UDK: 630*54:582.475(497.6) In expert activities of forest managements, the forest stand volume is most frequently determined by way of volume tables, the so-called management tariffs. For an evaluation of stand volume using this method, the method of volume tables, it is necessary to know the site class (rating) of the stand for present tree species that is used as an argument for the selection of suitable volume progression (management tariff). The site quality for certain species in mixed stands is determined by comparing the height of trees at certain diameters at breast height (dbh) with the height of appropriate dispositions of height site class curves. In so doing the focus is placed on the ratio between the heights of large diameter trees, and the quality of the stand is rated within an interval of more defined site quality classes. For the purposes of a more objective and simpler  assessment of site quality, there have recently been attempts to make site quality assessments mathematically, using appropriate formulas in which tree heights or average heights by diameter classes and heights determined by mathematical functions of site class curves are used. For economically important tree species in Bosnia and Herzegovina (fir, spruce, beech, sessile oak, black pine and scots pine), the dispositions of height site class curves (and classes) are constructed graphically and mathematical functions for them are not known. A large number of mathematical models that are often used to represent growth trends and that satisfy the needs of height curves is analyzed in this paper with a view to determining the most suitable regression model for simulating height site class curves for fir in high forests in Bosnia and Herzegovina. The expanded Prodan model (with an additional item in the denominator) has been selected as the most suitable one on the basis of statistical indicators of the regression model quality.                                                                                                                          

Scots pine (Pinus sylvestris L.) and European beech (Fagus sylvatica L.) dominate many of the European forest stands. Also, mixtures of European beech and Scots pine more or less occur over all European countries, but have been scarcely investigated. The area occupied by each species is of high relevance, especially for growth evaluation and comparison of different species in mixed and monospecific stands. Thus, we studied different methods to describe species proportions and their definition as proportion by area. 25 triplets consisting of mixed and monospecific stands were established across Europe ranging from Lithuania to Spain in northern to southern direction and from Bulgaria to Belgium in eastern to western direction. On stand level, the conclusive method for estimating the species proportion as a fraction of the stand area relates the observed density (tree number or basal area) to its potential. This stand-level estimation makes use of the potential from comparable neighboring monospecific stands or from maximum density lines derived from other data, e.g. forest inventories or permanent observations plots. At tree level, the fraction of the stand area occupied by a species can be derived from the proportions of their crown projection area or of their leaf area. The estimates of the potentials obtained from neighboring monospecific stands, especially in older stands, were poorer than those from the maximum density line depending on the Martonne aridity index. Therefore, the stand-level method in combination with the Martonne aridity index for potential densities can be highly recommended. The species’ proportions estimated with this method are best approximated by the proportions of the species’ leaf areas. In forest practice, the most commonly applied method is an ocular estimation of the proportions by crown projection area. Even though the proportions of pine were calculated here by measuring crown projection areas in the field, we found this method to underestimate the proportion by 25% compared to the stand-level approach.

Scots pine (Pinus sylvestris L.) and European beech (Fagus sylvatica L.) dominate many of the European forest stands. Also, mixtures of European beech and Scots pine more or less occur over all European countries, but have been scarcely investigated. The area occupied by each species is of high relevance, especially for growth evaluation and comparison of different species in mixed and monospecific stands. Thus, we studied different methods to describe species proportions and their definition as proportion by area. 25 triplets consisting of mixed and monospecific stands were established across Europe ranging from Lithuania to Spain in northern to southern direction and from Bulgaria to Belgium in eastern to western direction. On stand level, the conclusive method for estimating the species proportion as a fraction of the stand area relates the observed density (tree number or basal area) to its potential. This stand-level estimation makes use of the potential from comparable neighboring monospecific stands or from maximum density lines derived from other data, e.g. forest inventories or permanent observations plots. At tree level, the fraction of the stand area occupied by a species can be derived from the proportions of their crown projection area or of their leaf area. The estimates of the potentials obtained from neighboring monospecific stands, especially in older stands, were poorer than those from the maximum density line depending on the Martonne aridity index. Therefore, the stand-level method in combination with the Martonne aridity index for potential densities can be highly recommended. The species’ proportions estimated with this method are best approximated by the proportions of the species’ leaf areas. In forest practice, the most commonly applied method is an ocular estimation of the proportions by crown projection area. Even though the proportions of pine were calculated here by measuring crown projection areas in the field, we found this method to underestimate the proportion by 25% compared to the stand-level approach.

In the traditional forest management the non-living woody biomass in forests was perceived negatively. Generally, deadwood was removed during the silvicultural treatments to protect forests against fire, pests and insects attacks. In the last decades, the perception of forest managers regarding forest deadwood is changing. However, people’s opinions about the presence of deadwood in the forests have been few investigated. In view of this gap, the aim of the paper is to understand the tourists’ perception and opinions towards the deadwood in mountain forests. The survey was carried out in two study areas: the first one in Italy and the second one in Bosnia-Herzegovina. A structured questionnaire was administered to a random sample of visitors ( n =156 in Italy; n =115 in Bosnia-Herzegovina). The tourists’ preferences were evaluated through a set of images characterized by a different amount of standing dead trees and lying deadwood. The collected data were statistically analyzed to highlight the preferred type of forests related to different forms of management of deadwood (unmanaged forests, close-to-nature forests, extensive managed forests and intensive managed forests). The results show that both components of deadwood are not perceived negatively by tourists. More than 60% of respondents prefer unmanaged forests and close-to-nature managed forests, 40% of respondents prefer intensive managed forests in which deadwood is removed during the silvicultural treatments.

UDK: 630*222:582.632.2 (497.6 Sarajevo)           582.632.2:630*5(497.6 Sarajevo) The paper represents a methodological approach in categorization of coppice beech stands in Sarajevo Canton area in relation to their ecological, productive, structural and silvicultural characteristics. For the collection of necessary data, method of temporary experimental surfaces, systematically allocated in squares 200 meters distant from each other has been used, in accordance to design of simple systematic sample. Concentric circles whose radius depend on tree diameter has been used as sample units (STOJANOVİĆ & DRİNİĆ, 1975). Data have been conducted in 659 locations. Stands have been categorized in three categories in relations to predefined criteria of categorization based on stand environment, productiveness, structure, economic value and fostering needs. For each of the categories, average units of basic productive indicators of the stand have been determined: number of trees, basal area, volume and volume increment per year for marked and unmarked, as well as same indicators of marking timber volume and the intensity of felling. Statistical significance of difference between the indicators has been tested by the method of variant analysis. Based on the results, indirect conversion has been recommended for the first stand category, direct and combined conversion for second one, and third category didn't need conversion because they have predominantly protective character

Mixing of complementary tree species may increase stand productivity, mitigate the effects of drought and other risks, and pave the way to forest production systems which may be more resource-use efficient and stable in the face of climate change. However, systematic empirical studies on mixing effects are still missing for many commercially important and widespread species combinations. Here we studied the growth of Scots pine (Pinus sylvestris L.) and European beech (Fagus sylvatica L.) in mixed versus pure stands on 32 triplets located along a productivity gradient through Europe, reaching from Sweden to Bulgaria and from Spain to the Ukraine. Stand inventory and taking increment cores on the mainly 60–80 year-old trees and 0.02–1.55 ha sized, fully stocked plots provided insight how species mixing modifies the structure, dynamics and productivity compared with neighbouring pure stands. In mixture standing volume (+12 %), stand density (+20 %), basal area growth (+12 %), and stand volume growth (+8 %) were higher than the weighted mean of the neighbouring pure stands. Scots pine and European beech contributed rather equally to the overyielding and overdensity. In mixed stands mean diameter (+20 %) and height (+6 %) of Scots pine was ahead, while both diameter and height growth of European beech were behind (−8 %). The overyielding and overdensity were independent of the site index, the stand growth and yield, and climatic variables despite the wide variation in precipitation (520–1175 mm year−1), mean annual temperature (6–10.5 °C), and the drought index by de Martonne (28–61 mm °C−1) on the sites. Therefore, this species combination is potentially useful for increasing productivity across a wide range of site and climatic conditions. Given the significant overyielding of stand basal area growth but the absence of any relationship with site index and climatic variables, we hypothesize that the overyielding and overdensity results from several different types of interactions (light-, water-, and nutrient-related) that are all important in different circumstances. We discuss the relevance of the results for ecological theory and for the ongoing silvicultural transition from pure to mixed stands and their adaptation to climate change.

Mixing of complementary tree species may increase stand productivity, mitigate the effects of drought and other risks, and pave the way to forest production systems which may be more resource-use efficient and stable in the face of climate change. However, systematic empirical studies on mixing effects are still missing for many commercially important and widespread species combinations. Here we studied the growth of Scots pine (Pinus sylvestris L.) and European beech (Fagus sylvatica L.) in mixed versus pure stands on 32 triplets located along a productivity gradient through Europe, reaching from Sweden to Bulgaria and from Spain to the Ukraine. Stand inventory and taking increment cores on the mainly 60–80 year-old trees and 0.02–1.55 ha sized, fully stocked plots provided insight how species mixing modifies the structure, dynamics and productivity compared with neighbouring pure stands. In mixture standing volume (+12 %), stand density (+20 %), basal area growth (+12 %), and stand volume growth (+8 %) were higher than the weighted mean of the neighbouring pure stands. Scots pine and European beech contributed rather equally to the overyielding and overdensity. In mixed stands mean diameter (+20 %) and height (+6 %) of Scots pine was ahead, while both diameter and height growth of European beech were behind (−8 %). The overyielding and overdensity were independent of the site index, the stand growth and yield, and climatic variables despite the wide variation in precipitation (520–1175 mm year−1), mean annual temperature (6–10.5 °C), and the drought index by de Martonne (28–61 mm °C−1) on the sites. Therefore, this species combination is potentially useful for increasing productivity across a wide range of site and climatic conditions. Given the significant overyielding of stand basal area growth but the absence of any relationship with site index and climatic variables, we hypothesize that the overyielding and overdensity results from several different types of interactions (light-, water-, and nutrient-related) that are all important in different circumstances. We discuss the relevance of the results for ecological theory and for the ongoing silvicultural transition from pure to mixed stands and their adaptation to climate change.

UDK: 630*52/*56:528.8(234.422 Igman) Information about quantitative and qualitative forest attributes are the base for successful forest planning and management. Forest inventories collect number of data used for different estimations from large (management unit level) to small (forest stand) scales. Then, control sampling has to be done in order to confirm regularity of terrestrial work. Such sample becomes data source too.  Recent approach for forest characterization includes all available information as sources for additional non-standard insight. Here were used available data about wood volume and increment from control sample for high forest on mountain Igman. Also, recent Landsat TM image from vegetation period was available and used in this research. Here is applied k nearest neighbor’s estimation method. Five nearest neighbors and Euclidian distance is chosen for estimation and mapping. Biases for all forest attributes were non-significant. Obtain results show non significant differences between means and observed and estimated distributions of wood volume and increment. It is estimated higher mean wood volume and increment of broadleaves while means for conifers and totals are lower. That higher wood volume and increment is estimated in all diameter classes for broadleaves while lower quantities are estimated for conifers. Spatial mapping presents distribution of wood volume and increment respecting variability of vegetation in high forest on Igman.