Acta Scientiarum Polonorum
Silvarum Colendarum Ratio et Industria Lignaria

Abstract Despite the changes caused by anthropopressure, the ’Olszak I, II’ ecological land is one of the sites with high floral values. Its diversified and rich flora consists of 570 vascular plant taxons. The land is one of the last mainstays of rare and endangered plant species. There are 182 species on the Red Lists, 176 are on the list prepared for the city of Poznań. 14 of “the special care species” are legally protected, and 10 belong to the rare and endangered species of the Wielkopolska region. On the examined area, 4 species con-sidered extinct were discovered, and the existence of 10 dying out species was confirmed. The examined land is outstanding for the high percentage of monumental measure trees, as there are over 100 such trees. 76 most valuable nature monuments are legally protected.