Vít Grulich

Ecological and evolutionary significance of genomic GC content diversity in monocots

Significance Our large-scale survey of genomic nucleotide composition across monocots has enabled the first rigorous testing, to our knowledge, of its biological significance in plants. We show that genomic DNA base composition (GC content) is significantly associated with genome size and holocentric chromosomal structure. GC content may also have deep ecological relevance, because changes in GC content may have played a significant role in the evolution of Earth’s biota, especially the rise of grass-dominated biomes during the mid-Tertiary. The discovery of several groups with very unusual GC contents highlights the need for in-depth analysis to uncover the full extent of genomic diversity. Furthermore, our stratified sampling method of distribution data and quantile regression-like logic of phylogenetic analyses may find wider applications in the analysis of spatially heterogeneous data. Genomic DNA base composition (GC content) is predicted to significantly affect genome functioning and species ecology. Although several hypotheses have been put forward to address the biological impact of GC content variation in microbial and vertebrate organisms, the biological significance of GC content diversity in plants remains unclear because of a lack of sufficiently robust genomic data. Using flow cytometry, we report genomic GC contents for 239 species representing 70 of 78 monocot families and compare them with genomic characters, a suite of life history traits and climatic niche data using phylogeny-based statistics. GC content of monocots varied between 33.6% and 48.9%, with several groups exceeding the GC content known for any other vascular plant group, highlighting their unusual genome architecture and organization. GC content showed a quadratic relationship with genome size, with the decreases in GC content in larger genomes possibly being a consequence of the higher biochemical costs of GC base synthesis. Dramatic decreases in GC content were observed in species with holocentric chromosomes, whereas increased GC content was documented in species able to grow in seasonally cold and/or dry climates, possibly indicating an advantage of GC-rich DNA during cell freezing and desiccation. We also show that genomic adaptations associated with changing GC content might have played a significant role in the evolution of the Earth’s contemporary biota, such as the rise of grass-dominated biomes during the mid-Tertiary. One of the major selective advantages of GC-rich DNA is hypothesized to be facilitating more complex gene regulation.

High Plant Diversity of Grasslands in a Landscape Context: A Comparison of Contrasting Regions in Central Europe

Some regions and habitats harbour high numbers of plant species at a fine scale. A remarkable example is the grasslands of the White Carpathian Mountains (Czech Republic), which holds world records in local species richness; however, the causes are still poorly understood. To explore the landscape context of this phenomenon and its relationships to diversity patterns at larger scales, we compared diversity patterns in grasslands and other vegetation types in the White Carpathians with those in nearby regions lacking extremely species-rich grasslands, using data from vegetation plots and flora grid mapping of entire landscapes. Although small-scale species richness of grasslands and ruderal/weed vegetation of the White Carpathians was higher than in the nearby regions, the number of grassland and ruderal/weed species in the regional flora of the White Carpathians was not. Diversity of forests was not higher in this region at any scale. Thus the remarkably high local species richness of the White Carpathian grasslands does not result from a larger grassland species pool in the region, but from the fine-scale co-occurrence of many grassland species in this landscape, which results in the formation of grassland communities that are locally rich but with similar species composition when comparing different sites (i.e. high alpha but low beta diversity). This pattern can be partly attributed to the large total area of these grasslands, which reduces random extinctions of rare species, low geological diversity, which enables many species to occur at many sites across the landscape, and high land-cover diversity, which supports mixing of species from different vegetation types.

Chorological spectra of arable weed vegetation types in the Czech Republic.

A data set of 2,743 phytosociological releves was used for a comparison of the basic chorological characteristics of the main vegetation types of weed vegetation in the Czech Republic. All releves were classified by the cocktail method into the alliances: Caucalidion, Scleranthion annui, Veronico-Euphorbion, Oxalidion fontanae, Spergulo-Erodion and Arnoseridion minimae. The proportions of native species, archaeophytes and neophytes, as well as the proportion of species with particular distribution range types were calculated for each releve. The weed vegetation in the data set contained 560 species: 38.3 % of them were native, 56.2 % were archaeophytes and 5.5 % were neophytes. The highest proportion of natives was found for the weed vegetation of poor sandy soils (alliance Arnoseridion minimae) and of humid areas (alliance Oxalidion fontanae). The highest proportion of archaeophytes was found in the thermophilous weed vegetation of Caucalidion and Spergulo-Erodion alliances, and the highest proportion of neophytes in Spergulo-Erodion alliance. Czech weed vegetation is predominantly composed of species of Euroasian temperate range type. These species prevail in weed vegetation of alliances Scleranthion annui and Oxalidion fontanae. Macaronesian-Mediterranean range types and Oriental-Turcestani-Mediterranean range types make up 25-38 % of all weed species growing in the Czech Republic. These Mediterranean species dominate in the weed vegetation of alliances Caucalidion and Arnoseridion minimae, followed by alliances Veronico-Euphorbion and Spergulo-Erodion. The proportion of central European species is similar (about 10 % of species) in all the compared vegetation types except Spergulo-Erodion, where these species are rarer (only 5 %). Other chorological types are scarcely present in the weed vegetation of the Czech Republic.

Distribution and Communities of Crypsis Aculeata and Heleochloa Schoenoides in Slovakia

Distribution and Communities of Crypsis Aculeata and Heleochloa Schoenoides in Slovakia The distribution and communities of two annual grasses Crypsis aculeata and Heleochloa schoenoides were studied in Slovakia during 2003-2007. Herbarium and field data were used to reconstruct the occurrence of both taxa. A strong decline in C. aculeata localities was observed. This was mainly due to the destruction of periodically flooded saline habitats. By contrast, the occurrence of H. schenoides was changed only slightly. This species survives in secondary habitats (rural roads, field margins, field depressions). Point maps of historical and recent distribution are presented. Halophile vegetation of Crypsis aculeata and Heleochloa schoenoides has been sampled with the adapted Braun-Blanquet method. All collected relevés have been classified using the JUICE software. The results showed that the Crypsidetum aculeate Wenzl 1934 community is missing now in Slovakia, but Heleochloetum schoenoidis (Soó 1933) Topa 1939 was still recorded at a few sites. However, the community contained many ruderal plant species. Raziskave razširjenosti dveh enoletnih trav Crypsis aculeata in Heleochloa schoenoides smo raziskovali na Slovaškem med letoma 2003 in 2007. Za rekonstrukcijo pojavljanja obeh vrst smo uporabili herbarrijske in terenske podatke. Opazili smo močno upadanje števila nahajališč, kjer se pojavlja C. aculeata. Razlog je predvsem uničenje periodično poplavljenih slanih rastišč. Nasprotno pa se je pojavljanje vrste H. schenoides le malo spremenilo. Vrsta lahko uspeva tudi na sekundarnih rastiščih (kolovozi, robovi njiv, uleknine na njivah). Historično in recentno razširjenost smo prikazali na točkovnih kartah. Halofilno vegetacijo vrst Crypsis aculeata in Heleochloa schoenoides smo vzorčili s prilagojeno Braun-Blanquetovo metodo. Vse popisno gradivo smo klasificirali s programom JUICE. Rezultati so pokazali, da asociacije Crypsidetum aculeate Wenzl 1934 na Slovaškem ne najdemo več, medtem ko je bila asociacija Heleochloetum schoenoidis (Soó 1933) Topa 1939 najdena na nekaj rastiščih, vendar se v njej pojavljajo številne ruderalne rastlinske vrste.

Revision of historical and current distribution of Pholiurus pannonicus (Host.) Trin. in Slovakia.

Revision of Historical and Current Distribution of Pholiurus Pannonicus (Host.) Trin. in Slovakia Historical and current occurrence of the obligate halophyte Pholiurus pannonicus was studied in Slovakia during the period 2003-2009. The species had been occurring in the Podunajská nížina Lowland and the Východoslovenská nížina Lowland; 30 localities were found in total. Recently the number of localities has decreased markedly and the species was confirmed only in the Podunajská nížina Lowland. We documented only seven localities during the study. Therefore, we confirmed that Pholiurus pannonicus belongs to the critically endangered plants of Slovak flora. Preučili smo pojavljanje obligatne halofitske vrste Pholiurus pannonicus v Podunajski nížini in Východoslovenski nížini v letih od 2003 do 2009. Vrsta se je pojavljala. Našli smo 30 rastišč. V zadnjem času se je število rastišč močno zmanjšalo in jih najdemo samo še v Podunajski nížini. Med raziskavo smo dokumentirali le sedem nahajališč. Vrsta Pholiurus pannonicus zato sodi med kritično ogorožene vrste flore Slovaške.

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.

Carex cespitosa: reappraisal of its distribution in Europe

Abstract Jiménez-Mejías P., Hilpold A., Frajman B., Puşcaş M., Koopman J., Mesterházy A., Grulich V., Lye K. A. & Martín-Bravo S.: Carex cespitosa: reappraisal of its distribution in Europe. — Willdenowia 44: 327–343. 2014. — Version of record first published online on 31 October 2014 ahead of inclusion in December 2014 issue; ISSN 1868-6397;

Contributions to the distribution and ecology of Carex hordeistichos Vill. in the Czech Republic and Slovakia

Contributions to the distribution and ecology of Carex hordeistichos Vill. in the Czech Republic and Slovakia Current and historical occurrence as well as habitat requirements of Carex hordeistichos in the Czech Republic and Slovakia are presented. The study is based on the revision of herbarium specimens from 25 herbaria and a field survey carried out during 2004-2009. Altogether, 195 sites were documented in the Czech Republic, exclusively in the Moravia region. Recent occurrence was confirmed at only four localities (2% of sites), therefore the status of threat was confirmed - the species is critically endangered. In Slovakia, 184 localities of the species were recorded in total; 34 sites were found in period 1975-1999 and 35 sites were confirmed recently (19% of sites recorded), but only 6 in the Pannonia (3% of sites). The number of localities was stable over the last 35 years, therefore, we re-evaluated the IUCN status of C. hordeistichos in Slovakia. The species is now assessed in the category vulnerable - VU. Results of the study are summarised in the maps of historical and actual species distribution. C. hordeistichos usually occurred in various wet grassland communities and it had no well-defined coenotic relationships. On the basis of our knowledge, we consider C. hordeistichos as a facultative halophyte.

Biogeografické regiony České republiky

Kniha podrobně charakterizuje vsechny ctyři biogeograficke podprovincie a take 91 bioregionů CR. Každý bioregion je popsan z hlediska polohy, plochy, hornin, reliefu, půd, podnebi, aktualniho stavu krajiny, flory a fauny, vegetace potencialni i aktualni, dale pak dle geobiocenologicke typizace a kontrastů k okoli. Uvedena jsou i klicova chraněna uzemi. Soucasti publikace je podrobna mapa biogeografickeho cleněni CR v měřitku 1:500 000.