Olena Andreieva (1)*, Oleksandr Borysenko (2), and Ivan Martynchuk (1)

1. Polissia National University, 7 Stary Blvd., Zhytomyr 10008, Ukraine. *E-mail: andreeva-lena15@ukr.net
2. Ukrainian Research Institute of Forestry and Forest Melioration named after G.M. Vysotsky,
86 Pushkinska Str., Kharkiv 61024, Ukraine. E-mail: xalekter@gmail.com

Forest fires play an important role in the deterioration of forests. In 2020, in Zhytomyr region, 28,300 ha of forests were damaged by fire, including about 15,000 ha in Ovruch Specialized Forest Enterprise. Forest fire occurrence depends on forest site conditions, age and type of stands (coniferous or deciduous), and humidity index. However, the significance of neighbouring subcompartments for fire spread has been proved. The number and area of such subcompartments increase after bark beetles’ outbreaks or windstorms. The aim of this research was to evaluate the change in the class of fire hazard in Ovruch Specialized Forest Enterprise forests by baseline approach and considering the type of neighbouring subcompartments using GIS technologies. Considering the categories of lands of neighbouring subcompartments shows that for 2010–2018 the class of fire hazard decreased, i.e. the hazard has increased. The area of 1st class stands in 2018 is 3577.5 ha more in the approach of considering the neighbouring subcompartments compared to the baseline approach. Fire hazard in 2018 increased due to a 3063.6 ha increase in the area of subcompartments, which bordered with clear-cuts and unclosed plantations. The effectiveness of predicting the fire occurrence was confirmed by analysing data on the fire spread in 2020. Therefore, this approach is advisable to be widely implemented by the State Agency of Forest Resources of Ukraine to determine the list of forest compartments with a high risk of fire, to evaluate their area, to calculate the location of IP cameras, as well as for navigation and calculation of the optimal path for fire suppression.

Vasil Kolev

University of Forestry, Faculty of Forestry, Department of Hunting and Game Management,
10 Kliment Ochridski Blvd., 1797 Sofia, Bulgaria. E-mail: vassilie@abv.bg

This article presents the results of a study of the growth rates of Orpheus Dace from the rivers Topolnitsa and Luda Yana, tributaries of the Maritsa River’s middle zone. The study assesses species’ length and weight growth pattern. Samples were collected mainly in the autumns of 2006, 2007, 2010. A total of 552 fish were caught by electrofishing, 297 of which were caught in the Topolnitsa River and other 255 in the Luda Yana River. The oldest fish, caught in the Topolnitsa River, were four-year-old, while those from the Luda Yana River were three-year-old. More than 70 % of the specimens, caught in the Luda Yana River, were one-year-old. Average length of three-year-old Orpheus dace from the Topolnitsa River was 125 mm and average weight was 30 g. Average length of three-year-old fish from the Luda Yana River was 168 mm and average weight was 56 g.

Evlogi Angelov* and Gradimir Gruychev

Department of Wildlife Management, University of Forestry, 10 St. Kl. Ohridski Blvd., 1797
Sofia, Bulgaria. E-mails: evoangelov@gmail.com*, gradi.val@gmail.com

The Grey partridge (Perdix perdix L.) is a common gamebird in Bulgaria but some important parameters of its population are still poorly studied. In this paper we present results from the first radio telemetry study of wild Grey partridges in the country. A total of six partridge males were captured in two study sites in Upper Thracian Plain. Monitored birds stayed near the capture point with a mean dispersion distance of 486.9 m ±309.5 SD (min-max 54.28–1307.24 m). Sufficient data to define home range size was possible for only one adult individual and 100 % Minimum convex polygon (MCP) equaled 17 ha. Within its home range, this male partridge showed a preference for an unusual part of its home range, an area for the storage of straw bales used by a bioenergy production facility. This observation confirms the species ability to adapt to changing types of land use in agricultural ecosystems.

Panagiotis Michopoulos (1)*, Athanassios Bourletsikas (1), Konstantinos Kaoukis (1), George Karetsos (1), Evangelia Daskalakou (1), Constandina Tsagari (1), Marios Kostakis (2) et al.

1. HAO-DEMETER Institute of Mediterranean Forest Ecosystems, Terma Alkmanos, Athens 11528, Greece. *E-mail: mipa@fria.gr
2. Laboratory of Analytical Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimioupolis, Athens 157 71, Greece.
3. Environmental Pollution Control Laboratory, Department of Chemistry, Aristotle University of Thessaloniki, 541 24, Greece.

The distribution and cycling of nutrients were examined in a mature Bulgarian fir forest (Abies borisii-regis Mattf.) in the area of Karpenisi, Central Greece. More specifically, the current and second year concentrations of Ca, Mg, K, N, P, S, Fe, Mn, Cu and Zn in bulk deposition, throughfall and litterfall in the fir needles and fluxes were determined. In addition, their total amounts were measured in the standing and ground vegetation as well as in soil up to 80 cm. It was found that the throughfall deposition was a significant source of S and K. The foliar, woody and rest fractions of litterfall were 71, 19 and 10 % of the total litterfall, respectively. Among all the ecosystem components, the highest nutrient quantities were found in the mineral soil, forest floor, trunk wood, trunk bark and canopies of the fir trees. The trunk bark proved an appreciable pool for P and S. In order to calculate the mean residence time of nutrients in the forest floor, througlfall and litterfall fluxes were taken as input. It was found that the mean residence times of nutrients in forest floor followed the order Fe>Mn>Zn>Mg>Cu>P>N>Ca>K>S. According to nutrient concentrations ranges in conifer needles and soils, the fir forest is in a very good condition with regard to nutrient status. Consequently, all the environmental parameters measured in the forest can serve as a comparison reference level for other (mature) mountainous Abies forests in Europe.

Evgeni Tsavkov and Petar Zhelev*

Department of Dendrology, University of Forestry, 10 Kliment Ohridski Blvd., 1797 Sofia,
Bulgaria. *E-mail: petar.zhelev@ltu.bg

The paper presents a survey on the genetic variation of Quercus frainetto Ten., an economically important tree species. Allozyme markers were applied to detect intra- and inter-population variation. The level of genetic diversity within populations was relatively high, like in other oak species with similar life history characteristics – mean expected and observed heterozygosities were 0.231, and 0.196, respectively. The major part of genetic diversity was attributed to within-population component of variation. Genetic differentiation measured by F-statistics was 0.027. No significant isolation by distance and small-scale geographic subdivision was detected, whichindicates substantial gene flow among populations.