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Povzetek: The environmental performance of natural aggregates for concrete and road construction, extracted from a dolomite quarry, was investigated. Environmental hotspots were identified, and potential optimization measures to further reduce the environmental footprint were proposed. The natural aggregates extracted from the dolomite quarry have relatively low GWP and a low environmental footprint in general. The GWP of 1 tonne of natural aggregates used in concrete production is 1.13 kg CO2 equiv., while for 1 tonne of aggregates used in road construction, it is 0.97 kg CO2 equiv. The dolomite rock in the quarry in question is tectonically fractured, such that very intensive extraction is not required, taking into account the blasting of the rock and further processing. The use of non-road mobile machinery is already optimized. Additional reductions in environmental impact could be achieved by powering the screening process exclusively with electricity from renewable sources, such as a photovoltaic system. In this context, integrating on-site battery storage systems might present a promising solution for addressing the seasonal mismatch between solar energy generation and processing demands.
Ključne besede: rock extraction, global warming potential, environmental impact, optimization, sensitivity
Objavljeno v DiRROS: 15.10.2025; Ogledov: 553; Prenosov: 289
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Povzetek: Dams and reservoirs are a common and globally widespread anthropogenic disturbance with documented negative effects on riverine and riparian habitats. The two most well-known impacts of river damming are longitudinal fragmentation of surface running waters and a shift from lotic habitats towards habitats with lentic characteristics that affect the benthic and pelagic communities. However, there is very little empirical evidence about the effects of damming on the aquatic fauna inhabiting interstitial habitats extending in and alongside the river-bed (i.e., hyporheic zone). In this study, we investigated the patterns in the interstitial community composition upstream, downstream and within the reservoir that was formed 80 years ago, when the river was dammed for the hydropower production. We used the rare opportunity to directly access the bottom of the reservoir drained due to dam maintenance in January 2018, to compare physical, chemical and faunistic data from the reservoir area, with those from downstream and upstream reaches of the two gravel bed rivers that are flowing into the reservoir. We sampled the interstitial invertebrate communities at seven locations, using a Bou-Rouch pump at two depths (30–60 cm and 60–90 cm within the river bed) and at three sampling points within each location. At the same sampling points we measured also physical and chemical parameters (temperature, conductivity, oxygen and pH). The interstitial water from the deepest point of the drained reservoir had substantially lower oxygen concentration, lower pH, and higher conductivity than water from the other sampling localities. This was also the site where taxa richness was lowest, and only one obligate groundwater species (i.e. stygobiont) was found. Most probably, the changes in morphology of the river channel and speed of water flow due to damming, which increased sedimentation rate and clogging of interstitial habitat, resulted in such large differences in environmental conditions and invertebrate community composition. This study provides rare empirical evidence of the effects of damming on the river interstitial habitats and fauna within the reservoir area. We recommend that environmental impact assessments conducted prior dam constructions should include also assessment of the effect of river damming on the interstitial communities. These organisms are playing important role in driving important ecosystem processes, such as organic matter degradation on one hand, and on the other hand, are composed of many rare and endangered species that need to be protected.
Ključne besede: damming, interstitial habitats, subterranean fauna, invertebrate communities, stygobionts, dam, hydropower, environmental impact
Objavljeno v DiRROS: 22.11.2024; Ogledov: 1063; Prenosov: 557
Celotno besedilo (1,06 MB)
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Povzetek: The mechanistic pathways connecting ocean-atmosphere variability and terrestrial productivity are well-established theoretically, but remain challenging to quantify empirically. Such quantification will greatly improve the assessment and prediction of changes in terrestrial carbon sequestration in response to dynamically induced climatic extremes. The jet stream latitude (JSL) over the North Atlantic-European domain provides a synthetic and robust physical framework that integrates climate variability not accounted for by atmospheric circulation patterns alone. Surface climate impacts of north-south summer JSL displacements are not uniform across Europe, but rather create a northwestern-southeastern dipole in forest productivity and radial-growth anomalies. Summer JSL variability over the eastern North Atlantic-European domain (5-40E) exerts the strongest impact on European beech, inducing anomalies of up to 30% in modelled gross primary productivity and 50% in radial tree growth. The net effects of JSL movements on terrestrial carbon fluxes depend on forest density, carbon stocks, and productivity imbalances across biogeographic regions.
Ključne besede: atmospheric dynamics, climate-change ecology, climate-change impacts, environmental impact
Objavljeno v DiRROS: 20.04.2022; Ogledov: 2043; Prenosov: 1898
Celotno besedilo (3,68 MB)
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