The regeneration of oak forests in the hilly and mountainous areas is one of the most serious and complex problems forestry practitioners face in Serbia. The success of regeneration depends on the individual or combined (often synergistic) influence of numerous biotic, abiotic, and management factors. While there is significant knowledge and experience about this process in practice so far, there is still great uncertainty regarding its proper execution and control over the influencing factors. The paper critically evaluated the available literature and current experiences from practice through a questionnaire. A comprehensive literature search was conducted, taking into consideration various databases and search engines, mostly composed of peer-reviewed publications from ISI-listed journals. A total of 187 papers were included in the base. Aiming to better understand the current state and the main problems in the regeneration of hilly-mountainous oak forests in Serbia, surveys were performed among forest practitioners. Based on this, the paper synthesized the current knowledge and addressed future perspectives in hilly-mountainous oaks management. More specifically, the factors that dominantly influence the regeneration process, their modes of action, behavior in the case of modifications, as well as the possibilities of their interaction are defined. The success of regeneration is determined by canopy openness, microclimatic conditions, presence of competitive vegetation, initial number of seedlings, and seedling growth and health, as revealed in the literature. The proposed methods for more successful regeneration and restoration of oak forests, include producing high-quality seedlings, using advanced weeding methods, developing a specific strategy for restoring native oak forests, assessing genetic resources and long-term monitoring. Overall conclusion of the conducted literature analysis is that there is a great need for conducting further long-term research on improving the regeneration systems in hilly-mountainous oak forests in Serbia.

“Planning at the landscape scale” is the new paradigm of spatial development which embraces the management, protection, and restoration of the landscape character distinguished through “landscape approach” which differs from traditional sectoral and project-based approaches. The institutionalization of “the planning at the landscape scale” has shown an upward trajectory since the Republic of Serbia ratified the European Landscape Convention (ELC). The ELC aims to promote the institutionalization of landscape planning, management, and protection across all landscapes, whether urban, rural, or natural. The landscape planning approach integrates the principles of landscape ecology, principles of landscape aesthetics, and transdisciplinary research. This approach is solution-oriented, aiming to preserve, restore, and enhance the landscape’s character – the distinctive structure and image of the landscape. It achieves this through the “conservation and development of landscape patterns (mosaic), considering land use, the relationship between built and open spaces, and the distinct qualities of the buildings." (Spatial Plan of the Republic of Serbia, 2035). As one of the novel tools that can effectively support the achievement of national-level spatial planning objectives, the development of the Forest Landscape Restoration (FLR) methodology holds the potential for incorporating the following goals and principles related to landscape planning, protection, and sustainable utilization: - Integrating the landscape approach (emphasizing the value of landscape character) into the forestry planning and management system; - Forestry development aligned with the recognized values of the landscape character (quality objectives, landscape capacity, and sensitivity); - Urban landscape restoration, preservation, and enhancement of the characteristic structure and image of landscapes through; a) establishing urban spatial order and preserving remnant elements of the rural landscape (reforestation and afforestation within agroforestry areas, peri-urban mosaics complexes, surface watercourses) in suburban areas; d) preserving space for green infrastructure development, as a measure of the city's adaptation to climate change, and creating a network of green and public spaces that connect the natural and cultural values of urban settlements. In this paper, we present the Surčin Forest Landscape Restoration Plan case study, demonstrating landscape character assessment (LCA) as a research method. This method evaluates the sensitivity of landscape character, addressing both resource and visual aspects. The methodological approach seeks to address the critical questions of “what”, "where" and "how" in the context of establishing new forest areas within the broader landscape framework of the forest restoration plan. By providing a strategic and spatially informed approach, it ensures that the restoration efforts are not only ecologically sound but also optimally positioned to enhance the resilience, biodiversity, landscape diversity, and connectivity of forest ecosystems, as well as to improve the cultural ecosystem services of the Municipality of Surčin.

Container production of forest seedlings needs constant improvement, so in the aim to test the new container type this research was conducted. Quercus robur seedlings were produced in the container made of natron paper and compared  with seedlings produced in commonly used container types in Serbia. Q. robur seeds were sown in the first week of November 2020 in a total of 30 containers (10 of each type). After the first growing season in the nursery, on November 2021, seedlings’ morphological parameters (root collar diameter - RCD, height - H, dry weight of shoot (SDW) and root (RDW), seedling dry weight (SLDW), shoot to root ratio (S:R), sturdiness coefficient (SQ), dry weight of lateral roots (LRDW), percent of lateral roots (%LR), Dickson’s quality index (QI), root-bound index (RBI) as RBI-diameter and RBI-volume, and rooting intensity (ROIN)) were compared using one-way ANOVA. Seedlings produced in the new container showed better morphological parameters such as H, SQ, SDW, RDW, SLDW, LRDW, QI and ROIN. Differences of seedlings from different containers were not detected for H, RCD, SQ, SDW, %LR, RBI-diameter, so we can conclude that seedlings produced in the new container type are similar with other container seedlings. Larger volume of these cells indicate use for Quercus species which have strong roots. Results obtained from the nursery promote use of the new container in forest seedlings production and testing at the field.

Sessile oak is one of the ecologically and economically most important tree species in Europe. Recently, the importance of this species has been particularly highlighted in the context of climate change, where it is expected that these species will play a significant role within their natural range and beyond. To regenerate and expand the range of the sessile oak forests, a large amount of healthy acorns is needed. The acorn production and the acorns themselves are endangered by a large number of abiotic and biotic factors. As oak trees of different sizes do not produce the same amount of seed of the same quality, we investigated how the sessile oak tree diameter affects the acorn size, insect infestation, and germination rate. On the other side, as the acorn size influences the attack rates of the most significant acorn pest – Curculio glandium (Marsham, 1802), and the germination rates of both the damaged and healthy acorns we also investigated how the acorn dimensions influence the insect damage and germination rates, and how the insect damage influences the germination rates. We determined that the oak tree size influences some oak seed characteristics that are important for forest regeneration, while it does not affect others. A greater acorn yield was recorded on the bigger oak trees. The tree dimensions also had a significant influence on the acorn size. Greater average length, as well as greater average acorn diameter, were recorded on bigger trees. Although the tree size affects the acorn size, it does not influence the acorn insect predation rates or its germination rates. These parameters are affected by the acorn size itself. Bigger acorns had a greater germination rate. Insects preferred smaller acorns and had a significantly negative influence on the germination rate.

The leaf area of plant leave scan be considered as an indicator of the plant growth conditions, and its variability is usually associated with adaptation and response to the changing environment. The aim of this study is to investigate the relation of the leaf area parameters on growth of the narrow-leaved ash 1+0 seedlings from the nursery trial and determining variability between the 18 half-sib lines. The seedlings were obtained from seeds collected from 18 maternal trees found in the area of the special nature reserve Upper Danube Region. Ten randomly selected 1+0 seedlings per half-sib line were selected for further study, and all leaves per seedling were collected, herbarized and scanned. The leaf area of each leaf (LACL) was measured using an open-source image processing program – ImageJ, and the total leaf area per seedling (TLA) was calculated. Also, the number of leaves per plant (NCL) as well as the number of leaflets within each imparipinnate compound leaf (NLCL) were counted. The results showed that differences between studied attributes were statistically significant among 18 selected half-sib lines (p < 0.05). The most variable parameter was the total leaf area per seedling (TLA; CV=68.98%), which is strongly correlated to the leaf area per each leaf (LACL; r=0.95) and the number of leaflets (NLCL; r=0.94). In this study, we confirmed that leaf parameters were highly correlated to the growth of one-year-old Fraxinus angustifolia seedlings.

Beech is the most important tree species in forests of Serbia. However, despite its significance, the taxonomic status of beech in Serbia is unclear. Morphology of the cupules can be successfully used to distinguish species and within species taxa. In this paper we report results on cupules morphology, measuring the same attributes reported by Mišić (1955): 1) Length of the longest valve of cupule, 2) Width of that valve (at widest point), 3) Distance between base of the longest valve and peduncle, 4) Length of cupule without peduncle, and 5) Length of peduncle. The length of cupule and peduncle length from 12 populations in Serbia are in the range reported for Fagus sylvaticain Serbia and western Eurasia. Results of cluster analysis shows a grouping of populations in two groups:1) the southeast group, and 2) group consist of populations from northwest, east and southeast of Serbia. Populations from this southeast group also consist the group of populations on altitude over 850 m, indicating presence of ecotypes. The exception is population from Stara Planina (1,520 m a.s.l.) which is grouped with populations from altitudes under 850 m. Keywords: European Beech; cupules; variability

Aiming to produce forest reproductive material at the family level, we tested quality of twenty Fraxinus angustifolia Vahl half-sib lines in the nursery experiment. We measured height (HT) and root collar diameter (DIA) of one-year old seedlings, and we monitored germination rate and mortality during the first growing season. Seeds of 20 half-sib lines originating from Sombor area (north Serbia) were sown in seedbed on autumn 2016. The seed dormancy was not broken in all seeds equally, resulting with un-uniform germination over a two months period. All measured attributes shows a statistically significant differences, indicating a strong effect of genetic control. The highest average and DIA were measured in half-sib line 7 (22.62 cm; 5.79 mm, respectively). The lowest average DIA was measured in half-sib lines 18 (2.85 mm) and 19 (2.94 mm), which can be result of growing density effect (104 seedlings m-2 for line 18 and 126 seedlings m-2 for line 19, compared to 40 seedlings m-2 for line 7). The correlation between DIA and HT is strong and positive (R=0.90). Due to its morphological superiority, half-sib line 7 could be recommended for mass production of Fraxinus angustifolia seedlings at the family level. Keywords: Height; Root Collar Diameter; Seedlings Quality; Narrow leaved ash

Autochthonous poplar species were neglected during the intense establishment of plantations using various selected clones. This paper presents the results of seedlings quality comparison of two autochthonous poplars and three clones of poplar (129/81, I-214 and PE 19/66) in order to determine capabilities for mass production of autochthonous poplar seedlings. The seedlings of clone 129/81 have the largest diameter and height, and the seedlings of black poplar shows the smallest values. Seedlings of gray poplar have similar values as seedlings of clone PE 19/66, except diameter on 1 m above the ground. Clone I–214 shows least values relative to seedlings of other two clones. The results obtained in this study indicate the possibility of mass production of autochthonous poplar seedlings. Considering that the seedlings are used primarily for the purposes of conservation, the existing manufacturing technology, as well as the applicable standards of quality seedlings, which are used for highly productive clones of poplar, should be adapted to the production of a large number of genotypes.

Planted forests are an important source of various services (economic, environmental, and social) with increasing portion in the total world’s forest area. Genetic diversity is fundamental for success and sustainability of planted forests. Facing the concern of the reduction of genetic diversity in planted forests, this study offers a review of evidence on comparisons between the levels of genetic diversity in forests established by different regeneration methods. A total of 34 papers comparing genetic diversity in natural forests versus various regeneration methods of 24 tree species examined by the range of markers are reviewed. In most cases, there are no significant differences in genetic diversity between natural and planted forests, followed by an almost equal number of cases with decreased and increased level of genetic diversity. The loss of rare alleles, but also new alleles are reported in planted forests. Although the origin of planting material in the most cases are unknown, the size of parental population is determinant for the level of genetic diversity in the new forest, with the provenancing and seed collection strategy as the most important management practices in planting projects.

Projections of the regional climate model for Southeast Europe generally predict an increasing of temperature and a decrease in precipitation, with some local variations. Higher frequency of extreme weather events and increased flooding can also be expected. This climate change will, among other things, result in changes in habitats and species distribution, and a decrease in biodiversity. In most cases, forest ecosystems will be unable to adapt fast enough to keep pace with changes in climate. Extreme weather events and low precipitation during the growing season will cause high mortality of seedlings after planting. New forests will face the whole range of these changes because of the long lifetime of trees. Reforestation programs must take projections of climate change into consideration. In the long term, new guidelines for site-species matching, provenance selection, and genetic diversity need to be adopted. In the short term, site preparation, planting techniques, and post planting protection need to be improved. In addition, seedling quality (morphological, physiological, and genetic) and planting time need to be specific for each site. New site preparation, planting, and post-planting protection methods are useful tools for short term success measured in seedling survival and initial growth. Seedling quality is essential for short and long term success. Different strategies, such as assisted migration and increased genetic diversity of planting material, can provide better chances for long term success measured in growth, fitness, and capability to produce the next, better adapted generation.