Social Broadleaves. EUFORGEN genetic conservation network

Abstract

 The «Social Broadleaves» EUFORGEN network include temperate oaks and beeches, as broadleaved species living in large population in pure or mixed forest. Most important economic Social Broadleaves have a wide distribution (Q. petraea, Q. robur and F. sylvatica). They occupy also a large ecological range, giving many opportunities for natural selection to differentiate populations. Species delineation is imprecise in oaks, and various names and classification are proposed in different countries. The main objective of the network is the development of «joint, long-term, practically oriented gene conservation strategies». Most urgent needs were expressed by each member mainly in the area of in situ conservation methods. Other objectives are to «stimulate collaborative initiatives related to conservation activities». These initiatives concern dissemination of information and research results, and the raising of awareness on conservation issues. A review of the current knowledge on genetic structure and dynamics is summarised in order to define the Genetic Resource Conservation Strategy for Social Broadleaves. There is an important morphological variation that encompasses taxonomic units. There is clearly a need to provide some common methodology for assigning oak trees to taxonomic units. Oak species belonging to the same botanical section intercross naturally. Natural hybridization can be seen as a mechanism to enrich genetic diversity. Oaks and beeches are preferentially outbreeding, with extensive gene flow by pollen. There is a common agreement that practical actions should be taken, even if knowledge on population structure is still lacking. Conservation strategies should be established not only to maintain diversity but also to safeguard the evolutionary potential of the species. In situ conservation measures are implemented in most countries for both Fagus and Quercus (mostly Q. petraea and Q. robur) based mostly on pragmatic rules. Ex situ measures are promoted in a few countries in the case of oaks. No additional measures are requested by the different members in the case of beech, since natural regeneration is widely used to renew the stands.