The relationship between Biodiversity and Ecosystem Functioning in Grassland Ecosystems
The BMBF-funded project 'The relationship between Biodiversity and Ecosystem Functioning in Grassland Ecosystems' is a collaborative research effort of the Friedrich-Schiller-University and the Max-Planck-Institute for Biogeochemistry, both in Jena, and the Office for Ecological Studies in Bayreuth. Using grasslands in Thuringia as model ecosystems, the project is designed to investigate the relationship between genetic/phenotypic diversity and ecosystem processes such as carbon and nitrogen fluxes. Seven research groups in the areas of plant physiology, biogeochemistry, entomology, mathematical modelling, plant taxonomy, mycorrhizal biology, and landscape modelling will use experimental and theoretical approaches to investigate the importance of biodiversity for the stability and functioning of ecosystems.
Project leader
Prof. Dr. Wolfgang W. Weisser
Institute of Ecology
Friedrich-Schiller-Universität
Dornburger Str. 159
D-07743 Jena
Tel: +49.3641.94.9400
Fax: +49.3641.94.9402
Project Coordination
Dr. Kerstin Wiesner
Institute of Ecology
Friedrich-Schiller-Universität
Dornburger Str. 159
D-07743 Jena
Tel: +49.3641.94.9419
Fax: +49.3641.94.9402
Ilka Egerer
Institute of Ecology
Friedrich-Schiller-Universität
Dornburger Str. 159
D-07743 Jena
Tel: +49.3641.94.9417
Fax: +49.3641.94.9402
Duration of project: until 31.04.2010
Project Participants
Friedrich-Schiller-Universität Jena
Institute of Ecology
Prof. Dr. Wolfgang W. Weisser
Juliane Specht
Kerstin Wiesner
School of Economics and Business Adminstration
Prof. Dr. Andreas Freytag
Christoph Vietze
Angela Münch
Max-Planck-Institute for Biogeochemistry, Jena
Prof. E.-Detlef Schulze
Office of Ecological Projects
Dr. Wolfgang Völkl
Helmholtz Centre for Environmentel Research
Depart. of Community Ecology
Dr. Harald Auge
Dr. Daniel Prati
Claudia Stein
Depart. of Soil Ecology
Karoline Weißhuhn
Prof. Dr. François Buscot
Stefan Hempel
Dr. Elke Schulz
Marc Breulmann
University of Tuebingen
Institute of Geography
Prof. Dr. Thomas Scholten
Ralf Gründling
University of Goettingen
Depart. f. Agricultural Economics and Rural Development
Professor Dr. R. Marggraf
Dr. Jan Barkmann
Sandra Rajmis
Scientific goals of the subproject ENTO
It is generally accepted that large, plant-eating (herbivorous) vertebrates exert a great influence on vegetation dynamics. The importance of herbivorous insects for the structure and dynamics of natural plant communities has, however, only recently been recognized and investigated. Manipulative studies where insects were removed using biocides have shown that herbivory may not only change the diversity and composition of plant communities but also affect the direction of succession. In addition to trophic effects that arise directly or indirectly from removal of biomass by herbivores, herbivorous insects may also affect ecosystem processes through a number of non-trophic effects. Surprisingly, there have been very few studies on the effects of insect herbivores on ecosystem processes. The most convincing evidence that herbivores affect ecosystem processes comes from direct manipulations of herbivore populations. For terrestrial systems, such experiments have provided some clear demonstrations of significant effects of herbivores on ecosystem processes such as primary productivity and nutrient cycling, but so far they have only been performed with a focus on large mammalian herbivores. In almost all of the recent biodiversity-ecosystem function field experiments, the emphasis was on the manipulation of plant diversity only. Because insect herbivory will depend on plant species diversity, it can be hypothesized that insect herbivory will modify the relationship between plant diversity and ecosystem processes. While insects affect plant communities, the plant community itself exerts a strong influence on the diversity of the insects associated with the plant community. Virtually all ecological models predict that an increase in resource diversity supports a more diverse array of consumers. Similarly, increased herbivore density is predicted to result in an increased diversity of parasites and predators but there may also be direct effects of plant diversity on parasite and predator diversity as well as changes in the interactions between herbivores and their natural enemies. Thus, it is likely that increasing plant diversity affects the diversity of the whole insect complex, but the relationship can be complicated.The subproject ENTO has the following goals:
- To manipulate the presence of herbivorous insects in grassland plots to study the relationships between plant diversity, insect herbivory and ecosystem processes. The manipulation of insect herbivory will also help us to determine the role of insects in ecosystem responses to stress (drought).
- To assess insect diversity in the experimental plots to investigate the relationship between the compositional structure of the insect complex, plant diversity and plant productivity.
Contacts:
FSU Jena, Institute of Ecology
Prof. Dr. Wolfgang W. Weisser
Juliane Specht
Kerstin Wiesner
Scientific goals of the subproject STOFF/MYKO
Soil carbon as well as soil fungi and mycorrhizal fungi in grassland ecosystems with different diversity
Prof. Dr.François Buscot, Dr. Elke Schulz,
Helmholtz Centre for Environmental Research - UFZ, Department Soil Ecology
Focus of subproject STOFF/MYKO is quantification of the four nodal points input, transformation, accumulation, and loss of carbon in and from soils and understanding biological mechanisms behind in relation to plant diversity and land use intensity in different grassland ecosystems. Concerning carbon input into soils, we will especially analyse mycorrhizal symbioses between soil fungi and plant roots as they directly channel important amounts of photo-assimilates into soils. These readily available matter and energy resources promote microbial activity in the rhizophere and the bulk soil and have a high impact on the balance between litter mineralization and humification. These two processes cause a dynamic equilibrium between accumulation of more or less stable/stabilised fractions of organic carbon and their mineralization with corresponding carbon dioxide output from soils. The different nodes (mycorrhizza, microbial biomass, carbon accumulation and carbon dioxide output) are closely related to plant diversity but up to now mechanisms and interactions behind remain to disentangle.
Scientific goals of the subproject INDICATION
In the past phases, the the subproject INDICATION developped an easy system for evalution and indication in landscape conservation, which integrates both species richness and functional diversity. This includes several parameters such as the presence/absence of particular life-history strategies (monophagous/polyphagous species; univoltinous/bivoltinous/polyvoltinous species), the presence of species representing the available ecological niches and the completeness of the food web. The model was developped for grassland ecosystems, but the general results and approaches are transferable to other habitats dominated by an open landscape.
In the next phases, several additional factors shall be studied which are important for the application of the model. The study of regional aspects will render possible a differentiated application and evaluation in various geographic areas. The analysis of interactions between biodiversity, changes in land use and scio-economic variables (in cooperation with subproject ECOL-ECON) will it make possible to estimate the effects of changes in the landscape on biodiversity and to forecast the future situation. As a result, a regional-scaled indication system is planned. This model shall be applied in nature conservation for site evaluation and for efficiency control. Additionally, the model shall help to define minimum standard for the conservation of biodiversity in grassland ecosystems.
Contacts
Dr. Wolfgang Völkl
Dr. Maria Romstöck-Völkl
Address
Ökologische Planung
Hohe Eiche 6
95517 Seybothenreuth
Scientific goals of the subproject PHYTO
Plant diversity on grassland ecosystems: the relevance of regional species pool, herbivory and interactions
Biodiversity can be influenced by ecological processes acting on different spatial scales. On the one hand, plant species richness may depend on regional factors, e.g. the available species pool dispersal processes or the land use pattern including such effects like fragmentation and isolation. For instance, we demonstrated in the previous project phase the local plant diversity increases when seeds representing the regional species pool were added to the grasslands, pointing to dispersal limitation of plant species richness. Simultaneously, productivity increased with increasing diversity.
On the other hand, plant species richness may be influenced by local factors such as herbivory. We showed that excluding belowground insects induced a shift in plant species composition, because the proportion of dominant grass species increased.
In our further research we will also consider other species interactions in grassland ecosystems, for example the symbiosis between plants and arbuscular mycorrhiza or interactions between plants, herbivores and insectivores. Using experimental approaches and in close collaboration with the other partners in the project DIVA, we will answer following questions:
- How does insect herbivory change diversity and compostion of grasslands?
- What role do biotic interactions (soil-microorganisms-plant, plant-insects-parasitoids) play for biodiversity and ecosystem functioning?
- How do changes in land use influence biotic interactions and which consequences does it have for ecosystem functions?
- Which conclusions for sustainable use, maintenance of biological diversity and stability of grassland ecosystems can be deduced?
Contacts
Helmholtz Centre for Environmental Research - UFZ
Dr. Harald Auge
Department of Community Ecology
Claudia Stein
Karoline Weißhuhn
University of Potsdam
Institute for Biology and Biochemistry
Dr. Daniel Prati
Scientific goals of the subproject PEDON
Heterogeneity of site properties and water balance parameters within natural grassland stands
In the subproject PEDON, the heterogeneity of abiotic soil properties within and between natural grassland stands is recorded and quantified. In this respect, the study focuses on the question whether stable, mainly land use-independent soil parameters on the scale of single peda are influencing the biodiversity and its preservation. In order to validate the functional relevance of biodiversity with regard to the mechanisms of its preservation, not only the mean intensity of soil properties, but particularly their amplitude within the grassland stands has to be taken into account. Besides the natural pedogenesis, historical land use factors may be relevant in this connection. This study, hence, examines whether grassland areas with a higher amplitude of single soil properties show a greater diversity than others. Furthermore, the question whether large quantities of plant available water (AWC) contribute to the preservation of biodiversity by compensating annual variations of water supply, or whether they rather lead to the domination of single species and thus to ecosystems of small biodiversity, is another subject of this study.
In combination with the analysis of soil-scientific variations between single areas, the determination of the heterogeneity within grassland ecosystems allows an interpretation of the soil function regarding the various aspects of biodiversity within natural grassland ecosystems of low mountain range landscapes. This contributes to the interpretation of important mechanisms of biodiversity preservation. Moreover, the results lead to a reduction of the parameter error regarding the function of abiotic factors within the modeling. They may, however, be an important starting point for the extrapolation onto larger areas in connection with questions of land use optimizing.
There is a close interdisciplinary co-operation with other subprojects within the umbrella project. The areas for intensive examinations as well as the sampling points and depths are determined in co-operation with the subprojects ENTO, MYKO, and STOFF. Furthermore, the heterogeneity calculation will take into account the results of the botanic diversity record of the subproject PHYTO in order to exactly determine the function of the interaction between vegetation and soils. There is also a close co-operation with the subproject STOFF regarding the results of the 14C dating and soil carbone determination as well as the analysis of the former use of the areas and the existence of marker horizons caused by clearings. The soil water balance data are used by the subproject MYKO for the extended evaluation of the mycorrhiza status of grasslands, particularly the degree of mycorrhization.
Contact:
Prof. Dr. T. Scholten
Institute for Geography
University of Tübingen
Rümelinstr. 19-23
D-72070 Tübingen
Tel.: +49 (0)7071 2972400
Fax: +49 (0)7071 295391
Ralf Gründling
Institute for Geography
University of Tübingen
Rümelinstr. 19-23
D-72070 Tübingen
Tel.: +49 (0)7071 2977504
Fax: +49 (0)7071 295391
Scientific goals of the subproject ECOL-ECON
Besides the impact of biodiversity on ecosystems, there exists also a strong interdependency of biodiversity with socio-economic aspects. Thus, on the one hand, a negative impact of economic development on biodiversity has been proven. In particular, the alteration of land use lead to a worldwide loss of biodiversity. On the other hand, biodiversity may be seen as a precondition for sustainable economic develompent.
The goal of the subproject ECON-ECOL is to explore possible interdependency between ecological interactions detected by the other work groups and socio-economic aspects. In previous research stages already general linkages between socio-economic and ecological variables has been identified on a global level. The there found methods and insights are now applied to a regional an local level.
Following question will be the core of third research phase of ECON-ECOL:
- Which influence do socio-economic variables have on biodiversity in a local framework?
- Which kind of interdependency links local land use, changes of biodiversity in grassland and socio-economic developments in agriculture?
- How shall the gained knowledge about the interdependency of biodiversity and economy be integrated in existing landscape protection programs? How are actual institutional (sponsoring) settings to be adapted?
- How can the gained knowledge of ECON-ECOL (or other similar research programs) serve to raise the acceptance of local stakeholders for landscape protection programs?
Contact:
Prof. Dr. Andreas Freytag
Friedrich-Schiller-Universität Jena
Wirtschaftswissenschaftliche Fakultät
Carl-Zeiss-Str. 3
D-07743 Jena
Tel.: +49 (0)3641 943250
Fax: +49 (0)3641 943252
E-mail: A.Sauerbier@wiwi.uni-jena.de
Angela Münch
Friedrich-Schiller-Universität Jena
Wirtschaftswissenschaftliche Fakultät
Carl-Zeiss-Str. 3
D-07743 Jena
Tel.: +49 (0)3641 943255
Fax: +49 (0)3641 943252
E-mail: Angela.Muench@uni-jena.de
Scientific goals of the subproject ECON-VAL
Within the subproject ECON-VAL (ECONOMIC VALUATION) we aim to translate the ecological relations and results of the other subprojects into a willingness-to-pay dimension. We investigate preferences of the local population for biodiversity and ecosystem services in the region of Thüringer Schiefergebirge and Frankenwald. Ecosystem services are realized services of biodiversity or ecosystems in the broadest sense (direct or indirect), which can be described as social benefits (anthropocentric view). Environmental valuation follows the principle of consumer sovereignty. All interests and social values of respondents are considered. Such values are e.g. aesthetical values, existence values (to benefit from the pure existence of a plant/animal or landscape without ever using it) or pure material values. Because benefits from biodiversity and ecosystem services are not directly observable from behavior (there is no market for most of environmental goods), we have to set a situation where behavior could be observed. We use the Choice Experiment Method (Stated Preference Method), which combines (stated) preferences and choice behavior. 1. 2. 3. Which influences do socio-demographic variables have on WTP? 4. Are there other aspects influencing WTP (e.g. general attitudes towards environment)?
The following concrete questions are being answered in the subproject ECON-VAL:
- Which preferences does the local population have towards regional biodiversity and its ecosystem services (e.g. aesthetic values, agricultural production)?
- Which amount is the local population willing to pay for biodiversity and its ecosystem services?
- Which influences do socio-demographic variables have on WTP?
- Are there other aspects influencing WTP (e.g. general attitudes towards environment)?
Contact:
Prof. Dr. Rainer Marggraf
Georg-August-Universität Göttingen
Platz der Göttinger Sieben 5
D-37073 Göttingen
Tel.: +49 (0)551 39-4829
Fax: +49 (0)551 39-4812
E-mail: rmarggr@uni-goettingen.de
Dr. Jan Barkmann
Georg-August-Universität Göttingen
Platz der Göttinger Sieben 5
D-37073 Göttingen
Tel: +49 (0)551 39-4814492
Fax: +49 (0)551 39-4812
E-mail: jbarkma@uni-goettingen.de
Sandra Rajmis
Georg-August-Universität Göttingen
Platz der Göttinger Sieben 5
D-37073 Göttingen
Tel: +49 (0)551 39-4856
Fax: +49 (0)551 39-4812
Email: srajmis@uni-goettingen.de