SUCCESSION OF GROUND COVER VEGETATION IN HYLOCOMIOSA FOREST SITE TYPE AFTER THE CLEARCUT

Nowadays forestry sector uses forest site type descriptions developed from beginning of 20th century till 1980's and descriptions are obtained for pre-mature and mature stand age. There is less information about ground cover vegetation for full rotation cycle. In this research has been gathered information about ground cover vegetation succession in first 5 years after clear cut in mature Scots pine stand. The chronosequence method was used. The Brown-Blanquet and the point-square methods for accounting of ground cover plants were used. The ecological values of Ellenberg for describing the environmental status and the coefficient of Tschekanovsky for estimation of the difference between plant communities in forest young growths of different age were used. The biological diversity of species in this research compared to mature stand also is increasing. Ellenberg's ecological indicator values as light and nitrogen are also increasing: nitrogen value has increased the most - by 2.62 units. There are registered changes in vascular plants, mosses, lichens and trees projective covering's proportion. The most significant changes in individual species occurrence are between the second and third year's (Tschekanovsky coefficient = 0.19). Five years after clear cut the Tschekanovsky coefficient between the mature stand and five years old clearing is 0.18. In the 4th and 5th year after the clear cut there increase the projective cover of Monocotyledonae plants (families Graminaea and Cyperaceae) forming higher vertical structure and overtaking the dominance from another groups. The results obtained in this research promote further research in different stand age.