TROPHIC STATE INDEXES AND PHYTOPLANKTON IN THE TROPHIC STATUS ASSESSMENT OF WATERS OF A SMALL RETENTION RESERVOIR AT AN EARLY STAGE OF OPERATION

This paper will focus on determining the trophic status of the two basins of the Niwa Reservoir - Niwa I and Niwa II (Sawin commune, Lubelskie Province, SE Poland) at the sixth year of operation, by using partial TSI indexes – TSI(SD), TSI(TP), TSI(chl-a), as well as qualitative and quantitative structures of phytoplankton. As a supplementary, index TSI(TOC) was employed [Dunalska 2011]. We show that the phytoplankton abundance, as well as TSI(chl-a) and TSI(TP) were relatively low and typical for mesotrophic waters (with the exception of July TSI(TP) values for the Niwa II basin), although the evaluation of trophy based on other partial TSI indexes – TSI(SD), TSI(TOC) pointed to a eutrophic or even a hypertrophic water characteristic. The obtained results were discussed in detail and referenced to other, non-nutrient related trophy factors: morphometric features and geology of the basins, as well as the physicochemical properties of its water

(Ehr.) Diesing bloom formation in nine lakes of Polesie region (Central–Eastern Poland)

Using data from nine lakes, sampled between 2002 and 2010, as well as literature we have analysed blooms of Gonyostomum semen (Ehr.) Diesing in a new spreading area (Polesie region, Central–Eastern Poland). We tried to determine habitat suitability for high biomass of the species, including both physicochemical and morphometric features. High biomass of Gonyostomum (>1.4 mg.L−1) was found in three groups of coloured water bodies: (a) very small (<0.002 km2) peat pits with low pH values and mineral content; (b) larger ponds with neutral pH values and intermediate conductivity; (c) natural lakes with intermediate parameters in terms of area, pH and mineral content. There were no statistical differences regarding the values of the species biomass among the groups of lakes. Gonyostomum biomass was closely positively correlated with water colour, whereas it was weakly negatively correlated with lake area and depth. The results show that G. semen in a new spreading area bloomed in a broad spectrum of freshwater habitats

To What Degree Can the Specifics of Occurrence of Glacial Relic Betula humilis Schrank Be an Indicator of Habitat Conditions of Moderate Climate Peatlands?

Anthropogenic transformations of habitat conditions in moderate climate peatlands frequently cause a decrease in the number of sites of occurrence and the size of the population of many valuable plant species, including the boreal relic Betula humilis. The objective of this paper was an attempt to relate the specifics of the occurrence of the glacial relic Betula humilis in the peatlands of Central-Eastern Poland, which developed under moderate climate conditions, to the conditions of the natural environment identified through research into the physical and chemical parameters of the groundwater, as well as botanical research into its habitat. The study results confirm that shrub birch has a broad range of ecological tolerance to the majority of the studied factors and can therefore be an indicator of habitat transformation. Important environmental factors affecting its abundance are water relations and the contribution of calcium hydroxide and phosphorus fractions. A condition favouring the proper functioning of individuals of the studied species is TP values lower than other obtained values, in the following range: 0.08&ndash;0.32; P-PO4: 0.1; TN: 2.2&ndash;21.2; N-NH4: 0.1&ndash;0.46; DOC: 24.6&ndash;55.9 (mg&middot;dm&minus;3), as well as higher than average pH values, in the following range: 5.34&ndash;5.95; Ca: 5.67&ndash;28.1; Mg: 0.56&ndash;2.41 (mg&middot;dm&minus;3) and EC: 72.1&ndash;142.3 (&micro;S&middot;cm&minus;1)

Population resources of an endangered species Salix lapponum L. in Polesie Lubelskie Region (eastern Poland)

This research, carried out in the years 2011–2013, aimed to evaluate Salix lapponum stands in the peat bogs of Polesie Lubelskie Region as well as to determine the condition of the population and the changes that have taken place since the 1950’s. An inventory carried out in 25 stands of S. lapponum known from the literature shows that the number of its stands has decreased by 80% in Polesie Lubelskie Region. In all the confirmed locations, a decrease in population numbers was also found in relation to the data known from the literature since the 1950’s. In the majority of the population locations that were considered to be extinct, there were no significant changes in habitat conditions, and ecological succession and changes in hydrological conditions could have been the cause of habitat changes only at a few sites. In the light of the study, the preservation of the S. lapponum population in Polesie Lubelskie seems to be impossible if appropriate active conservation measures are not taken immediately. Because area-based conservation, which covers most of the habitats of the studied species, does not bring the expected results, the possibility of ex situ conservation and enlargement of the populations existing in the natural environment in peat bog ecosystems in Polesie should be explored

Pollen viability of Salix myrtilloides L. – an endangered species in Poland

Salix myrtilloides L. (swamp willow) is the most endangered species among the boreal Salix species in Poland. The number and size of its population have been decreasing constantly since the 1990s. The main aim of the study was to determine the viability of collected S. myrtilloides pollen and optimal conditions for its in vitro germination. The pollen of S. myrtilloides was collected from 25 male individuals from a population growing in the mid-forest peat bog Dekowina (Sobibór Landscape Park) in May 2014. Two methods were applied to estimate the viability of fresh and stored pollen: staining pollen with 2% acetocarmine solution and in vitro germinability. Various temperature (11°C, 23°C) and light conditions as well as different concentrations of glucose (1%, 2.5%, 5%, or 7.5%) were tested for the optimization of in vitro germination. We documented relatively high S. myrtilloides pollen viability. Pollen tube growth was found to be largely affected by both glucose content in the medium and thermal conditions during germination. Fresh pollen germinated most effectively on the medium with 2.5% glucose (stored pollen – in 5% glucose), at 23°C and in the presence of light. We conclude that pollen viability of S. myrtilloides does not seem to be a limiting factor for reproductive success. Moreover, the pollen is not sterile even after storage for 12 months. The S. myrtilloides individuals from the Dekowina peat bog produce viable pollen grains that are able to germinate and therefore it can be used to pollinate other populations present in the Polesie Lubelskie region for gene pool enrichment

Selenium-induced improvements in the ornamental value and salt stress resistance of Plectranthus scutellarioides (L.) R. Br.

Ornamental plants growing in urban areas are often exposed to salt stress that negatively affects their decorative value. Enhancement of their salt resistance to retain a high decorative value despite salt stress has therefore high practical importance. In our study, the exposure of Plectranthus scutellarioides (L.) R. Br. to NaCl-induced moderate (40 mM) or severe salt stress (80 mM) resulted in a number of stress responses including reduced growth parameters, decreased concentration of photosynthetic pigments, and an increase in the accumulation of anthocyanins and free proline. These changes were partially compensated for by the application of selenium (5 µM as Na2SeO4) to the growth medium. However, the beneficial effect of selenium on the growth and physiological parameters of P. scutellarioides was manifested only at the moderate level of salt stress. Under the severe salt stress, the application of selenium was not able to alleviate the phytotoxic effect of NaCl

Environmental factors related to the distribution pattern of Raphidiopsis raciborskii and R. mediterranea in Central East Europe

Raphidiopsis raciborskii originates from tropical and subtropical regions, however its expansion toward temperate zone during last decades has been observed. Phenotypic plasticity, occurrence of ecotypes differing in their environmental adaptations and climate changes are indicated among factors responsible for its successful expansion. Much less is known about distribution pattern of Raphidiopsis mediterranea native for warm areas along Mediterranean cost. Therefore, the aim of the study was to determine the current distribution of these species in Polish and Lithuanian lakes and to detect environmental factors related to their occurrence. The R. raciborskii was much more common and occurred in 31 out of 112 lakes, while R. mediterranea in 7 lakes. The contribution of these species in total phytoplankton biomass ranged from 0.1 to 31% and from 0.1 to 2.6% respectively. Similarly to previous studies R. raciborskii was much more common in Western Poland where it significantly increased its contribution in phytoplankton biomass however it was detected in several new lakes in Eastern Poland. In Lithuania its occurrence is still limited to one lake. R. mediterranea occurred in similar number of lakes in both regions of Poland only. Among environmental factors conductivity and temperature were positively correlated with R. raciborskii biomass