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Povzetek: The durability of Portland cement mortars is often affected by environmental factors, which can cause physicochemical and mechanical degradation processes. In this study, the performance of three products, calcium acetoacetate and calcium tetrahydrofurfuryloxide dissolved in two different solvents developed and tested as stone consolidants, was evaluated in terms of crack filling or sealing and consolidation. Realistic cracks were induced in quasibrittle cement mortar prisms using a custom-designed test rig. The effectiveness and the performance of the considered treatments, investigated on specimens, were evaluated by optical and scanning electron microscopy, colourimetry, water absorption rate, ultrasonic pulse velocity, and surface hardness measurements. Results revealed that, in the examined conditions, the products were more suitable as surface consolidants than as crack fillers.
Ključne besede: cement mortars, 20th century architecture conservation, calcium acetoacetate, calcium alkoxide, concrete repair, open access
Objavljeno v DiRROS: 04.05.2023; Ogledov: 547; Prenosov: 327
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Povzetek: Priority habitat types (HTs) within the Natura 2000 network are of the highest importance for conservation in Europe. However, they often occur in smaller areas and their conservation status is not well understood. One such HT is that of the Tilio–Acerion forests of slopes, screes and ravines (9180*). The Natura 2000 study site, Boč–Haloze–Donačka gora, in the Sub-Pannonian region of eastern Slovenia is characterized by a matrix of European beech forests and includes rather small, fragmented areas covered by Tilio–Acerion forests. The goal of this research was to examine the heterogeneity and conservation status of the selected HT through field mapping, which was performed in the summer of 2020. As the conservation of HT calls for a more detailed approach, we distinguished between the following four pre-defined habitat subtypes: (i) Acer pseudoplatanus-Ulmus glabra stands growing mostly in concave terrain, (ii) Fraxinus excelsior stands growing on slopes, (iii) Tilia sp. stands with thermophilous broadleaves occurring on ridges and slopes, (iv) Acer pseudoplatanus stands occurring on more acidic soils with an admixture of Castanea sativa. Field mapping information was complemented with the assessment of habitat subtype characteristics using remote sensing data. The results showed that habitat subtypes differed significantly in terms of area, tree species composition, forest stand characteristics, relief features and the various threats they experienced (e.g., fragmentation, tree mortality, ungulate browsing pressure). The differences between subtypes were also evident for LiDAR-derived environmental factors related to topography (i.e., terrain steepness and Topographic Position Index). This study provides a baseline for setting more realistic objectives for the conservation management of priority forest HTs. Due to the specificities of each individual habitat subtype, conservation activities should be targeted to the Natura 2000 habitat subtype level.
Ključne besede: forest habitat subtype, monitoring, biodiversity conservation, LiDAR, Slovenia, NATURA 2000
Objavljeno v DiRROS: 03.02.2023; Ogledov: 1160; Prenosov: 360
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Povzetek: Riparian vegetation supports high biodiversity providing many services and is, therefore, an important landscape element. Riparian ecosystems are subject to numerous pressures leading to population decline and genetic erosion of riparian plants. This may have cascading effects at various ecosystem levels, including decreasing ecosystem services, so identifying the current status of genetic diversity of riparian tree species is vital to improve the effectiveness of restoration efforts. We aimed to elicit expert views on the status and importance of genetic diversity of tree species, and conservation needs across European riparian ecosystems. Sharing of such information among researchers, managers and policymakers has the potential to enhance ecological restoration and management of riparian ecosystems. We identified experts in riparian genetic resources conservation and management across Europe. These included stakeholders with different perspectives, ranging from researchers to practitioners. We designed a set of questionnaires where our identified experts were asked to answer questions related to the status and conservation of genetic diversity of riparian tree species in their respective countries. Specifically, we asked about societal awareness, legislative tools, good practices and conservation or restoration projects accounting for intraspecific genetic diversity and differentiation of tree species in riparian ecosystems. Questionnaire responses were analysed and discussed in light of the scientific literature to define needs and priorities related to the management and conservation of genetic diversity of riparian tree species. The experts recognized that a combination of in situ and ex situ measures and/or integrative conservation of riparian ecosystems is the most appropriate option for conserving the genetic diversity of riparian tree species. Simultaneous application of conservation measures at the level of priority species, identified by experts, and protection of riparian areas are required. Synthesis and applications. This study revealed the importance of recognizing the ecological processes that shape the genetic diversity of riparian tree species in hydrographic networks (dendritic spatial configuration, specific patterns of gene flow among riparian populations, fragmentation of river by dams) but also the need to overcome socio-economic barriers, such as lack of policy priority, deficiency in funding and weak legislation framework.
Ključne besede: biodiversity conservation, genetic erosion, genetic resources conservation, knowledge transfer, management, riparian genetic diversity, vegetation
Objavljeno v DiRROS: 08.12.2022; Ogledov: 638; Prenosov: 410
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Ključne besede: conservation biological control, pest control, functional diversity
Objavljeno v DiRROS: 06.09.2022; Ogledov: 651; Prenosov: 316
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Povzetek: Climate change is seriously impacting coastal biodiversity and the benefits it provides to humans. This issue is particularly relevant in the case of the European Union’s Natura 2000 network of areas for nature protection, where the sensitivity of local ecosystems calls for intervention to increase resistance and resilience to climate-related risks. Given the complex ways in which climate can influence conservation hotspot areas, there is a need to develop effective strategic approaches and general operational models to identify priorities for management and inform adaptation and mitigation measures. Here, a novel methodological proposal to perform climate risk assessment in Natura 2000 sites is presented that implements the systematic approach of ISO 14090 in combination with the theoretical framework of ecosystem services assessment and local stakeholder participation to identify climate-related issues for local protected habitats and improve the knowledge base needed to plan sustainable conservation and restoration measures. The methodology was applied to five Natura 2000 sites located along the Adriatic coast of Italy and Slovenia. Results show that each of the assessed sites, despite being along the coast of the same sea, is affected by different climate-related issues, impacting different habitats and corresponding ecosystem services. This novel methodology enables a simple and rapid screening for the prioritization of conservation actions and of the possible further investigations needed to support decision making, and was found to be robust and of general applicability. These findings highlight the importance of designing site-specific adaptation measures, tailored to address the peculiar response to climate change of each site in terms of biodiversity and ecosystem services.
Ključne besede: ecosystem, ecosystem services, climate change adaptation, nature conservation, sustainability, coastal management
Objavljeno v DiRROS: 01.07.2022; Ogledov: 845; Prenosov: 544
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