Bioindicative value of potential natural vegetation was used in aim to evaluate conditions of agricultural production. Two maps from the south-east Poland in a scale 1 : 300 000 were compared. These were: the map of potential natural vegetation and the map of land capability units. Statisticaly significant correlation was found between phenomena presented on each of the maps. The unit of each of the maps was characterized in terms of the second map unit. Ecological amplitudes of the units of two typologies were determined. Legend symbols of both of the maps could be arranged in a consequent series. It resulted in the unequivocal division into groups of land use units connected with ecological and altitudional differentiation of the habitats. It enabled to evaluate agricultural production on a basis of data on potential natural vegetation, as well as, to describe potential plant community on the grounds of the map of land capability units. Conditions under which both soil-agricultural and potential-vegetation units could be fully parallelized were determined. Value of the map of potential natural vegetation as the grounds of evaluation of habitat potential independent of the land used is emphasized.