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

Papp, Beáta; Rajczy, Miklós: Contributions to the knowledge of bryophytes of the forests along the Fekete-Körös, SE Hungary

tion, because continuous riverine oak-ash-elm forests of considerable extension can only be found here in the Great Hungarian Plain. Compared to montane areas, riparian forests are usually relatively poor in cryptogamic plant species. The lack of particular substrates (i.e. basic or acidic rocks, acidic soil, etc.) definitely excludes the occurrence of species known for specific requirements toward such habitat conditions. However, the microclimatic conditions of some afforested areas along the Fekete-Körös, especially the Mályvád forest are suitable for a certain range of cryptogams, which usually live in montane forests. These places, as réfugia, provide some chances for their survival. A short history of the former bryological investigations There are very few bryological records from the studied habitats along the Fekete-Körös. Ádám Boros visited the area only four times (1922, 1936, 1938 and 1957). The following species are listed in his field notes (BOROS 1922, 1936, 1938) from the forests around Gyula and Doboz: Frullania dilatata, Radula complanata, Amblystegium varium, Anomodon viticulosus, Brachythecium rutabulum, B. velutinum, Leskea polycarpa, Leucodon sciurioides, Orthotrichum affine, O. obtusifolium, Pylaisia polyantha. In addition, the presence of Marchanda polymorpha was recorded in one occasion from a well, and Riccia crystallina was mentioned from a dead arm of the Körös river. Two species were added to this list by the comprehensive papers of BOROS and TÍMÁR (1962, 1963), Hypnum cupressiforme from the Gyulavár forest, and Porella platyphylla from the forest between Békéscsaba and Doboz. MATERIAL AND METHODS The studied forest areas are located along the Fekete-Körös in the surroundings of the town of Gyula, SE Hungary. Namely, Sitka and Mályvád forest - northeast of Gyula town; Sebesfok forest - northwest of Doboz village; Sarkad-Remete forest - southwest of Sarkad village; and Gerla-Maró forest - southwest of Doboz village (Fig. 1). Most of our records came from the vast, continuous Mályvád forest (containing some older stands of native trees as well), and a smaller amount from the other forests listed. The forest stands of different forest management, of different age and tree species composition were visited several times in 1998. Hierarchical cluster analysis (Jaccard's similarity, UPGMA fusion technique) and PCA was carried out to compare the corticolous bryophyte vegetation