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1.
Post-harvest forest herb layer demography : general patterns are driven by pre-disturbance conditions
Janez Kermavnar, Klemen Eler, Aleksander Marinšek, Lado Kutnar, 2021, izvirni znanstveni članek

Povzetek: Timber harvesting constitutes extensive anthropogenic disturbance in temperate forests, producing a broad range of ecological impacts that most often enhance the demographic processes of vegetation. This study monitored post-harvest herb layer demography over a 6-year period in mesic Dinaric fir-beech forests (Slovenia), a vascular plant diversity hotspot among European forests. Three experimental harvesting intensities, i.e. full harvest (FH), partial harvest (PH) and a control treatment (NH), were each applied over a circular area of 4000 m2 and replicated three times at each of three study sites. Vegetation sampling was conducted before harvesting (in 2012), and two (2014) and six (2018) years following it, in a 400 m2 circular plot positioned in the centre of each treatment area. We focused on identifying general demographic patterns and evaluating the effects of various pre-disturbance abiotic and biotic predictors on compositional responses to disturbance. Two years after harvest (2012-2014), compositional shifts were larger than those in the next 4-year period (2014-2018), confirming the general theoretical prediction that species turnover rate decreases along a successional gradient. The degree of compositional shifts in gaps (FH) and thinned stands (PH) was affected by local abiotic factors (geomorphology of karst sinkholes) and community attributes, such as pre-harvest species richness. Our results indicate that compositional stability is positively associated with pre-disturbance species richness. Over the whole study period, increases in plot-level species richness (alpha diversity) and overall enrichment of the species pool (gamma diversity) were accompanied by compositional convergence, i.e. a decline in floristic dissimilarity (beta diversity) between and within study sites. However, the observed tendency towards homogenization was rather weak and would have been even more pronounced if the demographic type of persistent resident species had not shown a high degree of resistance, thus leaving a strong imprint on post-harvest vegetation development by preserving the forest characteristics of the herb layer community.
Ključne besede: forest succession, demographic types, community assembly, pre-disturbance factors, floristic convergence, fir-beech forests
Objavljeno v DiRROS: 22.07.2022; Ogledov: 35; Prenosov: 26
.pdf Celotno besedilo (1,91 MB)
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2.
Artificial neural networks as an alternative method to nonlinear mixed-effects models for tree height predictions
Mitja Skudnik, Jernej Jevšenak, 2022, izvirni znanstveni članek

Povzetek: Tree heights are one of the most important aspects of forest mensuration, but data are often unavailable due to costly and time-consuming field measurements. Therefore, various types of models have been developed for the imputation of tree heights for unmeasured trees, with mixed-effects models being one of the most commonly applied approaches. The disadvantage here is the need of sufficient sample size per tree species for each plot, which is often not met, especially in mixed forests. To avoid this limitation, we used principal component analysis (PCA) for the grouping of similar plots based on the most relevant site descriptors. Next, we compared mixed-effects models with height-diameter models based on artificial neural networks (ANN). In terms of root mean square error (RMSE), mixed-effects models provided the most accurate tree height predictions at the plot level, especially for tree species with a smaller number of tree height measurements. When plots were grouped using the PCA and the number of observations per category increased, ANN predictions improved and became more accurate than those provided by mixed-effects models. The performance of ANN also increased when the competition index was included as an additional explanatory variable. Our results show that in the pursuit of the most accurate modelling approach for tree height predictions, ANN should be seriously considered, especially when the number of tree measurements and their distribution is sufficient.
Ključne besede: height-diameter models, national forest inventory, permanent sample plot, mixed forests, model comparison, principal component analysis
Objavljeno v DiRROS: 08.06.2022; Ogledov: 81; Prenosov: 15
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3.
Manual for forest genetic monitoring
2020, slovar, enciklopedija, leksikon, priročnik, atlas, zemljevid

Ključne besede: forests, forest genetics, genetic monitoring
Objavljeno v DiRROS: 16.04.2021; Ogledov: 2800; Prenosov: 2621
.pdf Celotno besedilo (13,01 MB)
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4.
Confirmed and potential wild hosts of the Spotted wing drosophila (Drosophila suzukii) in Slovenia
Maarten De Groot, Andreja Kavčič, Jaka Razinger, 2020, izvirni znanstveni članek

Povzetek: The spotted wing drosophila (Drosophila suzukii (Matsumura)) is a highly invasive species and attacking different species of berry carrying hosts. Much research has already been done on the crop hosts over the world and in Slovenia, but for wild hosts less is known. On basis of literature and fieldwork we prepared a list of potential and actual known species of wild hosts for Slovenia. In 2019, berries of different species were collected and D. suzukii was either reared from these berries or berries were dissected. In total we found in the literature for Europe 99 species which were used as host for D. suzukii. For Slovenia we found 71 potential hosts and 14 hosts which were actually infested. in Slovenia there was a broad range of potential hosts from 41 genera. The genera with the most potential hosts were Prunus, Lonicera and Vaccinium. Among the potential hosts were also many species which were invasive alien or alien species. The list was discussed in the context of management implications and further research on D. suzukii in Slovenia.
Ključne besede: spotted wing drosophila, berries, potential hosts, wild hosts, forests, pest control, Slovenia
Objavljeno v DiRROS: 11.12.2020; Ogledov: 720; Prenosov: 338
.pdf Celotno besedilo (459,64 KB)
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5.
Harvesting intensity and tree species affect soil respiration in uneven-aged Dinaric forest stands
Matjaž Čater, Eva Dařenová, Primož Simončič, 2021, izvirni znanstveni članek

Povzetek: Forest management, especially thinning and harvesting measures, has a significant impact on the forest carbon balance especially in the forests with long-term continuous cover history. We measured soil CO2 efflux (Rs) in three forest complexes of mixed, uneven-aged Dinaric forests with predominating silver fir (Abies alba Mill.), beech (Fagus sylvatica L.), and Norway spruce (Picea abies Karst.). Rs was measured after removal of mature forest stands with 50% and 100% intensity of living stock and compared with Rs on the control plots without any applied silvicultural measures. Rs was measured monthly in three consecutive 2012, 2013 and 2014 growing periods. Soil CO2 efflux increased after harvest of both intensities in all studied forest stands. The biggest increase was measured in beech stands and amounted up to 47 and 69% for 50% and 100% harvest intensities, respectively. The effect of harvest on Rs in spruce and fir stands was similar - up to 26% for 50% harvest intensity and 48% for 100% harvest intensity. Despite the biggest increase after harvest, Rs in beech stands returned the fastest to the level of the uncut forest and this levelling period (LP) took 14-17 months with a little delay of the stands with 100% harvest intensity. The LP for all fir stands, for spruce stands with 50% harvest intensity and for one spruce stand with 100% harvest intensity, was 26-29 months. At two spruce stands with 100% harvest intensity we did not record Rs levelling during our three-year study. This study involved forest stands of three predominating tree species growing under the same conditions, which allowed us to determine the species-specific sensitivity of soil CO2 efflux to the different harvesting intensities.
Ključne besede: harvesting intensity, soil CO2 efflux, silviculture, carbon release, silver fir forests, Beech forestrs, Norway spruce forests
Objavljeno v DiRROS: 08.10.2020; Ogledov: 838; Prenosov: 302
.pdf Celotno besedilo (1,11 MB)
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6.
Assessing the protective role of alpine forests against rockfall at regional scale
Christian Scheidl, Micha Heiser, Sonja Vospernik, Elisabeth Lauss, Frank Perzl, Andreas Kofler, Karl Kleemayr, Francesco Bettella, Emanuele Lingua, Matteo Garbarino, Mitja Skudnik, Daniel Trappmann, Frédéric Berger, 2020, izvirni znanstveni članek

Povzetek: Worldwide, mountain forests represent a significant factor in reducing rockfall risk over long periods of time on large potential disposition areas. While the economic value of technical protection measures against rockfall can be clearly determined and their benefits indicated, there is no general consensus on the quantification of the protective effect of forests. Experience shows that wherever there is forest, the implementation of technical measures to reduce risk of rockfall might often be dispensable or cheaper, and large deforestations (e.g. after windthrows, forest fires, clear-cuts) often show an increased incidence of rockfall events. This study focussed on how the protective effect of a forest against rockfall can be quantified on an alpine transregional scale. We therefore estimated the runout length, in terms of the angle of reach, of 700 individual rockfall trajectories from 39 release areas from Austria, Germany, Italy and Slovenia. All recorded rockfall events passed through forests which were classified either as coppice forests or, according to the CORINE classification of land cover, as mixed, coniferous or broadleaved dominated high forest stands. For each individual rockfall trajectory, we measured the forest structural parameters stem number, basal area, top height, ratio of shrub to high forest and share of coniferous trees. To quantify the protective effect of forests on rockfall, a hazard reduction factor is introduced, defined as the ratio between an expected angle of reach without forest and the back-calculated forest-influenced angles of reach. The results show that forests significantly reduce the runout length of rockfall. The highest reduction was observed for mixed high forest stands, while the lowest hazard reduction was observed for high forest stands dominated either by coniferous or broadleaved tree species. This implies that as soon as one tree species dominates, the risk reduction factor becomes lower. Coppice forests showed the lowest variability in hazard reduction. Hazard reduction due to forests increases, on average, by 7% for an increase in the stem number by 100 stems per hectare. The proposed concept allows a global view of the effectiveness of protective forests against rockfall processes and thus enable to value forest ecosystem services for future transregional assessments on a European level. Based on our results, general cost%benefit considerations of nature-based solutions against rockfall, such as protective forests as well as first-order evaluations of rockfall hazard reduction effects of silvicultural measures within the different forest types, can be supported.
Ključne besede: protection forests, rockfall, European Alps, rockfall hazard
Objavljeno v DiRROS: 13.07.2020; Ogledov: 1066; Prenosov: 624
.pdf Celotno besedilo (2,03 MB)
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7.
Three decades of urban forest and green space research and practice in Croatia and Slovenia
Silvija Krajter Ostoić, Dijana Vuletić, Špela Planinšek, Urša Vilhar, Anže Japelj, 2020, pregledni znanstveni članek

Povzetek: Background and Objectives: Urban forests and green space contribute to human wellbeing. Green infrastructure is recognized by the European Union as a planning tool that contributes to the implementation of many public policies, with urban forests and green space as its main building blocks. Croatia and Slovenia are young democracies and recent members of the European Union. Hence, they also need to contribute to the implementation of those policies. Previous review studies on urban forests and green space rarely addressed scientific or professional publications in those countries. Furthermore, the body of knowledge about urban forest and green space research and practice in post-socialist countries is still rather weak. The goal of the paper is (a) to show that urban forest and green space research and practice is much stronger in these countries than it is possible to assume based only on previous review papers or only by searching Scopus andWeb of Science, and (b) to describe publications written by scientists and professionals in the past 30 years. Materials and Methods: We used a trilingual systematic literature review to identify scientific and grey literature in various databases, as well as a snowballing technique, and yielded 211 publications in Croatia and 84 in Slovenia. Results: We identified many more publications on urban forests and green space science and practice in Croatia and Slovenia than it was possible to assume based only on previous review papers and when searching solely publications in English. Croatian authors showed continuity over time in terms of number of publications, while Slovenian publications have been on the rise in the past decade. In both countries, scientific papers were most frequent, and the vast majority of studies addressed capital cities. Croatian publications mainly focused on parks and park-forests, while Slovenian publications focused on urban forests. Interestingly, Croatian authors were a%liated with over 60 organizations, and in comparison to Slovenian authors, have stronger preference towards publishing in their local language. Green space planning and design followed by resource inventory were the most frequent themes. The least addressed themes in both countries were resource management, economic aspects, policy, legislation or governance. Conclusions: Important discussion in the future, especially in Croatia, would be regulation of urban forestry as a profession. Cross-sectoral and interdisciplinary studies, as well as focusing on cities other than capitals in future, can help in addressing issues such as climate change or application of participatory approaches.
Ključne besede: urban forests, urban forestry, green space, post-socialist countries, grey literature
Objavljeno v DiRROS: 26.05.2020; Ogledov: 1157; Prenosov: 734
.pdf Celotno besedilo (3,37 MB)
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8.
Evaluation of forest edge structure and stability in peri-urban forests
David Hladnik, Andrej Kobler, Janez Pirnat, 2020, izvirni znanstveni članek

Povzetek: In the presented research, we studied the forest edge structure of urban and peri-urban forests on the outskirts of Ljubljana (Slovenia) consisting of a number of patches covering the collective surface of 1884 ha. They differ from each other according to the degree of fragmentation and by the share of the interior forest area. On the basis of LiDAR data, we conducted an analysis of the edges of the persistent forest patches and estimated them with regard to the land use they bordered on. The horizontal estimation of forest edges and the changes of forest edges, in the last decades, were estimated using digital orthophoto images of cyclic aerial surveys of Slovenia, from 1975 to 2018. The data, provided by LiDAR, were used to obtain an accurate estimate of forest edges and the metrics of their vertical canopy structure. On the basis of the canopy height model (CHM), we determined the height classes, the heights of the tallest trees, and indices of canopy height diversity (CHD) as variables subjected to a k-means cluster analysis. To determine the forest edge and trees stability, their heights and diameters at breast height (DBH) were measured and their canopy length and h/d (height/diameter) dimension ratios were estimated. In the study area of the Golovec forest patch, more than half of the forest edge segments (56%) border on residential buildings. After the construction of buildings, 54% of the newly formed forest edges developed a high and steep structure. Unfavorable h/d dimension ratio was estimated for 16% of trees, more among the coniferous than among the deciduous trees. Similar characteristics of newly formed forest edges bordering on built-up areas were determined in other sub-urban forest patches, despite the smaller share of such forest edges (19% and 10%, respectively). Tools and methods presented in the research enable the implementation of concrete silvicultural practices in a realistic time period and extend to ensure that adequate forestry measures are taken to minimize possible disturbances.
Ključne besede: forest ecosystem services, forest edge stability, forest edge structure, LiDAR, urban forests
Objavljeno v DiRROS: 26.05.2020; Ogledov: 1282; Prenosov: 627
.pdf Celotno besedilo (5,67 MB)
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9.
The influence of abiotic and biotic disturbances on the protective effect of alpine forests against avalanches and rockfalls
Domen Oven, Barbara Žabota, Milan Kobal, 2020, pregledni znanstveni članek

Povzetek: Abiotic and biotic disturbances in alpine forests can reduce forest cover or change the structure of the forest and consequently reduce the protective effect of forest against natural hazards such as avalanches and rockfalls. In this review article, the effect of the main abiotic (forest fire, windthrow, ice break, snow break, avalanche and rockfall) and biotic (insects and pathogens) disturbances in protection forests are presented along with their potential influence on the protective effect of forest against avalanches and rockfalls. In general, natural disturbances negatively affect the protective effect of forest, especially in the case of large-scale and severe events, which in alpine areas are mostly caused by storms, bark beetle outbreaks, avalanches and forest fires. Climate change induced interactions between disturbances are expected to present challenges in the management of protection forests in the future.
Ključne besede: natural disturbances, natural hazards, abiotic disturbances, biotic disturbances, protection forests, protective effect, stand parameters, rockfall, avalanche
Objavljeno v DiRROS: 01.04.2020; Ogledov: 2398; Prenosov: 2337
.pdf Celotno besedilo (893,89 KB)

10.
Cultural ecosystem services provided by the biodiversity of forest soils : a European review
Jurga Motiejunaite, Isabella Børja, Ivika Ostonen, Mark Bakker, Brynhildur Bjarnadottir, Ivano Brunner, Reda Iršenaite, Tanja Mrak, Edda Oddsdottir, Tarja Lehto, 2019, izvirni znanstveni članek

Povzetek: Soil is one of the most species-rich habitats and plays a crucial role in the functioning of terrestrial ecosystems. It is acknowledged that soils and their biota deliver many ecosystem services. However, up to now, cultural ecosystem services (CES) provided by soil biodiversity remained virtually unknown. Here we present a multilingual and multisubject literature review on cultural benefits provided by belowground biota in European forests. We found 226 papers mentioning impact of soil biota on the cultural aspects of human life. According to the reviewed literature, soil organisms contribute to all CES. Impact on CES, as reflected in literature, was highest for fungi and lowest for microorganisms and mesofauna. Cultural benefits provided by soil biota clearly prevailed in the total of the reviewed references, but there were also negative effects mentioned in six CES. The same organism groups or even individual species may have negative impacts within one CES and at the same time act as an ecosystem service provider for another CES. The CES were found to be supported at several levels of ecosystem service provision: from single species to two or more functional/taxonomical groups and in some cases morphological diversity acted as a surrogate for species diversity. Impact of soil biota on CES may be both direct % by providing the benefits (or dis-benefits) and indirect through the use of the products or services obtained from these benefits. The CES from soil biota interacted among themselves and with other ES, but more than often, they did not create bundles, because there exist temporal fluctuations in value of CES and a time lag between direct and indirect benefits. Strong regionality was noted for most of CES underpinned by soil biota: the same organism group or species may have strong impact on CES (positive, negative or both) in some regions while no, minor or opposite effects in others. Contrarily to the CES based on landscapes, in the CES provided by soil biota distance between the ecosystem and its CES benefiting area is shorter (CES based on landscapes are used less by local people and more by visitors, meanwhile CES based on species or organism groups are used mainly by local people). Our review revealed the existence of a considerable amount of spatially fragmented and semantically rich information highlighting cultural values provided by forest soil biota in Europe.
Ključne besede: soil biota, forests, soil ecosystem services, Europe
Objavljeno v DiRROS: 20.02.2020; Ogledov: 1216; Prenosov: 606
.pdf Celotno besedilo (329,19 KB)
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