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Query: "work type" (1) AND "fulltext" AND "organization" (Slovenian Forestry Institute) .

801 - 810 / 1583
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801.
Seasonal radial growth of Black pine (Pinus nigra Arnold) from Bosnia and Herzegovina, monitored by the pinning method and manual band dendrometers
Simon Poljanšek, Jernej Jevšenak, Jožica Gričar, Tom Levanič, 2019, original scientific article

Abstract: Despite numerous dendroclimatological investigations into different tree species from Bosnia and Herzegovina, information is lacking on intra-annual wood formation patterns, which would help us to interpret the climate signal in tree rings better. Using the pinning method and manual band dendrometers, we investigated the seasonal dynamics of radial growth of black pine (Pinus nigra Arnold) trees in two successive growing seasons: 2011 and 2012. The up to 60-year-old trees grew in a stand at the base of a hill in the western, mountainous part of the Balkan Peninsula. The seasonal dynamics of wood formation and final number of cells differed between the studied years. Wood formation started in both years in early to mid-March. Differences were noticed in the wood production culmination; in 2011 it occurred at the end of May and beginning of June in 2012 and 2011, respectively. Xylem growth finished in 2012 in the middle of August and in 2011 in the middle of September. Based on the first derivative of the Gompertz function calculated rate of xylem growth was lowest in 2011. The dendrometers recorded a slow increment rate in spring, higher in summer and a decreasing rate again in the late summer in both growing seasons. In comparison with pinning, dendrometers showed a delay in the start of radial growth of up to 20 days in 2012. Additionally, dendrometers showed an increase in stem girth after the end of both growing seasons, when wood formation was already completed. Deviations between the two methods could be ascribed to the influence of water storage dynamics in the main stem and numerous structural processes in bark tissue, which are captured in dendrometer data. The influence of weather conditions on xylem phenology is also indicated by differences between the two studied years, although it is difficult to identify the influence of particular short-term weather events.
Keywords: pinning, manual dendrometers, radial growth, Pinus nigra, cambium, Balkan Peninsula
Published in DiRROS: 11.09.2019; Views: 4731; Downloads: 3869
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802.
Situation of Armillaria spp. and Heterobasidion spp. in Slovenia
Ana Brglez, Nikica Ogris, 2019, original scientific article

Abstract: Species of the genus Armillaria and Heterobasidion are among the most common causes of stem and root rot in Slovenia. Armillaria spp. infects deciduous and coniferous trees, while Heterobasidion spp. mainly threatens Norway spruce (Picea abies), pines (Pinus spp.), and silver fir (Abies alba). On the basis of the data about the sanitary felling of infected trees, we estimated the current state and calculated the proportions represented in total felling, total sanitary felling, total sanitary felling due to diseases, in wood stock, and in increments from 2013 to 2017. Since 2014, there has been a constant increase in the sanitary felling of deciduous and coniferous trees due to infections with Armillaria spp. In 2017, 32,849 m3 of timber were harvested due to Armillaria spp. Given the present situation, we assume that the amount of sanitary felling will continue to increase, but it will not account for large shares in wood stock or increment (< 1 %). In 2017, sanitary felling of infected conifers represented 27.6 % of all sanitary felling due to diseases. In the case of deciduous trees, the share was lower, i.e. 7.1 %. Armillaria spp. was the main cause of sanitary felling due to disease (51.9 %) in the Postojna forest management unit (FMU), while elsewhere shares of up to 10 % were recorded. With Heterobasidion spp., the amount of felling is decreasing over the years. In 2017, 33,922 m3 of wood, accounting for 15.7 % of the total sanitary felling due to disease, were felled due to Heterobasidion spp. A comparison of the felling of Norway spruce, silver fir, and Scots pine due to Heterobasidion spp. shows the different proportions of felling within the total sanitary felling due to the diseases. In Norway spruce, it is on average 79.5 %, in silver fir 12.9 %, and in Scots pine 34.3 %. We assume that the volume of timber harvested due to Heterobasidion spp. will gradually decrease over the years due to the lower wood stocks of Norway spruce, which has recently been hit by numerous natural disasters and infestation of bark beetles. However, the incidence will be higher due to climate change affects.
Published in DiRROS: 30.08.2019; Views: 2938; Downloads: 1146
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803.
Pseudodidymella fagi in Slovenia : first report and expansion of host range
Nikica Ogris, Ana Brglez, Barbara Piškur, 2019, original scientific article

Abstract: The fungus Pseudodidymella fagi is spreading in Europe and causing leaf blotch of European beech, Fagus sylvatica. Between 2008 and 2017, outbreaks of P. fagi were observed on European beech in Switzerland, Germany (also on F. orientalis), Austria, and Slovakia. In Slovenia, leaf blotch symptoms were first observed on F. sylvatica in 2018. P. fagi was identified as the causal agent of the observed symptoms in Slovenia by morphological examinations together with sequencing of the internal transcribed spacer (ITS) region of the rDNA. This study links the fungus to the expansion of the known distribution of the disease to Slovenia, and based on in vitro pathogenicity trials, also to a new potential host, Quercus petraea. The pathogenicity tests confirmed F. sylvatica and F. orientalis as hosts for P. fagi, but not Castanea sativa, where pathogenicity to F. orientalis was proved for first time in vitro. Although Koch%s postulates could not be proven for C. sativa, it seems to be partially susceptible in vitro because some of the inoculation points developed lesions. Additionally, damage to Carpinus betulus related to P. fagi near heavily infected beech trees was observed in vivo but was not tested in laboratory trials. Based on the results and our observations in the field, it is likely that P. fagi has a wider host range than previously thought and that we might be witnessing host switching.
Keywords: Pycnopleiospora fagi, leaf blotch, pathogenicity test, inoculation test, Fagus orientalis, Fagus sylvatica, Quercus petraea, mycopappus-like propagule, Carpinus betulus, host switching
Published in DiRROS: 23.08.2019; Views: 2476; Downloads: 1551
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804.
Daily climate data reveal stronger climate-growth relationships for an extended European tree-ring network
Jernej Jevšenak, 2019, original scientific article

Abstract: An extended European tree-ring network was compiled from various sources of tree-ring data from Europe, northern Africa and western Asia. A total of 1860 tree-ring chronologies were used to compare correlation coefficients calculated with aggregated day-wise and month-wise mean temperature, sums of precipitation and standardised precipitation-evapotranspiration index (SPEI). For the daily approach, climate data were aggregated over periods ranging from 21 to 365 days. Absolute correlations calculated with day-wise aggregated climate data were on average higher by 0.060 (temperature data), 0.076 (precipitation data) and 0.075 (SPEI data). Bootstrapped correlations are computationally expensive and were therefore calculated on a 69.4% subset of the data. Bootstrapped correlations indicated statistically significant differences between the daily and monthly approach in approximately 1% of examples. A comparison of time windows used for calculations of correlations revealed slightly later onset and earlier ending day of the year for the daily approach, while the largest differences between the two approaches arise from window lengths: Correlations calculated with day-wise aggregated climate data were calculated using fewer days than the monthly approach. Differences in the onset and ending dates of periods for the daily and monthly approaches were greater for precipitation and SPEI data than for temperature data.
Keywords: tree rings, dendroclimatology, tree-ring network, daily climate data, climate-growth relationships, dendroTools
Published in DiRROS: 21.08.2019; Views: 2281; Downloads: 1050
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805.
806.
Public preferences for the management of different invasive alien forest taxa
Anže Japelj, Jana Kus Veenvliet, Judita Malovrh, Andrej Verlič, Maarten De Groot, 2019, original scientific article

Abstract: Invasive alien species (IAS) require management to mitigate their impact on ecosystems. The success of management decisions often depends on whether they are socially acceptable and to what extent people are willing to be actively involved in an early warning and rapid response system (EWRR). We administered a nation-wide public poll to assess people%s knowledge on plant, insect and fungal IAS; their perception of IAS as an environmental problem; and their support for different IAS management measures. Most respondents (76%) knew the term IAS, and more than half (62%) provided a correct definition. Species with more media attention and those that are easily visible are more frequently identified correctly. Almost all respondents (97%) support an EWRR system; however, there is heterogeneity in terms of the types of actions people approve of. Non-lethal measures garner more support than lethal ones. Gender and previous knowledge also affect the level of agreement. The willingness-to-pay question largely confirmed this, as people were divided into four classes according to their preferences for either biological, mechanical or chemical measures to control IAS; completeness and location of removal; and having an EWRR established. Mechanical removal is the most preferred treatment in two of the four classes, and complete removal is preferred over partial removal in one of the four classes. Having an EWRR is consistently supported in all classes, and removal in urban areas is preferred over removal in forestland in only one class.
Keywords: Early warning and rapid response system, public attitudes, management measures, alien insects, alien plants, alien fungi
Published in DiRROS: 12.07.2019; Views: 2619; Downloads: 1435
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807.
Patterns of tree microhabitats across a gradient of managed to old-growth conditions : a case study from beech dominated forests of South-Eastern Slovenia
Kristina Sever, Thomas Andrew Nagel, 2019, original scientific article

Abstract: An inventory of tree microhabitats was done in two unmanaged forests (Kobile and Ravna gora forest reserves) and one managed beech forest in SE Slovenia. The purpose of this study was to determine the influence of forest management, natural disturbances, and tree characteristics on microhabitat patterns. Forest structure and microhabitats were recorded in systematically placed plots (500 m2 in size) across each area. In total, we inventoried 849 trees on 54 plots and 1833 tree microhabitats. The results showed that forest management had no significant influence on the abundance of microhabitats per tree, but there were differences regarding microhabitat type between managed and unmanaged sites. There were substantially more microhabitats related to standing dead and live habitat trees in unmanaged forest (e.g. woodpecker cavities, insect galleries and bore holes, branch holes, dead branches and fruiting bodies of fungi), whereas in managed forests there were more tree microhabitats related to management (e.g. exposed heartwood, coarse bark, and epiphytic plants). The results also indicate that disturbance, tree diameter, vitality, and species influence the density, diversity, and occurrence of tree microhabitats.
Keywords: forest management, biodiversity, tree microhabitats, beech forests, old-growth, veteran tree, natural disturbance, dead wood
Published in DiRROS: 08.07.2019; Views: 6942; Downloads: 2942
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808.
Pregled metod za določanje številčnosti prostoživečih parkljarjev
Katarina Flajšman, Urša Fležar, Boštjan Pokorny, Klemen Jerina, 2019, original scientific article

Abstract: Poznavanje absolutne in/ali relativne številčnosti prostoživečih parkljarjev je eden pomembnejših vhodnih podatkov, ki nam omogoča njihovo učinkovito trajnostno upravljanje. V večjem delu Slovenije so prostoživeči parkljarji gospodarsko, motivacijsko in ekološko najpomembnejša skupina divjadi. V procesu njihovega upravljanja trenutno ni uveljavljenih standardnih in rutinskih metod, na podlagi katerih bi lahko zanesljivo ocenjevali absolutno in/ali relativno številčnost na vsakoletni ravni. Metod za spremljanje številčnosti populacij prostoživečih parkljarjev je veliko; pri izbiri najustreznejše je treba upoštevati določene kriterije. Najpomembnejši kriteriji za izbiro metode so obravnavana vrsta parkljarjev, značilnosti habitata, velikost območja, gostota populacije, možnost kontrole in nenazadnje tudi stroški. V Sloveniji je bila za ocenjevanje številčnosti srnjadi in jelenjadi že v rabi metoda štetja kupčkov iztrebkov, poleg katere bi bila primerna tudi metoda kilometrskega indeksa. Pri divjem prašiču za najbolj zanesljive metode veljajo uporaba foto pasti, štetje na pogonih in daljinsko vzorčenje s pomočjo termovizije, pri gamsu pa štetje s tal in monitoring iz zraka.
Keywords: parkljarji, gostota populacije, številčnost populacije, metode za ocenjevanje številčnosti, metode za ocenjevanje gostote
Published in DiRROS: 08.07.2019; Views: 6965; Downloads: 9506
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809.
Raba krmišč pri navadnem muflonu (Ovis orientalis musimon) na Gorenjskem
Žiga Marenk, Miha Krofel, 2019, original scientific article

Abstract: Navadni muflon (Ovis orientalis musimon) je danes v Sloveniji najštevilčnejša, vendar zelo slabo raziskana tujerodna vrsta parkljarjev. Tudi drugod po Evropi so raziskave te vrste redke, še zlasti glede rabe krmišč, čeprav je dopolnilno krmljenje pogosta praksa v mnogih državah. V pričujoči raziskavi smo s pomočjo avtomatskih kamer ugotavljali sestavo tropov muflonov, ki so obiskovali pet zimskih krmišč na Gorenjskem. Spremljali smo tudi cirkadiano dinamiko obiskov krmišč ter pojavljanje drugih vrst divjadi pri krmiščih. Povprečna velikost tropov muflonov je znašala 3,5 živali; najpogosteje so krmišča obiskovale samice z mladiči. Zabeležili smo dva viška obiskov krmišč, in sicer okoli sončnega vzhoda in zahoda. Krmišča za muflone je obiskovalo še šest drugih vrst divjadi, med katerimi je bil najdominantnejši navadni jelen (Cervus elaphus). Spremljanje krmišč z uporabo avtomatskih kamer se je izkazalo za učinkovit način spremljanja populacije muflonov in njihove rabe krmišč.
Keywords: muflon, Ovis orientalis musimon, krmljenje, krmišča, socialni sistem, struktura tropov, cirkadiana aktivnost, medvrstne interakcije, foto-pasti, Slovenija
Published in DiRROS: 08.07.2019; Views: 7239; Downloads: 2742
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810.
Reliefne značilnosti tal in objedanje mladja s strani velikih rastlinojedih parkljarjev v jelovo-bukovem gozdu
Dušan Roženbergar, Robert Klevišar, Jurij Diaci, 2019, original scientific article

Abstract: Veliki rastlinojedi parkljarji (VRP) različno vplivajo na razvoj gozdnih ekosistemov. Eden izmed najbolj negativnih vplivov, ki ga imajo na dolgoročni razvoj gozdov, je posledica kroničnega čezmernega objedanja mladja. Namen raziskave je bil s pomočjo analize objedanja v delu dinarskih jelovo-bukovih gozdov ugotoviti, kakšen vpliv na intenzivnost objedanja imajo habitatne značilnosti prostora in relief. Povprečna objedenost mladja je bila 70 %, analiza višinske strukture mladja pa je pokazala, da ni prehajanja gorskega javorja in jelke v zgornje višinske plasti. Potrdili smo vpliv stopnje kritja za VRP in reliefa na stopnjo objedenosti. Največ poškodb smo zabeležili na grebenih in v vrtačah. Glede na rezultate naših analiz v prihodnje v jelovobukovih gozdovih na območju naše raziskave ne bo mogoče zagotoviti primesi jelke in gorskega javorja v zgornjih sestojnih položajih. Če želimo v tem delu Slovenije vzgojiti pestre gozdove, bo poleg gozdno-gojitvenega ukrepanja nujno nadaljevanje intenzivnega gospodarjenja z VRP v smislu zmanjševanja njihovih gostot.
Keywords: objedanje, gojenje gozdov, veliki rastlinojedi parkljarji, relief, pomlajevanje, Abies alba, Fagus sylvatica, Acer pseudoplatanus
Published in DiRROS: 08.07.2019; Views: 7050; Downloads: 2943
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