1. Differences in xylem and phloem structure in living stumps of Norway spruce (Picea abies (L.) Karst.) and silver fir (Abies alba Mill.)Jožica Gričar, Miha Drolc, Peter Prislan, Helena Šircelj, 2024, izvirni znanstveni članek Povzetek: Living stumps reported in many tree species were the first, circumstantial evidence of root grafting. Although stump overgrowth has been extensively studied in various tree species, anatomical observations have mainly focused on the xylem part. Here, we investigated the xylem and phloem structure in living stumps of two conifer species: Norway spruce (Picea abies (L.) Karst.) and silver fir (Abies alba Mill.). The mechanism of wound closure was similar in the two species, however, there were differences in the structure of wound tissues in wood and bark. Immediately after the injury, a callus consisting of parenchymal cells was formed, followed by wound-wood with wide increments. In addition, the wood structure and morphology of tracheids were changed. Tracheids lost their typical elongated and tapering structure; instead, numerous crooked and forked tracheids were present. Traumatic resin canals were present in both species but were more abundant in P. abies, which also had normal resin canals. While the structure of the xylem growth rings eventually normalized in both species, the width of the annual xylem increments was diminished. In both species, the typical structure of annual phloem increment was lost in the non-collapsed phloem and sclereids were very abundant in the collapsed phloem. In A. alba, the collapsed phloem was rich in swollen parenchyma cells containing blue-stained contents, while in P. abies, numerous large traumatic resin canals were conspicuous. The study showed that similar patterns of vascular tissue restoration exist in A. alba and P. abies in response to tree felling. However, there are certain species-specific peculiarities in the wood and phloem anatomical response, which might affect long-term stump functioning and survival. Ključne besede: wood physiology, phloem, xylem, Norway spruce, Picea abies, silver fir, Abies alba Objavljeno v DiRROS: 03.12.2024; Ogledov: 84; Prenosov: 1366 Celotno besedilo (10,92 MB) Gradivo ima več datotek! Več... |
2. Temporal and spatial variability of phloem structure in Picea abies and Fagus sylvatica and its link to climateJožica Gričar, Jernej Jevšenak, Kyriaki Giagli, Klemen Eler, Dimitrios Tsalagkas, Vladimir Gryc, Hanuš Vavrčík, Katarina Čufar, Peter Prislan, 2024, izvirni znanstveni članek Povzetek: Using a unique 8-year data set (2010–2017) of phloem data, we studied the effect of temperature and precipitation on the phloem anatomy (conduit area, widths of ring, early and late phloem) and xylem-ring width in two coexisting temperate tree species, Picea abies and Fagus sylvatica, from three contrasting European temperate forest sites. Histometric analyses were performed on microcores taken from tree stems in autumn. We found high interannual variability and sensitivity of phloem anatomy and xylem-ring widths to precipitation and temperature; however, the responses were species- and site-specific. The contrasting response of xylem and phloem-ring widths of the same tree species to weather conditions was found at the two Slovenian sites generally well supplied with precipitation, while at the driest Czech site, the influence of weather factors on xylem and phloem ring widths was synchronised. Since widths of mean annual xylem and phloem increments were narrowest at the Czech site, this site is suggested to be most restrictive for the radial growth of both species. By influencing the seasonal patterns of xylem and phloem development, water availability appears to be the most important determinant of tissue- and species-specific responses to local weather conditions. Ključne besede: wood anatomy, early phloem, European beech, late phloem, Norway spruce, sieve element area, xylem-ring width Objavljeno v DiRROS: 19.01.2024; Ogledov: 597; Prenosov: 361 Celotno besedilo (5,31 MB) Gradivo ima več datotek! Več... |
3. Ecological factors affecting the recent Picea abies decline in Slovenia : the importance of bedrock type and forest naturalnessJanez Kermavnar, Lado Kutnar, Anže Martin Pintar, 2023, izvirni znanstveni članek Povzetek: Norway spruce (Picea abies [L.] Karst.) has been at the centre of controversy for many decades. Recent evidence of its profound disturbance-induced damage and consequent stock depletions across forest landscapes in Europe has reinforced doubts regarding the sustainability and prospects of this tree species in the future. Like many other European countries, Slovenia has experienced significant Norway spruce mortality and a decrease in growing stock primarily as the result of several disturbance agents (bark beetle outbreaks, an ice storm, windthrows). We investigated a countrywide spruce growing stock decline based on data between 2010 and 2018. Particular focus was placed on identifying the main ecological drivers of this decline, namely geological conditions, climatic parameters, soil attributes, topographic factors and forest stand characteristics. The effects of potential predictors on the relative change (%) in spruce volume (m3 ha-1) during the period 2010-2018 were analysed with Generalized Additive Models. Based on a national dataset including forest compartments (n = 6355) with a spruce growing stock decline > 10%, we found mixed support for ecology-based hypotheses. While spruce decline responded to bedrock type as predicted (i.e., greater relative decline in carbonate compared to silicate compartments), higher forest naturalness (preservation of tree species composition) was not associated with a lower decline. Spruce decline was amplified by higher potential evapotranspiration and soil clay content but showed a strong negative relationship with spruce proportion in the year 2010. General trends along the gradients of other selected predictors (stoniness/rockiness and heat load index) were less pronounced. The results suggest that most of these ecological predictors interact with geology and forest naturalness in affecting Norway spruce decline. Our analysis reveals that bedrock type can play an important role due to its mitigating effects. However, forest naturalness is of secondary significance as intensified large-scale forest disturbances likely override its buffering potential. Ključne besede: Norway Spruce, bark beetle outbreaks, ice storm, soil-geology, relationship, tree species composition, Slovenia Objavljeno v DiRROS: 05.04.2023; Ogledov: 1204; Prenosov: 435 Celotno besedilo (917,30 KB) Gradivo ima več datotek! Več... |
4. Harvesting intensity and tree species affect soil respiration in uneven-aged Dinaric forest standsMatjaž Čater, Eva Dařenová, Primož Simončič, 2021, izvirni znanstveni članek Povzetek: Forest management, especially thinning and harvesting measures, has a significant impact on the forest carbon balance especially in the forests with long-term continuous cover history. We measured soil CO2 efflux (Rs) in three forest complexes of mixed, uneven-aged Dinaric forests with predominating silver fir (Abies alba Mill.), beech (Fagus sylvatica L.), and Norway spruce (Picea abies Karst.). Rs was measured after removal of mature forest stands with 50% and 100% intensity of living stock and compared with Rs on the control plots without any applied silvicultural measures. Rs was measured monthly in three consecutive 2012, 2013 and 2014 growing periods. Soil CO2 efflux increased after harvest of both intensities in all studied forest stands. The biggest increase was measured in beech stands and amounted up to 47 and 69% for 50% and 100% harvest intensities, respectively. The effect of harvest on Rs in spruce and fir stands was similar - up to 26% for 50% harvest intensity and 48% for 100% harvest intensity. Despite the biggest increase after harvest, Rs in beech stands returned the fastest to the level of the uncut forest and this levelling period (LP) took 14-17 months with a little delay of the stands with 100% harvest intensity. The LP for all fir stands, for spruce stands with 50% harvest intensity and for one spruce stand with 100% harvest intensity, was 26-29 months. At two spruce stands with 100% harvest intensity we did not record Rs levelling during our three-year study. This study involved forest stands of three predominating tree species growing under the same conditions, which allowed us to determine the species-specific sensitivity of soil CO2 efflux to the different harvesting intensities. Ključne besede: harvesting intensity, soil CO2 efflux, silviculture, carbon release, silver fir forests, Beech forestrs, Norway spruce forests Objavljeno v DiRROS: 08.10.2020; Ogledov: 1658; Prenosov: 821 Celotno besedilo (1,11 MB) Gradivo ima več datotek! Več... |
5. Red deer (Cervus elaphus) bark stripping on spruce with regard to spatial distribution of supplemental feeding placesKlemen Jerina, Mihec Dajčman, Miha Adamič, 2008, izvirni znanstveni članek Povzetek: Forest damages caused by red deer and some other large herbivore species occasionally feeding on tree bark, are a grave ecological and economic problem in many parts of the world. Winter supplemental feeding is commonly used to mitigate the problem, but its effects are poorly known. This study, carried out at Pohorje (Slovenia) and including over 2,300 trees, used binary logistic regression to analyse the effects of supplemental feeding and many other factors on the probability of bark stripping on spruce. The probability of bark stripping depends on distance from the forest edge, density, age and tree species diversity of stands, slope and aspect of terrain, and red deer density; contrary to expectations, it is not related to distance from feeding places. As much as 35% of spruce trees were damaged. The damage was the highest in younger, denser pure spruce stands, whose favourable protective and microclimatic conditions (thinner snow cover, higher effective temperatures) make them a preferred winter habitat for red deer. They contain,however, little other food but bark. To prevent / diminish bark stripping we propose a stronger thinning of such stands. Supplemental feeding may reduce damage only in exceptional cases, when animals are lured and concentrated in less sensitive areas, but in general we advise against the use of this measure due to its other negative effects. Ključne besede: red deer, Cervus elaphus, bark stripping, Norway spruce, Picea abies, forest damages, supplemental feeding, Slovenia, environmental factors Objavljeno v DiRROS: 12.07.2017; Ogledov: 4784; Prenosov: 2118 Celotno besedilo (597,09 KB) |
6. Use of different growth paramaters of Norway spruce (Picea abies (L.) Karst.) to study tree response to climateTom Levanič, Risto Jalkanen, Jožica Gričar, M. Gagen, Primož Oven, 2006, izvirni znanstveni članek Povzetek: In the paper, potential analysis of various growth parameters of Norway spruceare introduced at the macro and micro levels. Dendroecological measurements give information as to xylem growth ring widths, their density and content of stable isotopes in the xylem growth rings. Needle trace method of the terminal annual shoot allows retrospective view into needle density ofthe terminal annual shoot and consequently reconstruction of the several parameters linked to the needles and air pollution. Using pinning method, it is possible to follow intra-annual dynamics of the radial growth of trees at the cellular level and furthermore investigate the effect of climatic factorson cambial activity. Ključne besede: Norway spruce, multiproxy analysis, dendroecology, pinning, needle trace method Objavljeno v DiRROS: 12.07.2017; Ogledov: 4802; Prenosov: 1919 Celotno besedilo (4,90 MB) |
7. Odziv kambija navadne smreke (Picea abies) na ogrevanje in hlajenje deblaJožica Gričar, Martin Zupančič, Katarina Čufar, Primož Oven, 2004, izvirni znanstveni članek Povzetek: Proučili smo vpliv eksperimentalnega ogrevanja in hlajenja dela debla navadne smreke (Picea abies) na kambijevo aktivnost in celično diferenciacijo. Poskusasta potekala 30 dni; ogrevanje od 29.3.2004 do 3.5.2004, hlajenje pa od14.6.2004 do 20.7.2004. Vzorce floema, kambija in ksilema smo iz dreves odvzeli vsakih 10 dni, pripravili prečne prereze tkiv in preparate opazovali ssvetlobnim mikroskopom. Lokalno ogrevanje je po 10 dneh induciralo delitveno aktivnost kambija na floemsko stran, po 20 dneh pa tudi na ksilemsko. Po 30 dneh je pri ogrevanem vzorcu nastalo do 15 celic ranega lesa. V tem času se jeredna delitvena aktivnost kambija pri kontrolnem drevesu šele začela. Odziv kambija na hlajenje debla je bil manj izrazit. Anatomskih razlik med kontrolnim in hlajenim vzorcem po 10 in 20 dneh ni bilo. Po 30 dneh je pri hlajenem vzorcu začel nastajati kasni les, pri kontrolnem drevesu pa šele prehodni rani-kasni les. S poskusom smo demonstrirali, da je mogoče pri smrekiz umetnim ogrevanjem in hlajenjem debla vplivati na ksilo- in floemogenezo. Ključne besede: navadna smreka, Picea abies, kambij, celična diferenciacija, ksilem, floem, ogrevanje, hlajenje, svetlobna mikroskopija, Norway spruce, cambium, cell differentiation, xylem, phloem, heating, cooling, light microscopy Objavljeno v DiRROS: 12.07.2017; Ogledov: 5079; Prenosov: 2164 Celotno besedilo (1,85 MB) |
8. Biodiversity of types of ectomycorrhizae in a norway spruce stands on PokljukaUrša Vilhar, Igor Smolej, Tadeja Trošt Sedej, Lado Kutnar, Hojka Kraigher, 2004, izvirni znanstveni članek Povzetek: Types of ectomycorrhizae were studied in soil cores from a young regeneration center in an autochthonous Norway spruce stand on Pokljuka (Triglav National Park, 1200 m.a.s.l.). Soil cores of equal volume (274 ml, 0 - 18 cm deep) weretaken from 33 sampling plots. In the samples all the roots were counted and types of ectomycorrhizae briefly characterized. From these data diversity indices (species diversity (d) and Shannon- Weaver index of diversity (H)) were calculated. Interactions among mycorrhizae, light regime and survival of spruce seedlings were studied. Out of about 50,000 root tips approximately 1 %were non-mycorrhizal, 63 % were old unviable mycorrhizae and 36 % were identifiable ectomycorrhizal root tips, forming 27 different types of ectomycorrhizae. Sixteen types of ectomycorrhizae were briefly characterized. The Shannon diversity index for types of ectomycorrhizae was high (3.13) with respect to the above-ground diversity of vegetation (1.7). The direct site factor was shown to be negatively correlated to ~Piceirhiza cornuta. The diffuse site factor was negatively correlated to Cortinarius sp. (obtusus type) and positively correlated to Inocybe sp. The ground vegetation cover waspositively correlated to Piceirhiza gelatinosa and the total vegetation cover to Elaphomyces sp. Ključne besede: ectomycorrhizae, types of ectomycorrhizae, Norway spruce, natural regeneration, Pokljuka Objavljeno v DiRROS: 12.07.2017; Ogledov: 4781; Prenosov: 1997 Celotno besedilo (1,79 MB) |
9. Norway spruce (Picea abies (L.) Karst.) damage in the Zasavje district of Slovenia evaluated by two methodsNatalija Vidergar-Gorjup, Andrej Strniša, Franc Batič, 2000, izvirni znanstveni članek Povzetek: The Zasavje district has been heavily affected by air pollution due to mining,the presence of a coal-fired power plant, and industry. The extent of forest damage differs according to location because of specific climatic and orographic characteristics. Norway spruce damage was estimated by two methods at 10 locations in the Zasavje district using the Slovenian forestry method for the estimation of forest damage (KOVA et al. 1995), and a Czech method forestimation of damage to the branching system and needle loss and discoloration (CUDLIN & CHMELIKOVA 1995). Comparison of the results obtained by the two methods gave similar damage assessments at heavily polluted sites, although the data obtained by the two methods differ due to several environmental parameters. The Czech method did not give as good results as wasexpected. A possible reason might be that spruce trees in the investigated locations are less damaged than those in the Czech Republic, where the method was developed. Ključne besede: air pollution, Norway spruce, Picea abies (L.), tree damage, Zasavje, propadanje gozda, poškodovanost drevja, gozdno drevje, onesnaženost zraka, Zasavje, smreka, Picea abies (L.) Karst. Objavljeno v DiRROS: 12.07.2017; Ogledov: 5136; Prenosov: 2063 Celotno besedilo (876,54 KB) |