Provenance trials, as the subject of continuous analyses, provide empirical information about the plasticity of tree species. Changing climate and environmental conditions likely favor genotypes with high levels of plasticity. Finding the suitable provenance for the reintroduction of pedunculate oak to habitats that are threatened and where this species no longer exists provides important information for the targeted use of the available gene pool. The dominant ecological factors in the development of pedunculate oak forests are groundwater level and changes in the hydrological regime of habitats. In this study, we established nursery and field provenance trials to test two pedunculate oak seed provenances from different hydrological conditions to investigate the influence of seedlings' provenance and field microhabitat on growth parameters and survival. In the nursery trial, the height and ground level diameter were measured. After three years in the pilot object, the height and diameter were analyzed again, as well as the survival. To determine the microhabitat influence planting area was divided in two ways: three repetitions and two planting blocks. In this study, significant differences in analyzed growth parameters between the chosen provenances were obtained at the end of the first vegetation period. In later ontogenetic phases influence of the provenance is missing. As the difference between provenances disappears, the influence of microhabitat occurs (significant differences between repetition or planting blocks). After the second year of development, no significant difference was observed between the two provenances of different hydrological regimes, but there are significant differences between the microhabitats in the afforested area (established pilot object).

Norway spruce is one of the most commonly used species for new forest planting in Europe. It is planted in a large number of habitats, often without following the previous results in the success of afforestation. In order to improve Norway spruce afforestation, open field tests were established in which developmental phenophases are monitored. The use of planting material of different provenances, which had not previously been tested for habitat conditions, was often the cause of the decline of newly planted forests. Early budburst of Norway spruce causes losses due to the freezing of terminal buds. Norway spruce testing for different habitat conditions in Bosnia and Herzegovina (B&H) was conducted at two ecologically different localities: Srebrenica (eastern part of B&H) and Drinić (western part of B&H). During 3 years, the budburst on the seedlings originating from 6 populations (Han Pijesak 1, Han Pijesak 2, Foča, Olovo, Kneževo and Potoci) was monitored. The budburst dynamics was monitored in 2013, 2015 and 2016 and it was recorded for each seedling in two progeny tests. Seedlings from the Kneževo population budbursted the earliest. The seedlings would start budburst on different days of the year, depending partly on the temperature sums and their origin. The earliest budburst was recorded in 2013 (119th day of the year in Srebrenica and 121st day of the year in Drinić). During 2015 and 2016, the budburst started later (125th day in Srebrenica and 129th day in Drinić). Temperature cumulants indicate that a smaller sum of temperatures was required for the buburst in the Srebrenica test than in the Drinić test. However, the temperature sums did not clearly indicate the budburst pattern because they were different for each observed year, but the populations ranking was almost the same. This indicates the influence of some other variables on the budburst. The knowing of the data on the budburst dynamics are a prerequisite for a successful selection of starting populations from which planting material is produced and new forests are later planted. Population Kneževo had the earliest budburst but population Han Pijesak 2 had the latest budburst.

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.

Pedunculate oak (Quercus robur L.) is one of the most important deciduous tree species in the Serbian and European forests. Different negative factors limit natural regeneration of pedunculate oak forests, so producing of high quality seedlings becomes imperative to ensure successful forest restoration. This research was conducted with to aim to determine whether acorn size is related to seedlings quality. Acorns were collected from the natural pedunculate oak forest and divided into two groups by their size. Acorns were sown in the spring into plastic containers after five months cold storage. Size of acorns was in the standard species range, though germination was low (< 20 %). Germination was more then double in group of large acorns in comparison to group of smaller acorns (19.2 %, respectively 8.6 %). Height and root collar diameter of produced seedlings were lower than seedlings produced in seedbeds in commercial nurseries in Serbia, but it was in range of container produced seedlings in some similar researches. Height to root collar diameter ratio and shoot to root ratio were considered as satisfactory for containerized seedlings. There was not strong correlation between acorn size and seedlings quality attributes.

The paper presents the growth characteristics of one-year-old seedlings of three autochthonous oak species (Fagaceae family): Turkey oak (Quercus cerris L.), Hungarian oak (Quercus frainetto Ten.) and downy oak (Quercus pubescens Willd.) in suboptimal growing conditions. The analyzed oak species are widely distributed in Serbia. One of the most important benefits of oak species is wood production (Hungarian and Turkey oak), and they have a promising role for the use in the future regarding the climate change as all species can be encountered on dry sites. Acorns were collected in the autumn of 2017 in natural stands and a sample of 400 acorns per each oak species was immediately sown in a nursery seedbed in the form of a random block system with four replicates. At the end of 2018, the available sample of seedlings was analyzed morphometrically. The seedlings were classified according to the number of shoot growth flushes into one-flush-growth and multi-flush growth seedlings. Turkey Oak had the highest number of seedlings which also recorded higher values in total height, root collar diameter and number of leaves. These results were obtained on alkaline soil with the presence of weeds and rodents and the absence of irrigating. The presence of multi-flush growth was recorded in all three oak species. Differences between analyzed three oak species exist in these suboptimal conditions. However, in full light conditions, a similar growth pattern was recorded, indicating to the similar adaptability of the species.

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

The conducted research that involved the assessment of the census size of the black poplar population on The Great War Island, its viability and health status, levels of genetic diversity and recent changes in population served as the basis for defining the measures of in situ conservation of the available gene pool. A network of in situ conservation habitats, labeled A, B and C, were formed. The area of conservation habitat A is 27.90 ha and includes 455 individual trees of black poplar. Conservation habitat B spreads over an area of 7.84 ha and includes 192 individual trees of black poplar. Conservation site C spreads over an area of 21.25 ha and includes 260 individual trees of black poplar. Potential new areas suitable for natural regeneration have been identified in the vicinity of the conservation habitats. Their total area amounts to 16.50 ha and they are surrounded by reproductively mature black poplar trees and thus, seeds can easily be transferred to these areas. The suggested measures of in situ conservation are aimed at the maintenance and conservation of existing black poplar population in the area of Great War Island.