We conducted a phytosociological analysis of mixed deciduous forests on flysch and mixed flysch-limestone bedrock in the Central Soča Valley, the Karst, the Brkini Hills and in Slovenian Istria with dominating Quercus cerris in the upper tree layer. Based on the comparison with similar Quercus cerris communities in Slovenia, Italy, Hungary and Bosnia and Herzegovina we described a new association, Seslerio autumnalis-Quercetum cerridis, which we classified into the alliance Carpinion orientalis. We subdivided it into three subassociations: -asparagetosum acutifolii (Quercus cerris stands in Slovenian Istria where this tree species rejuvenates successfully and keeps through many generations), -hieracietosum sabaudi (a form on slightly acid flysch soil, also in Istria) and -campanuletosum rapunculoidis (a secondary Quercus cerris community on potential beech sites). Even though the described Quercus cerris stands are considered secondary (pioneer), they overgrow very large areas and we therefore propose they be classified as a new habitat and forest site type, littoral Quercus cerris woods on flysch.
Dak̇skobler et al. (Thu,) studied this question.