Zs. K. Komáromy szerk.: Studia Botanica Hungarica 17. 1984 (Budapest, 1984)

Szerdahelyi, Tibor: Rare ferns of Hungary III. The establishment of fern species in a planted pine forest

100% Fig. 2. R, T, F, and N values in percentage of the group pro rata RESULTS AND DISCUSSION I found that the floral elements of the species list is distributed as follows: 46 per cent Eurasian, 15 per cent Circumpolar, 11 per cent Cosmopolitan, 19 per cent European, 5 per cent are species of Asia Minor and the rest (4 per cent) are species of N-American, Mediterranean and Amphiatl antic. Figure 2 we can see that the R value is high, meaning that several species have no special requirements of soil. The main part of the species are indifferent to the type of soil. The T value is lower than R but it is nevertheless rather high. I have not detected any special temperature requirement among the species. The F value is very low, meaning that most of the spe cies have definite water regime. The N value is very low, similarly to the F value. In Figure 3 we can see the dendrogram of clustering a matrix of CZEKANOWSKI' s similarity index. Twelve groups are obtained at 0.425 similarity value. In some instances it is readily seen that sample plots in the vicinity of one another form groups. One sample plot (40) was completely separated. The reason for this is the location of this sample plot, namely the plots near to cutting are drier, receive more light and the moistore content is lower than in the forest. The other groups were formed probably because of the similar water requirements of the species. About the future of the forest The condition of the forest deteriorates from day to day. Increasing number of trees break because of wind and snow-slide. During the spring of 1981 the part of the forest richest in ferns was almost completely burnt, when it was set to fire twice within 3 days. After the litter fire the main part of the grass layer died. A lot of ferns were burnt and the stand thinned out. But the