B. Papp szerk.: Studia Botanica Hungarica 30-31. 1999-2000 (Budapest, 2000)

Lőkös, László; Farkas, Edit: Contributions to the knowledge of lichens of the forests along the Fekete-Körös, SE Hungary

Amandinea punctata, Xanthoria parietina, Physcia adscendens, Melanelia glabratula, Parmelia sulcata, Bacidia fraxinea appeared to be the most frequent species (in this order). These nitrofrequent species usually indicate strong anthropogenic influence. The following species, listed in the order of their frequency, (Physconia distorta, Punctelia subnidecta, Physconia enteroxantha, Physcia tenella, Lecidella elaeochroma, Hypogymnia physodes, Phaeophyscia orbicularis, Candelariella xanthostigma, Lepraria incana) are known to be common in heavily polluted places. Although the studied 42 forest stands do not cover the whole forest area, but might be sufficiently representative for the following conclusions. Most of the epiphytic lichens (51 species) occurred on Quercus (robur and cerris) bark, 44 species on Fraxinus and 22 species on Robinia pseudacacia. Considering, that Robinia is a non-native tree species, since it was introduced to Hungary only 250-300 years ago, the high number of lichens on Robinia bark was a surprise for us. These lichens grew also on other trees, while 16 (out of the 49 species) grew exclusively on Quercus, and 9 (out of the 44) on Fraxinus. Amandinea punctata occurred on the highest number (5) of tree species. Seven lichen species occurred on 4,18 species on 3,11 lichens on 2, and 25 lichens on only one tree species. No lichens were observed in the very young plantations (0-5 years) except that some species growing on old tree individuals (left standing after the trees were harvested), or on wooden fences, etc. The first colonisers were observed on twigs in a 7-year old Robinia plantation. The number of the lichen species is suddenly increasing in the ca 30-year old stands, even it reaches a maximum value (43 species), which perhaps may be attributed to the favourable environment of the semi-mature, still open, light-abundant habitat conditions of these stands. Thirty lichen species occurred in the ca 60-year old, and 28 in the 90-year old stands, while only 4-5 species were found on the more than 150-year old oak trees. All growth forms seem to show decreasing tendency with the age of the forest stands. * * * Acknowledgements - This work was supported by the Körös-Maros National Park, and the Hungarian Scientific Research Fund (OTKA T030209). REFERENCES BORBÁS, V. (1881): Békés vármegye flórája. - Értekezések a természettudományok köréből, MTA, Budapest, XI(I8): 1-8.