Das Projekt "Die Auswirkungen von erhoehten CO2-Konzentrationen und Stickstoffablagerung auf die Kohlenstoff- und Stickstoffassimilation von Fagus Sylvatica und Picea Abies und das 15/14N- bzw. 13/12C-Verhaeltnis" wird vom Umweltbundesamt gefördert und von Paul Scherrer Institut, Laboratorium Environmental and System Analysis durchgeführt. As a contribution to the ICAT-Project, the main goal of this investigation is to analyze the influence of elevated C02 and increased nitrogen deposition on the flux dynamics and the pools of C and N in individual plants (Fagus sylvatica and Picea abies) as well as in the ecosystem. A change in the C02 regime influences the nitrogen balance, and the alteration of the nitrogen regime greatly influences the carbon balance. The pathways ,and pools of these elements in plants and in the ecosystem will be studied and described, analyzing the stable isotope relationships (I5/l4N and 13/12C). In this study both 13C and 15N will be used as tracer elements as well. The use of these tracers will allow to study the translocation and remobilisation mechanisms of N and C under changed environmental conditions. The use of labelled nitrogen as the below ground N-source (l5N-H4+,15N- 03-) and 15NO2 for the above ground fumigation in separate chambers allows the study of the different nitrogen sources and the various pathways. Variations in physiological processes during the vegetation period will be studied by supplying and harvesting plant material from potted plants at clearly defined times. The study of the 13/l2C relationship will allow to estimate the long term water use fficiency. It is planned to use this data material for the development of mechanistic oriented models which allow the simulation of these processes. Leading Questions: 1. How does elevated CO2 influence the carbon and nitrogen balance alone or in combination with an elevated nitrogen deposition. 2. What is the influence of this situation on the C- and N-Pools a) in the individual plant, b) in the ecosystem 3. Will the turnover rates be accelerated or slowed down, or is it not influenced 4. Where and at what time will the metabolites be translocated with an elevated CO2 and nitrogen level, and how will it differ from the controls.
Das Projekt "Verhaeltnis zwischen Wachstum und Kohlenstoff bei Fichte/Buche-Modelloekosystemen mit erhoehter CO2- und Stickstoffkonzentration" wird vom Umweltbundesamt gefördert und von Universität Basel, Departement Integrative Biologie, Botanisches Institut durchgeführt. Model ecosystems of beech and spruce are exposed to elevated CO2 and enhanced wet nitrogen deposition in large open-top chambers and with deep natural soil and understory vegetation. Our part of this multidisciplinary project in growth analysis and system level carbon balance. The important aspect in this project is its high complexity and full grown coverage so that land area based data can be obtained (biomass, CO2 fluxes, leaf area index etc.). The experimental facility is at the Swiss Federal Institute of Forest Research at Birmensdorf near Zurich. The coordinator of the whole project is Ch. Brunold in Bern, the on site coordinator is J. Bucher (WSL). Leading Questions: - Will elevated CO2 influence forest tree growth and forest species diversity? - Will enhanced soluble nitrogen deposition influence forest growth and forest species diversity? - how will CO2 and N interact? - How will soil conditions influence these responses and interactions?
Das Projekt "Natuerliche Vielfalt und Reaktionen des Oekosystems auf erhoehte CO2-Konzentrationen bei Kalkwiesen" wird vom Umweltbundesamt gefördert und von Universität Basel, Departement Integrative Biologie, Botanisches Institut durchgeführt. This is a multidisciplinary long term project which aims at an understanding of plant and ecosystem processes under natural conditions when key environmental drivers are altered. Here we investigate the influence of elevated CO2 on species diversity and primary productivity of a highly diverse calcareous grassland. Biodiversity effects are explained by plant growth responses, water relations, soil processes and genotypic varience. We use a new CO2-enrichment technology-screen aided CO2-control (SACC) and also manipulated diversities. Leading Questions: Does biodiversity affect ecosystem functioning? Is biodiversity affected by elevated CO2 and how? What are the causes for species specific responses to elevated CO2? What are the longterm consequences of such changes for ecosystem functioning and species persistance (conservation)?
Das Projekt "Empfindlichkeits- und Unsicherheitsanalysen von Klimaszenarien und Reaktionen der Oekosysteme in den Alpen (SENSUALP) - Teil B2: Landwirtschaftliche Oekosysteme" wird vom Umweltbundesamt gefördert und von Eidgenössische Forschungsanstalt für Agrarökologie und Landbau, Institut für Umweltschutz und Landwirtschaft durchgeführt. This project is concerned with the sensitivity of managed grasslands in alpine regions to changes in climatic conditions and CO2, in relationship to grassland utilization, i.e. animal production. The aims are (a) to evaluate possible shifts in productivity and C-storage in response to different down-scaled local weather scenarios, which are derived from GCM projections for 2xCO2, and to compare the shifts between sites differing in altitude and in edaphic conditions, and (b) to assess consequences for agricultural management. The analysis is carried by using the mechanistic grassland ecosystem model PASIM. The work is divided into four levels, including simulations of grassland production at the patch-scale, regional aggregation, combination of forage and animal production at the farm-level, and exploration of uncertainty in future projections of regional sensitivities. Specific goals of the project are (a) quantification of the sensitivity of grassland ecosystem processes to climate change and increased CO2, (b) advancement of techniques and knowledge to understand mechanisms of uncertainty propagation across disciplinary boundaries, (c) comparison between grassland and forest responses, and (d) analysis of adaptation options for mountain farming at the farm-level. The modelling results are complemented by the evaluation of historical trGeo-Thesaurusction, and by an analysis of the public opinion among mountain farmers in different regions. Leading Questions: Sensitivity of the productivity of mountain pastures and meadows to changes in climate and (CO2). Shift in the cultivation limit of specific high-yielding grasses e.g. Lolium perenne) due to a change in snow cover: Implications for production at farm level. Consequences of changes in grassland productivity for animal husbandry (e.g. stocking density) and nutrient dynamics.
Das Projekt "Wechselwirkung zwischen Schmetterlingen und Pflanzen unter den gegenwaertigen Bedingungen und bei erhoehter CO2-Konzentration" wird vom Umweltbundesamt gefördert und von Universität Basel, Institut für Natur-, Landschafts- und Umweltschutz, Abteilung Biologie durchgeführt. Ziel dieses Projekts ist, grundlegende Faktoren zu identifizieren, welche die interaktionen von Pflanzen und Schmetterlingen und ihre Evolution unter gegenwaertigen und klimatisch veraenderten Bedingungen (erhoehtes CO2) bestimmen. Ebenso sollen Faktoren untersucht werden, die fuer den Schutz von Pflanzen und Schmetterlingen relevant sind. Im einzelnen konzentriert sich das Projekt auf (1) Langzeiteffekte von erhoehtem CO2 und von Habitatfragmentierung auf die Interaktionen zwischen Pflanzen und Schmetterlingen, (2) Nektarpraeferenzen von Schmetterlingen, (3) Effekte der Nektarqualitaet auf den Reproduktionserfolg von Schmetterlingen (4) den Bestaeubungseffekt von Schmetterlingen, (5) Effekte von erhoehtem CO2 auf die Larvalentwicklung von Schmetterlingen und (6) moegliche genetische Erosion in Schmetterlingspopulationen, die durch grossraeumige Habitatfragmentierung verursacht wird.