Lyubka Varbeva, Nasko Iliev*, and Milko Milev

University of Forestry, 10 St. Kliment Ohridski Blvd., 1797 Sofia, Bulgaria. *E-mail: ilievnasko@abv.bg

The reaction after treatment with selective herbicides was carried out in a nursery plot for production of one-year-old poplar saplings from the type 0/1 from the cultivars ′I-214′ and ′Vernirubens′. Water solutions of the 4 herbicides (H1–H4) with a concentration 5 ml.l-1 and a control variant were tested. Treatments were carried out in five terms: May, June, July, August and September. Final measurements were carried out after the growing season. The estimation of the influence of each herbicide was done after the following indices: survival, height and diameter of the stem; thickness and number of first grade roots; relative moisture of wood of poplar saplings. The results showed that tested herbicides do not influence on the survival of saplings with the exception of a negative influence on cultivar ′Vernirubens′, caused by the herbicide H2. Saplings of cultivar ′I-214′ have faster growth in height than cultivar ′Vernirubens′. Tested cultivars show specific reaction to applied herbicides and best tolerance to H3 (350 g.l-1 Butachlor + 350 g.l-1 Propanil). Herbicides H1 (150 g.l-1 Fluazifop-P-butyl) and H4 (240 g.l-1 Oxyfluorfen) oppress less the growth of saplings at both cultivars, compared to the outlined depressive effect of the herbicide H2 (240 g.l-1 Clethodim). As most suitable was determined the herbicide H3. In the course of production, weed control could be carried out with the help of this herbicide during all phoenophases of the development of saplings.

Leonid Melezhyk

National University of Life and Environmental Sciences of Ukraine, 15 Heroyiv Oborony Str., 03041 Kyiv, Ukraine. E-mail: leomelezhyk@hunter.ua

An effective way to solve the problem of becoming energy more expensive can be found in the use of organic mass of growing woody plants, which are obtained from special energy plantations. Certain positive changes in energy policy in Ukraine in recent years have contributed to a marked increase in the percentage of alternative renewable energy in the energy balance of the country – from 0.5 % of the amount of consumed fuel and energy resources in 1998 to 5.8 % at present. In this paper we evaluated the possibility of obtaining new high-yield willow hybrids based on domestic and foreign cultivars for the creation of energy plantations in the conditions of Polesia and the Forest-Steppe of Ukraine. Breeding works were carried out as interspecific hybridization. Hybridization was conducted in spring 2018 on the cut branches in the laboratory and on branches inseparable from the bush, on which before the flowering female inflorescences was isolated to prevent uncontrolled pollination. The best of the two-year-old hybrid willow forms we have obtained in the course of our research reach a height of 3.0–3.2 m, which indicates their high biological potential and the potential for use in creating energy plantations.

Teodora Teofilova(1)* and Nikolay Kodzhabashev(2)

1. Institute of Biodiversity and Ecosystem Research (IBER), Bulgarian Academy of Sciences, 1 Tsar Osvoboditel Blvd., 1000 Sofia, Bulgaria. *E-mail: oberon_zoo@abv.bg
2. Department of Hunting and Game Management, Faculty of Forestry, University of Forestry, 10 Kliment Ohridski Blvd., 1797 Sofia, Bulgaria. E-mail: ndkodjak@abv.bg

This is the second part of the study representing the first overall assessment of the ground beetle fauna in the region of the Zlatiya plateau. The study aimed at analyzing the ecological structure of the carabid fauna represented by 6598 adult carabid specimens, belonging to 138 species, 49 genera and 20 tribes. The dominant structure was characteristic with the presence of 2 eudominants numbering 26 % of all specimens (Harpalus rufipes and Harpalus tardus), 4 dominants (26 %), 1 subdominant (3 %), 17 recedents (27 %) and 114 subrecedents (18 %). The analysis of the life forms showed only a slight predominance of the zoophages (71 species; 52 %) over the mixophytophages (67 species; 48 %). Similar ratio (50: 50 %) is mostly approaching to the typical for the steppe zones, for the orchards from the forest-steppe zones, and for the vast deforested territories across Europe. Humidity preferences analysis showed the larger share of the mesoxerophilous carabids. The prevalence of the macropterous carabids reflected their higher mobility and adaptiveness.

Svetlana Anisimova

Department of Landscape Architecture, University of Forestry, 10 St. Kliment Ohridski Blvd., 1797 Sofia, Bulgaria. E-mail: sanisimova@ltu.bg

The paper considers the potential impact of allergenic pollen urban dendroflora on public health. The aim of the study was to make quantitative and qualitative analysis of urban park woody taxa emitting allergenic pollen in order to increase the awareness of landscape architects and medical practitioners. The case study was conducted in the second largest park in Bulgaria – Sveti Vrach, Sandanski. The town is famous as climatotherapy and spa resort of international importance. The total number of the investigated trees was 2673, and the number of shrub specimens – approximately 2640. The results from the detailed inventory of park dendroflora estimated that the total number of taxa was 199 in terms of species and the infraspecific taxa, belonging to 49 families and 109 genera. Analysis of the systematic structure of the examined specimens was performed. Geographic distribution, reproductive characteristics, foliage permanence, and allergenicity level of taxa were also analysed. Considering the allergenic potential value of tree species, 34.9 % of tree specimens had a high allergenic potential, 10.6 % of tree individuals had a very high allergenicity level, while 4.8 % – a moderate one. As a result, half of all the researched trees (50.2 %) had a moderate to very high allergic potential. The most frequent shrub species had moderate to low/very low alergenicity potential. Only 4.9 % of shrub specimens had a high to very high allergenicity level. Tree density and Diversity Index were also calculated, as factors that most affect the final allergenicity value of the park. Adopted strategies for risk mitigation has been suggested and addressed to future urban greening initiatives and landscape design for achieving biodiversity-friendly green infrastructure and sustainable urban environment.

Petro Lakyda(1)*, Svitlana Sytnyk(1), Viktoriia Lovynska(2), Ivan Lakyda(1), and Yuriy Gritsan(2)

1. Department of Forest Mensuration and Forest Management, National University of Life and Environmental Sciences of Ukraine, 15 Heroiv Oborony str., 03041, Kyiv, Ukraine. *E-mail: lakyda@nubip.edu.ua
2. Department of Garden and Parks, Dnipro State Agrarian and Economic University, 25 S. Yephremova str., 49060, Dnipro, Ukraine. Email: glub@ukr.net

The formation of live biomass of forests is premised on many factors, among which the dominant ones are stands growth conditions and biometric characteristics. The purpose of this research is to develop reference materials for the evaluation of crown live biomass structural components for stands of black locust (Robinia pseudoacacia L.) and Scots pine (Pinus sylvestris L.) for the conditions of the Northern Steppe of Ukraine. The field research has been carried out in Scots pine and black locust stands of artificial origin subordinated to the State Forest Resources Agency of Ukraine. The research employed the classical forest mensuration techniques for collecting and processing experimental material on 40 test plots. The modelling was preceded by the stage of statistical analysis of the input dataset, which characterizes the live biomass of forest stands’ crown. Mean age, diameter, and height of stands, as well as their relative stocking, have been identified as informative and statistically significant predictors. We have developed the two- and three-factor allometric regression equations for assessment of crown live biomass compo- nents – branches over bark and foliage based on the biometric indices of stands. The adequacy of the models has been estimated by the determination coefficient (0.47–0.71) and Fisher’s F-test. In black locust and Scots pine stands with the same average diameter and relative stocking, live biomass of branches and foliage will be larger in those, where the mean height of the main species is smaller. The obtained allometric equations for assessing the biophysical indices of live biomass subject to this research can be used for practical forestry purposes in the course of forest inventory, determination of harvest volumes, and assessment of ecosystems services.