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38 EUFORGEN: Quercus sube~NETWORKDelimitation of Regions of ProvenanceClimate, soil and other environmental parameters play an essential role in thepopulation dynamics of a species (Stem and Roche 1974; Anonymous 1991).Based on these considerations, it was decided to cover the entire territory of thecountry for delimiting Regions of Provenance (Fig. 1). The species' distributionpatterns in Portugal do not show any significant continuous zone where the specieswould be completely absent. A detailed splitting of the Regions of Provenancebased on each individual, small occurrence of the species would not be a pragmaticapproach to efficiently manage and control the transfer of forest reproductivematerial. It would also cause an even higher administrative load.The decision was facilitated by a broad view of the future use of Regions ofProvenance, beyond the economically important trade with seeds. Protection of theenvironment, conservation of genetic resources and specifically preservation ofsmall marginal populations with low commercial value are cases that are associatedwith this methodology.Regions of Provenance is a concept currently used in forestry practice toencompass several aspects of the management of genetic resources. The aim is tosample populations from geographical zones with correspondingly similar majorrelevant ecological parameters. Various authors have discussed the definition ofRegions of Provenance (e.g. Burley and Wood 1976; Zobel and Talbert 1984) and itconstitutes the basic terms of reference in the OEeD Scheme (OECD 1974).Region IRegion IIRegion IIIRegion IVRegion VRegion VIRegion VIINoroeste PortuguesCentro e OesteTras-os-Montes e Beira InteriorVale do Tejo e SadoAlentejo e Beira BaixaSudoesteBarrocal AlgarvioFig. 1. Regions of Provenance for cork oak in Portugal. III = stands of acorn collectionfor the international provenance/progeny trial under the Concerted Action EUIFAIR1 eT 95-0202.