bluuebunny/crossref_metadata_2025 huggingface dataset:
Constructive procedure for determination of absolute conic figure in general collinear spaces
Authors: Krasic Sonja , Nikolic Vladan
Published: September 2009

When they are collinear, projective spaces set with five pairs of biuni-vocally associated points are general. In order to map quadrics (II degree surfaces), in these spaces, the absolute conic was used. Geometrical position of all the absolute points in the infinitely distant plane of one space, i.e. an absolute conic of space cannot be graphically represented. To the infinitely distant planes are associated by the vanishing planes, and the absolute conics are associated by the conic in the vanishing planes, that is, figures of the absolute conics. Prior to mapping the quadrics, it is necessary to constructively determine the characteristics parameters such as the vanishing planes, axes and centers of space, and then the figures of the absolute conics, in the vanishing planes of both spaces. In order to constructively determine the figure of the absolute conic in the second space, a sphere in the first space was used, which maps into a rotating ellipsoid in the second space. The center of the sphere is on the axis of the first space, and the infinitely distant plane intersects it along the absolute conic. The associated rotational ellipsoid, whose center is on the axis of the seconds space is intersected by the vanishing plane of the first space along the imaginary circumference aI, whose real representative is circumference az. The circumference aI is the figure of the absolute conic of the first space. General collinear spaces are presented in a pair of Monge's projections.
Biology of forest tree protection: its tasks and perspectives
Authors: Tucovic Aleksandar , Karadzic Dragan
Published: September 2009

The logical conclusion of the short analysis of criteria on natural resource planning and management in situ and ex situ (scale, number, intraspecific variability, ecology of communities, policy, economy, organisation of research, recreation), referring to active biological protection of trees, is as follows: biological resources of trees in situ and ex situ should be large, diverse and geographically and ecologically distributed throughout the country. Their number and scale depend on our potentials. At the beginning of the new century, we have to create an active (functional) strategy of the protection of tree biology, especially endemic and relic species. Accordingly, the biologists interested in tree resource protection should already exercise their influence in solving these issues (organisation of active protection, more or less directed reproduction, of economically significant species, etc). The biological protection of trees has an intensive development in the developed countries of the world, while the developing countries are trying to follow the trend, depending on their material sources, culture and attitude of their state government Biological protection of trees is an open, new, and very wide area of further research in already set aside natural resources in situ and ex situ. This is a new field of research, without a long tradition. Along with the scientific value of this approach of the systematic and systemic solution of more or less directed tree reproduction, we also need an economic stimulation. The scope and the complexity of this field of research requires further scientific work of a greater number of teams, some of which should be supported by forestry profession and the society in general The introduction of the model of tree recombination system enables a completely new approach to quality control of the successive generations of trees. This means that all current and planned measures in the model must be clearly scientifically defined, integrally (ecosystem) understood and, most importantly, efficiently realized. Also, their definition and realisation must be synchronised and continual both in case of short-term and long-term measures, which are interdependent and inter-conditioned .
The natural effects of transverse structures in Gabrovacka reka torrent
Authors: Velojic Miljan
Published: September 2009

The classical European system based on the construction of transverse structures is very significant in the solving of the problems of deep and lateral erosion and sediment accumulation in torrent beds. However, due to their effective height on the upstream side, the dams check and accumulate the sediment making the siltation (deposition of silt) whose slope is called the slope of siltation. This paper presents the natural effects of transverse structures (dams) in Gabrova?ka reka, which can be quantified. The paper presents the effects of bed slope on the slopes of siltation and the amounts of accumulated sediment in the siltations, because the effects of technical works are primarily evaluated by the slopes of siltation and by the amounts of accumulated sediment. The analysis of the dependence of newly formed slopes of siltation (Iz) on natural bed slopes (It) was performed by the method of modeling, as the main method, and also by regression and correlation analyses (simple correlation), as concrete study methods. Under the hypothesis that the siltations have a regular wedge, i.e. prismatic form, the accumulated sediment W [m3] in the siltations was calculated by B. Kitin (1975) formula. The study results confirm the very high correlation between the slopes of siltation and bed slope and present the amounts of the accumulated sediment in the conditions of different natural bed slopes and valley widths. This is a useful information which can improve and make more efficient the work on torrent con1rol with similar orographic, petrographic and particle size characteristics.
Morphological characters and the range of the species Echinops banaticus Rochel (Asteraceae) in the flora of Serbia
Authors: Diklic Nikola , Obratov-Petkovic Dragica
Published: September 2009

The species Echinops banaticus Rochel. is one of the five plant species in the genus Echinops L. which have been found to grow in Serbia. The morphological descriptions in our and in foreign floristic literature contain a number of contradictory or incomplete data, which considerably impedes the regular and correct determination and identification of this species. This paper points to the above controversial morphological characters, presents the correct description of the species and the localities where it has so far been found in Serbia, according to field research and the inspection of herbarium material By morphological studies it was found that in the flower region, as correctly reported by Javorka (1925) and Nyarady (1964), pappus scales are joined together throughout their length, and that free tufts appear only at the top The leaves are, after Nyarady (1964), more or less pinnately lobed, green on the adaxial surface, covered with thin, soft, curved, glandular hairs As the range of the species in Serbia has not been sufficiently investigated, it was stated that the species Echinops banaticus Roch. was recorded at 14 localities in Serbia. All the localities are mainly situated in east parts of Serbia, east of the river Velika Morava as far as the borders of Romania and Bulgaria.
The accuracy of land form presentation in forest road Cross sections
Authors: Stefanovic Bogdan , Aleksic Velimir
Published: September 2009

Accurate presentation of natural land forms directly affects the accuracy of earth volume calculation, the component of technical documentation of the forest road master project. Consistent to legal provisions, forest road master project is characterised by high accuracy of the planned scope of works compared to the realised scope of works, which should amount to ?3%. The volume of earth material is calculated based on the road cross-sectional area and the distance between the cross sections. The accuracy of the area of cross sections depends on the accuracy of land form presentation Accurate presentation of natural land forms depends on a great number of factors, the most significant of which are the methods of surveying and acquisition of data necessary for land form presentation, preciseness of equipment and instruments used in surveying and acquisition of data, and the method of land form presentation. The accuracy of earth material volume calculation depends on the method of computation, method of presentation of natural and artificial cross sections, and the phase of design. The presentation of natural land form in the width occupied by roadway cross section depends on the validity of the obtained station point elevation (Ht) and the elevations of detailed points (Hi). A relevant factor of the accuracy of cross sectional area, compared to its other elements, is the accuracy of the depth of cut or the height of fill (h) which should agree with the required accuracy, i.e. the adopted tolerance of the earthwork bill of quantities deviation up to 3%.
Spontaneous and induced mutations in the trees and shrubs of Serbia and their usability value
Authors: Tucovic Aleksandar , Isajev Vasilije , Sijacic-Nikolic Mirjana
Published: September 2009

Mutations include the changes of the inherited material and they occur naturally, but very rarely. This paper presents the spontaneous and induced mutations, their frequency of occurrence and applicability for the needs of plant production in forestry. The initial material includes the trees and shrubs of Serbia, and the methods are the comparative morpho-physiological analysis, ionising radiation and chemical half-sib tests Spontaneous mutations in our country have been recorded more frequently since the sixties and the study of intra-variability of trees and shrubs in Serbia has been intensified. They include the changes of growth habit, character of increment, abnormalities in the structure of vegetative and generative organs. By selection and vegetative propagation, numerous ornamental tree and shrub varieties have been synthesised over a more or less long period. After the discovery of the vigour of triploid mutants trees, their mass production has been elaborated: by crossing triploid and diploid trees By the treatment of the reproductive material by ionising radiation (UV, gamma rays, terminal neutrons), and chemical materials, the frequency of mutations increased drastically, especially with higher doses up to 100% in the treated organisms. The mutants have, as a rule, reduced growth elements, reduced adaptation, and when selected and propagated vegetatively, they ensure a rich initial material for the synthesis of numerous ornamental cultivars of trees and shrubs. The method of radiation breeding is the most promising for the improvement of ornamental plants, while mass production of triploid mutants is the only method used in the improvement of forest trees.
Effect of fungus Heterobasidion Annosum (FR) bref. on fir and spruce dying in the region of the NP "Durmitor" and "Biogradska gora"
Authors: Andjelic Milosav
Published: September 2009

Several adverse factors of abiotic and biotic nature affect the vitality and decline of spruce and fir in the region of NP "Durmitor" and NP "Biogradska Gora". The most significant adverse abiotic factor is air pollution. Among the adverse biotic factors, the most significant is by all means the parasitic fungus Heterobasidion annosum. The damage caused by this fungus is especially severe in spruce and fir stands in the region of the NP "Durmitor". The infection intensity is approximately the same in both species. The damage caused by H. annosum is greater in the forests of NP "Durmitor", than in the forests of NP "Biogradska Gora". This can be explained by the fact that spruce and fir stands on Durmitor were felled without maintaining the forest order. In the virgin forest reserve NP "Biogradska Gora" in the past there were no fellings, i.e. the impact of anthropogenic factors was excluded. Fungus H. annosum cannot be eliminated form spruce and fir stands on Durmitor, but the treatment of stumps (immediately after the sanitation felling) with "Penofil" or "Borax" can check the velocity of its spread. In this way, the forest is given an opportunity to form more resistant populations through a long period by natural selection .
Characteristics of substrates used for nursery production of Austrian pine and Scots pine
Authors: Vratusa Vesna , Anastasijevic Nebojsa
Published: September 2009

This paper discusses research results concerning properties of substrates used for nursery production of Austrian pine (Pinus nigra Arn) and Scots pine (Pinus silvestris L) in the experimental field of the Faculty of Forestry in Belgrade There is no doubt that peat is the most favorable substrate for successful massive nursery production of various woody species. Favorable physical, chemical and biochemical properties guarantee nursery production success, on condition that all technical and technological procedures, characteristic for this production, are recognized. Certain shortcomings that may occur with different kinds of peat (inadequate air capacity, nutrient deficiency, excessive acidity, etc) may relatively easily be overcome with appropriate materials and procedures. Nevertheless, the main shortcoming of this most widely used nursery substrate, especially when the countries with economies in transition are concerned, is its high price. In order to overcome this problem, it is necessary to use domestic resources for creating a substrate of approximately the same characteristics, but much lower price Research results regarding the substrate ? mixture "Goc 1" show that this substrate, comprising 30% silica sand, 20% earthworm manure, and 50% bark humus, is characterised by all necessary starting prerequisites for fulfilling the cited functions. This material represents loamy sand of almost neutral reaction (pHH2O=6.9, pHCaCl2=6.40), and even though its CEC is relatively modest (33.08 cmol(+) x kg?1), it is extremely well supplied with bases (V=94.32%). Also, "Goc 1" is rich in humus (8.94%), with relatively high content of total N (0.47%), and favorable C:N ratio (11.0). It is extremely well supplied with available phosphorus and potassium (>50 cmol(+) x kg?1). Further research regarding stability of this artificial substrate and alterations of its physical, chemical, and biochemical properties in the course of exploitation, together with monitoring the growth and development of Austrian and Scots pine seedlings, will show if the composed mixture "Goc 1" is of good enough quality to successfully replace peat in massive nursery production of Pinus nigra Arn., and Pinus silvestris L. in the future.
Gremmeniella abietina (lagerb) morelet: Distribution in Yugoslavia, significance and control
Authors: Karadzic Dragan , Andjelic Milosav , Vemic Mioljub
Published: September 2009

Fungus G. abietina is one of the most dangerous pathogenic fungi inhabiting conifer plantations, and especially endangered species are the pines. Among the pines, the most susceptible species is Austrian pine, and endangered plantations are aged between 8 and 25 years. This fungus was detected in Serbia and Montenegro only on the mountains (Kopaonik, Vlasina, Go?, Durmitor). The fungus was identified on Austrian pine, Scots pine and spruce. In its development G. abietina forms both stages (anamorph and teleomorph). Its imperfect form i.e. pycnidial stage, is far more significant for the infection process, and mainly all infection is carried by conidia (=pycnospores). Infection of trees is possible throughout the year, but the critical period of infection is May-June. Conidia are transmitted by raindrops, and the infection is spread through the buds and bark of young shoots. Incubation period lasts for 9 months, i.e. if infection occurs in June of the current year, the first visible symptoms of infection occur in March of the following year. The symptoms of infection are visible at the base of buds (cross section), on the needles (initial orange discolouration at the base of the needles, and then the whole needle turns brown and drops) and on the bark of young shoots. Soon after infection symptoms, the fruiting bodies (i.e. pycnidia) appear on the necrotic tissues of the host. Apothecia form on the bark two years after tree dying. In the severely infested plantations, all dead trees should be felled and removed, and the remaining trees should be treated with copper fungicides. As this is a quarantine disease, care must be taken to prevent the spread of the disease to the new uninfected regions. This measure is imposed by the legal regulations on quarantine diseases.
Edaphic potentials of beech forests on Brezovica
Authors: Knezevic Milan , Kosanin Olivera
Published: September 2009

The study deals with the soils in the montane beech forest (Fagetum moesiacae montanum Jov. 53) in the management units "Ju?ni Ku?aj II" and "Bogovina I", on the mountain massif Brezovica. Soil genesis in the beech forests of Brezovica, along with vegetation and relief, was affected by the character of parent rock. The study soils occur over two types of bedrock: limestone and argilloschist The soil types and sub-types are defined based on the profile morphology, parent rock and pedogenetic processes Two types of soil were analysed on limestone: black earth (calcomelanosol) and brown soil (calcocambisol). Two sub-types of black earth were defined: organomineral and brownised. There are two varieties of organomineral black earth: colluvial and lithic. Also two sub-types of brown soils were defined and: typical and illimerised. The soils on limestone are characterised by great spatial variability. Different combinations of soil formations occur on a small area. Soil combinations consist of two or three development phases, the most represented of which are the following: organomineral black earth - brownised black earth; organomineral black earth - brownised black earth - typical brown soil; typical brown soil - illimerised soil Typical brown soil is formed on argilloschists and it occurs in two forms: medium deep, medium skeletal acid brown soil and deep, poorly skeletal acid brown soil The most productive sites of the montane beech forest on Brezovica are deep acid brown soils and the soil combination: typical brown soil - illimerised soil on limestone.
State and silvicultural problems of beech forests in Northeast Serbia
Authors: Krstic Milun , Medarevic Milan , Stojanovic Ljubivoje , Bankovic Stanisa
Published: September 2009

The state and silvicultural demands in beech forests of northeast Serbia were studied in the economic regions of Severni Kucaj, Timok and Juzni Kucaj, and in the region of the National Park Djerdap. The detailed analysis of state forests was performed: representation of beech forests according to silvicultural form, origin, age structure, stand state and productivity Average volume in high beech forests of 218 m3 x ha?1 is for about 5% lower than the average in Serbia (207.2 m3 x ha?1), and it amounts to 87% of the optimal volume of beech forests in Serbia. Volume increment of 4.5 m3?ha?1 is approximate to the average increment of high beech forests in Serbia, and it amounts to 75% of the optimal value. The average volume of coppice beech forests of 150 m3?ha?1 is 60% of the optimal volume of beech forests in Serbia The age structure is unfavourable, because the percentage of well conserved mature stands is only about 8%. Unplanned regeneration has started on about 15% of the area. Middle-aged and maturing stands account for more than 3/4 of the total area (80%). Stand state of beech forests in this region can be assessed as close to unsatisfactory, if the criteria are conservation, origin, vitality, and also the health state Based on the above state, the concrete silvicultural demands for each silvicultural situation were determined and the silvicultural measures were proposed aiming at their rational utilisation and improvement of forest state: measures aiming at the establishment of new, quality stands and measures aiming at the improvement of the state of existing forests.
Tiarosporella species: Distribution and significance
Authors: Karadzic Dragan
Published: September 2009

The genus Tiarosporella consists of eight species of which four occur on conifers. These fungi differ in conidial size and in the form of appendages that occur on the distal end of the conidia (pycnospore). In Europe only the two species have been recorded. T. parca occurs on the species of the genus Picea (P. abies and P. omorika), while T. durmitorensis infests fir (Abies alba). T. parca can be considered, as an endophyte, and it sporulates only when the needles die due to a stress or old age. T. durmitorensis is a very aggressive pathogen colonizing fir needles of all ages. Together with other fungi, it leads to tree death. So far, T. durmitotensis has been found only in European silver fir stands in the National Park "Durmitor" and in the National Park "Biogradska Gora".
Lag time on torrential catchments in Serbia
Authors: Ristic Ratko
Published: September 2009

Maximal discharge Qmax(p) is the basic input data for designing longitudinal and transversal objects in torrential beds. Calculation of maximal discharge Qmax, on unstudied catchments, is carrying out by usage the theory of synthetic unit hidrograph and SCS methodology for separation effective rain Pe by total rainfall Pb. One of the basic time characteristics of torrential floods was analyzed: lag time tp. Lag time tp was determined on the basis of processing of hydrographs and deriving representative unit hydrographs, on 93 control profiles. Dominant physical-geography characteristics were determined: magnitude of the catchment area A, length of the catchment area along the main stream L, the distance from the centroid of the catchment area to the outlet profile Lc, average slope of the river bed Iu, average slope of terrain on the catchment area Isr. Lag time and dominant physical-geography characteristics were the basis for deriving some equations with regional significance (tp=f(L, Lc, Iu); tp=f(L, Lc, Iu, Isr)). The relation between lag time tp and time of concentration Tc was determined (tp=f(Tc)).
Occurrence of poly-winged fruits on cultivated sycamore maples - Acer pseudoplatanus L
Authors: Ivetic Vladan , Tucovic Aleksandar
Published: September 2009

The occurrence of polycarpous fruits on six out of 100 sycamore maples, i e. with 3, 4 and 8 fruits on one carpophore is described. Eight-carpous fruits have not been recorded to date in the region of the Serbia and Montenegro, and wider. The cause of the development of polycarpous fruits has been hypothesized.
Test of resistance of Populus x euramericana cv. Pannónia to the attack of Discosporium populeum (sacc) Sutton in the conditions of Gornje Potisje
Authors: Keca Nenad
Published: September 2009

The simple crossing of different poplar species enables a relatively easy method of obtaining the new cultivars and clones by artificial selection combined with production characteristics. The first step in the study of resistance of the newly selected individuals to parasites is the artificial infection of the control plants. If the plant shows the adequate degree of resistance, it is introduced to individual sites and its behavior to the pathogen is monitored in the conditions of natural infections. After the tests with artificial infections, the cultivar Populus x euramericana cv. Pann?nia showed satisfactory results, so its monitoring was continued in the plantation production. This paper presents the study of this cultivar resistance to the infections by the fungus Discosporium populeum in natural conditions. Based on the study results, the cultivar Pann?nia can be recommended for use, especially at the sites with poorer hydrological characteristics.
Distribution of some heavy metals in the soils of beech communities in the NP Djerdap
Authors: Belanovic Snezana , Knezevic Milan , Kadovic Ratko , Danilovic Milorad
Published: September 2009

The concentrations of some heavy metals in the soils of beech communities (Fagetum submontanui luzuletosum, Fagetum submontanum drymetosum and Musco-Fagetum) were studied in the region of Djerdap. The significant difference was determined between the concentrations of heavy metals (Pb, Zn and Cd) in the soils, and also the dependence of the contents of elements in the soil on the soil depth.
Comparative study of rooting of leaf-bud and straight softwood elm cuttings
Authors: Grbic Mihailo
Published: September 2009

Parallel propagation tests of nine elm taxa - 6 species (Ulmus americana L., U. chenmoui Cheng, U. japonica (R) Sarg., U. laciniata (Tr) Mayr, U. laevis Pall. and U. parvifolia Jacq), 2 clones (U. 'Regal', U. 'Sapporo Autumn Gold') and 1 hybrid (U. pumila x japonica), by leaf bud cuttings and standard straignt softwood showed the results which point to the possibility of wider application of leaf bud cuttings. In some elm taxa, leaf bud cuttings can be the main method of propagation, and it can be used as an additional method in other taxa, because the seasonal timing is extended compared to standard cuttings.
Rainfall and runoff regime in the Golema reka watershed on the territory of the hunting ground Valniste
Authors: Kostadinov Stanimir , Stefanovic Tomislav , Braunovic Sonja , Bilibajkic Svetlana
Published: September 2009

Fenced hunting ground "Valniste" covers 410 ha on the slopes of the mountain Cemernik, in the Municipality Crna Trava. The hunting ground is situated in the Golema Reka watershed. Rainfall and runoff regime in the Golema Reka watershed were researched in order to create a hydrological base with the data on rainfall, available water resources and maximal discharges. Average annual rainfall design value for the watershed is 860. 14 mm. The highest monthly rainfall occurs in June and May, and the lowest in September and October. As there are no measured data, runoff regime was determined based on the method of parameter hydrology. The following calculation results are adopted for the maximal discharge: Q1000=19,0 m3?s-1 i Q100=10,90 m3?s-1. The adopted value of mean annual specific discharge (runoff module) is MQ=16,0 l?s-1?km-2.The study results of rainfall and runoff regime in the Golema Reka watershed show that hydrological conditions are favorable for the development of hunting and hunting tourism.
Beechwood density and changes of dimension at the locality Bor - Boljevac
Authors: Soskic Borislav , Todorovic Nebojsa
Published: September 2009

The density and changes of dimension of beechwood were studied at the site Bor - Boljevac. Four trees were analyzed from different selected and established series of scientific and production experiments in the management units. The results were presented and statistically processed for the data measured at the height of 1. 3 m, and also for the data at three height levels along the technically valuable part of the stem. The study results show the difference between the trees and also within the same tree The study results were compared to the results from other localities in Serbia. They should contribute to the analysis and production of wood in this region.
Development of artificially established spruce stand at the site of mountain beech after intensive selection thinning
Authors: Bobinac Martin
Published: September 2009

The effects of selection thinning were analyzed at a permanent sample plot in the artificially established spruce stand aged 32 years, on the site of mountain beech. The state in the 32-year-old stand was as follows: 3911 trees per ha, basal area 57.5 m2ha-1 and volume 378.3 m3ha-1. Selection thinning removed 1378 tree per ha (35.2%) and 110 m3ha-1 (29.2%), and in the period between the ages of 32 and 40 years, predominantly because of mortality, another 550 trees per ha and 21.8 m3ha-1. On the remaining trees during the period between the ages of 32 and 40 years, basal area increased by 33%, and volume by 67%. Current volume increment was 20.7 m3ha-1 and it was concentrated on the future trees (28% of the total number of trees produces 52% of volume increment). The disproportion in the intensity of diameter and height increment after the thinning resulted in the increase of form quotient.
Influence of nutrition and various substrates on spruce seedling growth
Authors: Djukic Matilda , Djunisijevic Danijela , Grbic Mihailo , Skocajic Dragana
Published: September 2009

The results of the influence of main macronutrients (N, P, and K) on growth and development of spruce (Picea abies L. Karst) one-year old seedlings are presented. They were grown in containers, in nursery conditions, on four different substrates. There is a good influence on biogenous element contents, height, root collar diameter, needle length and mass, root mass as well as physiological vitality of spruce seedlings. It was observed that the effect of nutrition depends also on the type of substrate.
Stand state, silvicultural demands and measures in beech forests of mixed origin in Boljevac area
Authors: Krstic Milun , Pantic Damjan , Matovic Bratislav
Published: September 2009

This paper presents the comparative analysis of stand state, productivity and silvicultural demands in beech stands of mixed origin, with a predominating percentage of trees of coppice origin, in different site and stand conditions, in the area of Cestobrodica and Straza. The main cruising elements were analyzed in three ecological units: Number of trees, basal area, volume, volume increment, mean stand diameters and height and the development of individual trees. The differences of the study ecological units, presented through the values of cruising elements and the phases of diameter, height and volume development of individual trees, are computed by the analysis of variance and LSD test. The analysis and the concluded significant differences enabled the real and comprehensive understanding of the state of these stands, based on which the long-term objectives of forest management were decided (conversion into a high silvicultural form) and actual silvicultural demands and measures - high selection thinning.
Hypoxylon species on beech and other broadleaves
Authors: Milijasevic Tanja , Karadzic Dragan
Published: September 2009

Fungi in the genus Hypoxylon cause wood decay and most of them are saprophytes on dead wood or parasites of weakness. The following species in this genus were identified in this study performed at several localities in Serbia and Montenegro: H. deustum, H. fragiforme, H. nummularium, H. multiforme, H. rubiginosum and H. fuscum. Among them the most significant species is H. deustum, the fungus causing root and butt rot of standing beech trees. It was recorded from all coppice and high forests of beech. This paper presents the morphological characteristics of the recorded fungi their range, plant hosts and significance.
Diameter structure modeling and the calculation of plantation volume of black poplar clones
Authors: Andrasev Sinisa , Vuckovic Milivoj , Roncevic Savo , Bobinac Martin
Published: September 2009

A method of diameter structure modeling was applied in the calculation of plantation (stand) volume of two black poplar clones in the section Aigeiros (Duby): 618 (Lux) and S1-8. Diameter structure modeling by Weibull function makes it possible to calculate the plantation volume by volume line. Based on the comparison of the proposed method with the existing methods, the obtained error of plantation volume was less than 2%. Diameter structure modeling and the calculation of plantation volume by diameter structure model, by the regularity of diameter distribution, enables a better analysis of the production level and assortment structure and it can be used in the construction of yield and increment tables.
Form of beech trees in coppice forests of Fruska Gora
Authors: Bankovic Stanisa , Medarevic Milan , Pantic Damjan
Published: September 2009

The study of tree form - form factors and form quotients and their interrelationship and the relation with other elements of volume is a necessary precondition for the construction of volume tables by the increasingly applied indirect methods. After the magnitudes of these parameters of tree form were defined, we studied the correlation between normal form quotients and normal form factor, between normal form factor and tree diameter and height, and between normal form factor and artificial form factor.
Some physical and chemical properties of substrates designed for container production of spruce (Picea abies (L) Karst)
Authors: Vratusa Vesna
Published: September 2009

Efficient nursery production of woody plants, as well as the level of their successful application in urban green spaces, greatly depends upon properties of substrates in which these individuals grow, develop and endure. Furthermore, quality of substrate does not only affect the quality of future product (plant individual or green space), but distinctly determines its price. This element, extremely significant for all countries in transition, thus Serbia as well, commands finding ways of making qualitative, but least expensive substrate. The most logical solution is to use mixtures/substrates of precisely defined properties, composed of domestic components. Results presented in this paper imply that it is possible to create precisely such standard mixtures from domestic resources at relatively low cost, adjusted to needs of particular species, which would ultimately lead to successful, non-expensive nursery production and application of produced stock, both on domestic and foreign markets.
Variability of half-sib progeny properties as the base of Moesian beech (Fagus moesiaca (Maly) Czeczott) breeding
Authors: Ocokoljic Mirjana , Anastasijevic Nebojsa
Published: September 2009

Based on the analysis of several morphological features and phenotype characteristics of seedlings in the juvenile test with 10 half-sib lines of Moesian beech (Fagus moesiaca (Maly) Czeczott), this paper gives the guidelines for further breeding and production of planting material for urban coenoses and the establishment of special purpose plantations of this species. The comparative analysis enabled the identification of the extreme planting material for further breeding programs aiming at dwarf varieties the selection of seedlings for tree rows, as well as the selection of planting material of special phenotype characteristics, which can be used as the initial material for the synthesis of the new varieties of Moesian beech.
Variability of chromosome number and morphology and gymnosperm improvement
Authors: Tucovic Aleksandar , Sijacic-Nikolic Mirjana , Vilotic Dragica
Published: September 2009

The causes of monotypic and polytypic variability of the gymnosperm chromosome complex were studied. The development of karyogram and idiograms of the species should be applied in the aim of upgrading the breeding method and technique. The study of the chromosome variability depends on the knowledge on gene function at the level of chromosome and at the level of genome, i.e. at the supra-chromosome level.
The most frequent powdery mildews on forest woody species and their impact
Authors: Karadzic Dragan , Milijasevic Tanja
Published: September 2009

The most frequent fungus species known as powdery mildews, causing the diseases of forest trees, were studied. Among forest woody species, oaks are especially susceptible to powdery mildew attack, and among them pedunculate oak (Quercus robur L) is highly endangered. This paper reports 49 species of powdery mildews. However, Microsphaera alphitoides has the greatest significance in forest economy, causing the decline of seedlings in nurseries and also aggravating the natural regeneration of pedunculate oak. This fungus, together with gypsy moth and honey fungus (Armillaria mellea) participates in the dying of old oak trees. Powdery mildews can be successfully controlled by fungicides, and sulphur fungicides Karatan and Rubigan are especially effective.
Causes and effects of morphological changes of the regulated channel of the river Toplica
Authors: Djekovic Vojislav , Gajic Grozdana
Published: September 2009

The regulation of small torrential watercourses outside the urbanized areas is often based on the so-called field type of regulation. In the selection of this concept, after the regulation works, the new channel is left to the natural process of the morphological formation of the water cross-section taking care not to disturb the general stability of the regulated channel. We present the process of morphological development of the regulated channel of the river Toplica, tributary of the river Kolubara, in the period 1982-2004 i.e. from immediately after the regulation works to the present day.
Electrical conductivity test for Serbian spruce seed quality estimation
Authors: Ivetic Vladan , Milovanovic Jelena
Published: September 2009

In this paper, for the firs time in our country, electrical conductivity test was used for seed quality estimation. Since this test is not standardized for most of tree species, main goal of this paper was to investigate possibility of its use for estimation of potential germination rate of Serbian spruce seed, like model species. Negative correlation with great statistical significance (r=-0.9003) was found between specific electrical conductivity and germination rate. On this basis, authors were give proposal for determination of Serbian spruce seed quality, after measuring of electrical conductivity. Results show great potential of this method for seed quality estimation, and justify further work on its standardization for Serbian spruce, and other tree species as well.
Interactions of polysporous cultures of antagonistic fungus Peneiphora gigantea (Fr.) Massee and some decay fungi of spruce from Stara planina
Authors: Lazarev Vladimir , Radulovic Zlatan , Milanovic Slobodan
Published: September 2009

In the control of the fungus Heterobasidion annosum the most frequently applied method is stump treatment with biological preparations containing dehydrated spores of the saprophytic fungus Phlebiopsis gigantea (syn. Peniophora gigantea /Fr./ Massee). In the field, this fungus is a competitor to the fungus Heterobasidion annosum. This paper presents the results of laboratory analyses of interactions of decay fungi isolated from the root and butt of uprooted spruce trees in the Nature Park "Stara Planina", and their relation to the fungus Ph. gigantea. The interactions of these fungi were analyzed at the temperatures of 20?C, 25?C and 30?C.
Forecasting of the processing time as the base of simulation of the production system behavior in real conditions
Authors: Vukicevic Milan
Published: September 2009

The absence of precise information on the magnitudes that determine the behavior of the production system generates the disturbances of the system. The consequence is the low efficacy of the system and the high costs. Therefore, it is necessary to create the base for the prediction of individual magnitudes and thus enable the simulation of the production system behavior in real conditions. The information on time norms has a special significance. It is the base of planning the terms and of defining a part of direct costs. Modern approach in the identification of standard times should be established on new foundations. It should appreciate the specificities of the present moment, as well as the future tendencies in wood processing. They are the production system dynamistic, conditioned predominantly by discontinuous production, as well as by the necessity of cooperation of the production systems. In this study, the approach to the identification of standard times is original, supporting the modern tendencies in wood processing and it has an applicative character.
Influence of different oak species (Q. cerris L. and Q. robur L.) and environment conditions on the gypsy moth development
Authors: Milanovic Slobodan , Markovic Nenad
Published: September 2009

This paper presents the results of the laboratory study of gypsy moth development on Q. cerris and Q. robur foliage in controlled and uncontrolled environmental conditions. The survival is higher in controlled conditions than in uncontrolled conditions. In uncontrolled conditions, sex ratio is higher in individuals fed on pedunculate oak foliage (0.55) compared to those fed on Turkey oak foliage (0.39), while in the controlled conditions the situation is the opposite. The increase of in star number is greater in pedunculate oak than in Turkey oak. There is a statistically significant difference between the means of all the study characters (length of development of the first and the second instars, length of premarital development, number of instars and fecundity) in uncontrolled and controlled environmental conditions. Also, there is a statistically significant difference between the means of all the study characters on different oak species, except in fecundity. There is an interaction between environmental conditions and host plant species in the length of development of the first and the second instars, as well as in the number of instars during the development. The study results show that Turkey oak is more favorable for the gypsy moth development than pedunculate oak.
Flexibility of production systems and prepare-finish time
Authors: Vukicevic Milan
Published: September 2009

One of the specificities of the large-serial and mass production is the almost neglected percentage of prepare-finish time in the production cycle. In the conditions of today dominant discontinuous production, it becomes a significant element of the production cycle. The eastern (Japan) doctrine of increasing the flexibility of the production systems, is based inter alia also on the extreme reduction of the prepare-finish time. For this reason, the aim of this study was to identify the types and percentages of individual jobs within the group of prepare-finish jobs. The sample consisted of 3 (three) production systems for the production of joinery, with the discontinuous production system. The research shows that the percentage of time of the jobs installation of work instruments, regulation of processing regime, and removal of work instruments is extremely long and that it ranges between 11.83% and 18.93% of the shift time. The reasons of the high percentage of these jobs are the wide range of products and the absence of the rationalisation of prepare-finish jobs. Within the efforts to minimize the effects of disruption and to increase the flexibility of the production systems, the rationalisation of prepare-finish jobs is the unavoidable condition.
On engineering of properties of wood-polypropylene composite
Authors: Djiporovic Milanka , Miljkovic Jovan , Dingova Eva
Published: September 2009

New materials based on wood have the advantage in the sense that their properties can be engineered so as to correspond to user demands. The properties which can be engineered are those relating both to their utilisation and machining, in particular - the tensile strength, elongation at break, modulus of elasticity and impact resistance. The research at the Faculty of Forestry and "Hipol" Chemical Industry related to the new type of wood-polypropylene composite. The content of wood filler was varied in the range between 40% and 70% mass contents of beech wood flour. After the highest tensile strength at 50% of filler content was determined, the effect of the wood filler origin was also examined at this content value. Therefore, wood flour of beech, poplar, acetylated pine and the waste MDF was used. The influence of the composition of the wood filler (beech combined with MDF, poplar and acetylated pine) in comparison with pure polypropylene matrix was also examined, as well as the effect of the type of coupling agent. Hopefully, the results obtained in this study might serve as the initial data for production of easily machined high-strength composites.
Effect of water regime on poplar cultivation
Authors: Letic Ljubomir , Ivanisevic Petar , Roncevic Savo
Published: September 2009

The effect of water regime on the growth and development of plantations of hydrologically conditioned species, poplars was researched in the alluvial plain of the river Tamis. The investigations were carried out during the period 2000-2003 on the area of FA "Opovo", KO Sakule, and the study results elucidate the very complex relationships between the hydrological conditions of the site and the growth and increment of the study poplar plantations, cl. I-214. .
Poplar efficiency in shelterbelts at some localities in Vojvodina
Authors: Lukic Sara , Dozic Stevan
Published: September 2009

The effect of poplar shelterbelts on the change of wind velocity has been studied. The measurements were performed by standard method at several points in front of the belt, behind and within the belt. Based on the study values, it can be concluded that poplar is efficient in reducing wind velocity, as the species for shelterbelts which are established for wind breaking. Their effect is significant at the distances up to 100 m behind the belt, which is significant when networks of shelterbelts are established to control wind erosion in the large deforested lowland areas which are mainly used for agricultural production. .
Analysis spatial distribution trees in forest stands
Authors: Stajic Branko , Vuckovic Milivoj
Published: September 2009

The analyses of the horizontal distribution of trees have not been used in the research of stand structure in Serbia?s forestry to date. Taking into account the high economic and ecological applicability of such information, this paper deals with the numerical description of the form of spatial distribution of trees. The applied methods are the so-called methods of statistical distributions and dispersion index. The study results in the all-aged mixed stand of fir and beech and in the mature pure stand of fir on the mountain Goc show that all trees together, but also the trees per species, are predominantly randomly distributed in space, with the tendencies towards a weaker or stronger aggregation or uniformity. Based on the identified spatial distribution of trees, it can be concluded that in the greater part of the study stands the environment is homogeneous and the basic conditions of tree growth are uniform. This points to the fact that real assessment of growth development and the competition of fir and beech, due to the identified absence of a marked competition for the basic growth factors, emphasizes, primarily, the quantification of the competition for growth space. .
Hydrogeological approach to the regional analysis of low flow in medium and small streams of the hilly and mountainous areas of Serbia
Authors: Nikic Zoran
Published: September 2009

During the long rainless spells of the dry season, flows in medium and small streams get reduced to what is generally known as "low flow". For ungauged streams, the controlling "low flows" are determined using the regional analysis method. In the presently described exploration, the method applied was based on the assumption that dry weather discharges in medium and small rivers depended on the hydrogeological conditions. The controlling effect of hydrogeology on the natural low flow in medium and small streams of the hilly and mountainous part of Serbia was analyzed applying the theory of multiple linear regression. The thirty-day minimum mean 80 and 95 per cent exceedance flows were taken for dependent variables, and quantified hydrogeological elements as independent variables. The analysis covered streams that had small or medium size catchment areas. The treated example encompassed sixty-one gauged catchments. The resulting regional relations for the thirty day minimum mean 80 and 95 per cent exceedance flows are presented in this paper. The quality of the established relation was controlled by relevant statistic tests.
Influence of partial serotiny of Aleppo pine, Italian, and Arizona cypress on seed germination
Authors: Grbic Mihailo , Kalicanin Dragana , Djukic Matilda , Djunisijevic Danijela
Published: September 2009

The usability of seeds for the production of seedlings, as well as the utilisation potential of seeds for natural regeneration was assessed by the comparative analysis of seed germination from the cones of different ages of three species with partial serotiny (P. halepensis Mill., Cupressus sempervirens L., Cupressus arizonica Greene). In cypress, serotiny is not so expressed as to be a reserve for extraordinary situations (fire). Fouryearold Aleppo pine cones should be collected for production purposes. Serotinous cones up to ten years old are efficient for natural regeneration of Aleppo pine forest after fire.