Volumen 35 (2016): Heft 2 (June 2016)

Heavy metals are present in low concentrations in reservoirs, but seasonal anthropogenic activities usually elevate the concentrations to a level that could become a health hazard. The dry season concentrations of cadmium, copper, iron, lead, mercury, nickel and zinc were assessed from three sites for 12 weeks in Oyun reservoir, Offa, Nigeria. Triplicate surface water samples were collected and analysed using atomic absorption spectrophotometry. The trend in the level of concentrations in the three sites is site C > B > A, while the trend in the levels of the concentrations in the reservoir is Ni > Fe > Zn > Pb > Cd > Cu > Hg. Ni, Cd, Pb and Hg were found to be higher than the WHO guidelines for the metals in drinking water. The high concentration of these metals was from anthropogenic watershed run-off of industrial effluents, domestic sewages and agricultural materials into the reservoir coming from several human activities such as washing, bathing, fish smoking, especially in site C. The health effects of high concentration of these metals in the reservoir were highlighted. Methods for the treatment and removal of the heavy metals from the reservoir during water purification such as active carbon adsorption, coagulation-flocculation, oxidation-filtration, softening treatment and reverse osmosis process were highlighted. Other methods that could be used include phytoremediation, rhizofiltration, bisorption and bioremediation. Watershed best management practices (BMP) remains the best solution to reduce the intrusion of the heavy metals from the watershed into the reservoir.

Comprehensive environmental studies taking under consideration the structure of the radiation balance during the vegetation growing seasons of 2001 and 2002 were carried out on the open sandy surface of the area called the Błędów ‘desert’ located on Silesian Upland. The research in each site covered the composition of plant species, their age and height, the condition of the substratum, the composition and structure of the soil and the meteorological conditions with elements of the radiation balance. The article presents some part of the research on meteorological elements and their impact on ecosystem. Special attention was devoted to radiation conditions on the open sandy surface in the context of the formation of BSC (biological soil crust). Having presumed that the values obtained on the grassy surface constituted 100%, the values of radiation reflection measured on the open sandy surface were 185% higher and the values of net longwave radiation were 105% higher in day time and 137% in night time. Values of net radiation of about 63% lower were observed on the sandy surface during a typical sunny summer day. It was found that a strong irradiation of the sandy surface (26 MJ·m^–2d^–1) creates extremely difficult conditions for the initiation of the process of ecosystem formation (including BSC or plant succession). The elements of the radiation balance, net radiation, albedo and temperature of the open sandy surface were represented quantitatively. The test surfaces were classified based on the value of the albedo: group I with low albedo values, up to 0.15 (spore-bearing plants on a dark surface), including BSC; group II with mean values of the albedo from 0.16 to 0.24 (spore-bearing plants and seed on a dark grey surface); and group III with high albedo values, above 0.25 (plants growing on bare or loose sands).

The Carabidae family (Coleoptera) is used frequently for its bioindication potential to detect the environmental burden. In 2013 and 2014, we studied the correlation of Carabidae on the biotopes of six areas in the Veporské vrchy Mts and the Juhoslovenská kotlina basin by using pitfall traps, Möricke plates and Bambara beetle traps. Out of 432 recorded specimens of beetles (53 species, 15 families), the Carabidae family were the highest number of species and specimens represented, with which we confirmed higher anthropogenic interference and disturbance of ecosystems in the Juhoslovenská kotlina basin. This statistic confirms the presence of the following species typically found on arable land: Anchomenus dorsalis, Calathus fuscipes fuscipes, Harpalus affinis and Pseudoophonus rufipes. The ecosystems in the Veporské vrchy Mts region show less disturbance, and the anthropological impact is smaller, indicated by the presence of the Carabus problematicus species, an important indicator of the conservation of natural forest ecosystems.

This study characterises an impact of secondary landscape structure on the introduction of non-native plant species during the years 2008 and 2010−2012. The field mapping was realised in the cadastral area of the Topoľčany town. The area of study consists of built-up area with surrounding agricultural land. During the period of our research, we identified the presence of total 55 non-native plant species, including 21 invasive, 11 casual and 23 naturalised. The highest dominance occurred in elements of ruderal vegetation without trees (22) and in the vegetation protection of aquatic dams (15). Several species were observed in a wide range of landscape elements. The occurrence in many structurally different types of habitats confirmed the ability of non-native species to tolerate a wide range of biotic and abiotic conditions.

The presence of water is one of the decisive factors of landscape’s natural potential. Water affects landscape’s predisposition for agricultural production, water supply available to the wide population and industry (the most important is the yield of water resources). Ponds, lakes and other water areas are zones of recreation and relaxation. Near sources mineral water, several world-famous spas were build. Waterways are also used to generate electricity. Geothermal underground water represents a very significant landscape potential. Determining hydrological potential of the area is important for the regional development. This paper assesses the landscape potential for water management regarding its surface waters in the micro-region Minčol. The micro-region was divided by a square grid, and for each square, we determined the appropriateness of this potential based on score points. The determining evaluation criteria were static reserves of surface water, waterway ranking and annual average discharge. First, we determined the significance (value) of individual criteria (classification characteristics), and then we calculated the values of individual classifiers, which were then multiplied by the value of the individual classifier intervals. The summary of points in each square belongs to a particular degree of suitability for water management based on surface waters. The potential was divided into five degrees (intervals): very unfavourable potential, unfavourable potential, moderately favourable potential, favourable potential and very favourable potential.

Urbanised landscape represents composed structures of technical and biotic elements where social and economy activities create living space for human society but with strongly changed environment. To dominant characters belong climate changes with increased air temperature, drought and emission load, which has developed wide spectrum of stress factors influencing the urban vegetation. For the assessment of plant growth and adaptation response, we have used Sycamore maple (Acer pseudoplatanus L.) as study model woody plant. In the framework of visual characters, we assessed the following indicators: (a) assimilation organs (leaf necrosis); (b) crown quality (degree of foliage and degree of dead tree crown); (c) trunk and branch quality (mechanical damage, incidence of wood destroying fungus and trunk cavities and callus healing of trunk wounds). Each indicator was assessed in five-point scale, and in the end, the common index of quality was calculated. The quality index achieved 9.33 points in the first and 10.33 in the second evaluation periods in the Nitra city and 2.66 at the both assessed periods in the comparable rural park. In the group of physiological indicators, chlorophyll a fluorescence marker and its F_v/F_m parameter were used. Within three repeating assessment during growing season (June, August and September), the average values reached F_v/F_m = 0.814 in the city and F_v/F_m = 0.829 in rural park. The results confirmed statistical significances between loaded city conditions and relatively clean rural locality. Used markers have shown as appropriate tools for growth response measurements of street trees in a changed urban environment.

In this study, we used bootstrap simulation of a real data set to investigate the impact of sample size (N = 20, 30, 40 and 50) on the eigenvalues and eigenvectors resulting from principal component analysis (PCA). For each sample size, 100 bootstrap samples were drawn from environmental data matrix pertaining to water quality variables (p = 22) of a small data set comprising of 55 samples (stations from where water samples were collected). Because in ecology and environmental sciences the data sets are invariably small owing to high cost of collection and analysis of samples, we restricted our study to relatively small sample sizes. We focused attention on comparison of first 6 eigenvectors and first 10 eigenvalues. Data sets were compared using agglomerative cluster analysis using Ward’s method that does not require any stringent distributional assumptions.

Riparian stands along streams are important landscape elements – biocorridors, allowing the dispersal of many small terrestrial mammals. Streams are, however, also barriers limiting dispersal, which leads to isolation and population-genetic changes. Communities of small terrestrial mammals (Eulipotyphla, Rodentia) were studied in 2004 to 2006 on five watercourses of varying widths in Central European cultural landscape situated in South Bohemia (Czech Republic). In total, 547 individuals from 10 species were captured by the Capture-Mark-Recapture method (CMR). Yellow-necked mouse (Apodemus flavicollis) and bank voles (Myodes glareolus) were eu-dominant species at all locations. Species diversity and equitability rose with the degree of the barrier – proportional to the width of the stream.

The terrestrial mobility of selected species was also assessed. Apodemus flavicollis indicated overall highest values of mobility, and Myodes glareolus males also scored higher values, however, the width of the stream did not correlate with mobility in these species. The animals crossed water-courses on the order of tens of meters wide in the period of 3 months. The frequency of crossing of Apodemus flavicollis decreased exponentially with the width of the stream and was dependent on population density.