Effects of the control method (Goč variety) in selection forest management in Western Serbia

The control method, one of the most reliable methods of selection forest management, has been applied in selection forests of western Serbia in a somewhat modified form (Goč variety) for fifty years. This paper analyzes the effects of the control method, i.e. its Goč variety, in the period from 1960/70 - 2000. It is based on the data of five successive complete inventories of the Forest Management Unit (FMU) 'Tara', whose high selection forest of spruce, fir and beech (Piceo-Abieti-Fagetum subass. typicum) trees on diluvium, brown and illimerised soil on limestone, and on limestone in formation with hornfels, are the best quality and the most spacious forests in the Management Class MC 491/1. The effects were monitored through the changes in the distribution of the number of trees and volume per diameter classes, separately for fir as the protagonist of the selection structure, and collectively at the level of a compartment, a typical representative of MC 491/1. Also, the analysis included the changes in the number of trees, volume, current volume increment, yield, and number of recruited trees per unit area (1 ha) by tree species in MC 491/1, occupying an area of 2,648.78 ha. The study results show that in the study period the average volume in MC 491/1 increased by 18.8%, the percentage of conifers increased from 66.0% to 78.5%, and the bearer of the changes was fir. The volume of the mean fir tree increased by 35.9% and it attained 1.086 m3. The volume increment increased by 15.7%. The selection structure of conifers was satisfactory, but there were problems with beech regeneration, in its stable presence and in its achievement of the targeted structure. The number of trees per unit area (1 ha) decreased, which in the long run could have detrimental consequences, but the sustainability in general was satisfactory. The levels of regeneration and recruitment were satisfactory. The health of the trees was improved; the stands were healthy, vital, and biologically and functionally stable. The study results point not only to a series of positive effects of the several-decades' long implementation of the Goč variety of the control method, but also to some problems, the understanding of which will have a corrective role in the future management of selection forests in western Serbia

Variability of features in half-sib posterity as a basis in plant breeding of the species Koelreuteria paniculata Laxm.

Based on the comparative morphophysiological analysis of the seedlings Koelreuteria paniculata Laxm. produced in a generative manner by using one line of the oldest half-sib tree and two lines of younger half-sib trees, data regarding the seedlings' features and the variability of the plant breeding are presented. Recorded parameters are the indexes which point to the influence of age over biological reproduction. This paper also puts forward that the variability of the seedlings exerts an influence on the selection of mother trees, and provides the technology of production of breeding plants with desired features and its practical usage in landscape architecture, horticulture and forestry. Namely, by selecting the superior genotypes and with their breeding, different sorts of koelreuteria (China-tree) could be synthesized and thanks to the high level of general adaptability would provide reciprocally high productivity of studied parameters and be the base material for plants for specific purposes.

DOI:10.2298/ABS1003693O VARIABILITY OF FEATURES IN HALF-SIB POSTERITY AS A BASIS IN PLANT BREEDING OF THE SPECIES KOELREUTERIA PANICULATA LAXM.

Abstract- Based on the comparative morphophysiological analysis of the seedlings Koelreuteria paniculata Laxm. produced in a generative manner by using one line of the oldest half-sib tree and two lines of younger half-sib trees, data regarding the seedlings ' features and the variability of the plant breeding are presented. Recorded parameters are the indexes which point to the influence of age over biological reproduction. This paper also puts forward that the variability of the seedlings exerts an influence on the selection of mother trees, and provides the technology of production of breeding plants with desired features and its practical usage in landscape architecture, horticulture and forestry. Namely, by selecting the superior genotypes and with their breeding, different sorts of koelreuteria (Chinatree) could be synthesized and thanks to the high level of general adaptability would provide reciprocally high productivity of studied parameters and be the base material for plants for specific purposes

The concept of green infrastructure and urban landscape planning: a challenge for urban forestry planning in Belgrade, Serbia

The beginning of the 21st century has witnessed a growth in our understanding of the importance of planning urban landscapes in the context of urban population growth and unpredictable climatic conditions. In the search for responses to the challenges set by the development of contemporary urban landscapes, researchers have offered solutions based on the concept of sustainable and resilient cities, whose spatial development would be based on an interdisciplinary approach to strategy development: biodiversity, urban ecological networks and connectivity, multifunctionality and modularity. Although the concepts of a green infrastructure, in their spatial and functional dimensions, allow the application of such strategies, there are still problems when it comes to implementation and measuring the results achieved. At the same time, there is a growing discussion of the important role played by urban forestry in the context of the collaborative planning of urban landscapes and the application of the ideas of a green infrastructure. The key question is: what are the modalities of application of the concept of green infrastructure in the process of planning the development of the modern city and how can the resulting benefits be evaluated? With the modalities of application of the concept of green infrastructure in mind, we discuss its multi-scale and multifunctional dimensions as applied in the case of Serbia. The realisation of the green infrastructure concept is presented through the example of the Urban Forest Management Plan for the City of Belgrade - Mladenovac Municipality. The results of using the spatial-ecological approach in creating the plan and establishing connectivity as a new aim in forest management planning show that the implementation of the green infrastructure concept, and the achieved multifunctional ecosystem values, can be presented on the basis of the parameters of landscape metrics. In light of the new urban world, future research should focus on the application of the landscape ecological approach of the green infrastructure concept in collaborative planning at the urban landscape scale, which allows the creation of ecosystem services and benefits to human well-being

Optimization and prediction of ibuprofen release from 3D DLP printlets using artificial neural networks

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. The aim of this work was to investigate effects of the formulation factors on tablet printability as well as to optimize and predict extended drug release from cross-linked polymeric ibuprofen printlets using an artificial neural network (ANN). Printlets were printed using digital light processing (DLP) technology from formulations containing polyethylene glycol diacrylate, polyethylene glycol, and water in concentrations according to D-optimal mixture design and 0.1% w/w riboflavin and 5% w/w ibuprofen. It was observed that with higher water content longer exposure time was required for successful printing. For understanding the effects of excipients and printing parameters on drug dissolution rate in DLP printlets two different neural networks were developed with using two commercially available softwares. After comparison of experimental and predicted values of in vitro dissolution at the corresponding time points for optimized formulation, the R2 experimental vs. predicted value was 0.9811 (neural network 1) and 0.9960 (neural network 2). According to difference f1 and similarity factor f2 (f1 = 14.30 and f2 = 52.15) neural network 1 with supervised multilayer perceptron, backpropagation algorithm, and linear activation function gave a similar dissolution profile to obtained experimental results, indicating that adequate ANN is able to set out an input–output relationship in DLP printing of pharmaceutics

Enhanced antimicrobial activity and physicochemical stability of rapid pyro-fabricated silver-kaolinite nanocomposite

The present research aims to enhance the antimicrobial activity of kaolinite surfaces by a one-step cost-effective and energy-efficient dry thermal reaction, producing an antibacterial and antifungal silver-kaolinite (Ag-Kao) nanocomposite agent. Pharmaceutical grade kaolin powder samples, with variable kaolinite structural order–disorder degree, were homogeneously mixed with silver nitrate in a proportion 1:4 AgNO3:kaolin (w/w) and sintered at 400 °C for 30 min. The composition, microstructure, microtexture and surface characteristics of the pyro-fabricated nanocomposites were characterized by XRD/XRF diffractometry, differential scanning calorimetry DSC, FT-IR spectroscopy, TEM/EDX, zeta potential (mV) measured within the 2–12 pH range, and BET method. Physicochemical stability was evaluated by silver dissociation testing under close-neutral and acidic conditions with Ag content assay using ICP-OES. The resulting Ag-Kao nanocomposites exhibited bulk silver contents ranging from 9.29% to 13.32% with high physicochemical stability in both neutral and acidic mediums (Ag dissociation rate 1) produced platelet edge-clustered silver nanocrystals due to the abundance of the dangling hydroxyls on platelet edges, while the highly disordered kaolinite (HI < 1) provided homogeneous platelet basal-doped silver nanocrystals due to the presence of some residual charges by exposed basal hydroxyl groups with interplatelet silver diffusivity. At pH 2, the magnitude of the positive surface charge was influenced by the silver nanocrystal size. Nanocomposites with the smallest silver nanocrystals (10–5 nm) exhibited the highest positive zeta potential (+15.2 mV to +17.0 mV), while those with larger silver nanocrystals (up to 30 nm) indicated lower positive zeta potential values (+9.5 mV to +3.6 mV). Under the same testing conditions using the Mueller-Hinton broth microdilution method, the raw kaolin samples did not show any significant antimicrobial activity, while all the pyro-fabricated Ag-Kao nanocomposite samples showed potent antibacterial and antifungal activity at low doses (MIC range 0.1–0.0125 mg/mL). Therefore, modulation of the effective electrostatic surface charge of the kaolinite platelets, via thermal doping of silver within their basal planes and edges, was found to be strongly dependent on the pH as well as the size and microtexture of the silver nanocrystals (mainly controlled by the order–disorder degree HI). The resulting modified nanostructure, with physicochemical stability and the efficient surface properties of the designed pyro-fabricated nanocomposite, led to an enhanced synergistic biophysical antimicrobial activity

Culture and silviculture: origins and evolution of silviculture in Southeast Europe

Silvicultural practices are generally developed to meet societal objectives given the constraints of the site. This simple premise is a foundation of modern silviculture. However, silviculture may vary for other reasons related to cultural factors. This paper reviews the differences in silviculture in the twelve countries that comprise southeastern Europe, an area that includes a variety of cultures, and a complex history. The silviculture generally follows three models: coppice systems that are largely unregulated, even-aged stands that include former coppice stands and other reforested sites, and systems to develop and maintain complex stand structures. Plantation management is not common. Cultural and historic drivers have affected the development of silviculture in this region. Additional drivers include forest access, the importance of wood for fuel, and proximity to central Europe. It is anticipated that European Union membership of countries in the region will lead to greater regional and international exchange and cooperation in the future.Publisher's Versio