Copyright © Czech Botanical Society

Abstracts of volume 76, 2004

Hájek M. & Hekera P. (2004): Can seasonal variation in fen water chemistry influence the reliability of vegetation- environment analyses? – Preslia 76: 1–14.
Temporal variation in fen water chemistry was studied in the Western Carpathian flysch zone (Czech Republic and Slovakia). Ten sites representing particular spring-fen types (tufa-forming fens, rich fens, spring-fen meadows, rich Sphagnum-fens, poor Sphagnum-fens) were studied.Water chemistry was determined three times a year (spring, summer, autumn) for 3 years. Water pH and conductivity were themost stable of the measured variables. Na+, K+, Ca2+ and SO42– were also relatively stable. In contrast, N-NO3, Cl, Fe, PO43– and redox-potential temporally varied. These fluctuating, unstable variables explained very little or insignificant amounts of the variation in plant species data in our study area, possibly because of their instability. Further, seasonal variation in physical-chemical properties of the water confounded associations with vegetation types when data from different seasons was used. The significance of the differences among vegetation types (between- subject effect in RM ANOVA) distinctly changed among seasons for temperature and Si, N-NO3 and Cl concentrations and to a slight degree, for Fe, Mg and water redox-potential. The differences in Ca, Na and SO42– concentrations, pH and conductivity were highly significant in all three seasons. The first axis of the PCA of the chemical variables reflects the gradient from mineral-poor to mineral-rich fens in all the analyses, i.e. spring, summer and autumn. The separation of the sites along this axis is clearest in the ordination of the autumnal data. Major vegetation types were separated in PCA even when data from all three seasons were pooled. There is no major-nutrient that is characteristic of meadow- species rich and more productive fen habitats, even when repeated water samples are analyzed.

Mandák B., Pyšek P. & Bímová K. (2004): History of the invasion and distribution of Reynoutria taxa in the Czech Republic: a hybrid spreading faster than its parents. – Preslia 76: 15–64.
The distribution of four alien Reynoutria taxa (R. japonica var. japonica, R. japonica var. compacta, R. sachalinensis and R. ×bohemica), native to East Asia, and history of their introduction to and spread in the Czech Republic was studied. The most widely distributed representative of the genus, R. japonica var. japonica, was first recorded in 1883 by A. Weidmann in cultivation in S Bohemia. The first record outside cultivation is from N Bohemia in 1902. Up to 2000, it has been recorded in 1335 localities, most frequently in riparian and human-made habitats. The dwarf variety R. japonica var. compacta is of a limited distribution that depends on rare cultivation and subsequent escape. The first herbarium specimen was collected in 1948 and the first record out of cultivation is from 1995. R. sachalinensis was recorded in 261 localities. It was first collected in 1921 in Central Bohemia. A herbarium specimen of a plant cultivated in the Botanical Garden of the Charles University in Prague, collected in 1950, has been re-determined as R. ×bohemica, the hybrid between R. japonica var. japonica and R. sachalinensis, and represents the earliest record of the hybrid in the Czech Republic. Since then, this taxon was observed in 381 localities. Herbarium records were used to compare the rate of spread among the three common taxa in 1952–1995, i.e. since when the hybrid started to appear in herbaria. R. japonica var. japonica has been spreading significantly faster than R. sachalinensis and the hybrid exhibits twice the rate of invasion of its parents.

Lososová Z. (2004): Weed vegetation in southern Moravia (Czech Republic): a formalized phytosociological classification. – Preslia 76: 65–85.
A phytosociological synthesis of weed vegetation of southern Moravia (Czech Republic) was performed using the Braun-Blanquet approach. Gradsect sampling, i.e. a priori stratified selection of sampling sites, was used for the field survey. Using this method, 115 quadrants of the Central European mapping grid (6 × 5.6 km) were chosen. Three hundred and ten relevés recorded in 1997–2002 were classified, based on the Cocktail method, which defines sociological species groups and then creates formal definitions of vegetation units. In total, nine associations of the class Stellarietea mediae were distinguished in southern Moravia. Three associations were included in the alliance Caucalidion lappulae (Lathyro-Adonidetum, Euphorbio- Melandrietum, Veronicetum hederifoliotriphylli) and three in the alliance Scleranthion annui (Aphano-Matricarietum, Spergulo- Scleranthetum, Erophilo-Arabidopsietum). For each of the alliances Veronico-Euphorbion, Spergulo-Oxalidion and Panico- Setarion one association was distinguished, respectively, Setario- Fumarietum, Panico-Chenopodietum polyspermi and Echinochloo- Setarietum pumilae. Species composition of these associations is documented in a synoptic table. Their structure, ecology, and distribution are commented.

Hroudová Z., Zákravský P. & Čechurová O. (2004): Germination of seed of Alisma gramineum and its distribution in the Czech Republic. – Preslia 76: 97–118.
The distribution of Alisma gramineum in the Czech Republic was determined using herbarium specimens, data in the literature and the authors’ own records. Comparison of records from four periods (before 1900, 1901–1945, 1946–1970, 1971–2001) revealed that the total number of localities has not decreased, but the occurrence changed considerably both in terms of the localities and regions where the species is found. Abundant populations were observed on exposed shores of water reservoirs. It has colonized the Třeboň Basin, S Bohemia, over the last few decades. Effect of water regime, light/darkness regime and temperature on germination and dormancy was studied. A. gramineum is adapted to germinate in water and in the dark; germination occurs in late spring, i.e. a period of high temperature. The high variation in the germination response to particular environmental factors may be accounted for the irregular occurrence of A. gramineum at certain localities. Best conditions for seed production are shallow water and recently exposed shores of water reservoirs, where plants can grow and set seed within one growing season. The ability to survive in a vegetative stage is more important in deep water, but seed banks in the mud at the bottom of reservoirs is the only way the species can persist when adult plants die.

Chrtek J. jun., Mráz P. & Severa M. (2004): Chromosome numbers in selected species of Hieracium s. str. (Hieracium subgen. Hieracium) in the Western Carpathians. – Preslia 76: 119–139.
Chromosome numbers of 23 species (including subspecies) of Hieracium s. str. from the Western Carpathians are presented. First chromosome numbers are reported for Hieracium kuekenthalianum (= H. tephrosoma, 2n = 36), H. praecurrens (2n = 27) and H. virgicaule (2n = 27); first counts from the Western Carpathians are given for H. atratum (2n = 27), H. bifidum (2n = 27, 36), H. carpathicum (2n = 36), H. inuloides (2n = 27), H. jurassicum (2n = 27), H. macilentum (= H. epimedium, 2n = 27), H. nigritum (2n = 36), H. pilosum (= H. morisianum, 2n = 27) and H. silesiacum (2n = 36). New ploidy level (tetraploid, 2n = 36) is reported for H. bupleuroides, hitherto published counts refer only to triploids (2n = 27). Previously published chromosome numbers were confirmed for several other species, i.e. H. alpinum (s.str., 2n = 27), H. bupleuroides (2n = 27), H. crassipedipilum (H. fritzei group, 2n = 27, 36), H. lachenalii (2n = 27), H. murorum (2n = 27), H. prenanthoides (2n = 27), H. racemosum (2n = 27), H. sabaudum (2n = 27), H. slovacum (H. fritzei group, 2n = 36), and H. umbellatum (2n = 18). Triploids and tetraploids predominate, diploids (2n = 18) were found in H. umbellatum. A comprehensive list of previously published chromosome numbers in Hieracium s. str. from the Western Carpathians is provided.

Kaplan Z. & Wolff P. (2004): A morphological, anatomical and isozyme study of Potamogeton ×schreberi: confirmation of its recent occurrence in Germany and first documented record in France. – Preslia 76: 141–161.
A combined study of morphology, stem anatomy and isozyme patterns was used to reveal the identity of sterile plants from two rivers on the Germany/France border. A detailed morphological examination proved that the putative hybrid is clearly intermediate between Potamogeton natans and P. nodosus. The stem anatomy had characteristics of both species. The most compelling evidence came from the isozyme analysis. The additive “hybrid” banding patterns of the six enzyme systems studied indicate inheritance from P. natans and P. nodosus. In contrast, other morphologically similar hybrids were excluded: P. ×gessnacensis (= P. natans × P. polygonifolius) by all the enzyme systems, P. ×fluitans (= P. lucens × P. natans) by AAT, EST and 6PGDH, and P. ×sparganiifolius (= P. gramineus × P. natans) by AAT and EST. All samples of P. ×schreberi are of a single multi-enzyme phenotype, suggesting that they resulted from a single hybridization event and that the present- day distribution of P. ×schreberi along the Saarland/Moselle border was achieved by means of vegetative propagation and long-distance dispersal. Neither of its parental species occur with P. ×schreberi or are present upstream, which suggests that this hybrid has persisted vegetatively for a long time in the absence of its parents. The total distribution of this hybrid is reviewed and a detailed account of the records from Germany is given. P. ×schreberi appears to be a rare hybrid. The risk of incorrect determination resulting from the identification of insufficiently developed or inadequately preserved plant material is discussed.

Kučera P. & Marvan P. (2004): Taxonomy and distribution of Lemanea and Paralemanea (Lemaneaceae, Rhodophyta) in the Czech Republic. – Preslia 76: 163–174.
Traditionally, all freshwater representatives of red algae with uniaxial cartilagineous and pseudoparenchymatous thalli were placed in the genus Lemanea. Two subgenera of this genus were distinguished, Lemanea and Paralemanea. The recently proposed elevation of these subgenera to genera is fully justified and generally accepted. However, the increasing data from natural populations of Lemanea shows that not all the traditional diacritical features are reliable for distinguishing species. This paper presents the results of a research project on the morphological variability of Lemanea in the Czech Republic. Of the four species Lemanea fluviatilis and L. torulosa appear to be well-defined but there are no clear differences between Paralemanea annulata and P. catenata. A survey of taxa and key to species are presented.

Řezáčová M., Neustupa J. & Šejnohová L. (2004): Five species of Mallomonas (Synurophyceae) new to the algal flora of the Czech Republic. – Preslia 76: 175–181.
Five new records of the scale-bearing chrysophytes Mallomonas multiunca, M. paxillata, M. portae-ferreae, M. prora and M. retifera are reported for the Czech Republic. M. multiunca was found in a mesotrophic oxbowlake of the river Vltava. M. paxillata, M. portae-ferreae and M. prora were found in a mesotrophic to eutrophic floodplain pool of the river Lužnice. M. retifera was recorded from alluvial pools associated with the Vltava and Lužnice rivers, respectively. Autecology and distribution of the species are discussed. Three of the species occur in temperate and subarctic regions, M. paxillata probably has a cosmopolitan distribution and M. portae-ferreae prefers warmer water, occurring most frequently in tropical to subtropical regions.

Czeika H., Czeika G., Guttová A., Farkas E., Lőkös L. & Halda J. (2004): Phytogeographic and taxonomical remarks on eleven species of cyanophilic lichens from Central Europe. – Preslia 76: 183–192.
Comments on 11 species of cyanophilic lichens are presented. A new combination Peccania cernohorskyi is proposed, commented on and typified. Anema nodulosum, A. prodigulum, Lempholemma intricatum, Leptogium ferax, Porocyphus rehmicus and Zahlbrucknerella calcarea are reported from Slovakia for the first time, Leptogium biatorinum and L. magnussonii from Hungary, and Anema prodigulum, Heppia adglutinata, Leptogium biatorinum and Psorotichia taurica from the Czech Republic. Leptogium cretaceum is lectotypified.

Rejmánek M., Rejmánková E. & Holzner W. (2004): Species diversity of plant communities on calcareous screes: the role of intermediate disturbance. – Preslia 76: 207–222.
The intermediate disturbance hypothesis predicts that species diversity in biotic communities should peak at intermediate levels of disturbance. The vegetation of eight calcareous screes in the Northern Calcareous Alps, Austria was studied to test this hypothesis. Data on total vegetation cover and on cover of individual species were obtained from 0.25 m2, 0.5 m2, and 1.0 m2 plots. An index [100 – vegetation cover (%)] was used as a surrogate for direct quantification of disturbance (movement of stones and destruction of biomass). Its suitability was substantiated by the observation of position changes of marked stones after two years. In agreement with the intermediate disturbance hypothesis, significant unimodal responses of both species richness and species diversity to disturbance were found using plots of all three sizes. However, the maxima of species richness- and species diversity-disturbance curves were shifted towards higher vegetation cover (= lower disturbance) with increasing mean diameters of the scree-building stones. This shift can be interpreted either as a synergistic effect of disturbance frequency combined with disturbance intensity/extent, or as a result of an increase in spatial heterogeneity promoting species coexistence in successionally more advanced patches of vegetation.

Krahulec F., Krahulcová A., Fehrer J., Bräutigam S., Plačková I. & Chrtek J. jun. (2004): The Sudetic group of Hieracium subgen. Pilosella from the Krkonoše Mts: a synthetic view. – Preslia 76: 223–243.
The present paper summarizes the results of research of Hieracium subgen. Pilosella done by using different methods. The apomictic complex of Hieracium subgen. Pilosella found in the Krkonoše Mts, consists of the following basic species: H. lactucella (2x, sexual), H. onegense (2x, sexual), H. pilosella (4x, sexual), H. caespitosum (4x, apomictic) and H. aurantiacum (4x and 5x, apomictic). These species are considered to be the parents of a further set of mostly apomictic hybridogenous types. The ploidy level, breeding system, isozyme phenotypes, chloroplast haplotypes and geographic distribution of this whole complex was analysed. The different hybridogenous types have different frequencies in the field and differ in the frequency of isozyme phenotypes (a conservative estimate of the number of genotypes). Most have uniform chloroplast haplotypes, but some haplotypes could have originated from reciprocal crosses. The comparison of chloroplast haplotypes suggests that apomictic species were not only pollen donors, but also contributed seed and gave rise to several hybridogenous types, illustrating the importance of the residual sexuality of apomicts in this group. H. pilosella is a central species in this group and is connected with other parental species, H. floribundum, H. lactucella and H. aurantiacum by a set of hybridogenous species that have a similar genetic structure. Some of the distinct hybridogenous types within the complex are of multiple origin. In contrast, crosses between the same parental types may generate diverse progenies, which can often be classified as distinct taxa. All taxa recorded in the past are surveyed and discussed with respect to present knowledge. We suggest that the taxonomy and origin of particular entities of this and other such complexes is best resolved using information from morphological, genetical, cytological and ecological studies.

Wilson J. B., Agnew A. D. Q. & Sykes M. T. (2004): Ecology or mythology? Are Whittaker’s “gradient analysis” curves reliable evidence of continuity in vegetation? – Preslia 76: 245–253.
Whittaker was one of the leading ecologists of his generation, introducing several ideas to plant community ecology. One approach involved deriving environmental-correlation curves in attempts to determine how the abundance of individual species changed along environmental gradients. These curves have been used extensively in the ecological literature of the last 50 years. However, there has been no examination of whether the methods used were sufficiently rigorous to justify Whittaker’s conclusions, let alone the very widespread use of them by others to draw general conclusions. Whittaker’s curves were based on large amounts of fieldwork. However, the sampling methods used were subjective, and the analyses of the data were often circular. When the curves are compared to the data on which they were based, it can be seen that many of the features that Whittaker claimed to see in his graphs are not supported. Whittaker’s main conclusions may have been correct but his studies do not stand up as pieces of scientific work.

Schofield W. B. (2004): Endemic genera of bryophytes of North America (north of Mexico). – Preslia 76: 255–277.
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.

Liška J. & Soldán Z. (2004): Alien vascular plants recorded from the Barentsburg and Pyramiden settlements, Svalbard. – Preslia 76: 279–290.
A list of alien plant species recorded from Svalbard in the summer of 1988 is presented. Two localities, the Russian settlements of Barentsburg and Pyramiden on the Isfjorden, Spitsbergen, were studied. Prior to this study, almost 60 alien species were recorded from Svalbard by other investigators. During the research reported here, 44 taxa were found, 14 of which are new records for the Svalbard archipelago. Six species are considered to be possibly naturalized; however, it is difficult to assess their naturalization status because of the severity of the climate in the study area. A complete list of species is presented, with information on height and phenological stage of particular specimens. Most of the alien plants recorded at the two settlements belong to the family Brassicaceae.

Knollová I. & Chytrý M. (2004): Oak-hornbeam forests of the Czech Republic: geographical and ecological approaches to vegetation classification. – Preslia 76: 291–311.
Vegetation classification should reflect the major environmental and phytogeographical gradients that influence species composition. However, the importance of different gradients depends on the geographical scale of particular studies. Locally defined vegetation units usually reflect local gradients, such as disturbance and soil properties, while regionally defined units reflect macroclimatic patterns and different evolutionary and migration histories of large regions. The classification of Central European oak-hornbeam forests (Carpinion alliance) is an example of a widely accepted, broad- scale classification with geographically delimited associations. However, in some cases it fails to describe adequately local vegetation patterns. In the Czech Republic, six associations, based on a broad-scale regional classification, were traditionally distinguished: (1) Melampyro nemorosi-Carpinetum – Hercynian association; (2) Primulo veris-Carpinetum – Pannonian association; (3) Carici pilosae-Carpinetum – Carpathian association; (4) Tilio-Carpinetum – Polonian association; (5) Stellario-Tilietum – local association of southern Bohemia; (6) Tilio-Betuletum – ecologically delimited and local association. The goal of this study was to evaluate, using a cluster analysis of a set of 601 geographically stratified relevés, whether the variation in species composition of oakhornbeam forests in the Czech Republic reflects the traditional geographically based classification. Hercynian, Pannonian and Carpathian types of oak-hornbeam forests were reproduced by cluster analysis. No support was found for the Polonian type and the two local associations, Stellario- Tilietum and Tilio-Betuletum. Instead, a distinct group confined to wet soils emerged. On the basis of this analysis, we suggest a classification that combines ecological and geographical principles and distinguishes four associations: (1) Hercynian (Melampyro nemorosi-Carpinetum or Galio sylvatici-Carpinetum); (2) Pannonian (Primulo veris-Carpinetum); (3) Carpathian (Tilio cordatae- Carpinetum or Carici pilosae- Carpinetum); (4) Stellario holosteae-Carpinetum, which is a geographically delimited association of atlantic northwestern central Europe, defined ecologically by its occurrence on wet soils within the Czech Republic.

Rotreklová O. (2004): Hieracium bauhini group in Central Europe: chromosome numbers and breeding systems. – Preslia 76: 313–330.
Chromosome numbers for 239 plants from 84 localities in the Czech Republic, Slovakia, Hungary, Germany and Poland are given. Most of the populations were pentaploid (2n = 45), while hexaploid (2n = 54) and tetraploid (2n = 36) populations were rarer. A long marker chromosomewas observed in plants from 8 pentaploid populations.Tetraploid plants occurred mainly in Slovakia and Hungary. In the Czech Republic and Germany, most populations were pentaploid. Hexaploid populations (2n = 54) were rare but scattered over the entire study area. The co-occurrence of two different cytotypes was documented at 7 sites. Most tetraploids were fully sexual and only a few tetraploid plants from Poland were apomictic; pentaploid and hexaploid plants were apomictic. Two morphotypes of H. bauhini were distinguished: tetraploid and hexaploid plants from Slovakia and Hungary, and some hexaploid plants from the Czech Republic were assigned to the H. magyaricum group, while tetraploids and hexaploids from the Czech Republic and Poland plus all pentaploids belong to the H. bauhini group.

Rybníček K. & Rybníčková E. (2004): Pollen analyses of sediments from the summit of the Praděd range in the Hrubý Jeseník Mts (Eastern Sudetes). – Preslia 76: 331–347.
Pollen diagrams, based on sediments from four small mires on the eastern summits of the Jeseníky Mts (the Praděd-Altvater group) in the Sudetes, the Czech Republic, show the development of vegetation in the area since the Subboreal period (ca 4700 B.P.). Stands of Corylus avellana with Picea abies and some Tilia cf. platyphyllos covered the eastern summits of the Jeseníky Mts between ca 5000 and 3000 B.P. Corylus avellana probably played the same role as Pinus mugo, common at similar altitudes in other Sudetes ranges. Between ca 3000 and 500–400 B.P. Picea abies, Fagus sylvatica and Abies alba dominated the natural precultural forests at the present alpine forest limit. An admixture of Acer (cf. pseudoplatanus) and Ulmus (cf. glabra) is very probable. Human impact (mountain summer grazing, hay making, selective beech cutting) influenced the summit vegetation and lowered the natural forest line from the beginning of the 17th century. The planting of spruce started at the beginning of the 19th century and is well expressed in the pollen diagrams. No traces of Pinus mugo, documented by Pinus sylvestris type of pollen or macroscopic material, were found.

Procházka F. (2004): A centre of occurrence of Viscum album subsp. album in eastern Bohemia and an overview of the diversity of its host plants in the Czech Republic. – Preslia 76: 349–359.
A literature survey revealed that the semi-parasitic evergreen shrub Viscum album subsp. album (Viscaceae) has been recorded on 53 taxa of deciduous trees and shrubs (including five hybrids) in the Czech Republic. Of the host taxa, 26 are native and 27 alien to the Czech flora. The range of hosts covers 13 families. Salicaceae (11 taxa), Rosaceae (11) and Aceraceae (7) are most represented among families. Of the 22 genera harbouring mistletoe, Populus (7 taxa), Acer (7), Tilia (5) and Fraxinus (4) are most represented. A locality at the castle park in the town of Heřmanův Městec, E Bohemia, is reported in detail. In 1978–1981 and 2001, Viscum album subsp. album was observed on 15 host taxa of trees and shrubs, which represents the second highest diversity of host trees in a single locality in the Czech Republic; the richest one, previously reported by Unar et al. (1985) is the Lednice castle park, S Moravia, with 24 taxa. Four more host taxa were recorded in the studied town of Heřmanův Městec outside the park, giving the total of 19 hosts concentrated within a limited area. The occurrence of mistletoe on Prunus padus is reported for the first time from the Czech Republic.

Jongepierová I., Jongepier J. W. & Klimeš L. (2004): Restoring grassland on arable land: an example of a fast spontaneous succession without weed-dominated stages. – Preslia 76: 361–369.
Vegetation succession was studied for 12 years on an abandoned nutrient- poor small field surrounded by a strip of natural grassland. No fertilizers or herbicides were applied. Few weeds or annuals were present during this period. Only two plants, i.e. Agrostis capillaris and Festuca rubra, dominated during the 12 years. At two spatial scales (0.04 and 0.4 m2) a dramatic increase in species richness was recorded during the first two years. However, no further trend in species richness occurred after the sixth year of succession. Successional changes were directed and continuous. The rate of succession depended on the distance from the neighbouring meadow. Vegetation at the margins of the transect developed more slowly and diverged from the middle during the succession.

Kirschner J., Rejdali M. & Drábková L. (2004): A new Juncus of the section Tenageia from Morocco and Egypt. – Preslia 76: 371–376.
A new annual species, Juncus maroccanus, of the section Tenageia, closely allied to Juncus foliosus Desf., is described from N Morocco. It differs from the latter in having smooth, glossy seeds, capsule shorter than perianth and shortly mucronate. The new species is known from a macrolocality in the Ksar-el-Kebir region, where it grows in non-saline sandy seepage sites. Another, much older specimen was collected in 1835 by W. Schimper in the Sinai Peninsula, Egypt. Syntype specimens of Juncus rhiphaenus Pau et Font Quer were examined and found to be conspecific with Juncus foliosus.


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