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Forschungs- und Technologiepolitik fuer eine nachhaltige Entwicklung

Zunaechst sollen die aktuelle Debatte ueber gesellschaftliche Innovations- und wirtschaftliche Wettbewerbsfaehigkeit sowie die Gestaltungsmoeglichkeiten der Forschungs- und Technologiepolitik analysiert werden. Darueber hinaus soll diese Thematik um die Diskussion ueber das Leitbild des Sustainable Development erweitert werden, und es soll aufgezeigt werden, welche Anforderungen an die Forschungs- und Technologiepolitik daraus abgeleitet werden koennen. Die Untersuchung wird in einem ersten Schritt auf die Moeglichkeiten der Forschungs- und Technologiepolitik, Beitraege zu einer nachhaltigen Wirtschafts- und Lebensweise zu leisten, begrenzt. Im Vordergrund steht die Operationalisierung des Leitbildes 'Nachhaltigkeit' fuer die FuT-Politik, d.h. das TA-Projekt konzentriert sich darauf, Inhalte zu definieren (1), Umsetzungsmoeglichkeiten und geeignete Foerderinstrumente und Foerderkonzepte zu entwickeln (2) und geeignete gesellschaftliche und politische Institutionen oder Organisationsformen herauszuarbeiten (3). Es wird zunaechst eine Uebersichtsstudie erstellt, die zum einen Einblick in bisher entwickelte Vorstellungen zu einer Orientierung der Forschungspolitik auf 'Nachhaltigkeit' hin geben soll und zum anderen die Ziele, Inhalte und Strategien der FuT-Politik und die Rolle des Leitbildes 'Nachhaltigkeit' im internationalen Vergleich auswertet.

Height, diameter, biomass, leaf area, and relative height volume growth of European beech, Norway spruce, and Douglas fir grown in monospecific and mixed pots under different light availability levels

Light is an exceptionally important but often limited resource. Light availability determines seedling survival, establishment, and growth. Regardless of species identity, trees growing under high light availability produce more biomass and are generally larger than trees receiving less light. How stressed trees become under the conditions of limited light availability depends on species-specific factors like shade tolerance and plasticity as well as the competitive situation. Additionally, the taller individuals have the advantage to obtain more light since competition for the resource is asymmetric. In competitive environments, the niche complementarity of the coexisting species can reduce the competitive pressure and facilitate higher biomass production (i.e., positive mixing effect). We established a controlled pot experiment to study the effect of light availability and competition type on growth and its allocation, biomass production and allocation, and leaf morphology of European beech (Fagus sylvatica L.), Norway spruce (Picea abies L. Karst), and Douglas fir (Pseudotsuga menziesii Mirb. Franco) seedlings. The study site was located at the Experimental Botanical Garden of the University of Göttingen (51.55684392372871, 9.953489533796636). We planted four seedlings per pot, each pot being either monospecific or mixed (two seedlings per species) and exposed to one of three different light availability levels (10%, 20%, and 50%). We planted in a total of 576 pots – 6 species combinations (monocultures + mixtures) x 3 light treatment levels x 32 replicates. For planting, we used 1-year-old European beech and 2-year-old Norway spruce and Douglas fir seedlings that were not undercut or transplanted. The experiment lasted from April 2018 – November 2019. All seedlings received the same water treatment through an automatic dripping irrigation system. Nutrients were provided using a controlled release fertilizer (Osmocote Exact Hi.End with 12-14 month longevity (ICL SF)).

Mechanisms underlying plant community productivity, stability and assembly (D-A-CH/LAE)

Previous work demonstrated diversity effects on plant community productivity, stability and assembly. However, underlying mechanisms are still largely unknown. Therefore, we address such mechanisms based on the long time series of plant performance data provided by the Jena Experiment, on new experimental manipulations and on complementary data about aboveground plant-plant and plant-pathogen interactions. In work package 1, we test whether complementarity increases over time in the main and dominance experiments of the Jena Experiment. Furthermore, we compare community dynamics without and with invasion to test how community stability is related to fluctuations in plant species abundances. In a new trait-based experiment we test whether deliberately large trait differences maximize complementarity. In work package 2, we derive and compare matrices of pair-wise plant interaction coefficients from glasshouse experiments and the main and dominance experiments. We use these interaction matrices to predict diversity effects in mixtures. In work package 3, we use the invasion treatment to test whether community assembly under invasion leads to convergence of diversity and productivity of all communities, but different species composition of initially different communities.

Predicting effects of invasion processes of Eurasian floodplain willows in Patagonia; SNP-Diagnose züchtungsrelevanter Eigenschaften von Salicaceanen

Effects of resource transport and supply rates on competition and coexistence

Explaning the coexistence of many plant species in a given area is a central topic in plant ecology. The ultimate goal of the proposed project is a better understanding of this coexistence. Specifically, we would investigate a factor that very probable influences the coexistence of plant species and has not been tested experimentally so far: the resource transport and supply rates. It has been shown with computer simulations that this factor influences coexistence, but it has - to our knowledge - not been tested experimentally so far. Basically, it is expected that low resource transport rates combined with high resource input rates have a positive effect on coexistence between different plant species. This is because under those circumstances a given individual of one species can not lower the resource level around an individual of an other species below the level where that can survive. In our proposed study we will highlight these effects by experiments ranging from strongly reductionistic to more complex conditions. We will mainly focus on nutrients as a resource. Our overall hypothesis is: High transport coefficients of nutrients and low resource input fluxes can lead to competitive exclusion of plant species and thus to reduced local diversity. Besides its scientific significance, this topic has gained more and more interest from an applied perspective in recent years as biodiversity might be threatened by invasive species, elevated CO2, warming, nitrogen deposition, changing precipitation patterns, and other global change factors. A better understanding of mechanisms enabling plants to coexist is a prerequisite to predicting the influence of anticipated changes and for setting priorities for appropriate counteractions.

Einfluß erhöhter CO2-Konzentration auf die genetische Variabilität von Pflanzenpopulationen in Kalkmagerrasen

In den nächsten 50 bis 100 Jahren wird sich die Kohlendioxidkonzentration in der Atmosphäre verdoppeln. Da zahlreiche Pflanzen eine intraspezifische Variabilität in der Reaktion auf CO2 zeigen, sind genetische Veränderungen in Pflanzenpopulationen in Folge des CO2-Anstiegs zu erwarten. Diese sind jedoch aufgrund der Interaktion mit anderen abiotischen und biotischen Faktoren derzeit nicht überschaubar. Um mikroevolutionäre Konsequenzen des CO2-Anstiegs abzuschätzen, wollen wir ein Experiment nutzen, bei dem Parzellen eines Kalkmagerrasens über 6 Jahre mit einer erhöhten CO2-Konzentration behandelt wurden. In Zusammenarbeit mit dem Botanischen Institut der Universität Basel wollen wir erstmals in einer realen Artengemeinschaft mittels molekularer und quantitativ-genetischer Methoden folgende Hypothesen testen: (1) Bei einem erhöhtem CO2-Angebot werden solche Eigenschaften selektiert, welche die Konkurrenzkraft beeinflussen. (2) Da nur konkurrenzkräftige Genotypen überleben, nimmt die genetische Diversität in den Pflanzenpopulationen ab.

The Response of CO2-Related Processes in Grassland Ecosystems in a Three-Year Field CO2-Enrichment Study

The rising atmospheric CO2 concentration generally increases the growth of C3 plants. The amount and the pattern of the plants response depend on the species or even on the genotypes, and on the growing conditions. Thus, the competitive ability of the plants in plant communities may change and as result alter their floristic composition. In this project the responses of serveral grassland species to increased CO2 are studied in the field. Three FACE (Free Air Carbon dioxide Enrichment) rings are used to increase CO2 on circular areas of 14 m diameter to 600 ppm. Three control areas of equal size at ambient CO2 concentration are included. One experiment is studing the CO2 related responses of the growth processes in the shoot and the root part of Lolium perenne L and Trifolium repens L growing in monocultures and in mixture. In addition to the two CO2 treatments high and low Nitrogen fertilizer treatments and cutting treatments with four and six cuts per year are included, respectively. In another experiment the genotypic variation of the growth response to increased CO2 is studied. The CO2 effects on the growth of a mixture of seven grassland species and the relative importance of CO2 related changes on root and shoot competition are studied in further experiments.

Biodiversity and Ecosystem Responses to Elevated CO2 in Calcareous Grassland

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)?

Erhaltung und Entwicklung von Naturwiesen durch angepasste Bewirtschaftung

Fuer eine effiziente und nachhaltige Wieslandnutzung werden Grundlagen zur differenzierten Bewirtschaftung und Entwicklung von Wiesenbestaenden erarbeitet: - Beeinflussung des Regenerationsvermoegens und der Konkurrenzkraft ausgewaehlter Futtergraeser. - Etablierung von Saemlingspflanzen zur Verbesserung der Zusammensetzung von Wiesenbestaenden. - Angepasste Nutzung, Duengung und Pflege verschiedener Naturwiesentypen im Hinblick auf ihre Erhaltung.

Methoden zur nachhaltigen Verbesserung degenerierter Naturwiesen

In diesem Projekt soll untersucht werden, durch welche Faktoren das Auflaufen und die Entwicklung von Saemlingspflanzen in einem Wiesenbestand beeintraechtigt werden. Aus den Erkenntnissen sollen mischungsspezifische Empfehlungen abgeleitet werden koennen, um den Erfolg von Uebersaaten in der Praxis zu verbessern. Da es wuenschenswert waere, statt der Zuchtsorten die standortangepassten Oekotypen zu foerdern, soll zusaetzlich abgeklaert werden, unter welchen Bedingungen einzelne Arten durch natuerliches Versamen zur Regeneration und Verbesserung von Wiesenbestaenden beitragen koennten.

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