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Na voljo sta dva načina iskanja: enostavno in napredno. Enostavno iskanje lahko zajema niz več besed iz naslova, povzetka, ključnih besed, celotnega besedila in avtorja, zaenkrat pa ne omogoča uporabe operatorjev iskanja. Napredno iskanje omogoča omejevanje števila rezultatov iskanja z vnosom iskalnih pojmov različnih kategorij v iskalna okna in uporabo logičnih operatorjev (IN, ALI ter IN NE). V rezultatih iskanja se izpišejo krajši zapisi podatkov o gradivu, ki vsebujejo različne povezave, ki omogočajo vpogled v podroben opis gradiva (povezava iz naslova) ali sprožijo novo iskanje (po avtorjih ali ključnih besedah).

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The interplay between forest management practices, genetic monitoring, and other long-term monitoring systems
Darius Kavaliauskas, Barbara Fussi, Marjana Westergren, Filipos Aravanopoulos, Domen Finžgar, Roland Baier, Paraskevi Alizoti, Gregor Božič, Evangelia V. Avramidou, Monika Konnert, Hojka Kraigher, 2018

Povzetek: The conservation and sustainable use of forests and forest genetic resources (FGR) is a challenging task for scientists and foresters. Forest management practices can affect diversity on various levels: genetic, species, and ecosystem. Understanding past natural disturbance dynamics and their level of dependence on human disturbances and management practices is essential for the conservation and management of FGR, especially in the light of climate change. In this review, forest management practices and their impact on genetic composition are reviewed, synthesized, and interpreted in the light of existing national and international forest monitoring schemes and concepts from various European projects. There is a clear need and mandate for forest genetic monitoring (FGM), while the requirements thereof lack complementarity with existing forest monitoring. Due to certain obstacles (e.g., the lack of unified FGM implementation procedures across the countries, high implementation costs, large number of indicators and verifiers for FGM proposed in the past), merging FGM with existing forest monitoring is complicated. Nevertheless, FGM is of paramount importance for forestry and the natural environment in the future, regardless of the presence or existence of other monitoring systems, as it provides information no other monitoring system can yield. FGM can provide information related to adaptive and neutral genetic diversity changes over time, on a species and/or on a population basis and can serve as an early warning system for the detection of potentially harmful changes of forest adaptability. In addition, FGM offers knowledge on the adaptive potential of forests under the changing environment, which is important for the long-term conservation of FGR
Ključne besede: forest monitoring, forest genetic monitoring, forest genetic diversity, silviculture
DiRROS - Objavljeno: 20.02.2020; Ogledov: 142; Prenosov: 102
URL Celotno besedilo (0,00 KB)

The impact of adverse weather and climate on the width of European beech (Fagus sylvatica L.) tree rings in Southeastern Europe
Stefan Stjepanović, Bratislav Matović, Dejan Stojanović, Branislava Lalić, Tom Levanič, Saša Orlović, Marko Gutalj, 2018

Povzetek: European beech (Fagus sylvatica L.) is the most important deciduous tree species in Europe. According to different climate scenarios, there is a relatively high probability of a massive decline in and loss of beech forests in southern Europe and in the southern part of central Europe. Thus, the authors of this study explored the dynamics of tree diameter increments and the influence of extremely dry years on the width of tree rings. This study used dendroecological methods to analyze the growth and diameter increments of European beech trees at locations in Serbia and the Republic of Srpska. The sampling was conducted along the vertical distribution of beech forests, at five sites at the lower limit of the distribution, at five optimal sites of the distribution, and at five sites at the upper limit of the distribution. Long-term analyses indicate that dry conditions during a growing season can reduce tree-ring width, but a reduction in tree growth can be expected as a result of more than one season of unfavorable conditions. Low temperatures in autumn and winter and prolonged winters can strongly affect upcoming vegetation and reduce tree development even under normal thermal conditions during a growing season.
Ključne besede: European beech, climate change, drought, air temperature, precipitation, tree rings, dendrochronology, Fagus sylvatica L.
DiRROS - Objavljeno: 20.02.2020; Ogledov: 154; Prenosov: 94
URL Celotno besedilo (0,00 KB)

The effects of a large-scale ice storm event on the drivers of bark beetle outbreaks and associated management practices
Maarten De Groot, Nikica Ogris, Andrej Kobler, 2018

Povzetek: Large-scale disturbances in forests are becoming more frequent due to a changing climate. Biotic disturbances can have cascading effects and therefore have a significant economic impact in forestry. It is therefore important to gain an understanding of the drivers of forest pest outbreaks in epidemic situations after large-scale disturbances and the implications for forest management. We investigated the influence of drivers on the bark beetle outbreaks following a large-scale ice storm in 2014 in Slovenia. A country-wide survey was done on the variables affecting ice storm damage to spruce trees. Additionally, the influence of the drivers of bark beetle attacks on outbreak intensity was assessed and compared under epidemic and endemic situations, and the effectiveness of forest management measures was assessed. Spruce trees were either uprooted or snapped, or the crown was lightly to severely damaged. The outbreaks under endemic situations were potentiated by the increasing amount of spruce and reduced by increasing slope. After the ice storm, the amount of sanitary felling because of outbreaks increased in areas with more steeper slopes, where the ice storm took place. An increase in the level of disturbance and a higher availability of dead and weakened trees positively affected bark beetle populations. The removal of dead trees alone in the first year after the ice storm was found to be an insufficient measure for preventing bark beetle outbreaks. The ineffectiveness of current practices suggests that bark beetle management should be reconsidered with regard to large-scale disturbances. When defining measures against bark beetle outbreaks, drivers in epidemic situations should be prioritized over those that are important in endemic situations. The results imply that the known factors that affect bark beetle attacks are not necessarily the same as those that drive bark beetle attacks after extraordinary disturbance events. Mixed stands should be promoted in forests for sustainable management.
Ključne besede: Bark beetle outbreaks, large-scale catastrophic event, Norway spruce damage, Sanitary fellings, Slovenia, eruptive forest pest, Ips typographus, Bark beetle
DiRROS - Objavljeno: 20.02.2020; Ogledov: 110; Prenosov: 74
URL Celotno besedilo (0,00 KB)

Streamflow as an ecological factor influencing radial growth of European ash (Fraxinus excelsior (L.))
M. Koprowski, Bernard Okoński, Jožica Gričar, Radosław Puchałka, 2018

Povzetek: The aim of our study was to find the hydrological, precipitation and temperature signal in tree rings and selected cell parameters of European ash (Fraxinus excelsior L.) in the floodplain forest of the Warta River. A total of 30 samples were taken at breast height, using a Pressler borer, from 15 trees (2 samples per tree) during the 2012 vegetation season. We measured the tree-ring widths, built the chronology, selected the tree that was the best correlated with the rest, and used both samples from this tree for cell analysis. For earlywood vessels, average and total density, as well as the percentage of water conductive area were calculated for the years 1950%2011. We found that high water levels during September to January of the previous year positively influence tree growth. This finding could be associated with the accumulation of nutrients, like nitrogen, in the floodplain soil, which are then used at the beginning of the growing season or earlier, when the trees transition from the true dormancy phase to relative dormancy. Temperature at the end of winter and early spring did not play a big role in tree-ring width, whereas low temperature in February negatively affected the number and the area of the earlywood cells. In addition, precipitation during the growing season, especially in June, had a positive effect on ring width. To summarize, our research showed that in the case of European ash from lowland flood-areas, river flows had a large influence on growth. Precipitation and air temperature, which both shape the river regime and directly supply forest ecosystems with water, were also important for tree growth and tree-ring structure.
Ključne besede: tree rings, dendroecology, dendrohydrology, wood anatomy, earlywood vessels, maximum river flow
DiRROS - Objavljeno: 20.02.2020; Ogledov: 99; Prenosov: 67
URL Celotno besedilo (0,00 KB)

Short-term changes in plant functional traits and understory functional diversity after logging of different intensities : a temperate fir-beech forest experiment
Klemen Eler, Janez Kermavnar, Aleksander Marinšek, Lado Kutnar, 2018

Povzetek: The concept of plant functional traits has been demonstrated to be very effective in unravelling the ecological mechanisms governing plant community response to disturbance, especially when research is focused on short-term post-disturbance vegetation dynamics. In this study, we established an experiment to quantify how logging intensity affects the trait composition and functional diversity of understory communities in fir-beech forests in the Dinaric Mountains in Slovenia. Three different silvicultural treatments were implemented: control (no logging), 50% of the growing stock removed and 100% of the growing stock removed. Vegetation surveys of vascular plants were made before (in 2012) and two years after (in 2014) logging. Changes in species traits, C-S-R plant strategies (sensu Grime) and community-level functional diversity were analysed. The importance of traits such as small and light diaspores, short life span and anemochory increased with logging intensity. Moreover, species with the ability of both sexual and vegetative reproduction, longer flowering duration and overwintering green leaves increased in abundance after logging. C-S-R strategies mainly shifted from stress-tolerators in pre-logging conditions towards a more ruderal component in post-logging stands. Logging in the short term increased functional diversity, mainly due to newly colonized species being functionally dissimilar from persistent residents. Results suggest that logging intensity strongly influences the magnitude of change in both functional composition and diversity, which also has important implications for biodiversity conservation. At the landscape scale, increasing spatial heterogeneity by creating a mosaic of forest stands subjected to different logging intensities will likely contribute to the enhancement of plant functional diversity.
Ključne besede: functional composition, functional diversity, life-history traits, understory vegetation, canopy gap, biodiversity, beech forest
DiRROS - Objavljeno: 20.02.2020; Ogledov: 99; Prenosov: 80
URL Celotno besedilo (0,00 KB)

Predictive analytics of tree growth based on complex networks of tree competition
Domen Mongus, Urša Vilhar, Mitja Skudnik, Borut Žalik, David Jesenko, 2018

Povzetek: Competition between individual trees is a major factor influencing the development of forests. However, due to the complexity of such interactions, that span over vast geographic areas, systematic analysis of competition has only recently become possible through the concepts of so-called predictive analytics. The rationale behind the utilised approach is that a prediction model, which is capable of forecasting future increments of tree development parameters accurately, contains knowledge about the underlying relationships that govern them. The analysis of such model, therefore, holds the potential to reveal new insights into the critical factors that influence forest developments. Within this study, we utilise an Evolutionary Algorithm in order to enable predictive analytics based on a complex-network representation of competition. This allowed us to study the patterns related to spatial distribution of individual trees. We discovered that triplets of competing trees, and their betweenness centralities, have significantly greater influence on the development of each individual tree than traditionally observed parameters like the number of a tree%s competitors and distances between them. While this indicates preferable spatial patterns for optimal forest development, the introduced methodology proved to be an efficient predictive analytics tool that allows for their discovery.
Ključne besede: tree competition, knowledge discovery, evolutionary algorithms, complex networks, topology
DiRROS - Objavljeno: 20.02.2020; Ogledov: 76; Prenosov: 56
URL Celotno besedilo (0,00 KB)

Predicting the vessel lumen area tree-ring parameter of Quercus robur with linear and nonlinear machine learning algorithms
Jernej Jevšenak, Sašo Džeroski, Tom Levanič, 2018

Povzetek: Climate-growth relationships in Quercus robur chronologies for vessel lumen area (VLA) from two oak stands (QURO-1 and QURO-2) showed a consistent temperature signal: VLA is highly correlated with mean April temperature and the temperature at the end of the previous growing season. QURO-1 showed significant negative correlations with winter sums of precipitation. Selected climate variables were used as predictors of VLA in a comparison of various linear and nonlinear machine learning methods: Artificial Neural Networks (ANN), Multiple Linear Regression (MLR), Model Trees (MT), Bagging of Model Trees (BMT) and Random Forests of Regression Trees (RF). ANN outperformed all the other regression algorithms at both sites. Good performance also characterised RF and BMT, while MLR, and especially MT, displayed weaker performance. Based on our results, advanced machine learning algorithms should be seriously considered in future climate reconstructions
Ključne besede: dendroclimatology, artificial neural networks, multiple linear regression, machine learning, vessel lumen area, Quercus robur
DiRROS - Objavljeno: 20.02.2020; Ogledov: 113; Prenosov: 74
URL Celotno besedilo (0,00 KB)

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