Population traits of the rare plant species Succisa pratensis Moench. in meadow overgrowing

Abstract

This paper examines the population traits of the rare plant species Succisa pratensis Moench. in the course of meadow overgrowing. The investigations were conducted in the years 2010-13, in Molinia caeruleae meadows situated in Krak?w-Kostrze (southern Poland). The study sites represented the early (Patch I), medium (Patch II and III) and late (Patch IV) stages of succession. The abundance of subpopulations diminished from Patch I, via Patches II and IV, to Patch III. The increase in abundance in consecutive years was noticed in Patch I; an inverse tendency was found in Patches II and III, whereas lack of variability was recorded in Patch IV. The signs of senescence found in consecutive years in all subpopulations were mostly pronounced in Patches III and IV. The number of rosettes per ramet cluster did not show either temporal or spatial variability. The number of leaves per rosette diminished, while the dimensions of rosette leaves gradually increased in time and space due to diminishing light availability. The number and height of flowering stems, number of cauline leaves, as well as number of flower heads per flowering stem increased from Patch I to Patch III due to lateral shading, and then it diminished in Patch IV due to shading from above. The performed studies indicate that the subpopulation occurring in Patch I has the greatest chance for maintenance in the colonized sites, while the subpopulation occurring in Patch III is the most endangered by extinction.