Technical efficiency analysis of oil companies in the Republic of Serbia

The subject of this paper is the assessment of the efficiency of oil companies operating in the Republic of Serbia. This paper presents the possibilities of applying non-parametric methods in researching the efficiency of oil companies in the Serbian market. In addition to the standard variables for measuring technical efficiency, the market share should be taken into account, because the oil market is an example of an imperfect competition market. By applying the quantitative-analytical method (Data Envelopment Analysis), obtained results show the development of the efficiency of oil companies in the relevant market, and indicate that the efficiency of oil companies improved during the analysed period. However, the results also indicate that there is still a problem of misallocation of resources. The reasons for this outcome are interesting and debatable for this industrial area

Supplementary data for article: Senerovic, L.; Zivkovic, M. D.; Veselinovic, A.; Pavic, A.; Djuran, M. I.; Rajkovic, S.; Nikodinovic-Runic, J. Synthesis and Evaluation of Series of Diazine-Bridged Dinuclear Platinum(II) Complexes through in Vitro Toxicity and Molecular Modeling: Correlation between Structure and Activity of Pt(II) Complexes. Journal of Medicinal Chemistry 2015, 58 (3), 1442–1451. https://doi.org/10.1021/jm5017686

Supporting information for: [https://doi.org/10.1021/jm5017686]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1659

STANJE STABALA AESCULUS HIPPOCASTANUM L. U DRVOREDIMA CENTRALNOG DELA OBRENOVCA

In urban areas treelined paths are the most vulnerable element. According expected functions treelined paths in certain street are unsatisfactory with their appearance and general condition. These are primarily biological, ecological, sociological and aesthetic functions. Because of negative anthropogenic influences trees are with low level condition, very low functionality and the unsatisfactory state of health. Most of the trees exist in very difficult circumstances of streets, there are crowded in the underground and in the aboveground part. In such circumstances, just as individual specimens of trees grow into individuals who manifest themselves in terms of morphology characteristics which are representative of its species. In this paper is presented the state of the avenue of horse chestnut (Aesculus hippocastanum L.) in two central streets of the old part of Obrenovca. The data were analyzed on the basis of the reviewed every tree and with the particular assessing the state of the crown and the state of the trunk. Based on the analysis of the results measures are proposed for the rehabilitation of individual trees as well as measures for the reconstruction of the entire tree line.U sistemu gradskog zelenila drvoredi su najugroženiji element. Drvoredi pojedinih ulica kod nas svojim izgledom i opštom kondicijom ne zadovoljavaju očekivane funkcije. To su u prvom redu biološke, ekološke, sociološke i estetske funkcije. Pod negativnim antropogenim uticajima stabla su niskog stepena kondicije, vrlo niske funkcionalnosti i nezadovoljavajućeg zdravstvenog stanja. Većina stabla egzistira u vrlo teškim uslovima ulice, stešnjena su i u podzemnom i u nadzemnom delu. U takvim okolnostima samo pojedinačni primerci izrastu u individue koje u morfološkom smislu manifestuju reprezentativne osobine svoje vrste. U radu je prikazano stanje drvoreda divljeg kestena (Aesculus hippocastanum L.) u dve centralne ulice starog dela Obrenovca. Analizirani su podaci na osnovu pregledanog svakog stabla posebno ocenjivanjem stanja krune i stanja debla. Na osnovu anlize rezultata predložene su mere za sanaciju pojedinih stabala kao i mere za rekonstrukciju celokupnog drvoreda

Belgrade’s Urban Green Areas Current Soil State and Its Way to Sustainability

Urban forests are important part of cities’ green infrastructure, especially in cities with great anthropogenic pressure as Belgrade is. Urban green areas enable people to connect with nature and contribute to livability in cities, but some studies reported soil pollution particularly with heavy metals. Due to that, soil samples from Avala Mt,. and Byford’s and Zvezdara Forests were collected from 15 sites and three depths (0-10 cm, 10-20 cm and 20-40 cm), making a total of 45 analyzed samples. Among all analysis, content of microelements was measured for the purposes of this research. No significant changes were observed comparing sites or depths and among all measured elements Zn was the most and Hg the least abundant. Analysis of microelements in soil showed that sustainable soil quality Ni levels are exceeded in all samples, while Cr, Cd and Co levels only in some. All of these results can be explained by forests’ age, geological origin and anthropogenic origin and influence. Even though due to Serbian Soil Quality Regulation no remediation is required for now, in the light of predicted climate change, regular monitoring and assessment should be done to display soil quality and to maintain or improve urban forests sustainability

Increase of Urban Forests Sustainability by Assessing Landscape Sensitivity

Urban forest includes individual trees, but also associated vegetation and the soil beneath the trees. In many regions, urban forests are the most extensive, functional and visible form of green infrastructure in cities and occupy an important place in mitigating and adapting to climate change and preservation of forest ecosystems. These forests are safe islands for biodiversity and play a key role in preserving human health and raising the quality of life in the city. However, urban forests face many challenges including difficult growing condition, insufficient resources for proper care and problems for development, which are enhanced by incomplete public understanding of benefits that urban forests provide. Urban soils are often subject to several degradation processes, such as erosion, compaction and pollution. The Košutnjak urban forest (Belgrade, Serbia), occupies a total area of 305.32 ha, of which 83% is forested. In 2014, 93% of the area was declared a Monument of Nature “Košutnjak Forest” while the remaining 7% of the forest is intended for recreation and general cultural and educational functions. The stand is mostly natural deciduous hardwood tree and covers almost 70% of the forest. Košutnjak is home to many plant and animal species, some of which are under strict protection. There are 521 plant species, including for example oak (Quercus sp.), chestnut (Aesculus hippocastanum), cedar (Cedrus sp.), pine (Pinus sp.), hazel (Corylus sp.). In 2015, the average age of the trees has been estimated to be 60–70 years. During the same year, about 50 ha of Košutnjak has been re-forested with 4,400 seedlings of ash (Fraxinus sp.) and sycamore (Platanus sp.). However, trees in Košutnjak present a poorly developed canopy, often rotten. The forest was seriously affected by the snowfall in December 2021, when a large number of trees fell, broke and bent. The general condition of the forest is unfavorable, the assembly is interrupted and damaged. Due to steep slopes and generally poor condition of vegetation, erosion processes are observed in the form of scouring, rills, gullies and local movements of soil masses. Other forms of physical degradation include compaction namely in observed wheel tracks. The aim of this study is to investigate the connection between the productivity of forest ecosystems and soil quality. Soil physical- chemical characteristics contribute to determining the sensitivity of the soil of the urban forest Košutnjak to degradation processes and the connection between the state of vegetation and soil quality. The study is based on the detail analyses of the data of the current state of land and vegetation, as well as expected deviations due to the impact of selected climate change scenarios. Three potential climate scenarios were tested and contribute to understanding the possibility of adapting the Košutnjak urban forest to degradation processes and soil nutrient losses favored by climate change. This knowledge will aid in determining proposed measures and strategies to mitigate the effects of land degradation processes based on the principle of environmental engineering. The study introduces a new framework for valorization of the current and future state of land and vegetation in the urban forest Košutnjak. The results provide a basis for mitigating or restoring land degradation, which inevitably arises from the management practices. With application of anti-erosion, remediation and prevention measures and application of natureinspired solutions and ecosystem services, the condition of the land will be improved

Origin and Spatial Distribution of Heavy Metals in Mountain Beech Forests Soils Across Europe

The objectives of this research were to investigate the concentration; characterize the distribution; and determine the sources of heavy metals in European mountain beech forest soils. Total of 37 soil samples were collected from 11 countries (Bosnia and Herzegovina, Bulgaria, Czech Republic, Germany, Italy, Poland, Romania, Serbia, Slovakia, Slovenia and Spain). Concentrations of As, Cd, Co, Cr, Cu, Ni, Pb, Zn, and Hg were in ranges of 0.98-22.98 mg kg-1, 0.99-6.03 mg kg-1, 2.51-26.01 mg kg-1, 4.22-83.42 mg kg-1, 11.25-39.77 mg kg-1, 4.79-56.34 mg kg-1, 1.38-91.76 mg kg-1, 32.50-252.20 mg kg-1, 0.20-5.07 mg kg-1, respectively. Hotspots of heavy metals were observed in luvisol and rendzina soils developed on carbonate bedrock. Multivariate analyses discriminated between component 1 with a large positive associations of As, Cd, Cr, Zn, Hg, Pb, CaCO3, Corganic, pH, EC, Mg, and Ca and component 2 with a large positive associations of Co, Cr, Cu, Ni, clay, Al, and Fe. Positive matrix factorization Factor 1 was defined by As, Pb, and Zn, Cu and Hg provided similar contributions for Factors 1 and 2. Cd, Co, Cr, and Ni provided the highest percentage contributions for Factor 2. Pollution index, Enrichment factor of Cr, Hg, As, Pb, Ni, Cd, Cu, Zn, and Co ranges: 0.05–1.17, 4.48–246.63, 0.01–3.21, 0.06–2.97, 0.18–3.40, 4.30–81.62, 0.56–3.20, 0.52–3.83 and 0.21–3.81, respectively

Increase of Sustainability of Urban Forests by Prevention of Land Degradation

An urban forest includes trees and shrubs, but these vegetative structures can be also found in parks, gardens and along streets within urban areas. In many regions, urban forests are the most extensive, functional, and visible form of green infrastructure in cities and have an important place in the combat against climate change, preservation of forest ecosystems. Urban forests are safe islands for biodiversity and play a key role in preserving human health and raising the quality of life in the city. The Kosutnjak urban forest, Belgrade, Serbia, occupies a total area of 305.32 ha, from which 83% is forested. Altitude varies in the range of 75 to 217 m above sea level and the climate is temperate-continental. In 2014, 93% of the area was declared a Monument of Nature "Kosutnjak Forest” while the remaining 7% of the forest is intended for recreation and general cultural and educational functions. The coniferous natural hardwood covers almost 70% of the total area. Generally, trees are characterized by poorly developed canopy, often rotten. The forest was seriously affected by the snowfall in December 2021. A large number of trees fell, broke and bent. The general condition of the forest is unfavorable, the assembly is interrupted and damaged. Due to steep slopes and generally poor condition of vegetation on the entire surface of the Kosutnjak forest, erosion processes are observed in the form of leaching, furrows, ravines and local movements of soil masses. Other forms of physical land degradation are compaction associated with occurrence of tracks. The aim of this study is to determine the connection between the productivity of forest ecosystems and soil quality. Soil physical- chemical characteristics contribute to determining the sensitivity of the soil of the Kosutnjak urban forest to degradation processes and the connection between the state of vegetation and soil quality. Furthermore, three potential climate scenarios were tested and contribute to understanding the need for adapting the Kosutnjak urban forest to degradation processes and soil nutrient losses exacerbated by climate change. This knowledge will aid in determining proposed measures and strategies to mitigate the effects of land degradation processes based on the principle of environmental engineering

Influence of the Soil Properties on the Sessile Oak Stands (Quercus petraea)

Oak forests are widespread forest communities in the deciduous vegetation. From the 10 species of oaks in Serbia, next to pedunculate oak (Quercus robur), the most valuable and common type of tree is sessile oak (Quercus petraea). Sessile oak is characterized by a relatively wide ecological amplitude, so it is almost present in all forest areas, as well as in low mountains. In addition to the economic importance of sessile oak forests, their protective role against soil erosion is also important. However, degradation and drying of sessile oak forests is very pronounced. Proper land management not only increases its productivity, but also provides a valuable mechanism for mitigating the effects of climate change and a way to preserve ecosystem services. The aim of this study is to determine the dependence of soil properties on sessile oak forest condition. For this purpose, properties of sites with endangered oak stands were compared with a sites with stand in a good health condition. Results indicate significant dependence of oak condition on soil properties. Sites with endangered oak have higher silt component and bulk density, lower EC-electrical conductivity, pH, Corg, porosity and Atterberg limits, while contents of micro and macroelements is similar between sites. This study contributes to understanding of the impact of soil properties on the natural regeneration of sessile oak forests, which is an important prerequisite for improving forest cultivation, especially related to the climate change

Утицај геолошке подлоге и начина коришћења терена на физичко-хемијска својства земљишта фрушк

Soil erosion is a problem that affects the landscape at different scales and represents a serious challenge for land management and soil conservation in both natural forests and meadows. The aim of this study was to determine how the parent material and land use affect the physical and chemical properties of the soil in the area of the Fruska gora Mountain. The soils were developed on five bedrock types: serpentinite, marl, trachyte, shale, loess and two land use types: forest and meadow. Twenty-three forest soil and 24 meadow soil from a depth of 0-20 cm were sampled from the Fruska gora Mt. Following properties were determined: pH, electrical conductivity, oxidation-reduction potential, content of organic carbon, sodium adsorption ratio, aggregate size and stability. There is no statistically significant difference in pH, Eh, EC, and SAR values between the analyzed forest and meadow soils, but there is a statistically significant difference in the content of Corg. It can be conculded that both the parent matrial, and to a slightly less extent, land use have a great influence on physico-chemical properties of the soil.Ерозија земљишта је проблем који утиче на пределе у различитим размерама и представља озбиљан изазов за управљање земљиштем и очување земљишта како у природним шумама тако и на ливадама. Циљ овог истраживања био је да се утврди како матична стена и начин коришћење земљишта утичу на физичко-хемијске особине земљишта на подручју Фрушке горе. Земљишта су развијена на пет типова стена: серпентинит, лапорац, трахит, шкриљац, лес, као и на два начина коришћења терена: шума и ливада. Са Фрушке горе узоркована су 23 шумска земљишта и 24 ливадска земљишта са дубине од 0-20 цм. Одређена су следећа својства: pH, електрична проводљивост (EC), оксидо-редокс потенцијал (Eh), садржај органског угљеника (Corg), однос адсорпције натријума (SAR), величина агрегата и стабилност. Не постоји статистички значајна разлика у вредностима pH, Eh, EC и SAR између анализираних шумских и ливадских земљишта, али постоји статистички значајна разлика у садржају Corg. Може се закључити да на физичко-хемијске особине земљишта велики утицај имају изворни материјал и у нешто мањој мери начин коришћење земљишта

Applicability of the PA-BAT+ in the evaluation of values of urban protected areas

The International Union for Conservation of Nature (IUCN) has a vision that the proper evaluation of protected areas (PAs) leads to a greater interest, more significant investment, and better conservation of natural resources. The evaluation of ecosystem services (ES) provided by protected areas (PAs) is of long-term importance to the local and national economies. Mapping the values of PAs, greater participation of decision-makers, and finally changes in public policies and the development of economic models that include natural resources in their development plans are significant but also long-term processes. IUCN has established the Protected Areas Benefits Assessment Tool+ (PA-BAT+), which provides initial information on how different stakeholders view the current state and potential values of PAs, which can help integrate natural resources and services provided by ecosystems in development plans. Such a tool makes it possible to identify the main factors relevant to the PAs and the country’s development policy, the flow of economic benefits, and the need for strategies that will enable the return of income to local people and PAs. Factors relevant to the importance of specific jobs in PAs - which is vital for the rural economy and necessary for decision-makers could also be identified with this tool. Identifying these factors can increase PA’s contribution to the Sustainable Development Goals, such as no poverty, zero hunger, good health and well-being for people, quality education, clean water and sanitation, sustainable cities and communities, climate action, life below water and life on land