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Search Results: 1 - 10 of 1762 matches for " Bjedov Ivana "
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Amorpha fruticosa L. on wet sites in Belgrade
Radulovi? Stojanka,Sko?aji? Dragana,Bjedov Ivana,?unisijevi?-Bojovi? Danijela
Glasnik ?umarskog Fakulteta , 2008, DOI: 10.2298/gsf0897221r
Abstract: Amorpha fruticosa is in many countries, and also in Serbia, one of the most dangerous invasive species. The detection of mechanisms which inhibit the spreading of Amorpha population would be of great significance for finding the adequate measures of biological control. In this sense, first of all it is necessary, inter alia, to determine Amorpha ecological and coenological characteristics. The vegetation studies of wet sites in Belgrade were compared. The study results indicate that Amorpha is present in forest communities, from the lowest elevations at the timber line to the highest elevations, where the periods of underground and flood waters are the shortest, or where they are absent. Amorpha forms thick brushland on meadows with different water regimes and in forest plantations of different canopy closure. If it is regularly removed by felling, Amorpha does not endanger the structure and the floristic diversity of meadow communities. Amorpha is absent or rare in forest plantations of the densest canopy, as well as in the communities which belong, or once belonged, to the alliance Magnocaricion Br.-Bl.
The content of heavy metals in the leaves of Hypericum perforatum L. on serpentinite soils in Serbia
Obratov-Petkovi? Dragica,Bjedov Ivana,Belanovi? Sne?ana
Glasnik ?umarskog Fakulteta , 2008, DOI: 10.2298/gsf0898143o
Abstract: St John's wort is one of the best known and used medicinal plants. The demands for St John's wort in Serbia is still supplied by the collection of native plants. Therefore it was necessary to examine the concentration of heavy metals in the soil and in plant material on serpentinites and to assess the potential safe harvesting and further utilisation of this plant species. The research was performed on three serpentinite sites in Serbia: Zlatibor, Div ibare and Go . The main soil types were determined and the contents of 7 chemical elements were analyzed in the soil and in the plant material. It was determined that the soils of all three localities had increased concentrations of nickel, chromium and manganese. The St John's wort plant material (leaves) showed the increased concentrations of iron, nickel and chromium. It was concluded that St John's wort was a tolerant species regarding the heavy metal content, and it was recommended to avoid its harvesting on the investigated localities.
Revegetation of ski runs in Serbia: Case studies of Mts. Stara Planina and Div ibare
Bjedov Ivana,Risti? R.,Stavretovi? N.,Stevovi? V.
Archives of Biological Sciences , 2011, DOI: 10.2298/abs1104127b
Abstract: Revegetation is the most sustainable method of soil stabilization at ski runs. In order to establish a stable plant community, it is recommended to use native species. However, non-native species are most often used. In this paper the revegetation of ski runs at two ski resorts is investigated: Div ibare and Stara Planina. Seven species were used for the revegetation of the ski run at the Div ibare ski resort of which six species were native. Six species were used for the revegetation of the Stara Planina ski resort, of which two species were native. It was established that the plant species used in the seed mixtures were suitable for erosion control at the investigated ski resorts.
Asteretum lanceolati: Xenospontaneous community on wet and riparian habitats
Obratov-Petkovi? Dragica,Bjedov Ivana,Sko?aji? Dragana,?unisijevi?-Bojovi? Danijela
Glasnik ?umarskog Fakulteta , 2011, DOI: 10.2298/gsf1103073o
Abstract: Invasive species Aster lanceolatus grows on moist habitats on the whole territory of Serbia. In Belgrade, this species is recorded with a higher degree of presence at a number of localities. With the aim to investigate the community in which this species is dominant, the wide area of Serbia was researched, and 8 localities on the territory of Belgrade were chosen for the analysis of the community. Floristic structure of the community was determined by the standard Braun-Blanquet method (1964), phytogeographical analysis was performed according to Gaji (1980, 1984), and determination of life forms according to Raunkier (Ellenberg, Mueller-Dombois, 1967). pH soil analysis and electric conductivity (EC) were performed at all investigated localities. It was established that the community dominates the moist habitats of Belgrade. It is composed of 104 species and among them Aster lanceolatus Willd., Cichorium intybus L., Agropyrum repens (L.) Beauv., Calystegia sepium (L.) R. Br., Cirsium arvense (L.) Scop., Symphytum officinale L. and Rumex obtusifolius L. are the most frequent. In relation to life forms, the community has hemicriptophytes character, and in relation to phytogeography Euroasian and Middle Europaean floral elements are dominant, with a high presence of cosmopolitan and adventive floral elements. On the locialities Veliko Ratno ostrvo (island) and Maki , EC values point to the fact that the amount of nutrient in the soil is higher than at other localities.
Analysis of the biological spectrum of vascular flora of Ravni Srem flood forests
Juri?i? Branislav,Obratov-Petkovi? Dragica,Bjedov Ivana,Bojat Nenad
Glasnik ?umarskog Fakulteta , 2011, DOI: 10.2298/gsf1104057j
Abstract: One of the essential analyses performed during the floristic study of a region is the analysis of the biological spectrum. The analysis of the biological spectrum of the flora includes the determination of the type of life form for each taxon described in the flora of the study region. If it is considered that life form is a specific structural-functional response to the environmental effects and the result of the adaptation during the species evolution, it is clear that the basic characteristics of the site are more or less reflected in any life form. This fact is confirmed by the analysis of the biological spectrum of the flora of Ravni Srem. The analysis of the Ravni Srem flora shows the domination of the hemicryptophytes and the subdomination of the phanerophytes with a considerable participation of the therophytes.
Soil organic carbon storage in moutain grasslands of the Lake Plateau at Mt. Durmitor in Montenegro
Kadovi? Ratko,Belanovi? Sne?ana,Obratov-Petkovi? Dragica,Bjedov Ivana
Glasnik ?umarskog Fakulteta , 2012, DOI: 10.2298/gsf1206113k
Abstract: Soil organic C storage in mountain areas is highly heterogeneous, mainly as a result of local-scale variability in the soil environment and microclimate. The aims of the present study were to estimate soil organic carbon density (SOCD) and stocks in leptosol on morainic deposits of high-altitude grasslands of the Lake Plateau of Mt. Durmitor National Park in Montenegro, and determine the soil variables that can be used as factors to determine the SOCD at 28 soil profiles. Our results indicated that SOC storage in the top 40 cm of the alpine grasslands were estimated at 560 414.86 t C, or 152.66 t ha-1, with an average density of 15.27 kg m-2. The soil organic carbon density increased significantly with soil moisture, clay and silt content, but only moderately with mean annual temperature. In conjunction, these variables could explain approximately 51% of the total variation in SOC density.
Ecology and distribution of an invasive species Aster-lanceolatus willd. on wet habitats in Belgrade
Obratov-Petkovi? Dragica,Bjedov Ivana,Radulovi? Stojanka,Sko?aji? Dragana
Glasnik ?umarskog Fakulteta , 2009, DOI: 10.2298/gsf0900159o
Abstract: The species Aster lanceolatus occupies a significant position in the world and European lists of invasive species. Its spreading potential is a hazardous factor to the biodiversity in many countries. There are no relevant data on the wider proportion of this species in the area of Belgrade. The sites of Aster lanceolatus are annual or pioneer communities along the water courses, abandoned and neglected areas, forest margins, moist meadows. The study areas are located near a choice of water courses in Belgrade. The aim of the study was to assess the species ecology and population density, synecological interrelationships among the coenobionts of the communities in which it occurs, and also to map its the habitats. The study of population density was performed on the supplemented and partially modified 'CPS SKEW' form, applied in West European countries, by the principle of squares. The species was determined by standard floristic method, and the species location by GPS system. It was concluded that Aster lanceolatus was dominant and wild at all study sites. The individuals and populations are especially numerous on the river islands Ada Ciganlija and Veliko Ratno Ostrvo, along the stream Kumodr aki Potok and the Danube left bank, where the number of individuals per squares is above 1300 and the degree of coverage is 100%. Its spreading potential is conditioned by the species biology, and the expansiveness by climate changes, anthropogenic impacts and the competitive interrelationships.
Presowing treatments to breaking seed dormancy of Pterocarya stenoptera C. DC. as an indicator of potential invasiveness
Grbi? Mihailo,Sko?aji? Dragana,Obratov-Petkovi? Dragica,Bjedov Ivana
Glasnik ?umarskog Fakulteta , 2011, DOI: 10.2298/gsf1103029g
Abstract: The Small-winged wingnut is a 12 to 20 metres tall, deciduous and fast growing tree with large substantial branches that spread as wide as the tree is tall. The 15 to 30 cm long winged fruit catkins, which turn brown in the autumn, are suspended below the branches. The species is not described by domestic authors in Serbia. The seed was introduced from Sofia (from the Arboretum of the Forestry University of Sofia, Bulgaria - Lesotehni eski universitet, Sofija), and subjected to classical stratification and naked stratification during the period of 1 and 2 months. Germination capacity varied among the treatments. The largest number of germinated seeds was observed in the shorter stratifications, (1 month) the classical (56.5%) and the naked (51.0%) with no significant difference. The values of real germination of all treatments were between 69-88%. High value of RG, compared to GC, indicated that more than 40% of the seeds were empty. However, the results of the control as well as other parameters of seed germination clearly point to the fact that practically no deep embryo dormancy was observed, but the seed is recalcitrant and microbiotic. The results indicate a non-invasive character of the species in terms of reproductive potential.
Biotope mapping of the Kumodra stream watershed
Tutund?i? Andreja,Cveji? Jasminka,Obratov-Petkovi? Dragica,Bjedov Ivana
Glasnik ?umarskog Fakulteta , 2010, DOI: 10.2298/gsf1001163t
Abstract: Increasing negative changes in the biosphere, many of them irreversible, impose the need for the recording of the state of abiotic and biotic environmental factors in order that, with adequate measures, left over significant areas protect, degradation process slows down and lost area compensation accordance with possibilities. Therefore, for ecological planning in many developed countries, method of mapping and assessment of biotopes was introduced, firstly in rural areas and later in urban zones as well. Due to characteristic position in the transition direction from the city frindge to towards its core, area of the Kumodra watershed area offered good basis for the application and examination of urban biotope mapping procedures. Different ways of land use, preservation of the relatively large area of open urban areas between two types of build structures and part of the free course of the Kumodra stream offer good base for the assumption that habitats worth being preserved can be expected. The paper present results of the investigations carried out in 2006, which were compared with previous investigations as well as with the state in 2009. Prominent heterogeneity of and use, spreading of illegal settlements, but also existence of structures, which can be significant for encasement of the system of green and open spaces indicate on inadequate development of this area and also need for further investigations, which would lead to adequately planning solutions. By the mapping of the whole stream waters head and collection of attributes which characterize biotopes in details information bases for the further work on the assessment of the town biotope was obtained, as well as for argumentation for the directing the development towards protection of the remaining green areas of the city fringe.
Phytogeographical analysis of vascular flora of Ravni Srem flood forests (Vojvodina, Serbia)
Juri?i? Branislav,Obratov-Petkovi? Dragica,Bjedov Ivana,Bojat Nenad
Glasnik ?umarskog Fakulteta , 2011, DOI: 10.2298/gsf1104041j
Abstract: The aim of phytogeographical analysis was to determine the plant species origin, genesis and migrations. The study results contribute to the knowledge of phytogeographical classification of the particular regions. The flora structure and composition was determined based on the effects of different chorions. The aim of the floristic research of flood forests of Ravni Srem was to identify the diversity of flora in the region, i.e., in a wider sense, the diversity of flora in Serbia. The phytogeographical analysis was based on floristic research. The identified plant species were classified into the corresponding floral elements, area groups, and area types. The data on their diversity and the degree of representation in the flora of Ravni Srem flood forests were obtained based on the percentage of each area type. It was concluded that the character of the flora of Ravni Srem flood forests was transitional, mostly Eurasian-Central European.
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