Scientific/Technical Objectives and Innovation

The objective of FRAXIGEN is to gain a fuller understanding of the biological and ecological processes which have shaped Fraxinus (F. excelsior, F. angustifolia, F. ornus) populations in Europe. This will enable the project to develop guidelines on selection of ecologically and genetically appropriate planting material for the conservation of genetic diversity and sustainable management of many woodland types. The research will combine comprehensive molecular studies with detailed research in reproductive biology and innovative ecological field trials.

Conventional germplasm selection has been for timber production, with an emphasis on growth rates, form and quality criteria. However, with the shift towards planting and managing woodlands throughout Europe for environmental rather than productive objectives there is a need to replace these with new criteria. Ecological restoration requires an emphasis on traits such as reproductive vigour, seed and seedling survival, adaptive capacity for extreme environments and ability to compete with other species. We therefore need to define the scale over which seed sources show adaptation to local conditions, to allow the development of collection guidelines for appropriate planting material.

By using a range of molecular markers we will study and describe the genetic diversity of the three Fraxinus species in Europe, the geographical relationships within species, and the current patterns of mating and pollen flow. Greenhouse trials will identify the impact of inbreeding (loss of genetic diversity) on growth (inbreeding depression), while field trials will reveal the extent of adaptive differences among populations and their relationship to the observed genetic diversity.

This fusion of a wide range of techniques, combined with a novel approach to the study of environmental adaptation using a network of reciprocal field trials, encapsulates the innovative dimension of FRAXIGEN. Fieldwork is often overlooked in molecular studies of plant populations, and this failing is an important issue for understanding evolutionary dynamics within tree populations and their management. The implementation of detailed laboratory and field studies across a geographical range over successive years, with standardised methodology and sampling, will allow analyses at a much broader scale than is usually attempted. Broad-scale perspectives that link ecological processes and genetic patterns are needed: the replication of carefully standardised studies across Europe will allow unprecedented insights into current and potential genetic status of three Fraxinus species.