We are interested in population genetics and ecological genetics of forest organisms. The focus of our research is on molecular genetic approaches to study patterns of genetic variation in forest organisms. Main fields of research are:
• Adaptation mechanisms and tree improvement at the molecular level
• links between genetic diversity, biodiversity at higher levels, and ecosystem processes and services,
• genetic variation of tropical forest trees.
Research results form a basis for tree improvement, the development of strategies for the presenvation of diverse and productive forest ecosystems in times of rapid environmental change (alteration of land use systems; climate change), the assessment of human impact on forest ecosystems, and nature protection including conservation of forest genetic resources.
Adaptation mechanisms and tree improvement at the molecular level
The adaptation mechanisms of plants to different environmental conditions and to global change and the role of variation at particular genes for adaptive traits and traits of economic importance are only poorly understood. This applies in particular to forest trees, which are characterized by an extraordinary long life-time, long generation cycles, late start of flowering, growth in heterogeneous environments, and high levels of genetic variation within populations.
We currently investigate sequence variation in candidate genes for drought resistance and phenological traits of oak (Quercus spp.) and pine (Pinus spp.). In a complementary approach, QTLs (Quantitative Trait Loci) are mapped in different oak families. QTLs for bud burst in oaks were identified based on existing and newly developed genetic maps mainly using AFLP polymorphisms.
Links between genetic diversity, biodiversity at higher levels, and ecosystem processes and services
Most forest tree species are characterized by high levels of genetic variation. However, the significance of genetic variation of trees and other keystone species for the overall biodiversity of forest ecosystems, for ecosystem processes and for the sustainable provision of ecosystem services is largely unknown. Likewise, our knowledge on the impacts of ecosystem management and changes of land use on patterns of intraspecific diversity is very poor.
We explore the spatial dynamics of genetic structures along gradients of species diversity and management intensity for selected forest tree species. We are also interested in the temporal dynamics of genetic structures within tree populations affected by anthropogenic disturbances such as fragmentation and by silvicultural management. We aim to improve our understanding on the role of genetic diversity for ecosystem processes and for the provision of ecosystem services. Genetic implications of the manifold human impacts on forest ecosystems are a focus of our studies.
Genetic variation of tropical forest trees
Tropical forests are centres of species diversity, and there is growing evidence that most tropical forest tree species show high levels of intraspecific diversity. We study the distribution of ‘neutral’ genetic diversity within selected tropical forest taxa at different scales. We aim to clarify the evolutionary relationships among selected taxa (molecular phylogenies), to assess variation patterns within selected species at different spatial scales, and to study gene flow and the mating system of tropical forest trees.
The development of molecular tools for the identification of the origin of wood from tropical tree species is of great interest for practical applications in the context of species protection and controlling the international timber trade. We developed methods to reliably extract DNA from tropical timber and to distinguish species and growing regions of the important Southeast-Asian tree family Dipterocarpaceae based on molecular genetic markers. These tools can be used to infer possible origin regions of timber and timber products, and to test the proclaimed origin of wood material using non-manipuable ‘genetic fingerprints’.