Long-Term Ecosystem Research Between Theory and Application - An Introduction -- The Significance of Ecological Long-Term Processes -- Theoretical Demands for Long-Term Ecological Research and the Management of Long-Term Data Sets -- Long-Term Ecosystem Dynamics: Theoretical Concepts of Environmental Change -- The Scientific Potential of Environmental Monitoring -- Exploring Long-Term Processes: International Experience -- Twenty-Eight Years of the US-LTER Program: Experience, Results, and Research Questions -- Introducing the Next Generation of Ecosystem Research in Europe: LTER-Europe's Multi-Functional and Multi-Scale Approach -- The Role of Ecosystem Modelling for Long-Term Ecological Research -- The Role of Statistics for Long-Term Ecological Research -- The Role of Remote Sensing in LTER Projects -- Concepts and Results: Presenting and Interpreting Long-Term Ecological Processes: Aquatic Ecosystem Research -- Long-Term Ecological Change in the Northern Wadden Sea -- Long-Term Model Simulation of Environmental Conditions to Identify Externally Forced Signals in Biological Time Series -- Long-Term Investigations in Brackish Ecosystems -- Long-Term Ecological Research in Freshwater Ecosystems -- Long-Term Monitoring in Rivers of South Germany Since the 1970s - Macrophytes as Indicators for the Assessment of Water Quality and Its Implications for the Conservation of Rivers -- Concepts and Results: Presenting and Interpreting Long-Term Ecological Processes: Terrestrial Ecosystem Research -- Long-Term Observations of Soil Mesofauna -- Tracing Biogeochemical Processes in Small Catchments Using Non-linear Methods -- Long-Term Measurements to Quantify the Impact of Arable Management Practices on Deep Seepage and Nitrate Leaching -- Long-Term Ecosystem Research in a Beech Forest of Northern Germany -- A Conceptual Framework for Integrated Functional Landscape Monitoring in the Wider Countryside of Central Europe -- Temporal Changes and Spatial Determinants of Plant Species Diversity and Genetic Variation -- Integration of Long-Term Environmental Data by the Example of the UNECE Heavy Metals in Mosses Survey in Germany: Application of a WebGIS-Based Metadata System -- Concepts and Results: Presenting and Interpreting Long-Term Ecological Processes: Linking Research and Applications -- Monitoring of Ecosystems: Two Different Approaches - Long-Term Observation Versus Success Control -- National Parks as Model Regions for Interdisciplinary Long-Term Ecological Research: The Bavarian Forest and Sumavá National Parks Underway to Transboundary Ecosystem Research -- Turning Long-Term Monitoring into Policy - Using the National Park Schleswig-Holstein Wadden Sea as an Example -- Design and Importance of Multi-tiered Ecological Monitoring Networks -- Future Demands and Challenges -- Conceptualising Long-Term Socio-ecological Research (LTSER): Integrating the Social Dimension -- Integrating Social Sciences into Long-Term Ecological Research -- Ecosystem Manipulation and Restoration on the Basis of Long-Term Conceptions -- Exploratories for Large-Scale and Long-Term Functional Biodiversity Research -- Conclusions -- On the Way to an Integrative Long-Term Ecosystem Research - Milestones, Challenges, and some Conclusions. Ecosystems change on a multitude of spatial and temporal scales. While analyses of ecosystem dynamics in short timespans have received much attention, the impacts of changes in the long term have, to a great extent, been neglected, provoking a lack of information and methodological know-how in this area. This book fills this gap by focusing on studies dealing with the investigation of complex, long-term ecological processes with regard to global change, the development of early warning systems, and the acquisition of a scientific basis for strategic conservation management and the sustainable use of ecosystems. Theoretical ecological questions of long-term processes, as well as an international dimension of long-term monitoring, observations and research are brought together. The outcome is an overview on different aspects of long-term ecological research. Concepts and results of case studies in both aquatic and terrestrial ecosystems are discussed. The different time dimensions, as well as scales from the community and ecosystems up to the landscape scale are included. Finally, research is linked with application in different fields of ecology, and urgent future infrastructural, methodological and research demands and challenges are described. This book will be of interest not only to ecologists, conservation biologists, biodiversity scientists and environmentalists, but also to administrators of protected areas and natural resource managers.