The advantage of the clonal plants over the nonclonal species in colonization of all biomes and biogeographical regions primarily is due to occurrence of two modes of reproduction. The creating of vegetative propagules with high vitality and survivability, enables the spread in the newly colonized site, while seed production increases the chances for successful recruitment of seedlings, ensuring the genetic diversity of the population. The differences in allocation into vegetative reproduction and generative propagation in relation to rising height of adjacent plants was investigated in populations of Serratula tinctoria L., occurring in Molinietum caeruleae meadows localized in Southern Poland. Each locality was represented by randomly established three permanent study plots: dominated by small meadow species (LOW), prevailed by large-tussock grasses (INTER) and overgrown by shrubs and trees (HIGH). In the years 2009–2011 the number of leaf rosettes and length of the longest leaf in rosette (as a measure of allocation in vegetative propagation), as well as height of generative stems, number of capitula per stem and number of seeds per capitulum (as indicators of investment in generative reproduction) were observed.
The allocation in vegetative reproduction decreased along the gradient of vegetation height. The gradually decline of number of rosettes might be caused by lack of free space suitable for establishment of new ramets, whereas the small leaf size could be due to drastically augmentation of shading. The allocation in generative reproduction increased along the gradient of vegetation height. The placement of structures necessary for generative propagation in higher layers of herbaceous canopy, as well as considerable number of capitula and seed production might increase the chances for successful recruitment of seedlings.
On the basis of obtained results combining with published data it should be assumed, that the substantial allocation in vegetative reproduction and the slight investment in generative propagation seems to be sufficient for persistence of Serratula tinctoria populations in patches dominated by small meadow species, while the considerable allocation in generative reproduction could be crucial for maintenance of population viability under competitive conditions.