Changes in species diversity and state of populations of herbaceous perennials in the plant community Ulmarietum centaureosum during vegetation demutations in Chornohora (Carpathians)

Abstract

The data are presented on the structure, quantity and stock of phytomass of the autotrophic block in the biogeocenosis of Ulmarietum centaureosum. A conclusion is made that main characteristics of the community as a whole are determined by 8–10 populations composing its phytocenotic core. They are characterized by regular seed and vegetative renewal, full-member and temporarily nonfull-member age spectrum and are qualified as populations of the normal type. The existence of the invasive and regressive populations in the structure of the community is explained by an accidental drift of seeds from other cenoses and by periodic character of this phenomenon. Back to top in 1974, there were eight full-members (Centaurea marmarosiensis, Filipendula ulmaria, Hypericum prinatum, Myosotis sylvatica, Primula poloninensis, Soldanella hungarica, Stellaria nemorum, Symphytum cordatum) and ten temporarily nonfull-member (Canthrisla, Canthrisis, neglectros , Geranium alpestre, Dentaria glandulosa, Leucanthemum waldsteinii, Senecio nemorensis, Thalictrum aquilegifolium, Allium victorialis) populations of normal type. The rest of the populations were represented by invasive, invasive-regressive and regressive populations: Aconituin variegation, Carex sylvatica, Chaerophyllum aromaticum, Heracleum carpaticum, Doronicum carpaticum, Lilium martagon, Ranunculus carpaticus, Anemonoides nemorosa, Dactylis glomerata, Deschampsia cespitosa. In 2019–2020, the author repeated these studies in full after forty-six years. They showed that the demutational processes that are now taking place in subalpine meadows violated the isolation of the Ulmarietum centaureosum community and opened the way for the invasion of secondary species of herbaceous perennials. And this negatively affected the state of aboriginal populations. Due to the invasion of Vaccinium myrtillus, Pulmonaria rubra, Petasites kablikianus and Caltha palustris, the total number of species in the community has increased to 30. At the same time, populations of such aboriginal species as Chaerophyllum aromaticum і Carex sylvatica have disappeared from its composition. The author states that the consequences of demutational transformations pose a threat to the preservation of the unique species diversity of Ulmarietum centaureosum. And if the isolation of this plant community persists and in the future its species composition will not change. But violation of this condition will cause negative changes in the population structure in the components of the Ulmarietum centaureosum community. In this case, the ontogenetic structure of their population becomes regressive. This does not give them the opportunity to maintain an optimal balance of generational renewal. The author concludes that the species diversity of Ulmarietum centaureosum is highly susceptible to isolation disturbances. Studies have confirmed the hypothesis that, when invasive processes are activated, it destroys life prospects for native plant species. The author proposes to use the results of these studies when carrying out work on the conservation of biodiversity in the natural ecosystems of the Carpathians.