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Magdalena Franczak and Bożenna Czarnecka

Unitary and iterative growth of clonal species individuals: significance for the spatial structure and the dynamics of population abundance

The aim of the study was to determine the dynamics of unitary and iterative genets and the ramets which they produce in the populations of two species represent diverse types of clonal growth: Filipendula ulmaria (L.) Maxim. and Lythrum salicaria L. An attempt was made to answer the following questions: Is there a demographic balance between the number of ramets produced by genets, i.e. vegetative reproduction, and recruitment of new genets? How significant may quantitative relations between unitary and iterative individuals be for the spatial structure and population abundance dynamics?

There was similarity in the dynamics of the abundance of genets and ramets in the Filipendula ulmaria and Lythrum salicaria populations. A slight increase in the number of genets and ramets was noted in the second study season. In the subsequent vegetation seasons, a decline in their number was observed. There was no statistically significant differences in the share of unitary and iterative individuals and ramets that they produced. The populations are characterized by a spatial clumped structure. During the observation, an increase in the mean number of ramets per one individual and the aggregation coefficient (Leksis' index) were noted.

Population of the species of hydrogenic habitats situated in river valleys are particularly exposed to groundwater fluctuations. In the study area, a rapid rise of the groundwater level related to beaver activity was observed. Water stress resulted in weaker growth of the existing genets and, first of all, in lower recruitment of new ones. Intensive vegetative growth of Carex acutiformis individuals and increase in the necromass layer thickness have a big significance for the population dynamics of the study species.

Open access

Piotr Sugier and Bożenna Czarnecka

Factors affecting the diversity of vegetation of chosen lakeland and riverine peatlands of SE Poland

The aim of the study was to present the diversity of peatland vegetation of two regions in south-eastern Poland. We also aimed to determine the relationship between particular edaphic factors as well as the structure of peatland communities and their diversity. The study was conducted in the lakeland peatlands of the Łęczna-Włodawa Lakeland and in riverine peatlands in the river breaks of the Central Roztocze Highlands. The lakeland peatlands are characterized by lower species richness and diversity expressed by the Shannon-Wiener index; yet, they exhibit greater phytocoenotic diversity in comparison to the riverine peatlands of Roztocze. Increased tree density in lakeland peatlands reduces the number of species and renders the communities less diverse. Such physico-chemical properties as soil acidity and content of Ca, and Na ensure species richness in Caricetum lasiocarpae phytocoenoses in the lakeland peatlands.

Open access

Joanna Czarnecka, Bożenna Czarnecka and Monika Garbacz

Secondary dispersal of seeds by the Magpie Pica pica L. in agricultural landscape

The aim of the study was to broaden the knowledge about the role played by the Magpie (Pica pica L.) in the secondary dispersal of seeds with help of nest material, which takes place in the agricultural landscape with the distinct dominance of arable fields. We also tried to assess which plant life-history traits can be helpful in the dispersal mediated by the Magpie. Six nests were collected after the breeding season; the mud (soil) layer was separated from the nests and the seed pool present there was studied with the use of the seedling emergence method. The number of seedlings detected in the study nests varied between 23 and 126 per 1000 g of soil dry weight, the total number of recorded taxa was 41 (the number of species in subsequent nests varied between 10 and 24). All recorded species can be divided into four ecological groups, which point to the source of the nest material: weeds, ruderal species, species connected with field roads, and grassland and meadow species. Among them, weeds are the best represented group. We think that the secondary dispersal by the Magpie is most beneficial for weeds with no adaptation for dispersal, with a persistent seed bank and a low seed weight.

Open access

Bożenna Czarnecka

Abstract

Abies alba and Senecio rivularis - two of 44 mountain species reported from the Roztocze Highlands, SE Poland were objects of the study. Both species reach the north-eastern limits of their occurrence in this region. In case of Abies alba, the extent of its habitat niche and possibility of adaptation to alternative niches at the range limits were investigated in two areas of the Roztocze Highlands - the Roztocze National Park (RNP) and gorge sections of four river valleys (RV) of a mountainous character. In both landscapes, fir prefers mineral soils that are too leachy for deciduous species and even for spruce. In the RV sites, fir seems to have a much broader ecological scale and often colonizes organic soils with wet mixed coniferous forests with spruce, ash-alder, and bog alder forests.

The studies on Senecio rivularis are an example of long-term ecological studies at the population level, conducted in the RNP since 1987, e.g., in terms of changes in the size structure of individuals compared to the changes in the surface area covered by this population. A nearly 3-fold increase in the area inhabited by the population was accompanied by changes in the spatial organisation of the population and individual size structure dynamics, which reflects the intensification of intra- and interspecific competition, and indicates condition changes in the population area.

Open access

Bożenna Czarnecka, Anna Rysiak and Łukasz Chabudziński

Abstract

The paper discusses the question whether geographical information systems (GIS) and digital elevation models (DEM) are useful tools for studying correlations between topographic attributes of a given area, and vascular flora requirements reflected by ecological indicator values (EIVs). The model object was a 4-km-long gorge section of the Sopot river valley (80.5 ha), the Central Roztocze Highlands, South-East Poland. Species lists for 40 ca. 200-m-long and 100-350-m-wide sections, according to the river course, separately for the left and right riverbanks, were made. The analysis of the area was based on a 3-meter resolution DEM. We applied primary topographic attributes: slope, and planar, vertical, and total curvatures and also secondary topographic attributes: solar radiation (SRAD) and topographic wetness index (TWI), as well as other terrain characters: denivelation, total, flat and upslope area of each section. Using the multivariate analyses, we analysed relationships between weighted averages of EIVs for each species and topographic attributes.

The GIS and DEM became useful tools for the detection of patterns of species with different habitat requirements. The species number correlated positively with the total and flat area of a section and the TWI, while the denivelation, mean slope and upslope area had a reverse vector. Among the most frequent and abundant herb species, we found several spatial patterns of distribution, namely those of: Maianthemum bifolium, Carex remota, C. acutiformis, Filipendula ulmaria, Dryopteris filixmas, and Urtica dioica. The rarest species represented Ajuga genevensis, Scorzonera humilis, and Stachys palustris patterns.