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Query: "author" (Ko��nik Mitja) .

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91.
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FAIR : načela za raziskovalne podatke
Mitja Vovk Iskrić, 2021, other monographs and other completed works

Keywords: znanstveno raziskovanje, raziskovalni podatki, načela FAIR, usmeritve
Published in DiRROS: 28.09.2021; Views: 872; Downloads: 465
URL Link to file

94.
Climatic regulation of leaf and cambial phenology in Quercus pubescens : their interlinkage and impact on xylem and phloem conduits
Jožica Gričar, Jernej Jevšenak, Polona Hafner, Peter Prislan, Mitja Ferlan, Martina Lavrič, Dominik Vodnik, Klemen Eler, 2022, original scientific article

Abstract: Increased frequency and severity of stressful events affects the growth patterns and functioning of trees which adjust their phenology to given conditions. Here, we analysed environmental effects (temperature, precipitation, VPD and SWC) on the timing of leaf phenology, seasonal stem radial growth patterns, and xylem and phloem anatomy of Quercus pubescens in the sub-Mediterranean in the period 2014%2019, when various adverse weather events occurred, i.e. spring drought in 2015, summer fire in 2016 and summer drought in 2017. Results showed that the timings of leaf and cambium phenology do not occur simultaneously in Q. pubescens, reflecting different environmental and internal constraints. Although year-to-year variability in the timings of leaf and cambial phenology exists, their chronological sequence is fairly fixed. Different effects of weather conditions on different stages of leaf development in spring were observed. Common climatic drivers (i.e., negative effect of hot and dry summers and a positive effect of increasing moisture availability in winter and summer) were found to affect the widths of xylem and phloem increments with more pronounced effect on late formed parts. A legacy effect of the timing of leaf and cambial phenology of the previous growing season on the timing of phenology of the following spring was confirmed. Rarely available phloem data permitted a comprehensive insight into the interlinkage of the timing of cambium and leaf phenology and adjustment strategies of vascular tissues in Mediterranean pubescent oak to various environmental constraints, including frequent extreme events (drought, fire). Our results suggest that predicted changes in autumn/winter and spring climatic conditions for this area could affect the timings of leaf and stem cambial phenology of Q. pubescens in the coming years, which would affect stem xylem and phloem structure and hydraulic properties, and ultimately its performance.
Keywords: pubescent oak, leaf development, radial growth, initial earlywood vessel, sieve tube, anatomy, cambial cell production, extreme weather events
Published in DiRROS: 06.09.2021; Views: 958; Downloads: 283
.pdf Full text (7,00 MB)
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95.
Hymenoptera venom immunotherapy : immune mechanisms of induced protection and tolerance
Ajda Demšar, Peter Korošec, Mitja Košnik, Mihaela Zidarn, Matija Rijavec, 2021, review article

Abstract: Hymenoptera venom allergy is one of the most severe allergic diseases, with a considerable prevalence of anaphylactic reaction, making it potentially lethal. In this review, we provide an overview of the current knowledge and recent findings in understanding induced immune mechanisms during different phases of venom immunotherapy. We focus on protection mechanisms that occur early, during the build-up phase, and on the immune tolerance, which occurs later, during and after Hymenoptera venom immunotherapy. The short-term protection seems to be established by the early desensitization of mast cells and basophils, which plays a crucial role in preventing anaphylaxis during the build-up phase of treatment. The early generation of blocking IgG antibodies seems to be one of the main reasons for the lower activation of effector cells. Long-term tolerance is reached after at least three years of venom immunotherapy. A decrease in basophil responsiveness correlates with tolerated sting challenge. Furthermore, the persistent decline in IgE levels and, by monitoring the cytokine profiles, a shift from a Th2 to Th1 immune response, can be observed. In addition, the generation of regulatory T and B cells has proven to be essential for inducing allergen tolerance. Most studies on the mechanisms and effectiveness data have been obtained during venom immunotherapy (VIT). Despite the high success rate of VIT, allergen tolerance may not persist for a prolonged time. There is not much known about immune mechanisms that assure longterm tolerance post-therapy.
Keywords: allergy and immunology, hypersensitivity, immunotherapy, immune tolerance, venoms, Hymenoptera, Hymenoptera venom, short-term protection, long-term tolerance
Published in DiRROS: 16.08.2021; Views: 864; Downloads: 277
URL Link to file

96.
Upravljanje z mestnimi gozdovi za boljšo kakovost bivanja v mestih
Mitja Skudnik, Polona Hafner, 2021, preface, editorial, afterword

Published in DiRROS: 02.08.2021; Views: 1105; Downloads: 293
.pdf Full text (45,01 KB)

97.
V Sloveniji se povečuje osutost bukove krošnje
Nikica Ogris, Mitja Skudnik, 2021, original scientific article

Abstract: V zadnjem času po vsej Sloveniji opažamo hiranje navadne bukve (Fagus sylvatica L.). Cilj prispevka je predstaviti dolgoročen trend osutosti krošnje navadne bukve v Sloveniji in pojasniti delež osutosti bukove krošnje s pomočjo podatkov iz popisa povzročiteljev poškodb v okviru vsakoletnega popisa razvrednotenja in poškodovanosti gozdov. Pri tem smo uporabili podatkovno zbirko o spremljanju osutosti in poškodovanosti dreves na M6 stalnih vzorčnih ploskvah (Nivo I) na sistematični mreži 16 % 16 km v obdobju 1993%2020. Rezultati kažejo, da se je povprečna osutost bukove krošnje od leta 1993 do 2020 povečala iz 13,9 % na 32,2 %. Dolgoročen linearen trend je pokazal, da se je povprečna osutost bukove krošnje povečala za 0,63 % na leto. Za trend povprečne osutosti bukve je bilo prelomno izjemno sušno leto 2003, ko se je trend osutosti povečal iz 0,61 % na 0,94 % na leto. Trend večanja osutosti bukve smo zaznali na vseh obravnavanih lokacijah. Ugotovili smo, da se povprečna osutost bukve hitreje veča na jugu in zahodu države. Katastrofalen žledolom leta 2014 je povzročil drastično spremembo povzročiteljev osutosti bukve. V obdobju pred žledolomom leta 2014 so osutost bukove krošnje najbolje pojasnjevale poškodbe zaradi žuželk. Po žledolomu leta 2014 so se povečale poškodbe bukve zaradi žleda, gliv, neposrednih človekovih vplivov (obsežne sanacije žledoloma) in drugih dejavnikov. Žledolom je na bukovih gozdovih pustil trajne posledice, saj so poškodbe zaradi žleda in posledično sanacije vidne še dandanes, kar je razvidno tudi iz popisa povzročiteljev poškodb bukve. V zadnjih dveh letih, 2019%2020, so glive najpomembnejše povzročiteljice poškodb bukve. Po letu 2014 pa se je zmanjšala poškodovanost bukve zaradi žuželk. Natančnih vzrokov za splošno slabšanje zdravstvenega stanja bukve po vsej Sloveniji še ne poznamo.
Keywords: Fagus sylvatica, bukev, osutost krošnje, poškodovanost, podnebne spremembe, žledolom, suša
Published in DiRROS: 02.08.2021; Views: 1536; Downloads: 402
.pdf Full text (462,16 KB)

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Stanje in spremembe slovenskih gozdov v zadnjih dveh desetletjih - rezultati velikoprostorskega monitoringa gozdov
Mitja Skudnik, Jernej Jevšenak, Aleš Poljanec, Gal Kušar, 2021, original scientific article

Abstract: V prispevku so predstavljeni rezultati velikoprostorskega monitoringa gozdov in gozdnih ekosistemov (MGGE), ki je na sistematični mreži trajnih vzorčnih ploskev (4 km x 4 km) prek celotne Slovenije potekal v letih 2000, 2007, 2012 in 2018. Predstavljeni so osnovni znaki o stanju (lesna zaloga in volumen odmrlih lesnih kosov) in spremembah (prirastek, posek, volumen novih sušic) slovenskih gozdov. Lesna zaloga merskega drevja se je med letoma 2000 in 2012 povečala iz 299 na 334 m3 ha-1. V letu 2018 je bila ocena za povprečno lesno zalogo 330 m3 ha-1. Vzorčna napaka ocene lesne zaloge je znašala od 4 do 5 %. Med letoma 2012 in 2018 se je predvsem zmanjšala lesna zaloga iglavcev, in sicer iz 156 na 144 m3 ha-1. Poglavitni razlog je bil povečan posek, ki je bil posledica številnih ujm in gradacij podlubnikov. Tako se je povečal posek, in sicer iz 4,3 v obdobju 2007/12 na 6.3 m3 ha-1 leto v obdobju 2012/18. K povečanemu poseku večinski delež prispevajo iglavci. V zadnjem obdobju je bil bruto prirastek z vrastjo in prirastkom posekanih dreves ocenjen na 7,9 m3 ha-1 leto. Ocena volumna odmrlih lesnih kosov za leto 2018 je znašala 24 m3 ha-1. V prispevku je podrobno predstavljena tudi metodologija izračunov ocen povprečij na podlagi sistematičnega vzorčenja. Podatki MGGE so bili uporabljeni predvsem za potrebe mednarodnega poročanja o stanju in razvoju slovenskih gozdov ter v omejenem obsegu tudi za nacionalno poročanje o trajnostnem razvoju slovenskih gozdov. Prednost vzpostavljenega sistema je mednarodno usklajena metodologija popisa na sistematični mreži ploskev preko celotne države. Trenutni sistem ima tudi določene omejitve, in sicer malo vzorčnih ploskev, kar vodi v večjo vzorčno napako pri izračunih nekaterih dendrometrijskih kazalnikov. V letu 2020 smo sistem MGGE nadgradili v kontinuiran panelni sistem, katerega osnova bodo nove trajne vzorčne ploskve na neuravnani sistematični mreži gostote 2 km x 2 km, kar je dobro izhodišče za uvedbo Nacionalne gozdne inventure (NGI) v Sloveniji.
Keywords: monitoring gozdov in gozdnih ekosistemov, lesna zaloga, prirastek, mortaliteta, odmrla biomasa, posek, sušice
Published in DiRROS: 12.07.2021; Views: 1266; Downloads: 497
.pdf Full text (686,93 KB)

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