Borys Honcharenko (1) and Olena Demchenko (2)

1. Departament of Dendrology, M.M. Gryshko National Botanical Garden of the National Academy of Sciences of Ukraine, 1 Timiryazevska Str., 01014, Kyiv, Ukraine. E-mail: boris_nbs@ukr.net

2. Department of Botany, Dendrology and Forest Tree Breeding, National University of Life and Environmental Sciences of Ukraine, 15 Heroiv Oborony Str., 03041 Kyiv, Ukraine. *E-mail: demchenkoo@nubip.edu.ua

In the Right-Bank Forest-Steppe of Ukraine, 6 species, 2 hybrids, 2 varieties and about 10 cultivars of the genus Forsythia Vahl are cultivated. The phoenology of the species of the genus is not sufficiently covered in the literature. The available information is mostly about flowering and fruiting periods of individual species, varieties and cultivars at various points of introduction. Due to the lack of information on the rhythms of growth and development of plants of most taxa of the genus Forsythia in the Right-Bank Forest-Steppe of Ukraine, there was a need to conduct such studies. The purpose of the work is to recognize the features in seasonal rhythms of growth and development of Forsythia taxa in th Right-Bank Forest-Steppe of Ukraine and to study their con- sistency with the natural and climatic conditions of this region. The studied objects are within the normal limits of 3–4 phoenodata. Only Forsythia ovata Nakai, whose phoenophases are shorter than normal, does not fit into this range. 20 % of the research objects are within the normal range for all phoenodata, and 93.33 % are within the normal range for 3–4 phoenodata. F. giraldiana Lingelsh., F. ovata ‘Tetragold’, F. suspensa (Thunb.) Vahl, F. suspensa var. fortunei, and F. suspensa var. sieboldii, growing in the city of Kyiv, are within the norm for the dates of onset of all phoeno- phases and have an unused part of the growing season in reserve. In the majority of forsythias (86.67 %), the phoenological atypicality indicator is less than 1, which indicates the correspond- ence of the seasonal rhythms of growth and development of most of the studied forsythias to the climatic conditions of the Right-Bank Forest-Steppe of Ukraine.

Received: 07 February 2024 / Accepted: 14 July 2024 / Available online: 02 August 2024

 Open Access: This article is licensed under a Creative Commons Attribution 4.0 International License.

Adriana Marinova* and Svetoslav Anev

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

This study aims to examine the impact of silvicultural interventions on the height and diameter growth, survival, and canopy structure of naturally regenerated European beech (Fagus sylvatica L.) saplings. In a field study, a system of six experimental sites was set up across three areas in the West Stara Planina region, selected according to the various types of cutting regimes within them. At each area, we chose two experimental sites – one of them with silvicultural intervention (Group selection system, Group shelterwood system and Short-term shelterwood system cuttings) and the other one – without silvicultural intervention during the last minimum twenty years (control). Biometric measurements of sapling number, height, and diameter were taken in 2018 and 2022, alongside assessments of the leaf area index (LAI). The results showed that cutting regimes influence beech regeneration growth patterns. Small canopy gaps (0.111 and 0.125 ha) in the Group selection and Short-term shelterwood systems led to similar survival and growth changes, selecting resilient individuals and increasing sapling sizes compared to controls, with no significant change in LAI. In contrast, the Group shelterwood system, with a larger canopy gap (0.555 ha), resulted in similar sapling numbers and sizes to the control but increased LAI over four years without sapling size growth. This indicates that larger gaps may have a less stimulating effect on beech regeneration compared to smaller gaps.

Received: 07 June 2024 / Accepted: 31 August 2024 / Available online: 05 August 2024 

Open Access: This article is licensed under a Creative Commons Attribution 4.0 International License.