Test and Application of a Vegetation- Based CO 2 and CH 4 Flux Estimate from Three Ombrogenic and Topogenic Peatlands in Southern Germany
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Swedish University of Agricultural Sciences Faculty of Natural Resources and Agricultural Sciences Department Ecology Universität Hohenheim Faculty of Agricultural Sciences Institute of Landscape and Plant Ecology (320) Department Landscape Ecology and Vegetation Science Test and application of a vegetation- based CO 2 and CH 4 flux estimate from three ombrogenic and topogenic peatlands in Southern Germany Birgit Weber Independent project in Biology, Masterthesis Environmental Science- Soil, Water and Biodiversity Uppsala / Stuttgart-Hohenheim, December 2010 Examensarbete 2010:19 Test and application of a vegetation-based CO 2 and CH 4 flux estimate from three ombrogenic and topogenic peatlands in Southern Germany Birgit Weber Supervisor: Prof. Dr. rer.nat Reinhard Böcker, Universität Hohenheim Assistant Supervisor: Dr. Peter Eliasson, Swedish University of Agricultural Sciences Examiner: Prof. Göran Ågren, Swedish University of Agricultural Science Prof. Dr. rer.nat Reinhard Böcker, Universität Hohenheim Credits: 30 hec Level: E-level Course title: Independent project in Biology – Master thesis Course code: EX0565 Programme/education: Environmental Science- Soil, Water and Biodiversity Place of publication: Uppsala, Sweden/ Stuttgart-Hohenheim, Germany Year of publication: 2010 Picture Cover: Drosera rotundifolia on Sphagnum mosses in the raised bog ‘Gründlenried’ ISBN: 978-91-576-9015-9 Online publication: http://stud.epsilon.slu.se Key Words: greengouse gas, GEST, peatland Swedish University of Agricultural Sciences Faculty of Natural Resources and Agricultural Sciences Department Ecology Universität Hohenheim Faculty of Agricultural Sciences Institute of Landscape and Plant Ecology (320) Department Landscape Ecology and Vegetation Science Abstract I Abstract A stabilisation and restoration of peatlands is seen as a sustainable strategie for climate change mitigation. To find the most suitable target areas, greenhouse gas fluxes have to be quantified. A vegetation-based flux estimate is seen as cost-effective alternative to avoid time consuming and expensive flux measurements. The present study aims to define current obstacles and limitations to a vegetation-based flux estimate and define a possible scope for vegetation-based flux estimates in Baden-Württemberg. A case study was performed in three ombrogenic and topogenic mires in Southern Germany using the tools Greenhouse Gas Emission Site Type (GEST) for non-forest sites and IPCC’s ‘Good Practise Guidance for Land Use, Land Use Change and Forestry’ (GPG-LULUCF) for forest sites. The study was limited to carbon dioxide (CO 2) and methane (CH 4) fluxes, shown as CO 2 equivalents (CO 2e). Based on 115 vegetation relevés, three vegetation classification systems on non-forest sites ‘vegetation forms’, ‘phytosociological plant communities’ and ‘Biotope types of Baden-Württemberg’ were compared to test if they can replace each other in a flux estimate. Calculation parameters for forest-sites were chosen for the study area. A greenhouse gas balance was established for the study area. The reviewed vegetation classification systems showed inconsistent overlaps. Hence, the vegetation classification systems were considered to be not completely compatible. As descripition of vegetation forms was considered to be insufficient for Southern Germany, an application of vegetation-based CO 2 and CH 4 flux estimates was considered to be difficult in Baden-Württemberg. -1 -1 Mean CO 2 and CH 4 emissions of 9,7 t CO 2e ha yr were estimated in the study area. Emissions from forested peat were smaller than from mire and from grassland on peat. However, the selection of parameters for GPG-LULUCF and associated inaccuracies influenced the estimate. Footpaths and roads, watercourses and lakes, pastures, cropland and clearcut were not considered and N 2O emissions were excluded from the estimate. Considering these limitations of the estimate, vegetation-based carbon estimates should be verified and refined before a statewide application. Acknowledgements II Acknowledgements Many people supported me during the time of my thesis. I want to thank my supervisor Prof. Dr. rer. nat. Reinhard Böcker, Universität Hohenheim, who supported the phytosociological classification, the identification of vascular plants and who was always open to any kind of questions. my supervisor Dr. Peter Eliasson, Swedish University of Agricultural Sciences, who supported me in all questions concerning the carbon cycle and forests and helped me to sort out all administrational issues. Special thanks for reading my draft and giving helpful feedback on my work. Prof. Göran Ågren, Swedish University of Agricultural Sciences, for reviewing my work. Dr. Markus Röhl, Institute of Applied Research Nürtingen, for suggesting the topic of this thesis. Dr. Ingo Holz, Universität Hohenheim, for his support in the identification of moss species. Dr. Björn Schäfer, Universität Hohenheim, for giving feedback on my work. my friends Julia Sauer and Katrin Wuchter for reviewing my draft and supporting me in all matters during the time of thesis writing. my husband Martin Weber, who diligently checked my vegetation tables and supported me all the time. This thesis was performed within the scope of the regional peatland development project (Regionales Moorentwicklungskonzept), Institute of Applied Research in Nürtingen. Content III Content List of figures ................................................................................................... V List of tables .................................................................................................. VIII Abbreviations .................................................................................................. IX 1 Introduction .............................................................................................1 2 State of the Art ........................................................................................4 2.1 Vegetation classification systems .............................................................4 2.1.1 Vegetation form concept ......................................................................4 2.1.2 Phytosociological system according to Braun-Blanquet.......................5 2.1.3 Biotope types of Baden-Württemberg ..................................................6 2.2 The GEST-Concept ..................................................................................6 3 Study area................................................................................................9 3.1 Size and location.......................................................................................9 3.2 Physiographic division.............................................................................11 3.3 Protection status .....................................................................................11 3.4 Climate....................................................................................................12 3.5 Bedrock and soil .....................................................................................13 3.6 Groundwater and watercourses..............................................................15 3.7 Historical land use and current vegetation structure ...............................15 4 Materials and Methods .........................................................................17 4.1 Selection of study area............................................................................17 4.2 Assessment of non-forest sites...............................................................17 4.2.1 Data collection....................................................................................17 4.2.2 Data evaluation ..................................................................................18 4.2.3 Nomenclature of plant species and plant communities ......................19 4.3 Assessment of forest sites ......................................................................20 4.3.1 Data collection....................................................................................20 4.3.2 Data evaluation ..................................................................................20 4.4 Estimation of CO 2 and CH 4 flux...............................................................21 4.4.1 Non-forest sites..................................................................................21 4.4.2 Forest sites.........................................................................................22 4.4.3 Synthesis of total CO 2 and CH 4 flux ...................................................26 Content IV 5 Results...................................................................................................27 5.1 Assessment of non-forest sites...............................................................27 5.1.1 GESTs and vegetations forms in the study area................................28 5.1.2 Identified GESTs in relation to other classification systems...............51 5.2 Assessment of forest sites ......................................................................54 5.2.1 Forests in the study area....................................................................55 5.3 Estimation of CO 2 and CH 4 flux...............................................................59 5.3.1 Non-forest sites..................................................................................59 5.3.2 Forest sites.........................................................................................61 5.3.3 Synthesis of