This thesis examines the invasion success of black locust (Robinia pseudoacacia L.) in a mature forest stand on Rožnik. We also tried to determine the prevalent type of regeneration (seeds, root sprouts, stump sprouts) and the optimal ecological conditions that enable or encourage the growth and spread of black locust. For that purpose, we located adult black locust trees growing on the edge of the study area and placed transects toward the forest stand interior. All together, we made three such transects and placed five plots measuring 5x5 m on each of them. The results showed that black locust does spread successfully into the inner parts of the forest. It was abundant in all height classes. We found that black locust spread primarily by means of its underground shoots, while seed regeneration was rare. As such, the density of young black locust plants depends on the density of larger black locust trees. The results suggest that light conditions also play a role in the spread of black locust, but the importance of light was less than expected. A potential obstacle for invasion of black locust is the understory herbaceous layer which % especially in well lit areas % may prevent further spread. A more pronounced spread of black locust may be prevented with existing adapted management measures, including small-scale silviculture and adult-tree management. It can also be prevented by tending native tree growth, enabling a higher stability and resistance to natural disturbances. The sensibility of intensive and direct removal is, however, questionable. The role of black locust is yet to be determined but we must face the fact that is has become a part of our environment.
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