Veronika Kalníková

Early vegetation succession on gravel bars of Czech Carpathian streams

Rivers with a natural flooding regime and gravel accumulations are an important natural habitat endangered by regulations and other types of human impact. Succession after disturbances by floods creates a mosaic of different vegetation types, some of them containing rare specialist species. We studied vegetation succession and changes in plant diversity on river gravel bars of four streams in the Western Carpathians and their foothills in the eastern Czech Republic. This area experienced extreme 50-year flood event in May 2010. Gravel bar vegetation was destroyed, some of the former bars were covered by sediments, and some new bars arose. We sampled gravel bar vegetation two months after the floods and repeated the sampling on each site during the next three years. Initial vegetation has developed through a sparse and species-rich stage into denser stands with more shade-tolerant species. In the fourth year, tall herbs, such as Urtica dioica, Phalaris arundinacea and the alien Impatiens glandulifera, dominated the communities, but shrub vegetation started to develop only in a few places. Species capable of vegetative dispersal prevailed over species dispersed by seeds only. Altitude and size of gravel/stone particles were identified as important factors affecting vegetation succession. The succession ran faster on gravelly substrates at lower altitudes than on stony substrates at higher altitudes. Although the studied streams are partly influenced by human interventions and host only few gravel bar specialists, they are of considerable conservation importance.

Relict occurrences of boreal brown-moss quaking rich fens in the Carpathians and adjacent territories

Quaking rich fens dominated by boreal semi-aquatic brown-mosses such as Scorpidium scorpioides and Calliergon trifarium are extremely rare in the Carpathians. These fens harbour endangered species persisting at few localities in the region. However, their phytosociological classification has not been sufficiently solved yet, because they lack Sphagnum species as well as calcicole species characteristic for the Caricion davallianae alliance. A recent pan-European synthesis on fen vegetation suggests that these fens belong to the Stygio-Caricion limosae alliance (boreal rich fen vegetation). The isolated occurrence of this alliance southward of the boreal zone and outside the Alps is rather exceptional and might represent a relict from an early post-glacial period. In this study, we compared phytosociological data for the Stygio-Caricion limosae alliance between Northern Europe and the Carpathians plus adjacent regions (the Bohemian Massif, the Dinaric Alps) using NMDS and cluster analysis. We found that the species composition of brown-moss quaking rich fens in Central and Southeastern Europe corresponds well with that in Northern Europe, confirming their assignment to Stygio-Caricion limosae. We further reconstructed the potential past distribution of the alliance in Czech Republic and Slovakia using available floristic and macrofossil data. Macrofossil data suggest that this vegetation type had been much more common in Central Europe and that today it persists only in ancient fens, showing the long-term stability of environmental conditions. The main causes of its present-day rarity are Middle-Holocene woodland phases in fens and recent water table decreases caused by anthropogenic deterioration of the water regime in the landscape.

Bryophytes on river gravel bars in the Balkan mountains: new records and insights into ecology

Abstract: Kalníková, V., Palpurina, S., Peterka, T., Kubešová, S., Plesková, Z. & Sabovljević, M. 2017. Bryophytes on river gravel bars in the Balkan mountains: new records and insights into ecology. — Herzogia 30: 370 –386. Gravel bars are a heterogeneous habitat on the border between the aquatic and terrestrial environments that can maintain a high diversity of bryophyte species. However, the bryoflora of river gravel bar habitats has rarely been explored, particularly in Southeastern Europe. We therefore carried out a two-year field survey on river gravel bars in selected mountains and foothills in the Balkan Peninsula, recording all bryophytes in 4×4 or 3×5 m plots. In total, we sampled 59 vegetation plots on 30 streams and rivers and recorded 85 bryophyte taxa. Here we report Bryum klinggraeffii (a new species for the floras of Albania, Montenegro and Serbia) and five data-deficient or vulnerable species. We found several drought-tolerant bryophytes on gravel bars, e.g. Barbula convoluta, Ceratodon purpureus and Tortella tortuosa, as well as typical hygrophilous species, e.g. Cinclidotus aquaticus, Fontinalis antipyretica and Platyhypnidium riparioides. The most common species in this transitional habitat were Brachythecium rivulare, Bryum argenteum, Oxyrrhynchium hians, Barbula unguiculata, Ceratodon purpureus and Bryum caespiticium. Dentrended correspondence analysis ordination technique identified the complex gradient of moisture and light conditions as the main environmental factor for bryophyte communities on the studied gravel bars.

Meesia triquetra, a New Relict Moss for the Republic of Macedonia

Abstract: n Peterka, T., Plesková, T., Palpurina, S., Kalníková, V., Lazarević, P. M. & Hájek, M. 2016. Meesia triquetra, a new relict moss for the Republic of Macedonia. — Herzogia 29: 66–71. Meesia triquetra is a circumpolar boreo-arctic moss species typical for well preserved fens, and is rare in southern Europe. During field research on mire vegetation in the Balkan Peninsula, a population of Meesia triquetra was found at the Begovo pole wetland in the Jakupica Mountains. It is the first record of this species for the Republic of Macedonia. A description of the locality, ecological conditions and vegetation is presented. The moss grows here in the sedge-moss vegetation similar to temperate fens of the alliance Caricion davallianae. The vegetation with Meesia triquetra in Begovo pole was evaluated in the context of fen vegetation more generally in the Balkans using detrended correspondence analysis. The study site appeared to be similar to other Balkan calcium-rich brown-moss fens without calcium carbonate precipitation. This habitat resembles the optimum habitat of the species in central and northern Europe.

Pseudocalliergon lycopodioides, a New Bryophyte Species for Montenegro

Abstract: Peterka, T., Kalníková, V. & Plesková, Z. 2017. Pseudocalliergon lycopodioides, a new bryophyte species for Montenegro. – Herzogia 30: 496–500. Pseudocalliergon lycopodioides is an European boreo-temperate species confined to extremely rich fens and other calcareous wetlands. The species belongs to endangered wetland biota; many localities across Europe have recently disappeared. Pseudocalliergon lycopodioides is rare on the Balkan Peninsula. Here we report the species as new for Montenegro. The moss was found on the plateau Jezerska Površ at the eastern edge of the Durmitor Mts. Pseudocalliergon lycopodioides grows here in moss-sedge vegetation of the Caricion davallianae alliance.