A total of 1113 oak trees from 222 populations originating from eight countries (Austria, Bosnia-Herzegovina, Croatia, Hungary, Romania, Slovakia, Slovenia, Yugoslavia) were sampled in natural populations or in provenance tests. The sampled trees belong to four different species (Quercus robur, Quercus petraea, Quercus pubescens, Quercus frainetto) and to several putative subspecies. Variation at four chloroplast DNA (cpDNA) fragments was studied using restriction enzymes, resulting in the detection of 12 haplotypes. One haplotype was present in 36% of the trees, and six were found in 6-17% of the trees. The haplotypes are shared extensively between species and subspecies. They belong to three different lineages (A, C and E) and are phylogeographically structured in the region investigated. Haplotypes of lineage E dominate to the east of the Carpathian mountains in Romania, whereas the Carpathian Basin seems to have been colonised along several different colonisation routes, from the Balkan peninsula but also from Italy. The data support the possible role of climatic instability during the late glacial period in shaping this complex geographic structure. The presence of several secondary refugia could be inferred in the region, which have played a major role in the second step of recolonisation, at the onset of the Holocene period. #

A questionnaire survey was carried out to examine the problems caused by invasive alien species (IAS) in Hungarian protected areas (PAs). Results from 144 PAs were evaluated and compared with a previous study of 21 European countries. In the European survey, the most important threats were habitat loss and fragmentation, Hungarian respondents put IAS in first place. Eradication, control and prevention were mentioned among the best strategies against invasive species in both surveys, but Hungarian PA managers emphasized the efficiency of habitat restoration and regulatory as well. Comparing the harmful animals and plants occurring in most Hungarian and European PAs, we found nearly 30% similarity. In most Hungarian PAs domestic cat (Felis catus Linnaeus, 1758) and black locust (Robinia pseudoacacia L.) were indicated as most harmful species. The results of our study draw the attention to the species, which are highly invasive in Hungary, but are missing from the European PAs list, therefore may pose a potential threat to other protected areas of Europe.

A legsúlyosabb veszélyeztető tényezők Magyarország és Európa védett, illetve Natura 2000 területein (kumulatív értékek).