Various stages in the succession of vegetation of peat bogs following disturbance were studied in the Třeboň Basin, Czech Republic. The disturbance was of two types: (a) natural, represented by windthrow, with subsequent bark beetle attack, and fire, and (b) human-made peat digging and industrial peat milling. The species composition at different stages in succession following disturbance were compared with that in undisturbed plots. Regeneration of peat bog vegetation was faster after a natural than after human-made disturbance. The lowest impact was caused by windthrow, followed by fire. Regeneration after peat digging took much longer. Regeneration after industrial peat harvesting only occurred if the groundwater table level remained high.
There are 20 endemic genera of mosses and three of liverworts in North America, north of Mexico. All are monotypic except Thelia, with three species. General ecology, reproduction, distribution and nomenclature are discussed for each genus. Distribution maps are provided. The Mexican as well as Neotropical genera of bryophytes are also noted without detailed discussion.
The composition of cryptogam (bryophyte and lichen) communities on fallen logs was studied in two old-growth forests in the Czech Republic. Altogether, 85 species (22 liverworts, 44 mosses, and 19 lichens) were recorded. The presence and abundance of the different species on 350 logs was attributed to habitat factors (e.g. humidity, wood decay, wood softness, log diameter, bark cover, thickness of humus layer and tree species) that were recorded separately for each of the logs. The aim was to identify the factors significantly affecting the composition of cryptogam communities. For the different ecological groups of species (epiphytes, epixylic species, and ground flora) forwarded canonical correspondence analysis (CCA) selected thickness of humus layer and tree species as the factors explaining most variability. In addition, the extent of log surface covered by bark, humidity and log decay were selected as significant determinants of cryptogam community composition.
On a semiarid sand grassland (Festucetum vaginatae) colonised by juniper (Juniperus communis L.) shrubs terricolous lichens and mosses segregate strongly between microhabitats: certain species grow in the open grassland, others almost exclusively in the shade of junipers. The contrasting irradiances of these microhabitats influence much the metabolism of these organisms, and thus affect their small-scale distribution. This was confirmed by determining the efficiency of photochemical energy conversion by measuring chlorophyll a fluorescence parameters. In the open grassland maximum photochemical efficiency of photosystem 2 (PS2, Fv/Fm) declined from the humid spring to the hot and dry summer in all species, and this was caused by an increase in base fluorescence (F0), but not by the decrease in fluorescence maximum (Fm). In summer, mosses and lichens growing in the open grassland generally possessed lower Fv/Fm than cryptogams growing in the shade cast by juniper shrubs. Thus mosses and lichens in the open grassland suffer lasting reduction in photochemical efficiency in summer, which is avoided in the shade of junipers. Juniper shrubs indeed influence the composition and small-scale spatial pattern of sympatric terricolous lichen and moss communities by-among others-providing a shelter against high light in summer. and T. Kalapos, K. Mázsa.
Species richness and above-ground biomass of vascular plants and bryophytes of poor acidic fens (the Sphagno recurvi-Caricion canescentis alliance), rich Sphagnum fens (the Caricion fuscae and Sphagno warnstorfii-Tomenthypnion alliances) and calcareous spring fens (the Caricion davallianae alliance including tufa-forming spring fens) were studied. The study area was in the western parts of the Outer Carpathians in the border region of the Czech and Slovak Republics. The numbers of species were recorded in plots ranging from 0.00196 to 16m2 and correlated with chemical factors and above-ground biomass. The chemical properties of springwater (mainly pH, conductivity, Ca2+, Mg2+) were the main factors influencing the species richness of vascular plants. Tufa-forming calcareous fen communities (Carici flavae-Cratoneuretum) had the highest species richness of vascular plants. In contrast, the highest species richness of bryophytes occurred at pHneutral sites, in peat forming calcareous fen communities (Valeriano-Caricetum flavae) and in those with Sphagnum warnstorfii and S. teres. Bryophyte species richness of small plots was correlated with the iron concentration in the springwater. The differences in species richness of calcareous fens were related to the mowing regime. Litter mass had a negative effect on the species richness of vascular plants. Mosses responded to high amounts of litter or vascular plant biomass by a significant decrease in biomass. Two types of Sphagnum fens: (a) strongly dominated by Sphagnum flexuosum or S. palustre (rich in phosphates) and (b) polydominant (poor in phosphates), were also compared. In the former, the slope of the regression for the dependence of bryophyte species richness on plot size was less steep.
This study was conducted at 17 peatlands in the Czech Republic mined either by the traditional block-cut method or industrially. Phytosociological reléves of 5 × 5 m were carried out in representative parts of successional stages in disturbed peatlands. Age and environmental characteristics were assessed for each relevé (position of water table, water pH, substratum chemistry, geographical area) or each locality (altitude, average annual temperature and precipitation). Phytosociological reléves recorded in natural vegetation, representing the respective target stages, were included into some analyses. Altogether, 210 relevés were analysed by the DCA ordination. Separately, relevés from milled and block-cut sites were elaborated by CCA with marginal and partial effects calculated. Despite the great variability in vegetation, especially among industrially harvested sites, there is a general tendency for peatland vegetation to recover spontaneously, especially at traditionally harvested sites, which all were, however, older than 50 years. The vegetation at the younger industrially harvested sites exhibited only a tendency to recover. All environmental variables investigated had at least some significant effect on the vegetation pattern, among them, soil pH, water table, nitrates, successional age and geographical location were most important. Abiotic site factors together and geographical location appeared to be more important in determining species composition than successional age.
Mosses are often overlooked; however, they are important for soil-atmosphere interfaces with regard to water exchange. This study investigated the influence of moss structural traits on maximum water storage capacities (WSCmax) and evaporation rates, and species-specific effects on water absorption and evaporation patterns in moss layers, mosssoil- interfaces and soil substrates using biocrust wetness probes. Five moss species typical for Central European temperate forests were selected: field-collected Brachythecium rutabulum, Eurhynchium striatum, Oxyrrhynchium hians and Plagiomnium undulatum; and laboratory-cultivated Amblystegium serpens and Oxyrrhynchium hians. WSCmax ranged from 14.10 g g–1 for Amblystegium serpens (Lab) to 7.31 g g–1 for Plagiomnium undulatum when immersed in water, and 11.04 g g–1 for Oxyrrhynchium hians (Lab) to 7.90 g g–1 for Oxyrrhynchium hians when sprayed, due to different morphologies depending on the growing location. Structural traits such as high leaf frequencies and small leaf areas increased WSCmax. In terms of evaporation, leaf frequency displayed a positive correlation with evaporation, while leaf area index showed a negative correlation. Moisture alterations during watering and desiccation were largely controlled by species/substrate-specific patterns. Generally, moss cover prevented desiccation of soil surfaces and was not a barrier to infiltration. To understand water’s path from moss to soil, this study made a first contribution.