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Abstract: This article examines the impact of financial support mechanisms and geopolitical factors on the profitability of investments in solar power plants within Slovenia. The European Union’s energy policy prioritizes increases in renewable energy sources, aiming to reduce dependency on unstable and volatile fossil fuel markets. Solar power plants play a vital role in this transition. The energy policy framework also includes mechanisms and support systems to operate such facilities. This article analyzes electricity price trends over the past decade and addresses which support type—guaranteed purchase or operational support—has proven more profitable for investments in solar power plants up to 50 kW in Slovenia, considering economic and geopolitical influences on the electricity market. Although the global energy market has been affected by various significant events in recent years, it was found that the COVID-19 pandemic had minimal impact on the electricity market. In contrast, the onset of the conflict in Ukraine has contributed to rising electricity prices and has influenced the support dynamics essential for the development and sustainability of renewable energy systems. Analyses from the past decade indicate a higher return on investment in solar power plants when operational support mechanisms are chosen over guaranteed purchase support.
Keywords: renewable energy sources, solar power plants, support system, investment profitability factors, electricity price
Published in DKUM: 16.12.2024; Views: 0; Downloads: 5
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Abstract: Most trees and other woody plants growing within urban areas are deliberately cultivated native or non-native plants. Opportunities for spontaneous establishment and spread of woody species are scarce in an urban environment, especially if the establishment begins from seeds. We hypothesized that urban hedges might offer safe sites for the spontaneous establishment of woody plants, which reach the hedges through propagule dispersal. We recorded the species composition of urban hedges in Maribor (NE Slovenia) in a gradient from the city centre outwards and evaluated the species' invasive potential and ecological requirements, along with hedge characteristics. Results show that hedges facilitated the survival and growth of 69 woody plants from 28 families. Among these, 62% were non-native and 10% were locally invasive. Most of recorded non-native woody plants were ornamentals. Moreover, for native species, we show that the stressful, warmer urban environment mostly facilitates the establishment of species in the genera Hedera and Acer. Comparison of non-native and native plants showed the former are more drought and heat tolerant than the latter. We further show that with distance from the city centre, the number of bird-dispersed species increases, in contrast to the wind-dispersed species. Additionally, our results suggest evergreen hedges may be less permeable to wind-dispersed propagules than deciduous hedges. Next, we stress the importance of paved surfaces and urbanization, selecting for the thermophile, drought tolerant, wind-dispersed woody plants that find refuge in urban hedges. Our results suggest urban hedges can facilitate the establishment of a wide range of woody plant species.
Keywords: biodiversity, green infrastructure, ornamental plants, species richness, urban ecosystem, vegetation
Published in DKUM: 03.12.2024; Views: 0; Downloads: 0
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Abstract: The application of highly porous and 3D interconnected microcellular polyelectrolyte polyHIPE (PE-PH) monoliths based on (3-acrylamidopropyl)-trimethylammonium chloride as soilless cultivation substrates for in vitro embryo culture is discussed. The embryo axes isolated from chickpea seeds are inoculated onto the surface of the monoliths and allowed to germinate. Germination study show that the newly disclosed PE-PH substrate performs much better than the conventionally used agar as the germination percentage, shoot and root length, fresh and dry weight as well as the number of leaves are enhanced. The PE-PHs exhibit a higher absorption capacity of the plant growth medium, that is, 36 g·g–1 compared to agar, that is, 20 g·g–1, and also survive autoclaving conditions without failing. The key advantage over standard agar substrates is that they can be reused several times and also without prior sterilization. These results suggest that PE-PHs with exceptional absorption/retention properties and robustness have great potential as soilless substrates for in vitro plant cultivation.
Keywords: absorption, catalyst supports, germination, plants, porosity
Published in DKUM: 15.07.2024; Views: 114; Downloads: 11
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Abstract: Background: As the countries of the Western Balkans (WB) have committed to sustainable development, the process of regulatory and economic adjustment is underway. As part of the aforementioned fact, the WB countries have commenced exploitation of energy from renewable sources, among which hydropower is the most important. The main objective of the study is to analyse the status of renewable energy transition in the WB region, focusing on the construction and exploitation of small hydropower plants (SHPPs), as well as a proposal for an original model for decision making in this field, based on a multidimensional decision-making space. Namely, in most cases, there is resistance to the construction of SHPPs in the WB territory, as well as divided opinion among investors, companies, environmental movements, academia, and citizens on this issue. This shows that the entire decision-making process has to be reviewed and re-designed. Results: The results of the study show that the construction of SHPPs caused damage to environmentally protected areas, living conditions of local communities, touristic and agricultural potential. All of the foregoing matters have led to mass protests by citizens and a high degree of mistrust so that the future of SHPPs in the WB is extremely uncertain. The assessment of the acceptability of existing SHPPs through the proposed model showed that 74% of SHPPs cannot be considered acceptable from the aspect of the location where they were built, and from the aspect of the impact on the quality of life of the local population. Accordingly, this paper provides suggestions for much-needed improvements. Conclusions: The construction of SHPPs is causing numerous controversies, opposition, and resistance. To find the right solution, and contribute to sustainable energy and economic development, it is necessary to develop a fully transparent and objective policy system in this field, and to use contemporary models for decision making with emphasis on the involvement local communities in the decision-making process.
Keywords: sustainable energy transition, small hydropower plants, environmental awareness, modelling, decision making process, Western Balkans
Published in DKUM: 28.06.2024; Views: 420; Downloads: 5
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Abstract: The main species composition drivers in temperate deciduous forests are environmental conditions, a stand's age and the site history, e.g., the succession stage and past land use, as well as disturbance regime and current management. We compared plant species diversity and composition in late successional and ancient forests, co-occurring on the same small river island applying species accumulation curves and nonmetric multidimensional scaling, respectively. Given the island's geomorphological characteristics, we expected these to be very similar before human intervention in the past. The forests experienced differing disturbance regimes in the past, while over the last 30 years, human intervention has been the same and reduced to a minimum. The ancient forest in this study had two major characteristics defining it as old, mature forest: continuity of presence for more than 200 years and specific composition. The late successional forest experienced major disturbance in the 20th century and was allowed natural regeneration by bordering on the ancient forest, representing a potential species pool, and by decades of minimum human intervention. Our results showed that, even though there was no difference in species richness, we could still detect differences between the forests, particularly in the abundance and species composition of the understorey, among which geophytes had the most indicative importance. To make our results useful on a broader scale, we composed from the literature a species list of plants indicative for ancient forest and tested its application. These results are important for distinguishing between old and mature secondary stands and particularly for identifying old forest stands, which should be conserved and, in the case of fragmented landscapes, included in a network connecting forest fragments.
Keywords: forest community, successional forest, indicator plants, plant diversity, understorey, geophyte, Slovenia
Published in DKUM: 03.06.2024; Views: 151; Downloads: 15
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