Ecologia Balkanica

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https://doi.uni-plovdiv.bg/handle/store/4

p-ISSN: 1314-0213 / e-ISSN: 1313-9940

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Now showing 1 - 20 of 67

Resistance of 3D - printed PVA filaments to bacterial degradation
(Plovdiv University Press "Paisii Hilendarski", 2025-11-20) Bashev, Anton; Assenov, Stanislav
This study systematically evaluates the resistance of 3D-printed PVA filaments (Bambu Lab) to bacterial biodegradation and their potential antimicrobial activity against two widespread environmental strains: Bacillus subtilis (Gram-positive) and Pseudomonas aeruginosa (Gram-negative). Using the standardized agar diffusion method, a 15% PVA solution was tested against a positive control (gentamicin). The results showed no inhibition zones around the PVA samples for either bacterial strain, which clearly confirmed the lack of statistically significant antimicrobial activity (p > 0.05). These findings unambiguously demonstrate that under the experimental conditions, the 3D-printed PVA material not only lacks bactericidal or bacteriostatic properties but also exhibits resistance to the metabolism of the test microorganisms. From an engineering and ecological perspective, this implies that although PVA is water-soluble, its ultimate biodegradation in nature may be slow and inefficient in the absence of specialized microbial consortia. Consequently, the widespread use of PVA in 3D printing could contribute to its accumulation in soil and aquatic ecosystems. This highlights the need for a re-evaluation of its environmental compatibility and the development of improved composite formulations or end of life management strategies aimed at ensuring true biodegradability.
IoT sensor node for ammonia monitoring in livestock
(Plovdiv University Press "Paisii Hilendarski", 2025-11-19) Assenov, Stanislav; Tokmakov, Dimitar; Bekyarova-Tokmakova, Anna; Shotarova, Snezha; Lyubomirov, Slavi
Increased concentrations of ammonia (NH₃) in livestock buildings pose significant risks to animal welfare, environmental sustainability, and worker safety. The current study presents the design and validation of an Internet of Things (IoT) based sensor node to monitor ammonia concentration (NH₃) in real time in agricultural environments. A microcontroller for local data processing and a wireless communication module that transmits measurements to a cloud platform or mobile application. The prototype has been tested both in controlled laboratory conditions and on real livestock farms, demonstrating high accuracy (±5 ppm), low power consumption (battery power and additional solar panel), and resistance in dusty and humid environments. The collected data is analyzed using machine learning algorithms to predict dangerous levels of NH₃ and automate ventilation controls. The results show that the proposed solution offers a cost-effective and scalable approach to reduce NH₃ emissions, improve animal welfare, and ensure regulatory compliance. Future work includes the integration of additional parameters (e.g., temperature, humidity) and implementation in smart farming systems.
A case of communal nesting of the Western broad-toothed field mouse (Apodemus epimelas Nehring 1902)
(Plovdiv University Press "Paisii Hilendarski", 2025-11-30) Nedyalkov, Nedko; Mladenov, Vladimir; Gospodinova, Plamena; Lohja, Tiziana
Here we report a case of communal nesting of Apodemus epimelas observed several times in a bunker in southern Albania. A. epimelas has a simple nest placed on the ground or in a small hole in the wall. The mice showed no aggressive behaviour.
Bioaccumulation of some heavy metals in plants and insects
(Plovdiv University Press "Paisii Hilendarski", 2025-10-20) Arnaudova, Desislava; Todorov, Krasimir; Stoyanov, Plamen; Georgieva, Deyana; Keranov, Hristo
The study in this scientific paper aimed to analyze the content of potentially toxic elements — heavy metals lead, cadmium, and zinc in soil, plant samples, and insect samples from three different areas: an uninhabited area, an industrial zone, and an urbanized area. Using inductively coupled plasma mass spectrometry (ICP-MS), it was found that the levels of heavy metals in soil, plants, and insects from the three studied areas were higher for lead, cadmium, and zinc in the industrial zone — soil: Pb - 850, Cd - 21.3, Zn - 996 (mg/kg); plants: Pb - 191, Cd - 7.79, Zn - 298 (mg/kg); insects: Pb - 24.5, Cd - 1.32, Zn - 160 (mg/kg). Based on the obtained data, the degree of bioaccumulation of lead, cadmium, and zinc was traced using the bioaccumulation factor (BAF) through the pathway: soil, plants, and insects. A BAF < 1 was found for plants, and a bioaccumulation process for cadmium and zinc was observed in two insect species (BAF > 2).
Roe deer (Capreolus capreolus) with atypical three antlers
(Plovdiv University Press "Paisii Hilendarski", 2025-11-19) Petrov, Rusko; Petrova, Lora
Roe deer (Capreolus capreolus) is a common sight in the forests, bringing joy to nature lovers. Like all wild animals they also have their own unique characteristics and anomalies that can cause amazement and confusion. Although there are well-documented problems related to the growth, replacement and regeneration of antlers in male specimens, there are few known documented cases of animals with three antlers. In this study, we present photographic material and information about three cases in Bulgaria, where three-antlered roe deer bucks have been observed. This unusual phenomenon raises many questions and stimulates interest in further studies and observations in order to establish the causes of this anomaly.
Which color are you?: A pilot study on microplastic accumulation in sediments from the Bulgarian Black Sea
(Plovdiv University Press "Paisii Hilendarski", 2025-11-11) Yancheva, Vesela; Stoyanova, Stela; Georgieva, Elenka; Valkanov, Kiril
Microplastic (MP) pollution in marine sediments is an emerging environmental concern, yet data on MP color and size in the Black Sea are scarce. This pilot study analyzed sediments from five Bulgarian coastal locations. These results provide baseline information on MP color and size in Bulgarian Black Sea sediments and highlight the importance of further studies on the environmental behavior and management of colored MPs.
Assessment of some ecosystem services in the region of Rhodope Mountain, Bulgaria
(Plovdiv University Press "Paisii Hilendarski", 2025-09-23) Petrova, Slaveya; Zlatkova, Meglena; Nikolov, Bogdan; Dakova, Megi
Human society directly depends on a number of natural products and services such as plant and animal resources, mushrooms and herbs, wood and aggregates, water for drinking and non-drinking purposes, fuels and others. For these reasons, in the last decade, intensive work has been done to deepen understanding of human dependence on natural processes at different temporal and spatial scales, as well as to search for appropriate economic and management criteria and indicators by which to measure the value of these ecosystem services. All of the above mentioned determines the relevance of the current study, related to the analysis of ecosystem services on the territory of two villages, situated into the region of the Rhodope Mountain - Brestnik and Belashtitsa, as a resource for social and ecological development. A total of 22 ecosystem services were identified, of which material ecosystem services include 9 classes, regulating and supporting services - 7 classes, and cultural services - 6 classes. These ecosystem benefits are an object of consumption and a resource for social and ecological development not only for local residents and agricultural producers, but also for visitors to the study area, which highlights their exceptional intrinsic value and the need for their conservation and sustainable use.
A toolkit for assessing cultural ecosystem services at a community level
(Plovdiv University Press "Paisii Hilendarski", 2025-08-10) Petrova, Slaveya; Valcheva, Ekaterina; Bileva, Tatyana; Dakova, Megi
Agricultural systems provide people with multiple benefits (both commodity and noncommodity products). Agroecosystem services in this context describe the anthropogenic contribution to the generation of agroecosystem services. Agroecosystem services include a range of services from agricultural ecosystems – provisioning, regulation, maintenance and cultural services. Agroecosystem services adapt the ecologically based concept of ecosystem services to the specifics of managed agricultural ecosystems, thus making this concept more applicable to economically oriented agricultural production systems and agricultural policies. Based on their specific features and nature, it is accepted to group ecosystem services into four categories – material, regulating, supporting and cultural. The majority of benefits from the group of cultural ecosystem services (e.g., leisure and recreation, aesthetic interactions, traditions and rituals) are intangible and therefore often remain undervalued by society. For these reasons, in the last decade, intensive work has been done to deepen understanding of human dependence on natural processes at different temporal and spatial scales, as well as to search for appropriate economic and management criteria and indicators by which to measure the value of these ecosystem services. In this study, we aimed to present a toolkit for assessing cultural ecosystem services provided by agroecosystems. The data obtained through the proposed toolkit can serve to shape recommendations for the sustainable management of agricultural ecosystems, protecting livelihoods and natural resources, so that agro-ecosystems can continue to deliver ES in addition to food production.
Influence of dietary disaccharides on glycosyl hydrolase profile in ecologically distinct Lactobacillus strains
(Plovdiv University Press "Paisii Hilendarski", 2025-10-22) Ivanova, Lidia; Mollova, Daniela; Dimcheva, Nina; Vasileva, Tonka; Bivolarski, Veselin; Nikolova, Mariana; Iliev, Ilia
This study examines glucosyl hydrolase enzymes from Lactobacilli strains isolated from probiotic foods and beverages (kefir, pickles and sauerkraut). Glycosyl hydrolases play a key role in the breakdown of complex carbohydrates, supporting gut health and finding wide biotechnological applications. During the screening stage, the metabolic potential of the strains to utilize various carbohydrates in modified, glucose-free media containing specific carbon substrates is tested. This points to the search for specific enzymes such as α-/β-glucosidase and α-/β-galactosidase. The results indicate that glycosidase activity in Lactobacillus varies by strain and is influenced by the available substrate, highlighting their potential applications in functional foods, prebiotic conversion, and the metabolism of polyphenolic compounds.
Implementation of an eco-friendly hybrid vehicle in engineering education: a case study
(Plovdiv University Press "Paisii Hilendarski", 2025-09-22) Shehova, Daniela; Asenov, Stanislav; Kanevski, Hristo; Raydovska, Velislava; Parushev, Anatoliy
This paper aims to present the integration of an ecological hybrid car test bench allowing for real-environment measurements and analyses into engineering education. The hybrid car test bench – Toyota C-HR Hybrid 1.8 (2019), equipped with the Hybrid Synergy Drive system, has been tested in the training of students from the Bachelor programs "Automotive Electronic Systems” and “Automotive Engineering” at the Faculty of Physics and Technology of Plovdiv University “Paisii Hilendarski” (Bulgaria). The implementation of the hybrid platform in a learning environment proved its potential as a teaching and technological tool, providing opportunities for students to measure exhaust gases emissions, fuel mixtures, fuel consumption and plan models related to the recovery. The inclusion of the hybrid platform in engineering education creates conditions for the development of knowledge and skills related to electromobility, energy efficiency and sustainable technologies, which directly correspond to the optimization of the environmental characteristics of hybrid vehicles.
Ecological aspects of DC-DC converters in hybrid electric vehicles – a review
(Plovdiv University Press "Paisii Hilendarski", 2025-09-22) Asenov, Stanislav; Raydovska, Vladislava; Shehova, Daniela; Kanevski, Hristo; Parushoev, Anatoliy
This paper aims to conduct a literature review on the ecological aspects of energy DCDC converters in hybrid vehicles. Modern technologies that enhance energy efficiency and reduce harmful emissions associated with these components are analyzed. The main trends, challenges, and future prospects for developing environmentally sustainable solutions in energy conversion for hybrid cars are presented. Furthermore, the present work emphasizes the necessity of studying and integrating DC-DC converters into engineering curricula to foster innovation and sustainable development in the automotive industry.
Specifics of the biocultural approach and its potential for interdisciplinary studies: on the example of anthropobiotic communit
(Plovdiv University Press "Paisii Hilendarski", 2025-09-16) Penkova, Stoyka; Stoilova, Elitza; Tasheva, Milena
The article makes an attempt at an analytical interpretation of the specifics of the biocultural approach and its potential for interdisciplinary research. Starting from the premise that the interest is incessantly growing in studies viewing the link between man and environment beyond the traditional disciplinary borders, and also that combining the expertise of natural and social sciences is in increasingly greater demand, this article will show the importance of the biocultural approach as an analytic instrument working on the borders between ecology, biology, anthropology and sociology. Linking into one ecological knowledge, cultural practices, and social structures, this approach fosters the analytic and methodological overcoming of hard limits between natural and social sciences. The article dwells on the case of beekeeping as an example of such a biocultural unity of human knowledge and experience in which the biological and the cultural are in dynamic interaction. As a theoretical and empirical contribution, we introduce the concept of anthropobiotic community, understood as a form of joint interaction between man and another form of life – the bee colony. This concept permits rethinking the coexistence of human communities and animal groups based on mutual dependence, care and co-participation in which humans are ‘with’ and not ‘against’ their environment which is ‘between’ humans and the things in it and which can connect then – also affectively, personally, emotionally – as a space of creation of a community, as a new form of togetherness.
Physico-chemical parameters and PCA approach to assess river water quality – a case study (Albania)
(Plovdiv University Press "Paisii Hilendarski", 2025-06-30) Hoxha, Belinda; Shyti, Bederiana; Papajani, Blerina; Mazrreku, Armela; Osmani, Marilda; Basha, Lule
Water quality refers to the physical, chemical and biological characteristics of water that determine its suitability for a specific use, such as drinking, industry, irrigation or supporting aquatic life. It is assessed by comparing water’s properties against established standards for various uses. Factors influencing water quality include natural elements like weather and geology, and human activities like pollution and land use. Water Quality Index (WQI) is a widely used tool for summarizing and communicating water quality information. It is a valuable and unique statistical approach that consolidates the experimental results of various physicochemical parameters into a single comprehensive and practical term in order to represent the overall quality status of water. The aim of the study is to demonstrate the ability of statistical methods in water quality prediction, specifically by identifying the most important parameters that influence the Water Quality Index (WQI). This involves the use of statistical techniques to analyze water quality data and identify the main factors that influence the overall water quality, potentially leading to a more efficient and accurate water quality management. The study takes in consideration physico-chemical parameters analyzed in Shkumbini River in Albania. The laboratory data from six sampling points during four years are gathered and analyzed based on water quality standards and statistically with PCA (Principal Component Analysis). The chosen parameters to evaluate water quality are TDS, GH, BOD, pH, DO, Cl, HCO3- and thermotolerant coliforms, which are also used to monitor the suitability of the PCA method in the determination of WQI. The physico-chemical parameters were evaluated against international water standards. Additionally, the PCA method showed that the order of indicators determining the WQI depends on the distance between the variables and the origin. The study reveals that using the PCA method, the recommended nine parameters are sufficient to determine the WQI value, and the cumulative proportion of Component 1, Component 2 and Component 3 explains nearly 63% of the total variance.
Taxonomic Composition and Environmental Drivers of Phytoplankton in Earthen Fish Ponds (Bulgaria)
(Plovdiv University Press "Paisii Hilendarski", 2025-06-29) Dochin, Kostadin; Ivanova, Angelina; Ilieva, Lena; Iliev, Ivan
This study presents a comparative analysis of phytoplankton taxonomic structure and its relationship with environmental factors in earthen aquaculture ponds located in Plovdiv and Trivoditsi, Bulgaria, during the period May–September 2024. A total of 114 phytoplankton taxa were identified across six phyla, with Chlorophyta and Cyanoprokaryota dominating the bio-mass. The results showed a pronounced shift towards higher phytoplankton biomass (PhB up to 60.3 mg L⁻¹) and chlorophyll-a concentrations (up to 133 μg L⁻¹) in the Trivoditsi ponds, associated with blooms of green algae and cyanobacteria. For the first time, the invasive and potentially toxic species Raphidiopsis raciborskii was recorded in Bulgarian aquaculture ponds, contributing up to 15.5% of the phytoplankton biomass during bloom periods. Environmental parameters such as elevated ammonium, phosphate, and COD were positively correlated with increased PhB, chlorophyll-a, and total viable counts (TVC) of heterotrophic bacteria. Redundancy analysis (RDA) highlighted the influence of nutrient enrichment and organic load on the biological variables. The observed co-variation between PhB and TVC suggests the presence of a dynamic microbial loop, where intensive primary production supports hetero-trophic bacterial growth. These findings confirm the role of eutrophic conditions and nutrient availability in shaping phytoplankton and microbial communities in earthen ponds used for aquaculture. This study provides new insights into the ecological interactions in such systems, contributing to future strategies for water quality management and sustainable aquaculture practices.
Seasonal characteristics of precipitation in the region of NAO Rozhen, Bulgaria, for the period 2023—2025
(Plovdiv University Press "Paisii Hilendarski", 2025-06-29) Paskaleva, Vesselina; Terziyski, Atanas; Kochev, Nikolay; Tenev, Stoyan; Petrov, Nikola
The article presents high-resolution observations of winter precipitation in the region surrounding the National Astronomical Observatory (NAO) Rozhen, Bulgaria, at an altitude of 1,730 meters above sea level, during the 2023–2025 period. Utilizing an array of advanced meteorological instruments, including the OTT Pluvio²L, Parsivel² disdrometer, WS100 radar sensor, and SHM31 snow depth sensor, we captured detailed in-situ data on precipitation type, intensity, and duration. The integrated sensor system enabled the classification and quantification of various precipitation events such as snow, rain, drizzle, and hail with minute-level resolution. The study features multiple precipitation-related variables, including total amount, intensity, and precipitation type. Seasonal and daily variations in precipitation behavior were documented, with snow dominating the winter period but often accompanied by mixed-phase events. The dataset supports enhanced understanding of precipitation dynamics in mountainous terrain and offers potential for model calibration, climate profiling, and natural air purification assessments. All data is provided in FAIR-compliant formats to support further research and environmental monitoring efforts.
Tracking Volcanic Atmospheric Waves: Insights from the 2022 Hunga Tonga Eruption observed with an Open Sensor Network in Bulgaria
(Plovdiv University Press "Paisii Hilendarski", 2025-06-29) Terziyski, Atanas; Tancheva, Gergana; Jeliazkov, Vedrin; Kochev, Nikolay; Paskaleva, Vesselina
The January 2022 eruption of Hunga Tonga was one of the most powerful volcanic events of the modern era, generating a vertical plume that reached over 50 kilometres above Earth’s surface. The initial explosion, followed by a high-speed atmospheric jet, triggered waves that circled the globe multiple times. The effects of the eruption on Bulgarian territory were detected and analysed using data from the METER.AC network, which includes a wide array of custom-designed and assembled ground monitoring stations, enhanced by a set of certified professional weather stations. These stations utilise the Internet of Things (IoT) paradigm to collect data from a variety of sensors and provide open access to the recorded measurements. We have developed a suite of algorithms to process the collected data through several methods, including semi-automated detection of wave minima and maxima, Fourier spectral analysis, and the integration of data from nearby instruments. This approach enabled us to identify and analyse the first two atmospheric waves that reached Bulgaria and to calculate their average propagation speeds—301 m/s and 315 m/s, respectively. This research highlights the significance and capability of the citizen science network, METER.AC, in providing valuable data for understanding global phenomena, particularly large-scale volcanic events. It also highlights the potential of IoT-based systems and data processing algorithms in advancing atmospheric research and environmental monitoring.
Polyphenol-containing water-soluble bio-composite films as alternative food packaging materials
(Plovdiv University Press "Paisii Hilendarski", 2025-06-29) Grigorov, Aleksandar; Viraneva, Asya
Historically, the development of better food preservation techniques has been one of the main factors in the prosperity and health of any human population, and with the exponential rise in food demand leads science in search of eco-friendlier solutions. One such path is the development of water-soluble biodegradable coatings based on easily accessible and abundant natural polymer materials. As a common byproduct of the food industry, corn zein is one of the most promising biopolymers for food packaging, offering excellent barrier properties. Its main drawback – poor mechanical strength – can be mitigated with the addition of other biodegradable polymers that would result in the creation of bio-composite materials with controllable properties. Further improvements of such biopolymer coatings can be achieved with the addition of other materials, such as different polyphenols, that may improve their antioxidant properties. The presented paper investigates water-soluble bio-composite films, created by dissolving equal parts zein and hydroxypropyl methylcellulose in ethanol solution (70:30 ethanol to water ratio). Polyethylene glycol was used as plasticiser in all samples. Two different polyphenols (quercetin and curcumin) were incorporated in the bio-composites at a concentration of 2 mg/cm2. The mechanical properties of the created films were studied with a use of Universal Testing Machine (Lloyd Instrument). The surface morphology was investigated with scanning electron microscopy and the surface free energy was determined with the use of the sessile drop method. The dependence of the normalized surface potentials on the storage time of the charged substrates was studied. Parameters, important for food preservation, such as water vapor permeability, were investigated.
Air quality control in Plovdiv, Bulgaria: the citizens' awareness. Results from a pilot quantitative study
(Plovdiv University Press "Paisii Hilendarski", 2025-06-29) Mitev, Tihomir; Tchalakov, Ivan; Keskinova, Donka; Parapanov, Petar
Air pollution is a leading risk factor for individual and public health. It is a major environmental stressor responsible for hundreds of thousands of premature deaths in Europe every year. Monitoring and controlling air quality is about the importance of managing public health, as is ensuring people are aware of the dangers of polluted air and getting them involved in the issue. The article presents a summary of the results and data analysis from a pilot study conducted in May-June 2025 on the awareness, interest, personal engagement, and assessment of citizens in Plovdiv (Bulgaria) – one of the most polluted cities in Europe – regarding the control of air quality in the city.
Tautomerism influence on QSAR/QSPR modelling of ecotoxicity and physicochemical properties of chemical compounds
(Plovdiv University Press "Paisii Hilendarski", 2025-06-29) Kochev, Nikolay; Paskaleva, Vesselina; Jeliazkova, Nina
The OECD guidelines for QSAR/QSPR (Quantitative Structure Activity/Property Relationship) modelling and ecotoxicity testing play a significant role in ecological studies by providing standardised, scientifically validated methods to assess the environmental impact of chemicals. Laboratory and terrain tests are combined with QSAR/QSPR models, ensuring consistency, reliability and support for regulatory acceptance, enabling screening and prioritisa-tion, global harmonisation and promotion of alternatives to animal testing. Tautomerism is a fundamental structural phenomenon that can significantly influence the predictive reliability of QSAR/QSPR models used for assessing ecotoxicity and physicochemical properties of chemical compounds. We examine how tautomeric variation affects molecular descriptors, data curation, and model performance. We propose practical incorporation of tautomer information into the model development and cheminformatics pipelines to enhance predictive accuracy and regulatory applicability. By generating exhaustive tautomeric ensembles, our approach sup-ports QSAR/QSPR modelling in line with OECD guidelines for regulatory ecotoxicity endpoints, contributing to the development of robust in silico predictions. By addressing the challenges posed by tautomerism, this work advances the use of computational methods in sustainable chemical safety assessment and supports innovation in non-testing approaches.
Protected Areas as a Context for Effective Science Communication and the Development of Sustainability Competences
(Plovdiv University Press "Paisii Hilendarski", 2025-06-29) Epitropova, Ani
This study analyses how Bulgarian protected areas can serve as platforms for meaningful science communication and as dynamic contexts for developing sustainability competences and supporting environmental conservation efforts. It focuses on how pre-service education students carry out science communication using digital tools and engage with ecological knowledge, how they interpret and communicate information from primary sources related to Bulgarian protected areas, and to what extent this process supports the development of sustainability competences in line with the GreenComp framework. The analysis covers 49 students’ projects focused on protected areas, developed within a structured educational model specifically designed for the study. The analytical approach focuses on three dimensions: (1) scientific accuracy and completeness of the ecological content—including accurate identification of systematic groups, characterized species of flora and fauna, specific ecosystems, and threats; (2) strategies used to communicate scientific information to non-specialist audiences; and (3) the extent to which students demonstrate key sustainability competences, aligned with the GreenComp framework, including: sustainability knowledge, systems thinking, critical thinking, personal and collective responsibility, collaboration, and initiative. The findings reveal competent patterns in information selection, use of visual and emotional tools, and consistent use of scientifically accurate language. Most students present the characteristics of the protected areas in a detailed, engaging, and scientifically sound manner, demonstrating contextual awareness of local environmental challenges and conservation priorities. These patterns support the use of GreenComp not only as a policy instrument but also as a useful analytical tool for measuring ecological awareness and engagement in academic settings. The study contributes to understanding how science communication and competence development intersect in educational settings, positioning future teachers as key mediators between ecology and society.

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