1. Continent-wide tree species distribution models may mislead regional management decisions : a case study in the transboundary biosphere reserve Mura-Drava-DanubeMarcus Sallmannshofer, Debojyoti Chakraborty, Harald Vacik, Gábor Illés, Markus Löw, Andreas Rechenmacher, Katharina Lapin, Sophie Ette, Dejan Stojanović, Andrej Kobler, Silvio Schueler, 2021, izvirni znanstveni članek Povzetek: 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.
Ključne besede: bioclimatic model, ecological niche model, forest management, tree species selection, riparian forest habitat, climate change adaptation
Objavljeno v DiRROS: 22.03.2021; Ogledov: 652; Prenosov: 428
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2. Effects of various cutting treatments and topographic factors on microclimatic conditions in Dinaric fir-beech forestsJanez Kermavnar, Mitja Ferlan, Aleksander Marinšek, Klemen Eler, Andrej Kobler, Lado Kutnar, 2020, izvirni znanstveni članek Povzetek: 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 Tmax and VPDmax in HMI treatment were up to 5.9°C (on average 3.5°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 Tmax 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.
Ključne besede: tree cutting, air temperature, relative humidity, vapour pressure deficit, karst topography, canopy cover
Objavljeno v DiRROS: 08.10.2020; Ogledov: 824; Prenosov: 275
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3. Zaznava velikopovršinskih poškodb gozdnega drevja s pomočjo vegetacijskih indeksov na primeru žledoloma 2014Nikica Ogris, Klemen Čotar, Andrej Kobler, 2016, kratki znanstveni prispevek Ključne besede: varstvo gozdov, satelitski posnetki, MODIS, NDVI, EVI, LAI, FAPAR
Objavljeno v DiRROS: 28.07.2020; Ogledov: 883; Prenosov: 392
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4. Ocena zgradbe in stabilnosti gozdnega roba kot pripomoček za ovrednotenje klimatske in zaščitne funkcije primestnih gozdovDavid Hladnik, Andrej Kobler, Janez Pirnat, 2020, izvirni znanstveni članek Povzetek: V prispevku podajamo razširjen povzetek iz članka, 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, zaščitne 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 zemljiščih prevladujejo visoki in strmi gozdni robovi. Predstavili smo preprosto metodologijo, na podlagi katere je mogoče z metodami daljinskega zbiranja podatkov zasnovati monitoring primestnih gozdnih površin in gozdnih robov.
Ključne besede: funkcije gozdov, stabilnost gozdnega roba, gozdni rob, zgradba gozdnega roba, LiDAR, urbani gozdovi
Objavljeno v DiRROS: 09.06.2020; Ogledov: 1551; Prenosov: 552
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6. Obvladovanje tveganj pri gospodarjenju s smreko v gozdovih Slovenije : zaključno poročilo projekta V4-1614Tom Levanič, Lado Kutnar, Andrej Kobler, Aleksander Marinšek, Matjaž Čater, Gregor Božič, Marjana Westergren, Maarten De Groot, Jernej Jevšenak, Samo Stopar, 2020, končno poročilo o rezultatih raziskav Ključne besede: gospodarjenje z gozdovi, smreka, Slovenija, smrekovi gozdovi
Objavljeno v DiRROS: 27.05.2020; Ogledov: 1108; Prenosov: 493
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7. Evaluation of forest edge structure and stability in peri-urban forestsDavid 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: 1280; Prenosov: 627
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8. Mikroklimatske razmere v sestojih in vrzelih dinarskih jelovobukovih gozdov Slovenije z vidika podnebnih spremembJanez Kermavnar, Mitja Ferlan, Aleksander Marinšek, Klemen Eler, Andrej Kobler, Lado Kutnar, 2019, izvirni znanstveni članek Povzetek: Dinarski jelovo-bukovi gozdovi so eden glavnih gozdnih vegetacijskih tipov v Sloveniji, v katerih so se v zadnjem obdobju zaradi naravnih ujm spremenile ekološke razmere. Namen raziskave je bila analiza izbranih spremenljivk mikroklime (temperatura zraka, relativna zračna vlaga) v strnjenih sestojih, v presvetljenih sestojih in v sestojnih vrzelih na treh raziskovalnih območjih (Trnovski gozd, Snežnik, Kočevski rog). Za strnjene sestoje je bila značilna visoka stopnja zastiranja tal s krošnjami dreves ( ~ 95 %). Sestojne vrzeli so nastale s posekom vseh dreves na krožni površini 0,4 ha, v presvetljenih sestojih pa je bila posekana približno polovica lesne zaloge gozdnega sestoja. Ukrepi so bili izvedeni leta 2012, meritve meteoroloških spremenljivk pa smo opravili prvo (2013) in drugo (2014) leto po sečnji. Primerjali smo, kako se mikroklimatske razmere v sestojih in vrzelih spreminjajo v vegetacijski sezoni (maj-oktober) in kakšne so razlike med dvema meteorološko razmeroma različnima poletjema v letih 2013 (več vročinskih valov, poletna suša) in 2014 (nestanovitno vreme z relativno veliko količino padavin). Izmerjene najvišje dnevne temperature zraka (Tmax) so bile izrazito višje v vrzelih kot v sestoju, v povprečju za 3,6 °C; najnižja relativna zračna vlaga (RVmin) pa je bila nižja, v povprečju za 15,0 odstotnih točk. Razlike v obeh spremenljivkah med sestoji in vrzelmi so bile največje v poletnih mesecih (junij-avgust) leta 2013 (Tmax: 4,9 °C; RVmin: -19,7 odstotnih točk), ki je bilo razmeroma vroče in sušno. Na podlagi meritev meteoroloških spremenljivk in zastora drevesnih krošenj (podatki LiDARskega snemanja) v presvetljenih sestojih smo ugotovili statistično značilno negativno linearno povezavo med zastorom drevesnih krošenj in Tmax ter pozitivno povezavo med zastorom krošenj in vrednostmi RVmin. Rezultate analiz smo prikazali v luči potencialnih vplivov podnebnih sprememb, katerim so dinarski jelovo-bukovi gozdovi zaradi kombinacije neugodnih dejavnikov npr. zmanjšana mehanska in biološka stabilnost sestojev zaradi velikopovršinskih motenj, poletne suše, vodoprepusten kraški teren ter pogosto plitva tla z majhno sposobnostjo zadrževanja vode - še posebej izpostavljeni.
Ključne besede: dinarski jelovo-bukovi gozdovi, temperatura zraka, relativna zračna vlaga, sestojne vrzeli, zastor krošenj dreves, podnebne spremembe, Slovenija
Objavljeno v DiRROS: 20.12.2019; Ogledov: 1888; Prenosov: 622
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10. Razvoj metod zaznavanja poškodb iglavcev zaradi smrekovih in jelovih podlubnikov ter izdelava modelov za napovedovanje namnožitev smrekovih in jelovih podlubnikov v slovenskih razmerah (V4-1623) : končno poročiloNikica Ogris, Andrej Kobler, Tatjana Veljanovski, Peter Pehani, Maarten De Groot, 2019, končno poročilo o rezultatih raziskav Ključne besede: model, napoved, prognoza, lps typographus, Pityogenes chalcographus, multispektralen posnetek, informacijski posnetek, informacijski sistem, sistem obveščanja, hiperspektralna kamera, žarišče podlubnikov, lubadarji, nadzor, ogroženost iglavcev, zdravstveno stanje dreves, javna gozdarska služba, rojenje podlubnikov, sistem zgodnjega odkrivanja
Objavljeno v DiRROS: 17.10.2019; Ogledov: 1475; Prenosov: 867
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