The aim of this paper is to analyze the effect of different degrees of mixing on the diversity structure in stands left to spontaneous development. The research included two communities of species endemic to the Balkan Peninsula—the Serbian spruce (Picea omorika Pančić Purk.) and the Macedonian pine (Pinus peuce Griseb). Data from eight sample plots were used in the research. The changes in diameter and height structure, spatial arrangement of trees, and diameter differentiation were analyzed. The analyzed parameters of structural diversity show relatively low to moderate values. Results showed an increase in mixing was reflected in the width and shape of distributions. A spatial analysis of stands with a higher degree of mixing showed a tendency towards a random to regular distribution of individuals, in contrast to stands with a lower degree of mixing which showed a tendency towards a clump distribution. The pronounced species’ dimensional and spatial diversity confirms their importance to the condition of modern forest management. Significant differences in the change of structure are shown by stands with a share of admixed species of above 20% by volume. The obtained results refer to stands left to spontaneous development, suggesting than an active research and management approach must be assumed to realize the goal of protecting rare forest ecosystems.

This paper analyzes changes in forested areas, as depicted in topographic maps, within the historical context of their publication in Serbia. The research focuses on the experimental field ?Goc- Gvozdac? of the University of Belgrade ? Faculty of Forestry, with additional reference to changes in Central Serbia. Changes were assessed across historical periods using four reference topographic maps: from 1893, 1929, 1971, and 1985. Data on shifts in forested areas (categorized as forest and other land) were obtained by vectorizing scanned analog maps using manual GIS editing tools. Additionally, currently available spatial data sets of land cover/use for 2021 were utilized for the analysis. The forest distribution across different geological formations was also evaluated. The results indicate a continuous increase in forested areas within the experimental field, rising from 77.6% in 1893 to 89.3% in 1985, and reaching 95.1% by 2021. The most significant increase occurred during the first reference period (1983? 1929), while the smallest growth was observed in the last one. Data for Central Serbia also reveal a general upward trend in forested areas throughout the 20th century, consistent with findings from the experimental field. However, analyses in the 21st century indicate only minor changes in the forested area. The historical data on forest area changes provide valuable insights, enhancing our understanding of forest development and informing better forest management planning, organization, and activity implementation. This is significant for enhancing knowledge from educational and scientific research perspectives, as well as providing the foundation for forest management in preservation and qualitative improvement.

The subject of this research are stands of bosnian pine in the area of the mountain massif Visitor with Zeletin in Montenegro. Considering the fact that these forests are unexplored, due to their small area and the absence of economic interest (the strictest protection regime), the research task of this paper is to conduct an adequate research of one of the most preserved white-bark pine populations in this areas in structural and partly production terms. The bosnian pine stands on Mt. Zeletin belong to two management units: FMU “Piševska Reka - Zeletin” and FMU “Kutska Reka” which occupy an area of 160 ha. The research included the accessible parts of sections 2/b, 3/a, 5/a, 28/a and 28/s, in which 8 sample plots (SP) of an 30 ar area each were established (4 SP in pure and 4 SP in mixed stands). The SPs are vertically distributed between 1,550 and 1,850 m a.s.l. In pure stands, the average number of trees (for 4 SPs) is 723 pcs∙ha-1, the basal area is 74 m2∙ha-1, and the volume is 529 m3∙ha-1, which are considered high values given the conditions in which these stands have developed. In mixed stands, the numerical elements show significantly higher values: the number of trees is 875 pcs∙ha-1, the basal area is 87 m2∙ha-1 and the volume is 721 m3∙ha-1. A high degree of correlation was found between the values of volumes (unweighted and weighted) and the values of dominant heights. The mixed stands reveal a more heterogeneous structural development. Bosnian pine trees cluster at short distances, which is probably the result of a struggle for survival in highly unfavorable conditions. As these stands are subjected to spontaneous development over a long period of time, their research provides the opportunity to get to know more about bosnian pine ecology. Considering its modest requirements towards habitat conditions, bosnian pine has considerable advantages when choosing a species for afforestation of the most unfavorable sites.

Background: Refugial coniferous forests of South-East Europe represent unique and poorly studied forest ecosystems. Shaped by contrasting maritime and continental climatic influences and complex orography, these forests support several endemic and relict tree species. Methods: We investigated soil and vegetation properties and their relationships in pure stands of Serbian spruce ( Picea omorika (Pančić) Purk.), Macedonian pine ( Pinus peuce Griseb.) and Bosnian pine ( Pinus heldreichii Christ.). Twelve sample plots covering a total area of 3.6 ha were established at three representative localities in Bosnia and Herzegovina (Veliki Stolac), Serbia (Beleg) and Montenegro (Zeletin). Soil profiles, phytocoenological records and forest inventory measurements were obtained, and soil samples from 5 -15 cm depth were analyzed for basic physicochemical properties. Results: All investigated refugial forests developed on limestone and shallow Leptosols. Clear differences in soil properties, vegetation and forest diversity were observed among the studied species. High organic matter values, changes in the C/N ratio among habitats, and relationships among soil parameters were identified. Forest-layer cover was significantly associated with soil properties. Orographic gradients were related to soil properties, vegetation composition and forest diversity. Conclusion: The results indicate that soil properties and forest diversity in refugial endemic coniferous forests are shaped by the interaction of orographic conditions, tree species, stand structure and ground vegetation rather than by altitude or substrate alone. The findings provide an ecological basis for improving conservation and management approaches for these highly valuable and fragmented forest ecosystems.

In high, mixed, middle-aged and maturing Penduculate oak stands, the possibility of using aerial photogrammetry in the inventory was tested, both to obtain informa?tion related to site and stand information and to determine numerical elements (number of trees, basal area and volume per hectare) obtained on the basis of data read from the images (crown diameter, height and estimated breast height diameter of the tree based on the selected mathematical model). Most of the information from the site and stand infor?mation, especially the information about the above-ground parts of the forest (presence of dead cover, ground vegetation, shrubs, weeds, saplings and the degree of their damage, etc.) could not be identified from the image. There was a significant difference in the aver?age number of trees, basal area of stands and stand volume per hectare determined on the basis of aerial image data, compared to the values determined by the terrestrial survey. In middle-aged stands, the number of trees determined from aerial image is 21.5 % higher and in maturing stands 9.5 % lower than the values determined by a total measurement. In middle-aged stands, the basal area AP-1 is 13.5 % higher and AP-2 15.6 % higher than the values determined in the total measurement. In the maturing stands, these deviations are 13.1 % and 3.7 %. The stand volume is the element with the greatest deviations compared to the total measurement. In middle-aged stands the difference is 31 % and 28.1 %, and in maturing stands 37.9 % in AP-1 and even 67.1 % in AP-2. The reasons for the impossibility of a precise interpretation of most of the information related to the information of the site and the stand and for the significant differences in the numerical elements compared to the total measurement lie in the broad and intertwined crowns (dense canopy closure) of the oaks in the upper storey and in the vertical structure of these mixed stands. The results obtained exclude the use of aerial photogrammetry in the inventory of this certain forests, as it does not provide a reliable information basis for the development of realistic forest management plans. Possible applications exist in distinguishing of land use, locating fire areas, areas af?fected by hurricanes and other disasters, etc., and even in the inventory of pure stands with low canopy closure.

The subject of the research is the selected stands in the Tara National Park, the Tara plateau mountain range within the management unit (MU) of the same name. These stands occupate over 90% of the total area of the MU and from a management aspect are characterized by structural neglect, significant deviation from the balanced state. The basic assumption of the research is reflected in testing the possibility of a significant impact on improving the structure of these forests during the management period and the possibility of recognizing the direction of their development as a result of the application of different treatments. Testing this assumption was carried out in relation to felling according to the real (planned allocation), possible (allocation in different stand situations in a specific section on six test surfaces of 10 ares each) and the assumed allocation (theoretical category). The development assessment was carried out according to the results of the impact of allocation (felling) on the change in the state at the end of the management period. To achieve the set goal, one section (section 66, section a) was selected as a typical representative of these stands. The results obtained indicate that the tested different variants of the referral can only partially correct the structural neglect of the stand. By applying the last (theoretical) variant of the referral, positive development elements of the stand are partially achieved (reducing the number of trees above the diameter of the cutting maturity). By analyzing the results, we conclude that recognizing the direction of stand development and its direction is the primary category of activity in a management period. The normal selection structure as a theoretical category is at the same time the main goal of its existence towards which it is necessary to direct activities. In specific stand forms, the main recommendation relates to understanding the problem as a long-term category, with elements that indicate an improvement in the condition at the end of the management period.