Issues

Abstract

The article presents a study on the growth patterns of Romanian barbel in the middle reaches of the Vit River, within the Danube River watershed in Bulgaria. The research utilized material collected by anglers along the Vit River, with a total of 209 individuals examined. Fish age was determined through scalimetry, while length and mass were calculated using scale length-radius and mass-length relationships, respectively. The study established four age groups, with the majority of the sample consisting of three and four-year-old fish. The length of the sampled individuals ranged from 88 mm to 192 mm. Growth analysis was conducted by back-calculating the length using the equation SL = 1.9331·S + 42.677 (r2 = 0.947). Furthermore, a relationship between gutted weight (W) and standard length (SL) was established using the equation W = 0.00003∙L2.8233 (r2 = 0.996). The obtained results were compared to nine local populations of Romanian barbel in rivers across Bulgaria.

Received: 09 October 2023 / Accepted: 14 December 2023 / Available online: 19 December 2023

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

Abstract

Cinnamomum sintoc Blume is native from the lowland region of Indonesia, and is an endemic plant in Mount Ciremai National Park. It is a medicinal plant that can be extracted into essential oil. The purpose of this study was to determine the chemical composition of essential oils contained in the leaves and bark of C. sintoc in Mount of Ciremai National Park. The extraction method uses steam distillation. The distillation results are analysed using gas chromatographymass spectrometry (GC-MS) to determine the chemical composition of the essential oil. The results showed there are differences in the composition of chemical compounds contained in the leaves and bark of C. sintoc, the main chemical compound components in the leaves were linalool (8.26–87.12 %), 1,8-cineole (33.20–49.21 %), caryophyllene (1.54–7.78 %), α-terpineol (1.02–17.23 %), β-selinene (1.02–4.16 %), germacrene β (1.02–4.03 %), and (-)-caryophyllene oxide (1.01–2.49 %) and in the bark were 1,8-cineole (11.70–51.88 %), α-terpineol (12.17–25.64 %), linalool (38.11–78.98%), 4-terpineol (3.71–10.11 %), caryophyllene (1.23–4.90 %), β-pinene (1.09–4.02 %), and d-cadinene (1.01–3.28 %). This research shows that the highest yields of essential oils are found on the western slopes of Mount Ciremai National Park.

Received: 07 August 2023 / Accepted: 08 December 2023 / Available online: 14 December 2023

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

Abstract

Biometric parameters of fruits and seeds of Paulownia tomentosa collected from trees grow- ing in soil and climatic conditions of different geographical locations of Odesa, Zakarpattia (Muk- achevo) and Lviv regions of Ukraine, as well as technical and absolute germination, germination energy, mean germination time and weight of 1000 seeds, were studied. The effect of different temperatures on seed germination in soil was evaluated under two temperature regimes. The influence of the duration of pre-soaking on seed germination was also determined. Pre-soaking of seeds in water and solutions of five different stimulants on germination in soil was also inves- tigated. It has been found that in the conditions of Odesa region, the species formed larger fruits and the seeds were characterized by significant rate and uniformity of germination. Lowering of germination temperature caused a decrease in germination energy, laboratory and absolute seed germination, and increased the mean germination time of seeds. Pre-soaking of seeds increased significantly germination rate and its duration was associated with the parameters: germination energy, technical and absolute germination. Among the three seed collections, the highest tech- nical germination was recorded for seeds from Lviv region. The seeds from Odesa region had the highest germination energy. The seeds were characterized by high germination rate in soil regardless of the geographical location of seed collection under the conditions of Ukraine. The highest germination in soil was found for seeds, collected in Lviv. Temperature during germina- tion significantly affected the germination of seeds in soil. Under the temperature regime of 21 to 25 °C, soil fertility parameters were significantly higher. Pre-soaking of seeds had the highest stimulating effect on further germination of seeds in soil among the studied treatments. Pre-treat- ment of seeds with germination stimulants had generally a positive effect, increasing germination in soil.

Received: 13 September 2023 / Accepted: 23 November 2023 / Available online: 28 November 2023 

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

Abstract

The aim of the study was: (i) to measure the different soil properties and infiltration rate; (ii) to determine the optimum soil infiltration rate model based on soil properties (soil porosity, bulk density, soil moisture, organic matter, clay, silt and sand) after shifting cultivation in Vietnam. Infiltration rates were measured using a double-ring infiltrometer at 36 sampling points, and the measurements were taken from February to June 2020. Location of each infiltration stations were marked using GPS device. The results showed that the infiltration rate in vegetation recovering (grassland, shrubland and small regenerating trees) after shifting cultivation varied from 2.41 to 3.23 mm·min-1, with an average measured infiltration rate of 2.87 ±0.22 mm·min-1. The soil poros- ity, organic matter content and sand have a positive correlation with infiltration rate, whereas bulk density, soil moisture, clay, silt have a negative one. The analysis performed for five models con- sidering the combination of soil properties and subjected to regression analysis. Result showed that in order to predict soil infiltration rate based on few properties of soil with four independent variables, multi-linear regression model IR = 1.745 + 0.026 (SP) + 0.016 (OM) - 0.026 (SM) + 0.003 (sand) with the coefficient of determination R2 = 0.856, Bayesian Information Criterion (BIC) = -55.77 and posterior probability = 15.5 % is the best model for the estimation of infiltration rate and recommended for the research area.

Received: 23 February 2023 / Accepted: 13 November 2023 / Available online: 22 November 2023

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

Abstract

Some modifications of the urban environment, such as changes in light intensity resulting from anthropogenic activities in the cities, affect the plant’s physiology. Examining physiological processes reveals the current state of plants and their potential for adaptation under changing environmental conditions. In a field study, we investigated the gas-exchange responses of seven tree species used in urban landscaping (Betula pendula Roth, Ailanthus altissima Swingle, Tilia tomentosa Moench, Tilia platyphyllos Scop., Tilia cordata Mill., Quercus robur L., and Paulownia tomentosa Siebold & Zucc) to variations of light using infrared gas analysis. Leaf light-saturated photosynthesis, dark respiration, and light use efficiency were obtained from the light-response curves. Carbon use efficiency was also determined. In this study, the highly shade-intolerant species, except for P. tomentosa, show lower carbon use efficiency. This suggests that the ex- isting environmental conditions are not conducive to intensive growth for species that demand substantial solar radiation. In contrast, P. tomentosa stands out as an exceptionally resilient and potentially productive species, capable of adapting to various changes in the current environ- ment, even when they do not align with its specific ecological requirements. Nevertheless, P. tomentosa’s high carbon use efficiency compared to the native experimental species suggests its potential invasiveness.

Received: 04 October 2023 / Accepted: 13 November 2023 / Available online: 17 November 2023 

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

Abstract

The aim of the study was to establish the effects of different levels of damage by surface fires on middle-aged Scots pine (Pinus sylvestris L.) stands in the green area of the city of Kremenchuk under increased recreational pressure. We used data from the sample plots established in Hradyzk Forestry in Kremenchuk Forest Economy Branch 3 years after a surface fire in a fairly common type of forest site conditions – fresh relatively poor forest site type. The main mensuration characteristics as well as impact features and impact of damage to Scots pine trunk with diferent level of severity were determined, taking into account the rough bark height and Kraft classes. The tree health dynamic and trees mortality several years after the fire were analysed. The possibilities for the tree regeneration and condition improvement were assessed, considering the long-term recreational pressure. A very strong correlations were found between the tree condition deterioration and the bark char height increase (r = 0.95) and the degree of thin bark burn injury (r = 0.98). The dependence of the tree mortality on the bark char height was also very strong (r = 0.94). A strong significant correlation (r = 0.84) was established between the proportion of dying trees and the degree of thin bark burn injury. Based on these data, it was possible to clearly trace the consequences and features of the most critical damages as well as to establish the values at which the trees almost completely survived.

Received: 30 August 2023 / Accepted: 01 November 2023 / Available online: 15 November 2023

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

Abstract

The article presents statistics of forest fires in Ukraine, characterizes large-scale forest fires in the world and their consequences. Presented methods of detecting and reducing the intensity of the spread of forest fires and fires in ecosystems that were under previous radioactive or chemical contamination do not always bring the desired result, so the authors suggest using their patented device to create a water curtain. The purpose of the article is to present a mathematical model of irrigation with this device. To conduct the research, a stand was used, with the help of which the results of changes in pressure, flow rate, spray radius were obtained experimentally. Empirical dependencies were established, on the basis of which a mathematical model of irrigation with a water curtain device was built. The model is necessary to determine the parameters of the device and improve the quality of calculations necessary during forest fire extinguishing.

Received: 02 March 2023 / Accepted: 07 October 2023 / Available online: 30 October 2023

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

Abstract

Forest phenology has gained increasing attention due to its role in understanding and moni- toring the effects of climate change on ecosystems. This article compares the main phenological events of European beech (Fagus sylvatica L.) over six years in three mountains in Western Bul- garia – Western Stara Planina, Osogovo, and Belasitsa. The correlations between the start of the season (SOS) date, max of the season (MOS) date, end of the season (EOS) date, and length of the season (LOS), on one hand, and the altitude and latitude, on the other, was assessed. Results showed that all studied phenological events of European beech correlate significantly with the elevation – SOS and LOS positively, while MOS and EOS – negatively. The relations were more substantial in the north-sloped mountains and poorer in the Osogovo Mt., where stands cover northern, but also eastern and southern facing slopes. The latitude was a significant factor for MOS and EOS, which occur the later the further south the mountain is. The latest SOS in Oso- govo, which leads to an alignment of LOS with that of Petrohan, decreases altitude’s influence on these phenological events. Analysing spatial patterns of vegetation changes can help identify variations in phenological events across different areas.

Received: 20 August 2023 / Accepted: 4 October 2023 / Available online: 12 October 2023

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

Abstract

Between 2014–2022 we monitored the arrival and departure date of European Turtle doves (Streptopelia turtur) in Bulgaria. We collected data on first arrival date trough observations in different part of the country between April 1 and May 1. In September, we collected data about the end of the species autumn migration. Data on breeding behaviour were collected between 2017–2022 from 41 nests. The correlation between the height of the position of nests and the height of the trees on which they were located was examined by Spearman rank moment test. Two peaks of fledging were established, i.e. at the end of June and the end of July. The mean height of the nests was 4.6 m. There is a significant positive correlation between tree height and nest height (r = 0.82, p < 0.0001). The mean clutch size was 1.84 and the mean brood size was 1.6 young/successful pair. Breeding success for all period was 82.76 %.

Received: 01 June 2023 / Accepted: 30 August 2023 / Available online: 06 September 2023

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

Abstract

The aim of this research is to analyse the growth and condition factor of Chub (Squalius cephalus L.) from the Ogosta River in north-western Bulgaria. The river belongs to the Danube basin. The study focuses on the Chub population in the middle zone of the Ogosta River, situated above the Ogosta Reservoir. The data was collected in November 2021, with a total of 76 specimens captured using electrofishing techniques. The sample consisted predominantly of three-year-old fish, with the most common size group falling within the size range 11–13 cm. The standard length of the fish ranged from 5.6 cm to 42.6 cm, while the gutted weight varied from 2.2 to 1270.2 g. The estimated length-size (L-S) relationship was determined as L = 0.1913·S+2.701 (r2 = 0.97), and the weight-length (W-L) relationship was derived as W = 0.0105·L3.15 (r2 = 0.99). The results were evaluated in comparison to 14 local populations of Chub in rivers across Bulgaria. The data indicate a relatively slow growth rate of the species in the Ogosta River. This study is the first of its kind to focus on the Chub population in the middle zone of the Ogosta River following the construction of the Ogosta Dam. It provides valuable insights into the impact of hydropower construction on the Chub population in the area.

Received: 09 July 2023 / Accepted: 17 August 2023 / Available online: 30 August 2023 

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

Abstract

Water is not just a commercial product, but a common good and a limited resource that should be protected and used in a sustainable manner, in both terms – of quality and quantity. However, water is under pressure due to variety of uses from different sectors, such as industry, agriculture, tourism, transport, energy, etc. which leads to deterioration in the quality of water resources. The aim of the study is to assess the chemical status of Chepelarska River, right tributary of the main river in Southern Bulgaria – Maritsa, based on more than 10 physico-chemical parameters for the period 2015–2021. Data were provided by the Executive Environmental Agency (ExEA) to the Ministry of Environment and Water (MOEW). The evaluation of the studied river is based on Ordinance No N-4/14.09.2012 (concerning the characterisation of surface waters) and Ordinance on environmental quality standards for priority substances and some other pollutants (Resolution of the Council … 2010), in accordance with the requirements of Directive 2000/60/EU. To achieve the set goal, the Canadian Complex Water Quality Index (CCME-WQI) was applied, through which a complex and differentiated assessment of the status of water in terms of its quality was carried out. The obtained results show constant excesses of the norms for the indicators nitrite-ni- trogen (N-NO2), total nitrogen (TN), total phosphorus (TP) and orthophosphates (P-PO4). Ac- cording to them, organic pollution of river waters is mainly of agricultural and municipal-domestic origin. The industrial activities in the area carried out for decades to this day could be considered as a source of a possible pollutant that led to an increased content of heavy metals – copper (Cu), cadmium (Cd), manganese (Mn) and especially zinc (Zn). The obtained new data is a key emphasis in making management decisions to mitigate and prevent current and future pollution of river systems, as a result of various anthropogenic impacts.

Received: 28 April 2023 / Accepted: 10 August 2023 / Available online: 21 August 2023

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

Abstract

Peat Swamp Forest (PSF) belongs to a unique ecosystem and will be very difficult to be recovered if already degraded, thus we need to be fully realised about this ecosystem. The re- search aimed to analyse the anthropogenic challenges of PSF degradation, to improve aware- ness and to make urgent emphasis in providing their restoration. This research was conducted within 2020–2023 in South Sumatra Indonesia. The research method applied field survey and laboratory work. Current PSF was threatened its existence, its various practical functions were neglected and favoured the economic benefits of oil palm (Elaeis guineensis Jacq.). The peat thickness is for determining its agriculture suitability, peat depth is allowed for agriculture if its thickness is < 100 cm (classified as marginally suitable, S2), peat thickness > 300 cm must be conserved (classified as not suitable, N). Patterns of PSF degradation are creating impermeability layers of water; changing plant type and density; and modifying plant types of land cover. The pattern of changing plant type and density (executed by land speculators) determined two-third the PSF degradation. Hence, the government has to make policy decisions based on PSF vulner- ability and the negative impact of its degradation at global, state, provincial, district, sub-district and local levels and followed by agricultural programs on how to improve income of local people.

Received: 07 June 2023 / Accepted: 04 August 2023 / Available online: 18 August 2023

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

Abstract

The ‘Khasia’ betel leaf-based agroforestry involving timber and non-timber crops is a natural non-destructive, chemical free traditional cultivation system adopted by the tribal communities of North Eastern India. The leaves are harvested five times a month and due to perishability the unsold leaves are discarded that sometime creates environmental pollution due to disease contamination in decomposed leaves. The excess leaves could be utilized for extraction of leaf essential oil having a shelf life of more than three years. The ‘Khasia’ betel leaves collected from Tripura state was used for extraction of essential oil with yield of 0.44% on fresh weight basis. The gas chromatography-mass spectroscopy (GC_MS) analysis detected 30 medicinally important components predominated by phenylpropenoid, sesquiterpenes and monoterpenes (90.3 %). The major components were chavibetol (50.4 %), chavicol (7.9 %), chavibetol acetate (6.1 %), chavibetol diacetate (2.3 %) and methyl chavicol (1.5 %). This phenylpropenoid class of aromat- ic compound are useful in pharmaceutical sector. The government aided training of the tribal communities in clean and green technology of essential oil extraction may open a new avenue of income generation, provide environmental sustainability, ecological equilibrium with articulate management of agroforestry waste.

Received: 09 April 2023 / Accepted: 03 August 2023 / Available online: 18 August 2023

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