Potentials And Limitations Of Ecosystem Analysis

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.

The biota of the earth is being altered at an unprecedented rate. We are witnessing wholesale exchanges of organisms among geographic areas that were once totally biologically isolated. We are seeing massive changes in landscape use that are creating even more abundant succes sional patches, reductions in population sizes, and in the worst cases, losses of species. There are many reasons for concern about these trends. One is that we unfortunately do not know in detail the conse quences of these massive alterations in terms of how the biosphere as a whole operates or even, for that matter, the functioning of localized ecosystems. We do know that the biosphere interacts strongly with the atmospheric composition, contributing to potential climate change. We also know that changes in vegetative cover greatly influence the hydrology and biochemistry ofa site or region. Our knowledge is weak in important details, however. How are the many services that ecosystems provide to humanity altered by modifications of ecosystem composition? Stated in another way, what is the role of individual species in ecosystem function? We are observing the selective as well as wholesale alteration in the composition of ecosystems. Do these alterations matter in respect to how ecosystems operate and provide services? This book represents the initial probing of this central ques tion. It will be followed by other volumes in this series examining in depth the functional role of biodiversity in various ecosystems of the world.

Proceedings of the symposium of the Working-Group for Theoretical Vegetation Science of the International Association for Vegetation Science held in Vienna, July 4-11, 1988

The challenges in ecosystem science encompass a broadening and strengthening of interdisciplinary ties, the transfer of knowledge of the ecosystem across scales, and the inclusion of anthropogenic impacts and human behavior into ecosystem, landscape, and regional models. The volume addresses these points within the context of studies in major ecosystem types viewed as the building blocks of central European landscapes. The research is evaluated to increase the understanding of the processes in order to unite ecosystem science with resource management. The comparison embraces coastal lowland forests, associated wetlands and lakes, agricultural land use, and montane and alpine forests. Techniques for upscaling focus on process modelling at stand and landscape scales and the use of remote sensing for landscape-level model parameterization and testing. The case studies demonstrate ways for ecosystem scientists, managers, and social scientists to cooperate.

Philosophers, writers and scientists, from cell biologists to ecologists, have long recognized the special nature of boundaries and interface areas of all kinds. Among ecologists in particular, there has been an upsurge in interest in the sensitive boundary areas of interaction between ecosystems, which are called 'ecotones' and which are often characterized by higher biological diversity than adjacent areas.

This volume quantifies carbon storage in managed forest ecosystems not only in biomass, but also in all soil compartments. It investigates the interaction between the carbon and nitrogen cycles by working along a north-south transect through Europe that starts in northern Sweden, passes through a N-deposition maximum in central Europe and ends in Italy. For the first time biogeochemical processes are linked to biodiversity on a large geographic scale and with special focus on soil organisms. The accompanying CD-ROM provides a complete database of all flux, storage and species observations for modellers.

The arctic region is predicted to experience the earliest and most pronounced global warming response to human-induced climatic change. This book synthesizes information on the physiological ecology of arctic plants, discusses how physiological processes influence ecosystem processes, and explores how climate warming will affect arctic plants, plant communities, and ecosystem processes. Key Features * Reviews the physiological ecology of arctic plants * Explores biotic controls over community and ecosystems processes * Provides physiological bases for predicting how the Arctic will respond to global climate change