Surface coal mining heavily disrupts vast areas of landscape. Previous studies conducted in these areas reveal that succession processes on unreclaimed sites support close to nature community. It's crucial to understand and be able to predict these processes in order to include spontaneous succession into restoration plans. The aim of my thesis is to clarify establishment and dispersion mechanisms of dominant pioneer woody species willow (Salix caprea), birch (Betula pendula) and aspen (Populus tremula). Study carried out on unreclaimed sites on a large colliery spoil heap near the town of Sokolov. I have studied establishment and growth of pioneer woody species on both graded and ungraded sites, representation of individual woody pioneer species was on sites in different distance from the edge of the spoil heap, birch's population age structure and reproduction potential of willow in accordance to age. All pioneer woody species establish and grow better on ungraded sites. The amount of willow decreases while the number of aspen individuals remains the same and the amount of birch increases with growing distance from the edge of the spoil heap. Birch's population age reveals establishment of new individuals in favourable climatic conditions. Willow is reproductively capable at the age of 10 years...

Darbo objektas – naujai sukryžminti hibridinės drebulės (Populus tremuloides x Populus tremula) ir karpotojo beržo ( Betula pendula) hibridai. Darbo tikslas – Atlikti tolimąją hibridizaciją ir išauginti augalus-regenerantus nesubrendusių gemalų kultūroje bei įvertinti genetinę įvairovę. Darbo rezultatai. Sukryžminus gauta skirtingi hibridai. Jų įvairovė įvertinta APPD metodu. Išmatavus augimo tempus nustatyta, kad hibridai 16.2 ir 16.4 auga greičiau nei hibridinės drebulės klonai. Ištyrus adaptacijos nesterilioje aplinkoje sąlygas, nustatyta šaknijimosi tempai. Tyrimo metu pastebėta, kad ūgliukų sodinimas į durpių substratą Jiffi tabletėse su šaknimis ir be jų ilgesniam nei 3 mėnesių laikotarpiui, neturi augimo skirtumų. / Aim of the work: new crossbred hybrid aspen (Populus tremuloides x Populus tremula) and birch (Betula pendula) hybrids Objekt of the work: make long hybridization and grow up new regeneration plants in unformed embrio culture and rate genetical variation Results: After crossing get new hybrids. His variation rated by RAPD metod. After measure growing speed, set that hybrids 16.2 and 16.4 growing faster than hybriding aspen clons. In adaptation study set root growing speed. In study notice that plants with root and without in Jiffi tablet peat substratum after 3 month get same height .