Limonka Gmelinova ( Limonium gmelinii ) na dálnicích České republiky

Limonium gmelinii bylo v České republice jako zavlečený druh poprvé nalezeno v roce 2009 na krajnici dálnice D1 u Ostrovačic na Brněnsku. V roce 2013 bylo zaznamenáno také ve středním dělícím pásu dálnice D2 na jih od Brna.The paper describes finds of Limonium gmelinii on the D1 and D2 motorways in southern Moravia (south-eastern part of the Czech Republic). Limonium gmelinii is a plant of continental halophytic vegetation, such as saline steppes and marshlands, with a large distribution range extending from south-eastern Europe over southern Ukraine, south-eastern European Russia to southern Siberia in the east and some parts of Central Asia in the south. It is reported here for the first time as a naturalized alien species of the Czech flora. Until now it has been known from four sites, of which one is situated on the D1 motorway near the village of Ostrovačice, west of the city of Brno (first recorded by J. Danihelka in 2009), and three on the D2 motorway southeast of Brno, near the villages of Otmarov, Opatovice and Rakvice (first recorded by P. Kocián in 2013 but already recognizable on Street View photographs of Google Maps from August 2009). The Ostrovačice site, harbouring a single specimen, is the only place where L. gmelinii is found at the road verge under steel beam barriers. At the remaining three sites, in contrast, plants are always found in the central reservation. While the population near Rakvice consists of up to 40 flowering specimens, the populations near Opatovice and Otmarov are less numerous, consisting of about 5 and 2 flowering individuals, respectively. The identification of our specimens (deposited at BRNU and OL) as L. gmelinii seems to be almost certain; however, we refrained from identification to the microspecies level (as L. hungaricum or L. hypanicum , both described by M. V. Klokov) because the infraspecific variation of L. gmelinii is insufficiently known. We assume that the seeds of L. gmelinii were introduced to the Czech motorways via international traffic from Hungary but this assumption is based solely on geographic considerations and cannot be supported by any other arguments

Cryptic invasion suggested by a cytogeographic analysis of the halophytic Puccinellia distans complex (Poaceae) in Central Europe

Introduction: Despite the wealth of studies dealing with the invasions of alien plants, invasions of alien genotypes of native species (cryptic invasions) have been vastly neglected. The impact of cryptic invasions on the biodiversity of plant communities can, however, be significant. Inland saline habitats and halophytes (i.e., salt-tolerant plant species) are especially threatened by this phenomenon as they inhabit fragmented remnants of largely destroyed habitats, but at the same time some of these halophytic species are rapidly spreading along salt-treated roads. To study potential cryptic invasion of halophytes, the patterns of genome size and ploidy variation in the Puccinellia distans complex (Poaceae), the most rapidly spreading roadside halophyte in Central Europe, were investigated. Methods: DNA flow cytometry with confirmatory chromosome counts were employed to assess ploidy levels of 1414 individuals from 133 populations of the P. distans complex. In addition, climatic niche modelling was used to predict the distributions of selected cytotypes. Results: Eight groups differing in ploidy level and/or genome size were discovered, one diploid (2x; 2n = 14), two tetraploid (4xA, 4xB; 2n = 28), one pentaploid (5x; 2n = 35), three hexaploid (6xA, 6xB, 6xC; 2n = 42), and one heptaploid (7x; 2n = 49). The hexaploids (mostly the 6xC cytotype) were widespread through the study area, spreading intensively in both anthropogenic and natural habitats and probably hybridizing with the natural habitat dwelling tetraploids. In contrast, the non-hexaploid cytotypes rarely spread and were predominantly confined to natural habitats. Discussion: The extensive spread of the hexaploid cytotypes along roadsides has most likely facilitated their incursion into natural habitats. The colonization of new natural habitats by the hexaploids may pose a threat to the indigenous Puccinellia populations by compromising their genetic integrity and/or by outcompeting them

Distributions of vascular plants in the Czech Republic. Part 2

The second part of the publication series on the istributions of vascular plants in the Czech Republic includes grid maps of 87 taxa of the genera Antennaria, Aposeris, Astragalus, Avenula, Bidens, Carex, Cenchrus, Centunculus, Convallaria, Crocus, Cryptogramma, Cyperus, Dryopteris, Gladiolus, Gratiola, Helictochloa, Hierochloë, Lindernia, Maianthemum, Myriophyllum, Notholaena, Nymphoides, Radiola, Schoenoplectus, Sisyrinchium, Spergularia, Tillaea, Veratrum and Veronica. The maps were produced by taxonomic experts based on all available herbarium, literature and field records. The plants studied include 56 taxa registered in the Red List of vascular plants of the Czech Republic, some of which showed remarkable declines. Spatial and temporal dynamics of individual species are shown in maps and documented by records included in the Pladias database and available in Electronic appendices. The maps are accompanied by comments, which include additional information on distribution, habitats, taxonomy and biology of the species

Distributions of vascular plants in the Czech Republic. Part 1

Despite a long history of botanical research on the Czech flora and the large amount of data on plant distribution that has been collected, there is still no comprehensive piece of work with distribution maps in this country and no distribution maps are available for more than a half of plant taxa. This paper is the first part of a series of publications prepared within the PLADIAS project, intended as the first step towards a complete atlas of the distribution of both native and alien vascular plants in the Czech Republic. It contains grid distribution maps of 75 taxa of the genera Achillea, Aegilops, Aira, Alopecurus, Avena, Bolboschoenus, Carex, Cladium, Elatine, Eleocharis, Eriophorum, Glyceria, Polypogon, Sclerochloa, Scheuchzeria, Sparganium, Tofieldia, Tragus and Viola. The maps are based on all available herbarium, literature and field records, which were stored at the CzechDistrib database, checked geographically and evaluated taxonomically, and shown inmaps using the Central European mapping grid template derived from quadrants of 5 × 3 arc minutes (corresponding to approximately 5.5 × 5.9 km). Many of these maps resulted from detailed revisions carried out during the work on the Flora of the Czech Republic. Maps of taxonomically difficult groups are based solely or mainly on herbarium specimens revised by taxonomic experts. If useful, recent versus old records, native versus alien occurrences, or records based on revised herbarium specimens versus all other records are distinguished using different symbols. Records used for producing maps are listed in electronic appendices. The maps are accompanied by texts that include an outline of general distribution, information on habitats and specific details on the distribution in the country. Where appropriate, comments on taxonomy, biology or spatial and temporal dynamics in distribution are given

Hedge funds: investment strategy and regulation

Even though hedge funds account for a small portion of global investment funds, they have achieved a strong position in investment options for institutional investors in last two decades. Due to recent financial crisis and a fear of possible risks connected with hedge funds, regulators start to focus more on regulation of this industry. This thesis focus mainly on investment strategies of hedge funds and on regulatory efforts in the USA. Before the work describes this, it is necessary to define and specify them. Then some of common used investment strategies are introduced in order to better describe the unique role of hedge funds to reader. In the end, after funds are specified, the thesis can describe regulatory efforts and evaluate them. Key Words hedge, fund, regulation, Dodd-Frank, AIFM, strategy, risk, performanc

Drivers of Macrophyte and Diatom Diversity in a Shallow Hypertrophic Lake

We studied macrophyte and diatom assemblages and a range of environmental factors in the large hypertrophic Dehtář fishpond (Southern Bohemia, Czech Republic) over the course of several growing seasons. The spatial diversity of the environment was considered when collecting diatoms and water samples in three distinct parts of the fishpond, where automatic sensor stations continually measuring basic factors were established. Macrophytes were mapped in 30 segments of the fishpond littoral altogether. High species richness and spatiotemporal variability were found in assemblages of these groups of autotrophs. Water level fluctuations, caused by the interaction of fish farming management and climatic extremes, were identified as one of the most important factors shaping the structure and species composition of diatom and macrophyte assemblages. The distance of the sampling sites from large inflows reflected well the spatial variability within the fishpond, with important differences in duration of bottom drainage and exposure to disturbances in different parts of the fishpond. Disturbances caused by intensive wave action are most probably a crucial factor allowing the coexistence of species with different nutrient requirements under the hypertrophic conditions of the Dehtář fishpond. Due to a range of variables tested and climatic extremes encountered, our study may be considered as a basis for predictive model constructions in similar hypertrophic water bodies under a progressing climate change