Problem to be solved
When and how did forest trees have come to occupy their present range in Europe, after the last ice age, when re-immigrating from their refuge? And what have been the consequences of these huge population movements on their levels of genetic diversity and their potential to cope to new climatic challenges? Since several decades, paleobotanists have attempted to understand the origin and migrations of our forest trees, using mostly fossil pollen remains. However, it is not always possible to distinguish the pollen of related tree species, and most of the migration routes inferred from these records remain hypothetical. Recently, the development of DNA techniques has shed new light on the re-immigration of trees. So far, these studies have been based on the sampling of existing tree populations only. But more direct historical evidence could be provided by molecular investigations of ancient tree remains excavated by the paleobotanists, provided that appropriate laboratory methods could be developed. Scientific objectives and approaches FOSSILVA aims at improving our understanding of the origin of the major European tree species. It associates geneticists and palaeoecologists in order to confront both approaches and to develop a new one, the palaeogenetic exploration of tree remains. Different types of plant remains (such as wood, macrofossils, pollen) are being tested for their ability to yield DNA suitable for genetic investigations. Fossil samples are studied in parallel with DNA isolated from living trees, to identify the relationships between modern tree populations and their putative ancestors, and check for possible human disturbances. The study area of the project is restricted to south western and western Europe, and focuses on six tree species. These include two broad-leaved species (beech and oaks) and four conifers (two species of pines, fir and spruce). These trees were selected for several reasons: their present day genetic diversity has already been explored, hypotheses on their history exist but need to be validated, and they are of major economical and ecological importance.
Workpackage 1. - Molecular Atlas for taxonomic identification of European woody plants found in fossil sediment (B and soon A). The identification of plant species is a prerequisite for studies of intraspecific biodiversity. In palaeobotanical studies, these identifications are often difficult, and often restricted to the genus or family level, although well-conserved macrofossils can sometimes allow precise species identification. . We considered at the outset of the project that the availability of a Molecular Atlas based on DNA techniques could prove extremely useful. This task, under the responsibility of "Sylvabio" (partner 12) was almost achieved at the end of year 2 and has been accomplished. But this private company did not succeed to maintain a sufficient level of activity and finally recently collapsed. The INRA Group will insure the diffusion of the data obtained within the FOSSIVA project. This molecular atlas which explore 315 woody species growing in Europe is one of the announced deliverable. It will be published soon and available on the FOSSILVA Webb site (Contact person: firstname.lastname@example.org).
Workpackage 2. (A) - Potential for aDNA studies with forest tree remains: from field collection to PCR. Here the deliverables consist to share the difficult experiences of the FOSSILVA group on the extraction of DNA from plant remains. Our experience was too short to produce any guidebook, but two papers (including a paper on the "blind test" experiment) are in preparation which will deal with the best suitable fossil material, and with the specific strategies to improve DNA extraction from fossil plants.
Workpackage 3. - a plant macrofossil database. Even if the compilation still needs to be improved, the existing set of data allows efficient comparisons with the pollen data, which will lead to a substantial reassessment of the previous hypotheses on the location of glacial refuges an the postglacial migration speeds. This database is hosted in Köln.
Work-package 4. - the European Pollen database. An administrative meeting of The EPD advisory board/executive committee has been held in conjunction with the last Fossilva meeting, September 2003, Bordeaux. This database predate the Fossilva project, but more than hundred new sites were included in the database and are open to the public domain according to the EPD rules: see the EPD Webbsite: http://medias.obs-mip.fr/paleo/epd/.
Workpackage 5. - Comparison of past and present genetic structure in 6 forest trees. Beside the series of papers linked with FOSSILVA and produced during the 4 years contract which are listed in the final report, six manuscripts summarizing for each of the selected taxa they postglacial setting and they present day status in Europe. They are based on the comparisons between phylogenetic maps and migration maps inferred from pollen and plant macrofossil data extracted from the databases mentioned above.
Funding SchemeCSC - Cost-sharing contracts
960 53 Zvolen
80 441 Gdansk