Kiril Vassilev (1)*, Beloslava Genova (1), Momchil Nazarov (2), and Nikolay Velev (1)

1. Department of Plant and Fungal Diversity and Resources, Institute of Biodiversity and
Ecosystem Research, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria.
*E-mail: kiril5914@abv.bg
2. Central Balkan National Park, 3 Bodra smyana Str., 5300 Gabrovo, Bulgaria.

Subalpine willow shrublands are locally distributed in Vitosha Mt. and are dominated by low-growing willows (Salix lapponum L., Salix waldsteiniana Willd.). During the 2021–2022 field seasons, 21 relevés were collected following the Braun-Blanquet approach. Complete informa¬tion on the species composition and abiotic characteristics of the environment (elevation, aspect, slope, soil depth) in all sample plots was collected. Diagnostic, constant and dominant species were identified for all established syntaxa. The aims of this study are: (1) to establish the syntaxonomical diversity of subalpine willow shrub vegetation on Vitosha Mt., Bulgaria; and (2) to reveal the species composition and vegetation structure of the established syntaxa. For the first time, the distribution of 2 associations representing subalpine willow shrublands has been established for the vegetation of the country – Salicetum lapponum Zlatník 1928 and Salicetum waldsteinianae Beger ex Oberdorfer 1978. Association Salicetum lapponum is dominated by the downy willow Salix lapponum. It reaches 1–1.5 m height and covers 85–100 %. Association Salicetum wald¬steinianae is dominated by Salix waldsteiniana, which covers 95–100 %. From ecological point of view, ass. Salicetum lapponum occupied wetter habitats with acidic soil reaction and lower nutrient content, whereas ass. Salicetum waldsteinianae is found in less acidic microhabitats, with higher nutrient content. Habitats of both willows are listed in the Habitat Directive 92/43/EEC (4080 Sub-Arctic Salix spp. scrub), Annex I of the Bulgarian Biodiversity Law and the Red Data Book of the Republic of Bulgaria. Main pressures and threats affecting those phytocoenoses are climate change and especially changes in precipitation regimes, natural succession and the influence of human activities.

Received: 01 July 2025 / Accepted: 07 September 2025 / Available online: 20 September 2025

Open Access: This work is distributed under the Creative Commons Attribution 4.0 License.

Desislava Angelova (1)*, Elitsa Blagoeva (2), and Stanko Stanev (1)

1. Institute for Roses and Aromatic Plants, Agricultural Academy, 6100 Kazanlak, Bulgaria.
E-mails: desita7706@abv.bg*, sdstanev@abv.bg
2. Agricultural Experimental Station at the Eastern Rhodopes, Agricultural Academy, 6600
Kardzhali, Bulgaria. E-mail: elica_blagoeva@abv.bg

An open-field study was carried out in 2023–2024 at the Institute for Roses and Aromatic Plants – Kazanlak, aiming at evaluation of herbicide weed control in lavender plantation (Lavandula angustifolia Mill.) cultivar ‘Yubileina’. Herbicide efficacy and selectivity of BeFlex (500 g·L-1 beflubutamid) and Battle Delta (400 g·L-1 flufenacetate + 200 g·L-1 diflufenican) were determined, applied on soil in two concentrations before beginning of lavender vegetation. The effect of the herbicides on weed infestation and on lavender growth and development was followed. Results analyses show that BattleDelta successfully controls annual dicotyledonous and monocotyle¬donous weeds (Chenopodium album L., Polygonum aviculare L., Veronica agrestis L., Sonchus oleraceus L., Alopecurus myosuroides Huds., Poa annua L.). The soil activity of the herbicide persists up to the 60th day after treatment. That makes it possible to eliminate the competitive impact of weeds on lavender growth after beginning of growing. BeFlex exerts effective action on annual dicotyledonous weeds reducing their number by 14–17 % compared to the control. No phytotoxicity was observed after herbicide application. On the contrary, lavender fresh mass and oil yields were higher in treated area than from the untreated control.

Received: 26 June 2025 / Accepted: 09 September 2025 / Available online: 20 September 2025

Open Access: This work is distributed under the Creative Commons Attribution 4.0 License.

Kristiyan Stoyanov and Svetlana Anisimova*

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

Botanical gardens and arboreta play an important role in plant science research and biodiversity conservation. In recent decades, the social role and cultural functions of botanical gardens,as urban green infrastructure elements and tourist attractions, have influenced their design. The University of Forestry’s Petrohan Arboretum serves primarily as an educational resource. In addition, it plays a key role in scientific research on tree species’ responses to climate change and their adaptation to the local environment. The beautiful nature makes the campus attractive as a centre for workshops, seminars, and green schools. It has great potential for further development, particularly as an attractive destination for educational tourism. The aim of this research is to develop a contemporary landscape design concept for the rehabilitation of the University of Forestry’s Petrohan dendrological park and its transformation into both a functional hub for education and research, and an inspiring green space that enhances the landscape’s aesthetic value while promoting biodiversity. The preliminary studies involved data collection and analysis of the current condition of vegetative and non-vegetative elements. The key design principles for the rehabilitation of the Arboretum were: (1) enhancing biodiversity; (2) providing engaging educational opportunities; (3) developing a sustainable design. These principles emphasise the importance of creating enriching, multifunctional nature-based open spaces that not only support biodiversity and scientific research, but also serve as educational and recreational resources for students and the community. A master plan following the new concept of functions and structural planning has
been designed based on the site analysis

Received: 30 June 2025 / Accepted: 20 September 2025 / Available online: 29 September

2025 Open Access: This work is distributed under the Creative Commons Attribution 4.0

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

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

‘Golak’ hill and Karkariya ridge of the Western Rhodope Mts. are subjected to high anthropogenic load from various activities (now and in the past). However, a number of protected species live there, which procured for targeted monitoring. Between March 2023 and June 2024, we surveyed nine sampling plots via 54 pitfall traps and manual collecting of material. Here we present the data obtained about one of the indicative groups of animals, the ground beetles (Coleoptera: Carabidae). A total of 3229 specimens from 92 species were collected. Calathus distinguendus Chaudoir, 1846 and Carabus convexus Fabricius, 1775 were eudominants; Carabus montivagus Palliardi, 1825 and Laemostenus cimmerius (Fischer von Waldheim, 1823) were dominants. Carabus convexus was euconstant, collected in all sampling sites. Beetles belonged to 22 categories from the five faunal types of Bulgarian carabids, as the European-Asiatic (30 species; 33 %) and Mediterranean (21; 23 %) complexes prevailed. We found relatively low number of winged beetles (57 %), which is comparable only with typical montane habitats. The established ratio between the life forms classes (54 % Zoophagous and 46 % Mixophytophagous species) is close to the typical for the meadow steppes from the Forest-steppe zone of Eurasia. In relation to their humidity preferences, mesoxerophilous (38 %) and mesophilous (28 %) carabids predominated. Mathematical processing showed that: 1) there was a clear separation of the forest habitats, based on two indicator species; 2) overgrazed habitats formed another well-defined group; 3) in addition to the habitat type separation, the ecotone edge effect and ecological catastrophic effect were both present, as well.

Received: 05 July 2025 / Accepted: 21 September 2025 / Available online: 29 September 2025

Open Access: This work is distributed under the Creative Commons Attribution 4.0 License.

Simona Kostadinova (1), Kameliya Petrova (2)*, and Diana Malinova (1)

1. Faculty of Ecology and Landscape Architecture, University of Forestry, 10 Kliment Ohridski Blvd.,
1797 Sofia, Bulgaria.
2. Faculty of Forestry, University of Forestry, 10 Kliment Ohridski Blvd., 1797 Sofia, Bulgaria.
*E-mail: kpetrova@ltu.bg

Forest soil is a key component of mountain ecosystems, providing water storage, nutrient cycling, carbon sequestration, and biodiversity support. This study assessed essential physical and chemical parameters related to the health status of Cambisols in mature Norway spruce (Picea abies L.) stands within Pirin National Park, Southwestern Bulgaria. Ten soil profiles were sampled across an altitudinal range of 1386–1790 m a.s.l. Soil depth varied between 30 and 67 cm, according to WRB (2022) and regional classification criteria, all were considered shallow, potentially limiting root development and water storage capacity. In the A horizon, pHH2O ranged from 4.1 (very strongly acidic) to 6.2 (slightly acidic), while CEC was high to very high (11.96– 33.52 cmol(+)·kg-¹), largely dominated by exchangeable Ca²+. Base saturation varied from 61 % to 99 % in surface horizons, but unsaturated conditions (<50 % BS) occurred in 50 % of the Bw horizons. Organic carbon content in the A horizon ranged from 25.81 to 63.36 g·kg-¹, with C/N ratios from 8 to 15, and available water holding capacity from 32 % to 68 %. These results indicate that although the soils are well supplied with organic matter and have favourable porosity and bulk density, acidity, low base saturation in some profiles, and dominance of chemically inactive texture fractions (sand and silt) may constrain soil health. The findings provide a regional baseline for soil health assessment in Pirin National Park, with practical implications for sustainable forest management and conservation planning in other mountainous protected areas.

Received: 16 July 2025 / Accepted: 22 September 2025 / Available online: 29 September 2025

Open Access: This work is distributed under the Creative Commons Attribution 4.0 License.