A class of continua that are not attractors of any IFS

This paper presents a sufficient condition for a continuum in $R^n$ to be embeddable in $R^n$ in such a way that its image is not an attractor of any iterated function system. An example of a continuum in $R^2$ that is not an attractor of any weakly contracting iterated function system is also given

Actual State and Changes of Flora and Vegetation in the Broczówka Steppe Reserve

This paper presents floristic characterization of xerothermic plant associations and analysis of changes of flora within Broczówka steppe reserve. The floristic research was carried out in 2004-2009. Numerous species that were noted here almost 30 years ago were not found in the present study, the size of other populations decreased. Nevertheless, many plant species occurring in the reserve are rare, endangered or protected. Six major plant associations, impoverished form of two ones and one plant community are distinguished in the whole area of the reserve. Occurrence of two plant associations was not confirmed

Spring weed communities of rice agrocoenoses in central Nepal

Rice field weed communities occurring in central Nepal are presented in this study. The research was focussed on the classification of segetal plant communities occurring in paddy fi elds, which had been poorly investigated from a geobotanical standpoint. In all, 108 phytosociological relevés were sampled, using the Braun-Blanquet method. The analyses classified the vegetation into 9 communities, including 7 associations and one subassociation. Four new plant associations and one new subassociation were proposed: Elatinetum triandro-ambiguae, Mazo pumili-Lindernietum ciliatae, Mazo pumili-Lindernietum ciliatae caesulietosum axillaris, Rotaletum rotundifoliae and Ammanietum pygmeae. Due to species composition and habitat preferences all phytocoenoses were included into the Oryzetea sativae class and the Ludwigion hyssopifolio-octovalvis alliance. As in other rice field phytocoenoses, the main discrimination factors for the plots are depth of water, soil trophy and species richness. The altitudinal distribution also has a significant influence and separates the Rotaletum rotundifoliae and Elatinetum triandro-ambiguae associations. The study shows that anthropogenic rice fields can harbour relatively rich rush and water vegetation. More than 80 species were noted in the vegetation plots. Several of them are considered to be extremely rare and have been recorded on the world Red List

Microscale spatial variation of soil erodibility factor (K) in a young hummocky moraine landscape in Northern Poland

Soil erodibility is one of the crucial parameters for modelling soil erosion, expressed as the K-factor. The presented study tries to illustrate the spatial variance of K-factor on a local scale through the investigation of soil properties and descriptive spatial analysis utilising GIS tools at microscale in a young hummocky moraine landscape in Northern Poland. The results of the interpolation of K-factor values illustrate their changing from high values in eroded pedons on the tops of hummocks to low values in kettle holes. The middle position is occupied by slightly and non-eroded pedons. The mean weight results were very similar to data that were found on the scale of Europe and Poland. In landscapes with heterogeneous soil cover, there are signifi cant differences in maps based on different approaches to data visualisation. There are advantages and disadvantages to both (1) referring to mean values of the K index for soil contours representing different soil types and (2) interpolating the values obtained from individual points (GIS tool). Interpolation can be used for a thoroughly examined area with a high number of input points, while a map based on mean K index values for soil contours would be more effective in homogeneous areas

Riesz transform characterization of H^1 spaces associated with certain Laguerre expansions

For alpha>0 we consider the system l_k^{(alpha-1)/2}(x) of the Laguerre functions which are eigenfunctions of the differential operator Lf =-\frac{d^2}{dx^2}f-\frac{alpha}{x}\frac{d}{dx}f+x^2 f. We define an atomic Hardy space H^1_{at}(X), which is a subspace of L^1((0,infty), x^alpha dx). Then we prove that the space H^1_{at}(X) is also characterized by the Riesz transform Rf=\sqrt{\pi}\frac{d}{dx}L^{-1/2}f in the sense that f\in H^1_{at}(X) if and only if f,Rf \in L^1((0,infty),x^alpha dx)

Dwarf shrub vegetation of rock ledges and clefts in the Pamir Alai Mountains (Middle Asia: Tajikistan)

The paper presents the results of phytosociological researches on rocky slope vegetation in Tajikistan with the aim to establish a comprehensive syntaxonomical classifi cation system. Field studies were conducted in 2010–2014 in Pamir Alai ranges and Pamirian plateau. Nearly 500 relevés documenting rock and scree vegetation were made according to the Braun-Blanquet method. Numerical analyses of selected 58 relevés representing dwarf shrub vegetation on rock ledges made it possible to distinguish: Ephedro glaucae- Spiraeion baldschuanicae and Ephedrion regeliano-fedtschenkoi alliances, as well as Spiraeetum baldschuanicae, Rhamnetum coriaceae, Pentaphylloidetum parvifoliae and Pentaphylloidetum dryadanthoidis associations, community of Ephedra glauca and community of Rhamnus minuta. The classification of vegetation of dwarf shrubs on rock walls occurring in the Pamir Alai Mts is proposed. Because of the species composition, physiognomy and microhabitat conditions, the plant communities were included into Artemisio santolinifoliae- Berberidetea sibiricae class Ermakov et al. 2006. The main factors determining the species composition of the classifi ed associations seem to be the elevation above sea level.The newly described syntaxa are largely defined by species restricted to very narrow ranges in Middle Asi

Phylogeny and morphology of Anthracoidea pamiroalaica sp. nov. infecting the endemic sedge Carex koshewnikowii in the Pamir Alai Mts (Tajikistan)

A novel Anthracoidea species, A. pamiroalaica on the endemic sedge Carex koshewnikowii, is described and illustrated from the Pamir Alai Mts in Tajikistan (Central Asia). The new species is phenotypically nearly identical with Anthracoidea sempervirentis, but clearly divergent genetically. Phylogenetic analyses based on LSU sequences showed affinity of Anthracoidea pamiroalaica to A. baldensis, A. rupestris, A. capillaris, and A. vankyi infecting host sedges in different Carex sections (Baldenses, Rupestres, Chlorostachyae, and Phaestoglochin, respectively), but not to A. misandrae, and A. sempervirentis, two sequenced species parasitic on host species from the section Aulocystis. This phylogenetic placement is briefly discussed in the context of Anthracoidea evolution