. Responses to Water and Nutrients in Coniferous Ecosystems.- I. Introduction.- II. Growth of Pinus sylvestris in Sweden.- III. Growth of Pinus radiata in Australia.- IV. Comparative Aspects of Growth in Pinus.- V. Conclusions.- References.- E. Physiological Ecology, Disturbance, and Ecosystem Recovery.- I. Introduction.- II. Physiological Ecology and Ecosystem Complexity.- III. Disturbance and Response in Closed Forests: an Example.- IV. Conclusions.- References.- F. A Hierarchic Approach in Causal Ecosystem Analysis. The Calcifuge-Calcicole Problem in Alpine Grasslands.- I. Introduction.- II. Case Study: The Calcifuge-Calcicole Problem in Alpine Grasslands.- III. Which Is the Most Important Factor for the Floristic Differences Between Calcifuge and Calcicole Alpine Grasslands?.- IV. Hierarchy of Factors; Causal and Correlative Factors.- V. Hierarchy of Answers to the Question: Which Is the Relatively Most Important Factor for Floristic Differences Between Plant Communities?.- VI. Conclusions.- References.- G. Extinction and Naturalization of Plant Species as Related to Ecosystem Structure and Function.- I. Introduction.- II. Long-Term Development of Vergetation: Migrations Following the Ice Age.- III. Extinction and Decline of Species.- IV. Introduction and Naturalization of Species.- V. Conclusions.- References.- H. Flowers as Food Sources and the Cost of Outcrossing.- I. Introduction.- II. Flowers as Food Sources.- III. Flowers Are More Than Food Sources.- IV. Conclusions.- References.- 3 Processes and Functions at the Consumer Level.- Preface.- A. Species Richness, Species Packing, and Evolution in Insect-Plant Systems.- H. Zwölfer.- I. Introduction.- II. Species Richness in Phytophagous Insects: a Literature Review.- III. Parameters Determining the Species Richness of Insects Associated with Cardueae Flower Heads.- IV. Adaptations of Phytophages to Différent Scales of Cardueae Flower Heads.- V. Conclusions.- References.- B. Niche Structure and Evolution in Ecosystems.- I. Introduction.- II. The Niche Concept.- III. The Niche Concept and Exploitative Competition.- IV. A Model for Genetical Ecology.- V. Null Models.- VI. Invasion, Extinction, and the Buildup of Communities.- VII. Potentials and Limitations.- VIII. Conclusions.- References.- C. Predictability in Lake Ecosystems: the Role of Biotic Interactions.- I. Introduction.- II. Seasonal Succession of Phytoplankton.- III. Size Structure of the Zooplankton Community.- IV. Conclusions.- References.- D. Saline Lake Ecosystems.- I. Introduction.- II. Characteristics of Saline Lake Ecosystems.- III. Conclusions.- References.- E. Characteristics of Lotic Ecosystems and Consequences for Future Research Directions.- I. Introduction.- II. Environmental Variability and Species Richness.- III. Biological Interactions in Stream Communities: Facultative or Obligate?.- VI. Energetics in Benthic Macroinvertebrate Communities.- V. Conclusions.- References.- F. Experimental Analysis of Processes Between Species on Marine Tidal Flats.- I. Introduction.- II. Uncertainty in Field Experiments.- III. Species Connections on Tidal Flats.- IV. Conclusions.- References.- G. On Methods of Analyzing Ecosystems: Lessons from the Analysis of Forest-Insect Systems.- I. Introduction.- II. The Objective "Control".- III. The Objective "Basic Research".- IV. Balance or Shift in Objectives?.- V. Lessons We Can Learn.- VI. Conclusions.- References.- Synthesis (With 1 Figure).- Spezies Index.