Plant succession on allochthonous substrates placed in the soil of an oak-hornbeam forest

The aim of the experiment was to investigate the way and rate of colonisation by vegetation on allochthonous substrates introduced into the forest soil. In the subsequent years of the experiment, the durability of this substrate in the conditions of the forest environment and the possibility of its transformation, absorption and finally neutralization of its potential impact on vegetation were determined. The experiment was carried out in Tilio-Carpinetum forest on permanent research plots. On individual study plots (1 m2 each), the soil was removed to a depth of 20 cm and replaced by one of six types of alien soil: dune sand, moraine gravel, clayey soil, silt, loess clay and sand from the alluvium of a large river. In the following years (1971-1977) overgrowing of these substrates by forest floor vegetation was observed and changes in chemical properties of the substrates were studied. Changes in the degree of substrate cover by vegetation were recorded using photographic methods and direct measurements; within each research plot a list of vascular plants was made and the traits of particular plant individuals were measured.

Fifty years after the initial survey, it was decided to investigate whether any characteristics of the forest herb layer (species composition and abundance) allow detection of the earlier soil replacement. We also plan to take soil samples in order to repeat basic physicochemical tests and to examine the degree of formation of oak-hornbeam forest soil seed banks in alien substrates.