Kakovost in vrednost macesna (Larix decidua Mill.) v Karavankah

Although European larch is a commercially important tree species in the Alps, this study is among the first focusing on the quality and value of larch trees. Data from permanent sample plots of the Slovenia Forest Service (802 plots1851 trees) was used to model the quality and value of standing larch trees. The share of excellent and very good quality timber amounted to 49%, but the share of veneer logs and sawlogs I was only 11.7%. The quality and value of larch trees were positively influenced by the diameter at breast height and stand basal area, and negatively by altitude and harvesting intensity. In addition, timber value was higher in stands in regeneration and uneven-aged stands and in stands with a low share of spruce or high share of deciduous tree species. Trees from higher social layers and undamaged trees also proved to have more valuable timber. The quality of larch trees was lower on extreme beech and pine forest types.Čeprav je evropski macesen v Alpah ekonomsko pomembna drevesna vrsta, je ta študija med prvimi, ki obravnava kakovost in vrednost macesnovih dreves. Za modeliranje kakovosti in vrednost macesnovih dreves smo uporabili podatke s stalnih vzorčnih ploskev Zavoda za gozdove Slovenije (802 ploskev1851 dreves). Delež dreves odlične in zelo dobre kakovosti je znašala 49 %, delež furnirja in žagovcev I pa 11,7 %. Pokazalo se je, da na kakovost in vrednost macesnovih dreves pozitivno vplivata prsni premer drevesa in temeljnica sestoja, negativno pa nadmorska višina in intenzivnost sečenj. Vrednost je večja tudi v sestojih v obnovi in raznomernih sestojih ter pri nižjem deležu smreke oziroma višjem deležu bukve. Prav tako imajo višjo vrednost drevesa, ki pripadajo zgornji plasti in so nepoškodovana. Kakovost macesna je slabša na skrajnejših bukovih in borovih rastiščih

Growth characteristics of common ash (fraxinus excelsior l.) in Slovenia

Prispevek obravnava rastne značilnosti velikega jesena na štirih skupinah gozdnih rastišč v Sloveniji. Analizirali smo višinsko in debelinsko rast 162 velikih jesenov z 20 lokacij. Pokazalo se je, da najhitreje raste v višino veliki jesen na gabrovjih, po 70. letu ga prehiti jesen z jesenovih rastišč. Izrazito najpočasnejše rasti je jesen na gorskih bukovih rastiščih z apnenčasto matično podlago. Na teh rastiščih pokaže jesen zmerno, toda izrednovztrajno debelinsko rast, ki s starostjo ne upada in pri 80-90 letih preseže vse pre-ostale tri rastiščne skupine. Debelinska rast jesenovih, gabrovih in bukovih rastišč silikatne oziroma mešane podlage je do 50. leta strma, potem začne upadati, najpočasneje na jesenovih rastiščih. Tekoči višinski prirastek kulminira najpogosteje do 10. leta, povprečni starostni višinski prirastek pa do 20. leta. Tekoči debelinski prirastek kulminira med 6. in 67. letom, najpogosteje med 11.in 30. letom. Povprečni starostni debelinski prirastek kulminira v širšem razponu kot tekoči, in sicer med 12. in 99. letom, le redko pa pred 30. letom starosti. Razlike v višinskem in debelinskem priraščanju so lahko precejšnje tudi znotraj istih rastiščnih enot.This contribution analyses the growth characteristics of common ash on four groups of sites in Slovenia. The analyses of height and diameter growth on thebasis of 162 ash trees from 20 different locations have been carried out. The results show that the fastest height growth was found in ash growing on hornbeam sites, but in the age class of over 70 growth was fastest in ash trees growing on ash sites. Ash trees on mountainous limy beech sites recordedthe slowest height growth. On the same sites, however, the diameter growth of ash is moderate, but very persistent and does not decline with age. At the age of 80-90 years the diameter growth of ash on limy beech sites exceeds the growth curves of ash from the other site groups. In fact, the diameter growth of ash on ash sites, hornbeam sites and beech sites of mixed or silicated bedrock continues to rise until the age of 50, and after that it starts decreasing, the decrease being slowest on ash sites. The current annualheight increment most often culminates before the tree is 10 years old but the mean annual height increment reaches the peak before the age of 20 years. The current annual diameter increment culminates between the age of 6 and 67 years, mostly between the age of 11 and 30 years. The mean annual diameter growth increment (MAI) culminates over a wider period than the CAI. It reaches the peak between the age of 12 and 99 years, but very rarely beforethe tree is 30 years old. The differences in height and diameter growth could be significant even within the same site units

Growth characteristics of sycamore (Acer pseudoplatanus L.) in Slovenia

Prispevek obravnava rastne značilnosti gorskega javorja na štirih skupinskih gozdnih rastiščih v Sloveniji. Analizirali smo višinsko in debelinsko rast 191gorskih javorjev s 30 lokacij. Na treh izmed njih smo opravljali desetdnevne meritve višinskega priraščanja mladic gorskega javorja. Pokazalo se je, da gorski javor v višino najhitreje raste na javorovjih, sledijo bukovja in nazadnje jelovo bukova rastišča. Kar zadeva debelinsko rast, v mladosti najhitreje rastejo javorovja, kasneje pa jih prehiti gorski javor z bukovih in jelovo bukovih rastišč. Debelinsko priraščanje je v pozitivni povezavi z velikostjo krošnje. Tekoči višinski prirastek najpogosteje kulminira med 12. in 14. letom starosti, debelinski pa med 20. in 40. letom. Povprečni starostni višinski prirastek doseže kulminacijo večinoma med 20. in 25. letom, povprečni debelinski prirastek pa med 30. in 50. letom starosti. Višinsko priraščanje gorskega javorja ima eno in izrazito kulminacijo v rastnisezoni, čas intenzivnega priraščanja pa traja 30-40 dni.In the present contribution, the growth characteristics of sycamore in four site groups in Slovenia are analysed. Analyses of height and diameter growth on the basis of 191 sycamore trees from 30 different locations were carried out. Additionally, the height increments of sycamore\u27s seedling from three locations were measured every ten days during the growing period. The results show that on maple sites the sycamore grows faster in height than the sycamoreon beech and silver fir-beech sites. Concerning the diameter growth, the sycamore on maple sites has a higher rate of growth in the early years, but is later on overtaken by sycamore from beech as well as silver fir-beech sites. The largeness of sycamore\u27s crown influences the tree ring width. The current annual increment of height most often culminates between 12th and 14thyears of age, while diameter CAI culminates between 20th and 40th years ofage. The mean annual increment of height reaches the peak mostly between 20th and 25th years of age, while diameter MAI reaches it mostly between 30th and 50th years of age. The height increment of sycamore has a single distinct culmination in the growing period, with intensive growth of height lasting for30 to 40 days

Rastne značilnosti bukve (Fagus sylvatica L.) na rastišču Isopyro-Fagetum KOŠ. 62

In this paper, growth characteristics of European beech (Fagus sylvatica L.) stands on site of Isopyro-Fagetum KOS. 62 are analysed. The research was carried out in Zasavje, where in mature beech stands five plots measuring 30x30 m were set. All trees above 10 cm were measured and cut for stem analyses. Increment of the last 10 years is statistically significantly influenced by (chronologic) age of trees, shade effect, diameter at breast height, social class and very rarely by crown dimensions. The time of current increment culmination is dependent on age, diameter at breast height, social class and on shade effect. As regards site productivity of the analysed site, a very broad range was ascertained. Variation is almost completely explained by altitude. On three plots sites, productivity increase was confirmed, whereas on one plot the changes were not significant and on one plot site productivity decreased, probably due to the transmitter on Mt Kum.Prispevek obravnava rastne značilnosti bukovih (Fagus sylvatica L.) sestojev na rastišču Isopyro-Fagetum KOS. 62. Raziskavo smo opravili v Zasavju, kjer smo v bukovih debeljakih postavili 5 ploskev velikosti 30x30 m. Vse nadmersko drevje smo izmerili in posekali za debelne analize. Na prirastek drevja v zadnjih 10 letih imajo statistično značilen vpliv (kronološka) starost drevja, učinek zastrtosti, prsni premer, socialni razred in presenetljivo redko dimenzije krosnje. Čas kulminacije tekoèega prirasèanja je odvisen od starosti, prsnega premera, socialnega razreda in učinka zastrtosti. Ugotovili smo izredno širok razpon produkcijske sposobnosti analiziranega rastišča. Variiranje v produkcijski sposobnosti je praktično v celoti odvisno od nadmorske visine. Na treh ploskvah smo potrdili dvig produkcijske sposobnosti rastišča, na eni spremembe niso statistično značilne, na eni izmed ploskev pa se je produkcijska sposobnost rastišča, domnevno zaradi vpliva oddajnika na Kumu, znižala

Structure of highquality beech stands with regard to their volume and value, and their increment in Slovenia

Namen raziskave je bil ugotoviti strukturo lesnih zalog, tekočega volumenskegaprirastka, (denarne) vrednosti lesne zaloge in tekoči vrednostni prirastek po različnih socialnih kolektivih v visokokakovostnih bukovih sestojih. Analizirani so bili sestoji z 18 rastiščnih enot, pri vsaki s po petimi ploskvami velikosti 30 x 30 m. Na vseh 90 ploskvah je bila napravljena debelna analiza vsega drevja nad merskim pragom in ocenjena kakovost debel po četrtinah. Na podlagi debelnih analiz in ocenjene kakovosti smo ugotovili volumen sestojev, tekoči desetletni volumenski prirastek, vrednost sestojev intekoči desetletni vrednostni prirastek. Nad 90 % volumna in še nekaj večji delež vrednosti pripada strehi sestoja. Kolektiv 100 najdebelejših dreves na hektar zavzema okoli polovico volumna oziroma vrednosti sestoja. Delež furnirske kakovosti je izredno nizek (3 %), delež hlodovine za luščenje pa petkrat višji. Sestoji dosegajo najvišje vrednosti na rastiščih montanskih bukovij.The aim of the paper was to establish the structure of growing stocks, current volume increment, (commercial) value of growing stocks and current (commercial) value increment by different social collectives in highquality beech stands. In order to do so, beech stands from 18 site units were analysed, with analyses of five plots measuring 30 x 30 m carried out on each site unit. For all trees above the measurement threshold, the stem analyses were performed. The stem quality was estimated by quarters. On this basis, the volume, current decade volume increment, value and current decade value increment of stands were established. More than 90% of volume and even aslightly higher share of value go to the trees from the stand canopy. The collective of 100 the thickest trees per hectare covers about half of the stands volume or stands value. The percentage of sliced veneer quality is extremely low (3%), while the percentage of peeled veneer quality is five times higher. The highest values are achieved by stands from mountainous beech sites

The Incidence of Rot in Norway Spruce and its Influence on the Value of Trees in Slovenia

Rot is one of the most important defects in timber assortments of Norway spruce (Picea abies). With the aim to investigate this phenomenon, we analyzed 1,334 spruce trees from 65 locations across Slovenia. The study showed that the incidence of rot was higher in even-aged stands compared to uneven-aged stands. Lower-trunk rot (for the purpose of this study, lower-trunk rot is rot that affects the stem up to 5 m above ground) is significantly connected with the diameter of the tree, whereas rot in the upper part of the trunk, i.e. upper-trunk rot, does not show such dependence. Rot is most commonly associated with dolomite bedrock. Its incidence increases with tree age, site productivity, and site altitude. Mechanical stem injury is another contributing factor. On the other hand, slender trees, sun-exposed sites, and uneven-aged stands carry a lower risk for the studied defect. The incidence of rot may decrease the value of usable timber by as much as 19 €/m3, with the decrease being highest in 50 to 70 cm tree diameter

Quality and Timber Value of European Beech (Fagus sylvatica L.) Trees in the Karavanke Region

The paper studies the quality of beech trees in the Karavanke mountain range. The data obtained for this study came from the permanent sample plots (here in after PSPs) of the studied area. The timber assortment structure of mature beech trees in stands was calculated on the basis of the estimated quality of a total of 7,154 beech trees from 2,088 plots and a small sample of harvested trees. The established timber assortment structure and the prices of timber ex forest road were then used to determine the value of beech wood. The study showed that the assortment structure was extremely unfavorable, with the share of trees with sliced and peeled veneer quality lower than 1%, and the share of sawlogs totaling 1.6% of the net volume of analyzed trees. The quality is highest in beech trees measuring 50–55 cm in diameter at breast height. Quality values were higher in rejuvenation stands, and in stands with a comparatively high share of fir or a low share of conifers (spruce). The value drops with altitude and inclination and is higher on slope sites. Undamaged trees from higher social layers are also more valuable. Furthermore, beech timber value is positively affected by high harvesting intensity. In dense stands with a basal area exceeding 60–65 m2/ha, the value begins to decline. In order to improve the quality structure of beech stands, beech would have to be grown in beech-dominated clusters or stands, and thinned at the correct time. Particular attention needs to be paid to minimize the damage to dominant trees during harvesting. Quality assessment carried out within the forest inventory enables to assess the stand quality and value potential of forests at different spatial scale. The research has highlighted several possibilities to use quality data in connection with other parameters to enhance the efficiency of forest management

Rastni dejavniki pri odraslem gorskem javorju (Acer pseudoplatanus L.) na krbonatni matični podlagi

This paper presents the growth potential of sycamore (Acer pseudoplatanus L.) on four types of forest sites located on carbonate bedrock. The research covers sycamore sites (Aceri-Fraxinetum ill.), beech sites (Lamio orvalae-Fagetum), beech sites planted with Norway spruce, and silver fir-beechsites (Omphalodo-Fagetum aceretosum). The analyses for each forest type were carried out on five plots. Our aim was to determine the effect of site factors and stand parameters on sycamore growth. Site productivity (SP) is positively correlated with soil depth, coarse silt percentage in the cambichorizon, the content of phosphorus in leaves and, partly, with potassium. The effect of nitrogen supply on height growth or SP was not confirmed. Furthermore, height growth on sites with a higher rate of nutrient cycling, higher macronutrient supply and higher sand percentage in the cambic horizon is significantly faster. As to the growth of basal area, in addition to positive dependences of crown size, many other correlations with site factors were confirmed.V prispevku je obravnavan rastni potencial gorskega javorja (Acer pseudoplatanus L.) na štirih tipih gozdnih rastišč na karbonatni matični podlagi. V raziskavo so zajeta javorovja (Aceri-Fraxinetum ill.), bukova rastišča (Lamio orvalae-Fagetum), zasmrečena bukova rastišča v isti gozdni združbi in jelovo bukova rastišča (Omphalodo-Fagetum acereretosum). Za vsak rastiščni tip smo napravili analize na petih ploskvah. Namen raziskave je ugotoviti rastiščne faktorje oziroma sestojne parametre, ki vplivajo na rast pri odraslem gorskem javorju. Proizvodna sposobnost je v pozitivni povezavi z globino tal, deležem grobega melja v kambičnem horizontu, s koncentracijo fosforja v listih in deloma tudi s kalijem v listih. Vpliv preskrbe z dušikom na višinsko rast oziroma proizvodno sposobnost ni potrjen. Višinska rast je bila hitrejša na rastiščih z hitrejšim kroženjem snovi, boljšo preskrbljenostjo z makrohranili in višjim deležem peska v kambičnem horizontu.Glede temeljnične rasti smo poleg pozitivne odvisnosti od velikosti krošnje potrdili še številne povezave z rastiščnimi dejavniki

An analysis of horizontal structure in beech stands using data from permanent sample plots

Na vzorcu petih izbranih gozdnogospodarskih enot smo po glavnih sestojnih tipih analizirali horizontalno zgradbo bukovih sestojev. Zgradbo smo prikazali z indeksi diverzitete, podrobneje smo obravnavali razmestitev dreves in diferenciacijo njihovega premera. Ugotavljali smo vpliv nekaterih okoljskih dejavnikov ter intenzivnosti poseka na razmestitev. Za analizo smo uporabili podatkovno zbirko stalnih vzorènih ploskev (SVP) Zavoda za gozdove Slovenije. Razmestitev v sestojih se priblizuje naključni enakomerni razmestitvi, opazne so posamezne tendence dreves k sopasti oziroma sistematični razmestitvi. V sestojih prevladuje povprečna diferenciacija premerov, kar kaze na veèjo enomernost. V mlajših razvojnih fazah je nekoliko močneje nakazana sopasta razmestitev, diferenciacija premerov je manjsa. Na manjšo diferenciacijo premera vplivamo z večjo intenziteto poseka, šopasta razmestitev dreves je močneje nakazana na terenih s strmejsimi nakloni. Različne indekse diverzitete lahko izračunamo s podatki s SVP, ki so primerni predvsem za metodo izbranega drevesa in njegovih štirih najbližjih sosedov. Vzorec horizontalne zgradbe omogoča natanènejsi vpogled v sestojno zgradbo, pomemben je pri ocenjevanju mehanske stabilnosti sestojev, biodiverzitete, sestojne gostote in učinkov gospodarjenja.On the sample of five forest management units, we analysed horizontal structure of beech stands by prevalent stand types. We used several diversity indices to describe horizontal stand structure (spatial distribution of trees and differentiation of their DBH). We checked if spatial distribution is influenced by site parameters and cutting intensity. Data was used from measurements on permanent sample plots of the Slovenia Forest Service. The results show mainly average DBH differentiation and random tree positions withsome tendency to clustered and regular arrangement. Trees in younger stages are prone to clustered distribution and their DBH differentiation is smaller. Small DBH differentiation in younger stages is caused by higher intensity of cutting and clustered arrangement is more common on steeper slopes. Several diversity indices can be calculated based on data from PSP, which are suitable mostly for sampling method of reference tree and its four nearest neighbours. A pattern of horizontal stand structure gives a more precise insight in stand structure and is also important when assessing stand stability, biodiversity, stand density and management impact

An analysis of horizontal structure in beech stands using data from permanent sample plots

On the sample of five forest management units, we analysed horizontal structure of beech stands by prevalent stand types. We used several diversity indices to describe horizontal stand structure (spatial distribution of trees and differentiation of their DBH). We checked if spatial distribution is influenced by site parameters and cutting intensity. Data was used from measurements on permanent sample plots of the Slovenia Forest Service. The results show mainly average DBH differentiation and random tree positions withsome tendency to clustered and regular arrangement. Trees in younger stages are prone to clustered distribution and their DBH differentiation is smaller. Small DBH differentiation in younger stages is caused by higher intensity of cutting and clustered arrangement is more common on steeper slopes. Several diversity indices can be calculated based on data from PSP, which are suitable mostly for sampling method of reference tree and its four nearest neighbours. A pattern of horizontal stand structure gives a more precise insight in stand structure and is also important when assessing stand stability, biodiversity, stand density and management impact