Research Activities and Research Perspectives

Goals

• Study behavior of terrestrial ecosystems in a changing climate (modeling and simulation) with emphasis on mountainous forest ecosystems
• Understand relationships between biophysical forcing factors and ecosystem functions
• Develop systems theory of ecological systems

Foci

• Issues: Climate Change impact on ecosystems (e.g. agroecosystems, forests), mitigation of green-house-gas emmissions (e.g. in forestry), and sustainable utilization of natural resources via Adaptive Environmental Assessment and Management (AEAM).
• Models and Theories: Development of state-of-the-art ecosystem models (e.g. ForClim or ForLand) and development of a systems theory of ecosystems (theoretical systems ecology) based on standard formalisms such as DESS (Differential Equation System Specification), SQM (Sequential Machines or simply Automata) and DEVS (Discrete EVent system Specification)
• Tools: Interactive modeling and simulation tools such as RAMSES (Research Aids for Modeling and Simulation of Environmental Systems), which includes e.g. Modelworks (interactive modeling and simulation environment for PCs and workstations), ISIS (Integrative Systems Implementation Software), or RASS (the RAMSES Simulation Server).

Programmes

Our research forms also part of the following national and international research programmes:

• OPTICONTROL >> Optimal Control of heating in buildings to save energy by profiting from latest developments in weather forecasts and control theory - a collaborative effort by the ETH Zurich, EMPA Dübendorf, MeteoSwiss and Siemens Building Technologies
• C2SM >> Center for Climate Systems Modeling of ETH Zurich improving the understanding of the Earth's climate and weather
• NCCR Climate >> (Climate Variability, Predictability and Climate Risks) NCCR - The National Centers of Competence in Research are managed by the Swiss National Science Foundation on behalf of the federal authorities

Recently completed research programmes:

• NFP48 >> National Research Programme NRP48: Landscapes and Habitats of the Alps Nationales Forschungsprogramm NFP48: Landschaften und Lebensräume der Alpen
• Contribution of Forests and Forestry to Mitigate Greenhouse Effects - COST E21 >> COST - European Cooperation in the field of Scientific and Technical Research

Examples of past or ongoing research studying the behavior of terrestrial ecosystems in a changing climate

ForClimSense

Purpose: Furthering our understanding of the sensitivities of forest ecosystems in the Alps to climatic change and the associated uncertainties. Approach: The dynamic forest patch-model ForClim has been developed to assess the impact of future climatic changes on forests, particularly in the alpine region. It simulates successional patterns in forest ecosystems by simulating explicitly all abiotic, i.e. mainly climatic, factors. Currently ForClim is validated in past climatic change scenarios using various proxy data such as isotopes and pollen records for a time window covering the end of the last ice age. Results: Simulations at selected test sites revealed a large spectrum of forest responses to the same changes in the climatic input, which range from primary successional growth to complete die-backs. Perspectives: The core of the current project is a systematic analysis of the sensitivity of species compositions to local climate change scenarios and the related uncertainties (see project ”Case Studies in Bioclimatic Scenario Derivation’). Furthermore the cohort based stochastic model ForClim is aggregated to a structured population dynamics model. The latter will be used to describe tree species migration in a complex topography forced by a changing climate.

ForAgroClim

Purpose: Modeling the carbon-dynamics in forest ecosystems under the influence of climatic change. Approach: The carbon fluxes exerted by a terrestrial ecosystem play a major role as biospheric feed-backs in the climatic system. The forest gap-model ForClim provides a basis to simulate the elemental fluxes of C and N. Given the importance of carbon, both in the context of the global carbon cycle and as a key element in ecosystem functioning via coupling with nutrients, ForClim is presently refined to include the major fluxes driving the C-cycle. Results: Soil-borne processes and soil organic carbon in particular have been recognized as major components of the carbon balance of forests. Parameters were identified and the structure of the soil carbon submodel has been improved. Perspectives: Integration of the soil submodel into the larger ForClim. Parametric sensitivity analysis. Validation of the new ForClim variant and model applications to assess quantitatively impacts of climatic change on boreal and temperate forests.

Bioclimatic Scenario Derivation

The project is aimed at developing, testing, and applying methods to derive future climate scenarios as required by specific ecosystem case studies in a mountainous region. Statistical ”downscaling’ techniques are developed to empirically link regional climatic changes to global climate variations, and then applied to estimate possible future shifts in regional climates from simulations with General Circulation Climate Models (GCMs). Stochastic time series models and weather generators are used to describe climate and weather variability at different time scales. Interpolation techniques are developed to estimate base-line climate and climatic changes at any location of interest. In close collaboration with ecosystem modelers, the resulting application-specific bioclimatic scenarios are applied to study the sensitivities of ecosystem models, and to assess possible future ecosystem responses in the European Alps.

RAMSES - Methodology of computer-assisted Research Aids for Modeling and Simulation of Environmental Systems

Based on the modeling and systems theory by Wymore (1984) and Zeigler (1976, 1984) we work on the theoretical basis and the needed mathematical formalisms to model and simulate ill-defined systems, which are often studied in environmental sciences in various contexts. Workstation-aided structureda, modular modeling and interactive simulation require software tools, to support an efficient and scientifically rigorous mathematical modeling and analysis of complex systems. Curent implementations of RAMSES tools are embedded in flexible system architectures to support not only text-book but real research needs typically arising in ecological modeling projects. Case studies (see other projects) allow to test the validity of the tools in supporting earlier as well as later phases of research. In earlier phases the emphasis is typically on the support of a flexible model development which can only be provided by an open, yet robust system architecture; in later phases the focus shifts to extensive simulation experiments such as sensitivity analysis, parameter identification, or optimal systems control. The current focus is on simulation servers (RASS) running within a local area network and supporting the batch execution of distributed simulation experiments of model definition programs originally developed only for an interactive environment.