Assessment of the adaptive and phytoremediation potential of Miscanthusxgiganteus grown in flotation tailings

Mining activities produce enormous amounts of metal-contaminated waste that is the source of ecosystem pollution by metals. Owing to complex adverse environmental conditions, the surface of abandoned flotation tailings is completely devoid of vegetation cover and is therefore very susceptible to fluvial erosion, wind dispersal to neighboring ecosystems and leaching of heavy metals into ground waters. The aim of this study was to estimate the adaptive potential of Miscanthusxgiganteus (Poaceae) to grow on flotation tailings without any input. In this field experiment, plants were grown for four months in flotation tailings and in unpolluted control chernozem soil. Plants accumulated and retained the major part of metals within their roots, exhibiting their very low transfer to aerial parts, which all define M. xgiganteus as a phytoexcluder plant species. Plants grown in flotation tailings showed significant reduction in the net CO2 assimilation rate and growth parameters, and there was no negative impact on pigment content, maximum quantum yield of PSII photochemistry, lipid peroxidation level and total antioxidative capacity in leaves. The obtained results indicate that despite reduced growth, M. xgiganteus can be cultivated for phytoremediation of flotation tailings

Orchid species Anacamptis morio as a potential bioremediator of As, Cd and Pb

In this study concentration of toxic elements as, Cd, and Pb were determined in different soil types and belonging orchid species Anacamptis morio vital parts, in order to examine accumulation patterns and provide new insights about the potential use of this orchid in bioremediation technology. Soils developed on limestone, serpentine, and the chert were subjected to the BCR sequential extraction. Samples of orchid roots and tubers, as underground parts, and stems, leaves, and inflorescences, as above-ground organs, were also analyzed for the content of as, Cd and Pb. During this research, it was observed that metal content in soil is directly proportional to its content in the plant, more specifically in roots, which suggests that A. morio can potentially be used in the phytostabilization of contaminated sites. Values for BCF factors showed Cd immobilization in roots regardless of the soil type. A certain level of arsenic was transferred from roots to leaves indicating the potential for accumulation of this element into aboveground organs. Assessment of the phytoremediation potential of this orchid or another plant species from diverse environments is important as it provides information about the possibility of their future application in environmental remediation programs

PRELIMINARY NOTES ON THE SPIDER FAUNA (ARACHNIDA, ARANEAE) OF THE SPECIAL NATURE RESERVE ZASAVICA

Based on literature data and preliminary investigations a total of 104 spider species can be recorded from the Special Nature Reserve (SNR) Zasavica. Five species, Cyclosa oculata (Walckenaer, 1802), Mendoza canestrinii (Ninni, 1868), Philodromus albidus Kulczynski, 1911, Heriaeus graminicola (Doleschall, 1852) and Sibianor aurocinctus (Ohlert, 1865), were not recorded in Serbia until the present study. The rediscovery of the species Dolomedes plantarius (Clerck, 1757), Cresmatoneta mutinensis (Canestrini, 1868), Hypsosinga heri (Hahn, 1831) and Argyroneta aquatica (Clerck, 1757) represents an important result that could possibly be used as a guideline for future faunistic and ecological studies with the purpose of successful protection and conservation measures in the SNR Zasavic

Use of high-energy ionizing radiation for microbiological decontamination of coastal soil in the Kolubara river basin, Serbia

The Kolubara river pollutes the coastal land in the river basin and makes it unsuitable for agricultural activities in that area. Also, contaminated land poses a risk to the environment. Different methods can be used for soil decontamination. These methods include biological treatment/bioremediation, chemical oxidation, soil stabilization, physical methods, such as soil leaching, or treatment with high-energy ionizing radiation. Gamma irradiation of soil is a well-known method of inhibiting microbial activity. This paper investigated the influence of different doses and dose rates of gamma irradiation on microorganisms' decontamination of coastal soil, in the Kolubara river basin. The irradiation effects on reducing the total number of microorganisms and removing mold and pathogenic bacteria from soil samples were examined. Gamma radiation affects the soil's organic matter, causing the formation of free reactive radicals, which act as reducing and oxidizing agents, cleaving C-C bonds, and depolymerizing carbohydrates. It was found that a dose of 3 kGy of gamma radiation, neutralizes all pathogenic bacteria, a dose of 5 kGy deactivates mold in soil samples, and a dose of 10 kGy is optimal to kill all microorganisms in the samples and sterilize exposed soil. The research showed that the dose rate does not significantly affect microbiological decontamination of soil using gamma irradiation. The content of heavy metals in soil was determined, and the obtained values were compared with the remediation limit values prescribed by the regulations. It was concluded that the content of heavy metals in the analyzed soil samples is below the limit of remediation values. The only exception is the slightly increased copper content in one sample. The result of this research is the conclusion that the coastal land from the Kolubara basin can be decontaminated by gamma radiation treatment. This advanced soil treatment technology is available in Serbia because there is an industrial plant for gamma radiation treatment within the Vinča Institute

Zbijenost zemljišta različitih teksturnih klasa u zasadima malina ariljskog malinogorja

The principal aim of the present investigations was to establish the influence of threading by agricultural machines or people on the changes of penetration resistance (compaction) of the soils of various textural classes in Arilje raspberry growing area. The investigations included two most abundant soil types in the region, which differed significantly from the aspect of their textural composition: young non-carbonate sandy-loam alluvial soil (fluvisol) and silt-loam brown forest acid soil (dystric cambisol) on micashist. Measuring of penetration resistance in vertical direction, to the depth of 60 cm, between the rows of raspberry plants, at each 10 cm, was performed in the summer 2005 in two raspberry patches 10 years old. For the measurement of the penetration resistance a hand static penetrometer with cone of 30° and radius of 12.3 mm was applied. Repeated (10-20 times a year, according to the statement of the owner) passages of agricultural machines, frequently in very wet weather, as well as people passing (30-50 times a year) lead to a significant increase of penetration resistance (compaction) of the investigated soils in those areas, i.e. paths where machines and people moved. In these areas penetration resistance is 2 to 3 times higher than in surrounding untouched surfaces between the rows of raspberry plants. The values of penetration resistance (compaction) on the threaded paths vary between 1000 and 5000 kPa. The compaction increase made the penetration of raspberry roots into deeper soil layers very difficult.Cilj ovih istraživanja je bio utvrđivanje uticaja gaženja mehanizacijom i od strane ljudi, na izmene otpora penetracije (zbijenosti) zemljišta različitih teksturnih klasa u ariljskom malinogorju. Istraživanjima su obuhvaćena dva najzastupljenija tipa zemljišta u tom malinogorju koja se međusobno jako razlikuju po teksturi, i to: mlado beskarbonatno peskovito ilovasto aluvijalno zemljište (fluvisol) i praškasto ilovasto kiselo smeđe šumsko zemljište (distrični kambisol) na mikašistu. Merenje penetracionog otpora u vertikalnom pravcu, do 60 cm dubine, između redova malina na rastojanju od 10 cm obavljeno je u leto 2005. godine, i to u dva malinjaka starosti 10 godina. Za merenje penetracionog otpora korišćen je ručni statički penetrometar sa konusom od 30o i prečnikom 12.3 mm. Mnogobrojni (10-20 puta godišnje, po izjavi vlasnika malinjaka) prolazi poljoprivrednim mašinama često i po jako vlažnom zemljištu, kao i prolazi ljudi (30-50 godišnje) doveli su do znatnog povećanja otpora penetracije (zbijenosti) istraženih zemljišta na radnim stazama po kojima su se kretale mašine i ljudi. Na tim površinama penetracioni otpor je 2 do 4 puta veći nego na okolnim negaženim površinama između redova malina. Vrednosti otpora penetracije (zbijenosti) na radnim stazama variraju od 1000 do 5000 kPa. Povećanje zbijenosti jako je smanjilo prodiranje korena maline u dublje slojeve zemljišta, što je utvrđeno pri kopanju zemljišnih profila

Evaluacija utjecaja razine konteksta na učenička postignuća i samopercipirana kognitivna opterećenja u problemskim zadatcima iz kemije

This study was conducted with the aim to examine the effect of context on perceived cognitive load and students’ achievements in problem-solving tasks. It included 161 eighth-grade students. The tasks in the test, which was used as a measuring instrument for assessing knowledge, were designed at three levels of complexity: without context, with moderate and with rich context. Each task was followed by a 7-point Likert-type scale, as a measure of perceived cognitive load. The analysis of obtained results showed that the highest average achievement was reached in the group of tasks without context, followed by the group of tasks with moderate context, while the group of context-rich tasks was characterized by the lowest achievement. Furthermore, the results have shown that there is a statistically significant difference between achievement in tasks without context and tasks with moderate context, as well as between achievement in tasks without context and context-rich tasks, while there was no statistically significant difference between achievement in tasks with moderate and context-rich tasks. Similar results were obtained for the perceived cognitive load, thus indicating that context-rich tasks abound in information and therefore impose high cognitive demands on learners. These findings may represent a significant contribution to the still under-researched area of context-based assessment thus paving way for further research in this area, such as investigating the influence of prior knowledge or motivation on solving context-rich tasks.Ova je studija provedena s ciljem ispitivanja utjecaja konteksta na samopercipirana kognitivna opterećenja i učenička postignuća u problemskim zadatcima. Njome je obuhvaćen 161 učenik osmog razreda osnovne škole. Test je korišten kao mjerilo za procjenu znanja. Zadatci na testu bili su dizajnirani u tri razine kompleksnosti – bez konteksta, s umjerenim i bogatim kontekstom. U okviru svakog zadatka nalazila se ljestvica Likertova tipa sa sedam stupnjeva za mjerenje samopercipiranog kognitivnog opterećenja. Analiza dobivenih rezultata pokazala je da je najviše prosječno postignuće ostvareno u skupini zadataka bez konteksta, zatim u skupini zadataka s umjerenim kontekstom, a najniže je prosječno postignuće ostvareno u skupini zadataka s bogatim kontekstom. Nadalje, rezultati su pokazali da postoji statistički značajna razlika u postignućima u zadatcima bez konteksta i zadatcima s umjerenim kontekstom, kao i između postignuća u zadatcima bez konteksta i zadatcima s bogatim kontekstom, a da razlika u postignućima u zadatcima s umjerenim i zadatcima s bogatim kontekstom nije statistički značajna. Slični rezultati dobiveni su za samopercipirana kognitivna opterećenja, što upućuje na to da zadatci bogati kontekstom obiluju informacijama i stoga učenicima nameću visoke kognitivne zahtjeve. Ti pokazatelji mogu predstavljati važan doprinos do sada nedovoljno istraženom području kontekstualiziranih zadataka, otvarajući put za daljnja istraživanja u tom području, kao što su ispitivanja utjecaja predznanja ili motivacije na rješavanje zadataka bogatih kontekstom

Ecophysiological and biochemical traits of three herbaceous plants growing on the disposed coal combustion fly ash of different weathering stage

The ecophysiological and biochemical traits of Calamagrostis epigejos (Roth.) Festuca rubra L. and Oenothera biennis L. growing on two fly ash lagoons of different weathering stage (L1-3 years and L2-11 years) of the “Nikola Tesla- A” thermoelectric plant (Obrenovac, Serbia) were studied. Species-dependent variations were observed at the L1 lagoon; the greatest vitality (Fv/Fm and Fm/Fo) followed by higher photopigment and total phenolic contents were measured in O. biennis in relation to C. epigejos (p<0.001) and F. rubra (p<0.001). At the L2 site, higher vitality was found in O. biennis (p<0.001) and F. rubra (p<0.01) compared to C. epigejos. O. biennis had the highest photosynthetic capacity. The results obtained in this study indicate that all examined species maintained a level of photosynthesis that allowed them to survive and grow under the stressful conditions in ash lagoons, albeit with lower than optimal success. [Projekat Ministarstva nauke Republike Srbije, br. 173018

Analysis of benzoic and cinnamic acid derivatives of some medicinal plants in Serbia

Natural phenolics, which are ubiquitously distributed in plants, have been reported as functional factors in phytotherapy. We have examined phenolic compounds in the leaves and inflorescences of five significant medicinal plants of different plant families: Salvia officinalis (Lamiaceae); Achillea clypeolata (Asteraceae); Nymphaea alba (Nymphaeaceae); Rumex acetosella (Polygonaceae) and Allium ursinum (Alliaceae). The examined species were rich in total phenolics (up to 30.88 mg/g dry weight). According to their total phenolics contents, the plants can be arranged in the following order: A. clypeolata>N. alba>S. officinalis>R. acetosella>A. ursinum. Free phenolics prevailed in all species in comparison to the bound forms (63.72-82.68% of total phenolics). The highest content of total free phenolics was measured in the tissues of A. clypeolata and N. alba, and the lowest in A. ursinum. Five phenolic acids were isolated and measured. p-Coumaric and ferulic acids as derivatives of cinnamic acid prevailed in the leaves of R. acetosella and A. ursinum (up to 4.81%).Projekat ministarstva br. 17301