Recession of Tussilago farfara (L.) population from the agrocoenose as a result of cultivation abandonment. II. The effect of fallowing on shoot morphological properties and their biomass

The paper is concerned with changes in morphological properties of Tussilag farfara (L.) shoots in the abandoned agrocoenose. An increase in the shading and a decrease in the available space, both caused by overgrowing of two grass species Agropyron repens (L.) PB. and Dactylis glomerata (L.), resulted in considerable changes of all analysed properties. In the first three years after cultivation had been abandoned both shoot height and leaf blade size increased, but later a decrease in both was found due to a growing intensity of interspecific competition. Mean values of other properties decreased with the fallow age. Under the conditions of strong competition the variation of Tussilago shoots increased while their above and belowground biomass diminished.