The understanding of spatial distribution patterns of native riparian tree species in Europe lacks accurate species distribution models (SDMs), since riparian forest habitats have a limited spatial extent and are strongly related to the associated watercourses, which needs to be represented in the environmental predictors. However, SDMs are urgently needed for adapting forest management to climate change, as well as for conservation and restoration of riparian forest ecosystems. For such an operative use, standard large-scale bioclimatic models alone are too coarse and frequently exclude relevant predictors. In this study, we compare a bioclimatic continent-wide model and a regional model based on climate, soil, and river data for central to south-eastern Europe, targeting seven riparian foundation species-Alnus glutinosa, Fraxinus angustifolia, F. excelsior, Populus nigra, Quercus robur, Ulmus laevis, and U. minor. The results emphasize the high importance of precise occurrence data and environmental predictors. Soil predictors were more important than bioclimatic variables, and river variables were partly of the same importance. In both models, five of the seven species were found to decrease in terms of future occurrence probability within the study area, whereas the results for two species were ambiguous. Nevertheless, both models predicted a dangerous loss of occurrence probability for economically and ecologically important tree species, likely leading to significant effects on forest composition and structure, as well as on provided ecosystem services.

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.

V prispevku podajamo razsirjen povzetek iz clanka, objavljenega v reviji Forests z naslovom Evaluation of forest edge structure and stability in peri-urban forests (Hladnik in sod., 2020). Dodali smo predloge o prenovi varovalne, zascitne in klimatske funkcije gozdov ter predloge ukrepov, ki izhajajo iz izsledkov raziskave gozdnih robov. Analizirali smo vertikalno zgradbo gozdnih robov in opozorili na pomen dimenzijskega razmerja dreves h/d na gozdnih robovih primestnih gozdnih zaplat ob Ljubljani, kjer ob pozidanih zemljiscih prevladujejo visoki in strmi gozdni robovi. Predstavili smo preprosto metodologijo, na podlagi katere je mogoce z metodami daljinskega zbiranja podatkov zasnovati monitoring primestnih gozdnih povrsin in gozdnih robov.

Forest microclimate is strongly affected by local topography and management activities, as these directly alter overstory structure. In the present work we analysed the dependence of observed patterns of spatio-temporal microclimatic variations on topographic, canopy- and management-related factors. A forestry experiment was conducted in managed fir-beech forests in the Dinaric Mountains (Slovenia), which are characterized by rugged karstic terrain with numerous sinkholes. In 2012, cutting treatments representing a range in the intensity of overstory removal were performed: uncut controls (CON), 50% cut of stand growing stock (intermediate management intensity - IMI) and 100% cut (high management intensity - HMI) creating 0.4 ha canopy gaps. Fine-scale variation in aspect and slope and its effects on microclimate was assessed by comparing central, south-facing and north-facing within-sinkhole positions. We measured microclimatic variables (air temperature - T, relative humidity - RH) 0.5 m above the ground over three consecutive post-treatment growing seasons. Microclimatic variables showed an increase (T and vapour pressure deficit - VPD) or decrease (RH) with management intensity. Daily T-max and VPDmax in HMI treatment were up to 5.9 degrees C (on average 3.5 degrees C) and up to 1.4 kPa (on average 0.6 kPa) higher than those in CON treatment, respectively, whereas daily RHmin was up to 22.7 (on average 13.0) percentage points lower. Regarding intra-seasonal patterns, microclimatic differences between treatments were largest during the summer. South-facing plots in the HMI treatment overall exhibited the most extreme conditions, i.e. the highest T-max and lowest RHmin. Differences in microclimate between treatments were strongly modulated by canopy cover. The results also suggest that overstory removal increases topography-mediated variation in microclimate, as evidenced by significant differences in T, RH and VPD along the fine-scale topographic gradient within the created canopy gaps.

A dendrochronological analysis of the spruce's radial increment at eight different plots was conducted throughout Slovenia. The plots selected were diverse: five of them were natural spruce stands; in others, the spruce was introduced anthropogenically in the past for economic reasons, or its natural share in stands was increased. We took samples of at least 20 trees per plot and examined them in the dendrochronological laboratory using Advanced Tree-Ring Image Capturing System (ATRICS) and specialized dendrochronological software. We compared the growth in natural spruce stands with the secondary (anthropogenic) ones and found no statistical differences in growth patterns between these two groups. However, we found some evidence for climate change effect on radial increment at locations Sorsgko polje, Ravnik and Masun, which indicates that air temperature and precipitation now have stronger effect on spruce growth than in the past. Analysis of pointer years suggests that extreme events (exceptionally warm and dry years) are more common and widespread in the last 30 years.

We analysed basic demographic indicators (population size, population density) and selected landscape indicators (forest cover, number of forest patches, area of the largest forest patch, share of core areas in the forest) in the Karst landscapes of Inner Slovenia, their changes over four decades and the correlations between them. Using the Pearson correlation coefficient, we determined multiple statistically significant correlations between demographic and landscape indicators. In areas with higher population density, the share of forest has been significantly lower in both studied years. As expected, in areas with a higher share of forest, the share of core forest and the largest forest patches area are larger.

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.

We analysed basic demographic indicators (population size, population density) and selected landscape indicators (forest cover, number of forest patches, area of the largest forest patch, share of core areas in the forest) in the Karst landscapes of Inner Slovenia, their changes over four decades and the correlations between them. Using the Pearson correlation coefficient, we determined multiple statistically significant correlations between demographic and landscape indicators. In areas with higher population density, the share of forest has been significantly lower in both studied years. As expected, in areas with a higher share of forest, the share of core forest and the largest forest patches area are larger.

A dendrochronological analysis of the spruce's radial increment at eight different plots was conducted throughout Slovenia. The plots selected were diverse: five of them were natural spruce stands; in others, the spruce was introduced anthropogenically in the past for economic reasons, or its natural share in stands was increased. We took samples of at least 20 trees per plot and examined them in the dendrochronological laboratory using Advanced Tree-Ring Image Capturing System (ATRICS) and specialized dendrochronological software. We compared the growth in natural spruce stands with the secondary (anthropogenic) ones and found no statistical differences in growth patterns between these two groups. However, we found some evidence for climate change effect on radial increment at locations Sorško polje, Ravnik and Mašun, which indicates that air temperature and precipitation now have stronger effect on spruce growth than in the past. Analysis of pointer years suggests that extreme events (exceptionally warm and dry years) are more common and widespread in the last 30 years.

The saproxylic beetle, Cucujus cinnaberinus, has received increasing research attention in Europe since the adoption of the Habitats Directive and establishment of the Natura 2000 network. The history of the species has been investigated as well as the influence of abiotic and biotic variables on the distribution of C. cinnaberinus in Slovenia which is at the limit of its range and also terra typica for the species. The species was first described in 1763 by Joannes A. Scopoli in Carniola, a duchy of the Habsburg Monarchy. Today, most of the territory of Carniola is situated within Slovenia. C. cinnaberinus is particularly common in the eastern part of the country, but very scarce in the mountainous western part. According to historical and recent distribution patterns of C. cinnaberinus in the former Carniolan territory, the region of Ribnica-Kocevje in southern Slovenia is proposed as the most probable type locality of the species. Although the bulk of the C. cinnaberinus population in Slovenia is confined to the lowlands, the species has been found up to 1095 m a. s.l., albeit at a much lower abundance due to the influence of climate and forest structure. Although C. cinnaberinus is a quite an opportunistic species regarding host tree selection, it has been shown to exhibit a preference for Tilia, Populus and Robinia. It is suspected that the high abundance of C. cinnaberinus in lowland floodplain forests is due to the recent human-induced increase in preferred fast-growing and shortlived host trees, i.e. the planting of poplar trees and spread of invasive Black Locust ( Robinia pseudoacacia) after the 1960s. In contrast, in montane forests, preferred host trees (e.g. Tilia) represent < 1 % of all growing stock. Although montane C. cinnaberinus populations are rare, they could still be important for the conservation of the species, since montane habitats cover the largest area within the species' distribution range.

V letu 2016 smo razvili model za napoved debeline žleda in nevarnosti žledoloma do 12 ur v naprej (Ogris in sod., 2016) s prostorsko ločljivost 1 km in časovno ločljivostjo 1 ure.Vir meteoroloških podatkov za oceno debeline žleda je sistem za kratkoročno napoved INCA (ARSO), iz katerega model črpa podatke o količini dežja, ki zmrzuje, hitrosti vetra in temperaturi zraka.Model za oceno debeline žleda simulira tudi taljenje žleda.Model za oceno nevarnosti žledoloma je empirični model na osnovi indeksa, v katerega smo vključili debelino žleda, indeks drevesne sestave, naklon terena in indeks matične podlage.Model za napoved debeline žleda in nevarnosti žledoloma smo nadgradili z možnostjo napovedi do 72 ur v naprej.Vhodne meteorološke podatke dobimo iz numeričnega meteorološkega modela ALADIN-SI (Pristov in sod., 2002), s prostorsko ločljivost 4,4 km, meteorološke spremenljivke pa napove za 72 ur v naprej na vsako uro.Na ARSO so dodali izračun dodatne spremenljivke, tj.tip padavin,

In managed Dinaric montane fir (Abies alba Mill.) and European beech (Fagus sylvatica L.) forests, the light response of young beech and fir in gap microsites was studied during three consecutive growing periods (2009, 2010, and 2011) under controlled environmental conditions in stands of single-tree and irregular shelterwood silvicultural system. According to maximal quantum yield, the different response between species in microsite light categories was evidenced for silver fir on microsites with predominating diffuse light and for beech on microsites with predominating direct light, respectively.Abundance and change of share in microsite light categories was compared over different elevation belts on comparable sites between two silvicultural systems. The share of forest edge area was bigger in the irregular shelterwood system. Change in width of forest edge (20, 30 and 40 m) did not affect the proportion and share of the microsite in both regions of different silvicultural system. Separation of microsite areas between both silvicultural systems, evident in lower elevation belts was not evident in the most conflict and highest elevation zone, while the absolute values of all categories above 700 m in both systems were almost identical, indicating the same, small-scale irregular shelterwood system, known also as the freestyle silvicultural approach. (C) 2017 Elsevier B.V. All rights reserved.

Many wildlife populations are declining due to anthropologic and environmental pressures. Indicators can facilitate detection of and reaction to population declines. We tested spatial population pattern variables as indicators for the future fate of capercaillie populations in Slovenia. This population was surveyed from 1979 to 1983, 1998 to 2000, and 2008 to 2011. We tested the following indicators of spatial population patterns: the proportion of occupied leks in the neighbourhood of each lek, the distance to the nth nearest occupied lek, the distance to the centre of the cluster and the distance to the closest neighbouring cluster. The AUC and conditional and marginal R2 were used to evaluate the strength of the indicators. There was a steep decline in the number of leks in the Dinaric Mountains during the period 1980–2010, while the number of leks in the Eastern Slovenian Alps and Julian Alps decreased until 2000 and then stabilized. There was an increase in the distance to the nearest occupied leks over the years, but there were differences in this indicator between the clusters. A combination of the distance to the fourth nearest occupied lek and the occupancy of the first nine leks best predicted the future of a lek, showing that the indicators used in the study can be used to predict the future fate of a lek. Our results can help guide future conservation and management decisions to conserve capercaille populations.

Uvod Ob gozdni ujmi je ključnega pomena hitra pridobitev ocene o njeni razsežnosti. Pri tem si lahko pomagamo z multispektralnimi satelitskimi posnetki, kjer iz razmerij med odboji svetlobe v posameznih delih spektra izračunamo tako imenovane vegetacijske indekse. Za namen opazovanja gozdnih površin se pogosto uporabljata vegetacijska indeksa NDVI (ang. Normalized Difference Vegetation Index) in EVI (ang. Enhanced Vegetation Index). Vegetacijski indeks NDVI temelji na razmerju med vrednostmi odbojnosti svetlobe v rdečem in bližnjem infrardečem delu spektra. NDVI loči zeleno vegetacijo od ostalih površin, ker klorofil absorbira rdeči del vpadnega spektra sončevega sevanja in odbija bližnji infrardeči del spektra zaradi notranje sestave lista. Visoke vrednosti NDVI kažejo na velike listne površine, visoko listno biomaso in sklenjenost krošenj. NDVI izračunamo po formuli: NDVI = (NIR – RED) / (NIR + RED), kjer je NIR vrednost odbojnosti v bližnjem infrardečem spektru, RED pa v rdečem delu spektra (Solano in sod., 2010). V gostih sestojih, kjer je površina listov velika, uporabljamo vegetacijski indeks EVI. EVI je v osnovi podoben NDVI, katerega vrednosti izboljšamo s pomočjo vrednosti odbojnosti v modrem delu spektra. To omogoča popravek vpliva spektralnega odboja od tal in atmosferskih motenj. Izračunamo ga po naslednji formuli (Solano in sod., 2010): EVI = 2,5 × [(NIR – RED) / ((NIR) + (6 × RED) – (7,5 × BLUE) + 1)]. NDVI odraža količino klorofila, EVI pa zazna strukturne spremembe v krošnjah dreves, vključno z listno površino, fizionomijo rastline in zgradbo krošnje. Pogosto za zaznavo sprememb v vegetaciji uporabljamo še indeks listne površine (LAI, ang. Leaf Area Index) in FAPAR (ang. Fraction of Absorbed Photosynthetically Active Radiation). LAI je pri listavcih opredeljen kot listna površina (ena stran lista) na enoto površine tal in pri iglavcih kot pol celotne površine iglice na enoto površine tal (Myneni, 2012). LAI uporabljamo za napoved primarne produkcije, evapotranspiracije in kot referenčno orodje za oceno rasti vegetacije. Indeks FAPAR opisuje absorpcijo svetlobe v sklenjenih krošnjah in je opredeljen kot delež absorbiranega sevanja pri valovnih dolžinah med 400 in 700 nm, kjer je vegetacija zmožna proizvajati fotosintezo. Zato FAPAR neposredno odraža primarno produkcijo fotosinteze, nekateri modeli pa ga uporabljajo tudi za oceno asimilacije ogljikovega dioksida v vegetaciji. Izračun navedenih indeksov omogočajo multispektralni posnetki instrumenta MODIS (ang. Moderate Resolution Imaging spektroradiometer) na krovu satelitov Terra (prvotno znan kot EOS AM-1) in Aqua (prvotno znan kot EOS PM-1). Terra kroži okoli Zemlje od severa proti jugu, medtem ko Aqua kroži od juga proti severu. Terra MODIS in Aqua MODIS pregledata celotno Zemljino površino vsakih 1 do 2 dni, podatke pridobivata v 36. spektralnih kanalih (Solano in sod., 2010). Razpoložljivi produkti, izvedeni iz več dnevnih opazovanj, imajo različno prostorsko in časovno ločljivost. Pri raziskavi uporabljena indeksa NDVI in EVI (produkt MYD13Q1) imata prostorsko ločljivost 250 m in časovno ločljivost 16 dni ter indeksa LAI in FAPAR (produkt MCD15A3) prostorsko ločljivost 1 km in časovno ločljivost 4 dni. Cilj raziskave je bil preveriti ali vegetacijski indeksi instrumenta MODIS lahko zaznajo velikopovršinske poškodbe gozdnega drevja v treh časovnih ločljivosti: dan, mesec in leto. Za študijski primer smo izbrali izjemen žledolom, ki se je zgodil 30. 1.–10. 2. 2014 (ZGS, 2014).

Report of the international project Life ManForCBD.