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IZVORNI ZNANSTVENI ČLANCI – ORIGINAL SCIENTIFIC PAPERSŠumarski list br. 9–10, CXXXV (2011), 437-448 UDK 630* 811 + 48: 249 (001) THE IMPACT OF SILVICULTURALTREATMENTS ON THE STRUCTURE AND RED HEART FORMATION IN BEECH FORESTS UTJECAJ ŠUMSKOUZGOJNIH ZAHVATANASTRUKTURU I FORMIRANJE NEPRAVE SRŽI U BUKOVIM SASTOJINAMA 123 Vladimír RAČKO, Milan SANIGA, Igor ČUNDERLÍK ABSTRACT: The issue of occurrence and size of red heart and the possibilities of its limitation in beech assortments have been researched in worldwide measures for a long time. There are many ecological, phenological, geological factors which more or less influence its formation. The results of a long-term research of different silvicultural treatment confirmed that a big crown of crop trees creates conditions to achieve the target diameter with a low assumption of red heart formation and so rises the quality and price of produced assortments. The different shaping of tree crowns on two investigated compartments had a significant impact on the size of dehydrated zone and subsequently on the frequency of red heart. On the contrary, it did not have a significant impact on the size of red heart, even though red hearts in the both investigated forest stands were small. We also found the different qualitative structure of assortments in both types of investigated compartments. Key words:Fagus sylvaticaL., silvicultural methods, red heart formation, sapwood, dehydrated zone INTRODUCTION – Uvod Red heart (RH) and growth stresses appearing in1969, 1973a, 1973b, Sachsse1991, Schmidtand beech species are the main phenomena which influenceMehringer1989, Sorzand Hietz2008, Torelli the quality of raw wood and so they decrease signifi-1984, Torelli2001,Zycha1948)etc. cantly the financial value of the produced range of raw Findings from the specialized literature point out that wood (Beckeretal. 2005).The topic of RH formation beech RH is subjected by, in fact, two main factors: for- in beech wood species has been the subject of the rese mation of the dehydrated zone (DZ) and by entering of arch for long. There were published many extensive air into this zone (Bosshard1974, Torelli1984, monographs and papers about the structure, formation, Torelli2001,Zycha1948).The absence of one of and development of red heart from the viewpoint of these factors excludes formation of RH. Decreasing of physiology, macroscopic and microscopic changes of vitality the parenchyma cells and breaking down ofthe beech wood (Bosshard1967, 1968, Hösliand water transport system in central part of a stem is a conBosshard1975, Kochetal. 2003,Necesany1958, sequence of decreasingphysiological activity of tree, impacted mainly by ageing. Thiscentral DZisalso 1 Dr.Vladimír Račko,Technical University Zvolen, Faculty of calledasa ripeormaturewood.Water/gaz ratioin the Wood Sciences and Technology, Department of Wood Science, T.G.Masaryka 24, 960 53 Zvolen, Slovak Republic; vesselsof DZ isimportantfor a potentialRH formation racko@vsld.tuzvo.sk (Sachsse1967, Torelli1984).The wound of a trunk 2 Prof. Dr. Milan Saniga, Technical University Zvolen, Faculty of and branches causes that air enters into vessel system of Forestry, Department of Silviculture, T.G.Masaryka 24, 960 53 Zvolen, Slovak Republic; saniga@vsld.tuzvo.sk sapwood (SW) and DZ.Thepenetration rateof airinto 3 Prof. Dr. Igor Čunderlík, Technical University Zvolen, Faculty thezonesSW and DZ has different partialpressuresin ofWood Sciences and Technology, Department of Wood the stemandthe atmosphere(Bosshard1967, Zie- Science,T.G.Masaryka 24, 960 53 Zvolen, Slovak Republic; gler1968).The relatively vital parenchyma cells (adja igor@vsld.tuzvo.sk |
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V. Račko, M. Saniga, I. Čunderlík: THE IMPACT OF SILVICULTURALTREATMENTS ON THE STRUCTURE ...Šumarski list br. 9–10, CXXXV (2011), 437-448 cennt to vessels) react to the embolism by plugging the vessels with tyloses (Zycha1948,Necesany1958, BonsenandKucera1990). Simultaneously,oxidativereactionstranstormthe starchandsolublecarbohydrates inlivingcellsintocolouredphenol substances. Subsequently,colouredphenol compoundsform parenchyma cells aredepositedinthe surroundingxylem (Bauchand Koch2001). RHformationwill terminatewhenthewound isclosed.An important factor in this process is the closure rate of injuries to new growth rings of wound wood (ShigoandLarson1969). The RH formation (frequency and size) froma ma cros copicviewis significantlyinfluenced by theage, diameter at breast height(DBH)of stem (Knokeand Wenderoth2001,KremplandMark1962,Mahler andHöwecke1991,Raczetal. 1961, Walter andKucera1991), the occurrence ofinjury (Büren 1998, Keller1962, Kucera1991, Raunecker 1956, Wernsdörferetal. 2005), crown size and socio logical status of the tree in a forest stand (Cho vanec 1974, Torelli1984, Vasilievič1974), forest soil and geological bedrock (Büren1998,Furst et al. 2006,Schmidtetal. 2005)etc. Recently,a lot of authors have been dealing with an assessment of forest stand quality impact and the impact of tending and regeneration silvicultural methods on the log quality from the viewpoint of the RH frequency (Kadunc2006, Knoke2003, Kudraetal. 2003, Prka2003, Schmidtetal. 2005). The knowledge that generally applies is that incase of formation and frequency of RH, forest stand age, trunk diameter and also in some cases, group of forest types (Mahlerand Höwecke1991)are of a significant importance. Sustaining the whole section of beech trunk in an active profile depends on the capacity of its crown. Considering the value production of beech wood, the lower third of a trunk is preferred.This part represents 90% of its value production. This knowledge is used during intensive crown thinning focusing on bigger target diameter which is then achieved considerably sooner.The intensive crown thinning has an impact on lower frequency of RH occurrence in case when we accept the target diameter of 40–50 cm (Kadunc2006,Kudraetal. 2003). Silvicultural methods which create large growth space for crop trees and so the shorter time to achieve thick dimensions decrease the risk of wood devaluation by RH (Knoke2002,Knokeand Wenderoth2001). As mentionedabove,there are a lot of factors influencing formation and dynamics of development of RH in beech stands.The aim of the paper is to evaluate the impact of two silvicultural techniques which create different conditions for crown development, RH occurrence in homogenous beech forest stands, while other factors (soil type, stand origin, slope aspect, altitude, etc.) are the same. MATERIALSAND METHODS – Materijali i Metode To verify the stated aim sample trees of beech were chosen and processed.To maximize the elimination of other factors the sample trees were chosen from two compartments(CMTs)placed next to each other when each of them was cultivated by a different silvicultural technique. The forest stands belong into the Forestry Enterprise of the Technical University in Zvolen and have been monitored in detail for research purposes for 30–45 years by the employees of the Department of Silviculture at the Forestry Faculty in Zvolen. In the CMT513 were set up two sample permanent plots (SPPs) in 1980. In the CMThas been used quality crown thinning up to 1980. In 1986 and 1991 there was done selective thinning, from 1991 to 2009 there was done selection cutting twice with the volume of 70–80 m/ha. The CMT514b is located next to the CMT513. It has the same parameters group of forest types. The CMT514b presents a set of four SPPs which have been cultivated by crown thinning with a positive selection since 1966 focusing on maximal release of crowns of future crop trees.Before every thinning since that time there were done measurements of selected dendrometric parameters. The relative thinning weight in the thinning interval of 5 years up to 1991 was at 16–18%. In the 1991 the last release increment thinning was done with the volume 24–26% from the forest stand. The altitude of the both CMTs is 510–540 m, the slope aspect is south-west, slope declination 20–25%, and geological parent rock is andesite, soil type Cambisoil, group of forest types: Fagetum pauper. Dendrometric parameters were measured in 1986, 1991, 1997, 2001, and 2009. From two CMTs there were chosen 14 dominant trees (7+7 trees from each CMT), in the age of 93–112years.The crown volume of selected trees (C) was calculated according to (Jurča1968) k 2 k C= (./8) ×b× l(1) wherebis the crownwidth andlis the crown length in meter. The final dendrometric parameters are in the Table 1. |
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V. Račko, M. Saniga, I. Čunderlík: THE IMPACT OF SILVICULTURALTREATMENTS ON THE STRUCTURE ...Šumarski list br. 9–10, CXXXV (2011), 437-448 Figure3Dependency of the tree height on DBH. (a) – CMT513 with a selection structure, (b) – CMT 514b with release increment thinning Slika 3.Ovisnost visine stabla o prsnom promjeru (DBH). (a) – CMT 513 preborna struktura sastojine, (b) – CMT 514b sastojina njegovana visokom proredom Figure 4Dependency of DBH on crown volume. (a) – CMT513 with a selection structure, (b) – CMT 514b with release increment thinning Slika 4.Ovisnost prsnog promjera (DBH) i volumena krošnje na uzorkovanim stablima. (a) - CMT 513 preborna struktura sastojine, (b) – CMT 514b sastojina njegovana visokom proredom ter growth of a tree trunk.This significant finding proves the fact that there are more than 55% of other factors not considered by us which take animpact on the increment of sample trees at DBH in a selection forest. From the point of view of RH occurrence we can see (Fig. 5) that its frequency in trees and logs coming from CMT 513 is considerably lower than the frequency in the CMT514b. On contrary, the influence of various ways of forest stand tending on portion of RH was not proved as sta- Figure 5Frequency of RH in trees and logs for individual CMTs Slika 5.Frekvencija pojavnosti neprave srži (RH) na stablima i trupcima na istraživanim plohama (CMTs) |
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V. Račko, M. Saniga, I. Čunderlík: THE IMPACT OF SILVICULTURALTREATMENTS ON THE STRUCTURE ...Šumarski list br. 9–10, CXXXV (2011), 437-448 Table 1Basic dendrometric characteristics of beech sample trees from the individual SPPs. Tablica 1.Osnovne dendrometrijske značajke reprezentativnih bukovih stabala na trajnim istraživačkim plohama (SPPs) CMT Odjeli Tree Stablo Tree age at DBH Dob stabla na prsnom promjeru DBH Prsni promjer Tree height Visina stabla Crownwidth Širina krošnje Crown length Duljina krošnje Crown volume Volumen krošnje No(year)(cm)(m)(m)(m)(m 3 ) 5137511247.230.99.820.3765.2 51319010849.830.510.7513.9630.5 5138511147.629.310.4512.1518.6 5134110855.633.312.725.31601.7 51312011043.231.69.117.2559.1 51315411145.729.68.514.3405.5 5131910846.428.59.6516.8614.0 514b1510353.934.012,1524.21402.2 514b339838.028.18.818.2553.2 514b219840.328.81019.8777.2 514b3010249.630.610.519.1826.5 514b429639.427.67.112.8253.3 514b379443.029.59.9517.4676.1 514b39342.727.99.3516.8576.5 The data were measured on standing trees before cutting in December 2009 Podaci su uzimani na dubećim stablima prije sječe u prosincu 2009. godine The marked trees were cut, delimbed, bucked into 12–14 m transportation lengths and transported into the forest depot.The sample removal was carried out during bucking of logs according to the scheme on Fig. 1. Samples –Uzorci Logs Trupci Figure 1 Cutting scheme of samples.Variable log length (l1, l2…ln) depended on quality assessment Slika 1.Shema prereza uzoraka. Duljina trupca (l1, l2,...ln) ovisna o procijenjenoj kvaliteti sortimenta In total there was taken 60 samples, out of which 10 samples contained RH + DZ (Fig. 2a) and 50 samples contained only DZ (Fig. 2b).The first sample type was cut from the butt part.The position of the other sample types in a trunk depended on the length of bucked logs and it moved depending on the stated quality of logs within 2–6 m.The position (distance) of every sample and every log from the butt was recorded in meters. The quality of every log according to (STN EN 1316-1 2000)was stated. In half an hour after cutting the sample, a visible dry DZ appeared on the cross section of the sample. The samples were planed from one side and photographed in the JPG format of 24-bit RGB in resolution 1536 x 1024 pix, 300dpi (Fig. 2). Figure 2Cross section of samples (a) – the samples containing both zones (RH and DZ) (b) – the samples containing only DZ Slika 2.Poprečni prerez uzoraka (kolut) (a) – uzorci koji imaju nepravu srž (RH) i piravost (DZ). (b) – uzorci koji imaju samo piravost (DZ) |
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V. Račko, M. Saniga, I. Čunderlík: THE IMPACT OF SILVICULTURALTREATMENTS ON THE STRUCTURE ...Šumarski list br. 9–10, CXXXV (2011), 437-448 The diameter of samples and the width of the DZage (CA) of the trunk were counted.The ratio of DZ to and RH were measured.At the same time, the age ofRH was calculated as ratio of DZ width or RH and diathe tree at DBH and at other heights and the cambialmeter of the trunk as a percentage. RESULTS – Resultati The analysis of theTable 1 and Table 2 points outtrees, obtained from the CMT 513, have,at partially that the DBH structure of tree samples for a differentdifferent age,higher parameters of the DBH and volusilviculture technology is different. In case of the CMTmes of the down third of a trunk. Higher parameters of 513, the DBH are statistically significantly bigger thanquantitative production are the result of a considerably CMT514 b. In CMT513, where trees of an upper levelhigher capacity of assimilation apparatus of a crown. are autonomous in growth during practically whole ob-The analysis of production parameters of beech samservation time, creates assumptions of more intensiveples confirmed, despite their partially different age,that diameter growth. Moreover, it is necessary to add toselection structure of a stand creates significantly good this fact partially the factor of age, whereas observedqualitative assumptions for its quantitative and value samples are approximately 10 years older.The sampleproduction. Table 2T-tests of mean values of tree characteristics for investigated CMTs. Tablica 2.T-test srednjih vrijednosti značajki stabala istraživanih sastojina (CMTs) CMTTree agep-valueDBHp-valueCrown lengthp-value OdjeliDob stabalap vrijednostPrsni promjerp vrijednostDuljina krošnjep vrijednost 513109.7±1.5847.9±3.6317.1±4.15 0.0001***0.0494*0.5846ns 514b97.7±3.5143.8±5.3818.3±3.18 Meanvalues(within the same column mean ± standard deviation (SD)) werecalculatedbased onmeasurementstakenin december 2009. Student´st-test(p-value – level of statistical significance, *p < 0.05, **p < 0.01, ***p < 0.001, ns - not statistically significant, p > 0.05). Srednje vrijednosti (u istoj koloni dane su srednje vrijednosti i standardna devijacija) temeljem mjerenja iz prosinca 2009. godine. Student-ov t-test (p-vrijednost – stupanj statistički značajne razlike – ns nije statistički značeno). 3 Table 3Comparisonof crownvolumes C(m) developmentduring the last23 yearsfor investigated CMTs Tablica 3.Usporedba volumena krošanja Ck k (m3) tijekom 23 godine motrenja na istraživanim plohama CMTs CMT Odjeli 19861991199720012009 C k p-value p vrijednost C k p-value p vrijednost C k p-value p vrijednost C k p-value p vrijednost C k p-value p vrijednost 513 514b 297±133 175± 69 0.0432* 391±156 197± 74 0.0328* 582±234 357±188 0.0087** 624±266 386±145 0.0432* 727±401 723±353 0.9812ns Within the same column (mean ± SD).Student´s t-test(p-value – level of statistical significance, *p < 0.05, **p < 0.01, ***p < 0.001, ns (not statistically significant, p > 0.05). U istoj koloni dane su srednje vrijednosti i standardna devijacija. Student-ov t-test (p-vrijednost – stupanj statistički značajne razlike – ns nije statistički značeno). The average crown volumes forindividualCMTs duringthe past23 yearssignificantly differed, withthe exception ofthe lastgrowthperiod2001–2009.The average crown volumes (in theyears1986–2001)inthe CMT513was about 23–35% higher,thanin theCMT 514b (Table 3). The analysis of correlation strength between tree samples DBH and their height for the whole period of observation (23years) is characterized in the Fig. 3a, 3b. While we are assessing this dependency on CMT513 (Fig. 3a), determination coefficient has a significantly higher value, i. e. in case of growth relations between the diameter and the height of sample trees there is a stronger dependency. The analysis of the relationship between the volume of a crown and the DBH of beech sample trees is interesting. In case of the sample trees from the CMT513 the determination coefficient is significantly lower than for sample trees from the CMT514b, which were cultivated by crown thinning with a positive selection (Fig. 4a, 4b). The mentioned fact confirmed that beech sample trees in the stand cultivated by crown (increment) thinning with the support of crop trees take up to 68% impact on diameter growth of a trunk. On the other hand, crown of beech sample trees which are in the upper layer of selection forest in a autonomous position for a long 2 time have determination coefficient R= 0.453, i. e. the capacity of a crown takes only 45% impact on a diame |
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V. Račko, M. Saniga, I. Čunderlík: THE IMPACT OF SILVICULTURALTREATMENTS ON THE STRUCTURE ...Šumarski list br. 9–10, CXXXV (2011), 437-448 tistically significant, but average values in both obser-sume that considering higher age of the trees from ved CMTs were considerably low (Table 4).CMT513 (109.7 years) the portion of DZ compared to the CMT514b (97.7 years)should be higher.But the From the viewpoint of the size of created zone of results present an opposite trend. (Table 2, Table 4). DZexpressed by its diameter proportionwe can as Table4 T-tests of mean values of DZ portion (%) and RH portion (%) for investigated CMTs Tablica 4.T-test srednjih vrijednosti postotnog udjela piravosti (DZ) i neprave srži (RH) na istraživanim plohama (CMTs) CMT–OdjeliDZ portion –DZ udjelp-value –p vrijednostRH portion –RH udjelp-value –p vrijednost 513 514b 19.4±6.67 23.9±6.49 0.0097** 11.7±3.76 10.3±3.96 0.5806ns Within the same column (mean ± SD).Student´s t-test(p-value – level of statistical significance, *p < 0.05, **p < 0.01, ***p < 0.001, ns (not statistically significant, p > 0.05). U istoj koloni dane su srednje vrijednosti i standardna devijacija. Student-ov t-test (p-vrijednost – stupanj statistički značajne razlike – ns nije statistički značeno). Table 5 Linear regression dependences between DZ or SWwidth (cm) and CA(year) or H in trunk (m) for investigated CMTs. Tablica 5.Linearna regresija ovisnosti širine piravosti, odnosno bijelji (SW) izražena u cm s kambialnom starosti debla (CA) (godina) ili visinom debla (H) za istraživane plohe (CMTs) Dependency –Ovisnost y= a + b.x CMT–Odjeli 513CMT–Odjeli 514b yxabRp-value p vrijednost abRp-value p vrijednost DZ width × CAin trunk DZ širina × CA debla-3.5710.11930.63520.0000***-0.1640.1050.57940.0015** DZ width × H in trunk DZ širina × H debla9.702-0.2790.57360.0005***10.746-0.3320.61080.0007*** SWwidth × CAin trunk SW širina × CA debla9.7770.2210.59420.0002***3.7820.2810.69620.0000*** SWwidth × H in trunk SW širina × H debla35.145-0.6120.63670.0000***31.728-0.6890.56650.0020** H –height in trunk (m) from bottom of tree; a – absolute coefficient, b – regression coefficient, R – correlation coefficient, p-value – level of statistical significance correlation coeficient *p < 0.05, **p < 0.01, ***p < 0.001, ns (not statistically signi ficant, p > 0.05), y – dependent variable,×– independent variable H –visina debla (m); a – apsolutni koeficijent, b – regresijski koeficijent, R – korelacijski koficijent, p-vrijednost – stupanj statistički značajne razlike korelacijskog koeficijenta *p < 0.05, **p < 0.01, ***p < 0.001, ns (nije statistički značajno, p > 0.05), y – zavisna varijabla,×– nezavisna varijabla Table 6 Theverticaldistribution and position oftheRH in Between the width of DZ or SWand CAof a trunk trunk. RHL(m) means RH length at the specified there were found increasing linear regression depenposition in trunk. dences with relatively high correlation coefficients Tablica 6.Vertikalno rasprostiranje neprave srži (RH) u (Table 5).The given fact points out at the relatively deblu stabla. RHL (m) označava visinu do koje se strong influence of age on DZ and SWformation. rasprostire neprava srž (RH) CMT Odjeli Tree Stablo No. RHL Visina do koje se rasprostire neprava srž 5131540 - 5 513856 – 8 and 23 – 24 514b420 – 2 514b30 – 5 514b370 – 7 and 14 – 16 514b151 – 6 514b338 – 11 Table 6 presents distribution and position of RH along the trunk length. It can be clearly seen that RH in most trees in both forest stands occurs in 0-8m distance from the butt.Therefore, the wound, which was a cause of such RH formation, occurred at tree butts and was caused by a wound of butt parts. For the sample trees No. 85 (CMT513) and No. 33 and 37 (CMT514b) the wound was caused by dieback of thick branches of yet standing trees in the lower parts of the crowns. |
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V. Račko, M. Saniga, I. Čunderlík: THE IMPACT OF SILVICULTURALTREATMENTS ON THE STRUCTURE ...Šumarski list br. 9–10, CXXXV (2011), 437-448 443 Different qualitative structure of produced assort- ments coming from the observed forest stands, which contained RH at least at one of the cross sections, can be seen at Fig. 7.The analysis of quality of produced logs confirmed that the higher quality and so the value yield was achieved for the assortments coming from the CMT 513. Significantly higher portion of logs was achieved in quality classes A and B. Compared to this, there was a considerably lower proportion of logs in class C. Figure6Surface wounds in the bottom of the trunk documenting their relation to RH formation. (a) – large injury (tree no.37) lead to expansion of RH up to 7m and decay up to 2 m. (b) – small injuries (tree no.3) did not affect the RH formation.The RH have been formed in height of 0 to 5 m from a larger branch in 2.8 m height. Slika 6.Dokumentacija utjecaja oštećenja žilišta na formiranje neprave srži (RH). (a) – Veliko oštećenje (stablo br. 37) dovelo je do širenja neprave srži (RH) do visine od 7 m i truleži do 2 m. (b) – Malo oštećenje (stablo br. 3) nije imalo utjecaja na nastanak neprave srži (RH). Pri tome je neprava srž na visini od 0 do 5 m bila formirana zbog velike grane na visini od 2,8 m. Figure 7Quality structure of logs from individual CMTs Slika 7.Kvalitativna struktura prereza sa istraživačkih ploha CMTs |
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V. Račko, M. Saniga, I. Čunderlík: THE IMPACT OF SILVICULTURALTREATMENTS ON THE STRUCTURE ...Šumarski list br. 9–10, CXXXV (2011), 437-448 DISCUSSION – Rasprava To start with, it is necessary to remember that the analyzed experiment is based on the exact data on change dynamics of chosen dendrometric parameters of chosen trees of the same ecotype in the same ecological and geological conditions with a different silviculture technique. Homogenization of ecological and geological conditions creates assumptions to find a relatively clear answer to the questions on the influence of different silviculture techniques on the formation of RH for beech. The results confirmed that autonomous and long- term position of beech trees with the crown length longer than a half of a tree height in the upper layer of selection system forest (CMT513) creates conditions to achieve target DBH of 45–50cm (age 100–110 years) with a very low assumption of RH formation. Similar results were achieved in case of crown thinning with a positive selection (CMT514b) and grading its relative thinning strength to24–26% of the taken volume capacity of beechstand in the age of 80 years. To achieve target beech diameter in the age of 100–110 years it is necessary to form its crown according to the above mentioned parameters (Mahlerand Höwecke 1991). By this way the assumptions are created for fully functional activity of the whole section of a trunk.The found parameters correspond with the requirements ofBachmann(1990)for quality forming of the lower third of a trunk which in case of beech presents 60% of its volume and up to 90% of its value production. The achieved results about frequency of RH confirmed that we can help to decrease it by the different way of silviculture treatment. Especially the selection system achieved considerably lower frequency of RH (Fig. 5). In comparison with literature (Mahlerand Höwecke1991)it was considerably lower for the same age of 100-120 years and for the trunk diameter at the DBH 40–49 cm. By Prka (2003), who investigated this issue of beech stands in a regeneration phase in the age of 100 to 110 years, the frequency of RH was approximately 50%. The issue of the changing size of DZ (Table 4) can be understood as an important restricting factor of formation and size of RH.Therefore, a keyfactor ofinjurieson the bottom of tree waspartiallyeliminated by a widezone ofSW.The air entering into the trunk had to overcome a bigger distance between the trunk surface and DZ. Largeinjuries at the bottom occurredonly inafew cases (Fig. 6a), more often small wounds were closedby new formed wound wood even before air enteringinto DZ (Fig. 6b). With changing CA at the different height of a trunk there appears the change of DZ width (Table 5). From the viewpoint of frequency of RH it is apparent that the RH occurred especially in the parts of trunk with higher CAand predominantly in those trees where the DZ was wider. However, we can see from the Table 6 that RH was formed in a few cases in the upper parts of trunk. Wernsdörferet al. (2005)pointed that only some wounds and branch marks on the bark are responsible for the RH formation.Torelli(2001)defines the formation of dry central zone in the middle of a beech trunk as a dynamic process analogical towards the RH formation for other wood species, while a tree adjusts the SW size (active transpiration area) to the crown size. In general, it applies that the age has a dominant influence on ageing and dieback of parenchyma and so on the increase of DZ portion at the expense of SW (Bosshard1965). On the other hand,the influence of crown volume contributes to alteration of portion between SW and DZ width (Torelli1974, 1984).Also, quality of the crown (leaves size, foliage density, ration of shadowy and lighted leaves as well as their proportional or disproportional distribution) have influence on average annual growth ring width (Assmann1961)and transpiration flow of water through the trunk (Bartelink 1997, Deckmyn et al. 2006).This must consequently show at the higher capacity of vital parenchyma which is capable to fulfill a supplying function in a tree. However, the crown development ofhealthytreesshouldbe understoodas a dynamicprocess, whichismainlyinfluenced byageandperformed thinning activities. Different methodsof thinning activitiesperformed on investigatedCMTsinthe last23yearscausedthat the averagecrownvolumes (apart from the last 8 years) differed significantly(Table 3). Itcaused differences in final average DZportions(Table 4). The achieved results entitle us to assume that even in the higher age of trees it is possible to influence positively the ratio between SWand DZ by a suitable silviculture activity leading to an increase of the crown size and quality from the photosynthesis point of view and so contribute to a decrease of frequency of occurrence and size of RH.This will consequently show at the quality and price of the produced assortments. ACKNOWLEDGMENTS – Zahvala This publication is the result of the project imple-Research & Development Operational Programme fun- mentation Centre of Excellence „Adaptive Forest Eco-ded by the ERDF. systems“, ITMS: 26220120006, supported by the |
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V. Račko, M. Saniga, I. Čunderlík: THE IMPACT OF SILVICULTURALTREATMENTS ON THE STRUCTURE ...Šumarski list br. 9–10, CXXXV (2011), 437-448 podacima (Mahler and Höwecke 1991) učestalost pojavnosti neprave srži (RH) bila je značajno niža pri sličnim faktorima starosti od 100-120 godina i prsnom promjeru 40–49 cm. Prema Prki (2003), koji je istraživao problematiku obnove bukovih sastojina, učestalost pojavnosti neprave srži bila je oko 50 %. Dobiveni rezultati zbog toga nas upućuju na pretpostavku da se i u zreloj dobi stabala može pozitivno utjecati na odnos širine bijelji i piravosti (DZ). Primjerenim uzgajivačkim zahvatima koji su usmjereni na povećanje volumena i kvalitete krošnje smanjit će se pojavnost neprave srži (tablica 4 i slika 5). To će imati i značajan utjecaj na povećanje kvalitete i cijene izrađenih sortimenata (slika 7). Ključne riječi:Fagus sylvaticaL., uzgajivački zahvati, neprava srž, bijelj, piravost |
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V. Račko, M. Saniga, I. Čunderlík: THE IMPACT OF SILVICULTURALTREATMENTS ON THE STRUCTURE ...Šumarski list br. 9–10, CXXXV (2011), 437-448 REFERENCES – Literatura Assmann, E.1961:Waldertragskunde. B.L.V., Mün- chen-Bonn-Wien, Germany. Bachmann,P.1990: Produktionssteigerung im wald durch vermehrte berücksichtigung des wertzuwachses. Berichte - EidgenossischeAnstalt fur das Forstliche Versuchswesen. Wald Schnee Landschaft 327: 73. Bartelink, H.1997: Allometric relationships for biomass and leaf area of beech (Fagus sylvatica L.).Annals of Forest Science54: 39–50. Bauch,J., G.Koch2001: Biologische und chemische untersuchungen über holzverfärbungen der rotbuche (Fagus sylvaticaL.) und möglichkeiten vorbeugender massnahmen. Abschlussbericht, Bundesforschungsanstalt für Forst und Holzwirtschaft, Universität Hamburg, Germany. Becker,G., U., U. Seeling, H. Wernsdörfer 2005: Relationship between silvicultural methods and beech wood quality - the German experience. Revue Forestiere Francaise 57: 227–238. Bonsen, K. J.M., L. J.Kucera1990: Vesselocclu si ons in plants – morphological, functional and evolutionary aspects. Iawa Bulletin n.s. 11: 393–399. Bosshard, H. H.1965:Aspects of the aging process in cambium and xylem. Holzforschung 19:65–69. Bosshard, H. H.1967: Über die fakultative farbkernbildung. Holz als Roh und Werkstoff 25: 409–416. Bosshard, H. H.1968: On the formation of facultatively colored heartwood in Beilschmiedia tawa. Wood Science and Technology 2: 1–12. Bosshard, H. H.1974: Holzkunde. Zur biologie, physik und chemie des holzes. BiräuserVerlag 312,Basel, Switzerland. Büren, S. v.1998: Buchenrotkern: Erkennung, verbreitung und wirtschaftliche bedeutung. Schweizerische Zeitschrift fur Forstwesen 149: 955–970. Deckmyn,G., S. P. Evans,T. J. Randle2006: Refined pipe theory for mechanistic modeling of wood development. Tree Physiology 26: 703–717. Furst,C., T. , T. Seifert, F. Makeschin2006: Do site factors affect the wood quality of European beech (Fagus sylvaticaL.)? Results from a pre-study on red heartwood. Forst und Holz 61: 464–468. Hösli, J. P., H. H. Bosshard1975: Überprufung der tränbarkeit von rotkernigen buchenholz mit steinkohleteeröl. Tränkerfolg in abhängigkeit der thylleheufigkeit. Schweizerische Zeitschrift für Forstwese 126: 965–875. Chovanec, D.1974: Possibilities of preventing the formation of beech heartwood. Lesnicky casopis 20:339–354. Jurča, J.1968: Pěstební analytika. SPN, Praha, Czech Republic. Kadunc, A.2006:The quality and value of European beech roundwood (Fagus sylvaticaL.) with special regard to red heartwood formation. GozdarskiVestnik 64: 355–376. Keller, H.1962:Vonrotkern der buche. Schweizerische Zeitschrift fur Forstwesen 113: 498–502. Knoke, T.2002: Value of complete information on red heartwood formation in beech (Fagus sylvaticaL.). Silva Fennica 36: 841–851. Knoke, T.2003: Felling strategies in beech stands (Fagus sylvaticaL.) in the context of risks of red heartwood –a silvicultural/forest economics study. Forstliche Forschungsberichte Munchen 193: 11. Knoke,T., S. S. Wenderoth2001:An approach to predict probability and extent of red coloured heartwood in beech (Fagus sylvaticaL.). Forstwissenschaftliches Centralblatt 120: 154–172. Koch,G., J. Puls, J. Bauch2003: Topochemical characterisation of phenolic extractives in disco- loured beechwood (Fagus sylvatica L.). Holzforschung 57: 339–345. Krempl,H., E. Mark1962: Untersuchungen über den kern der rotbuche.Allgemeine Forst Zeitung 73:186–191. Kucera, L.1991: Die buche und ihr holz eine einfuhrung in die problematik. Schweizerische Zeitschrift für Forstwesen 142: 363–373. Kudra,V.S., R. M. Viter,Y. I.Gaida2003: Effect of false heart on the quality of beech wood. Lesnoe Khozyaistvo 5: 23–24. Mahler,G., B. Höwecke1991: Verkernungserscheinungen bei der buche in Baden-Württenberg in abhängingkeit von alter, standort und durchmesser. Schweizerische Zeitzschrift für Forstwesen 142: 375–390. Necesany, V.1958: Jadro buku: struktura, vznik a vyvoj. SlovakAcademy of Sciences, Bratislava, Slovakia. Necesany,V.1969: Forstliche aspekte bei der enstehung des falschkerns bei der buche. Holz Zentralblatt 95: 563–564. Necesany,V.1973a: Kinetics of secondary changes in living xylem. Pt. I.Time dependent formation |
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V. Račko, M. Saniga, I. Čunderlík: THE IMPACT OF SILVICULTURALTREATMENTS ON THE STRUCTURE ...Šumarski list br. 9–10, CXXXV (2011), 437-448 of tyloses and polyphenolic substances. Holzforschung 27: 73–76. Necesany,V.1973b: Kinetics of secondary changes in living xylem. Pt. II. Some biophysical aspects. Holzforschung 27: 77–79. Prka, M.2003: Occurrence of false heartwood in beech trees and technical beech roundwood coming from thinning and preparatory felling in the area of Bjelovar Bilogora. Sumarski List 127:467–474. Racz,J., H. Schulz, W.Knigge1961: Untersuchungen uber das auftreten des buchenrotkerns. Der Forst undHölzwirt 16: 413–417. Raunecker, H.1956: Der buchenrotkern nur eine altersercheinung. Allgemeine Forst und Jagdzeitung 127: 16–31. Sachsse, H.1967: Uber das wasser/gas - verhaltnis im holzporenraum lebender bäume im hinblick auf die kernbildung. Holz als Roh undWerkstoff 25:291–303. Sachsse, H.1991: Kerntypen der rotbuche. Forstarchiv 63: 238–242. Shigo, A.L., E. H.Larson1969:APhoto guide of the pattern discolouration and decay in living northern hardwoods trees. USDARP-NE-127. Schmidt,M., K. vonGadow, H.Hofle2005: Occurrence and extent of facultative heart-wood formation in beech located on limestone and claystone sites in southern Lower Saxony.Allgemeine Forst Und Jagdzeitung 176: 200–212. Schmidt,O., H. Mehringer1989: Bacteria in beechwood from forest decline areas and their significance for wood discolouration. European Journal ofWood and Wood Products 47: 285–290. Sorz,J., P. Hietz 2008: Is oxygen involved in beech (Fagus sylvaticaL.) red heartwood formation? Trees –Structure and Function 22: 175–185. STN EN 1316-1 2000: Hardwood round timber. Qualitative classification. Part 1: Oak and beech. Slovak office of standarts, metrology and testing, Bratislava, Slovakia. Torelli, N.1984:The ecology of discolored wood as illustrated by beech (Fagus sylvaticaL.). IAWA Bulletin 5: 121–127. Torelli, N.2001: Response of trees to deep and superficial wounds as illustrated by beech (Fagus sylvaticaL.) with particular emphasis on aetiology and ecology of wound initiated discoloured wood (“red heart”).A review. Gozdarski Vestnik 59:85–94. Vasilievič, J.1974: Beech heartwood formation in the region ofZrinjska Gora Mountain (Croatia). Šumarski list 98: 475–520. Walter,M., M., L.Kucera1991:Vorkom und bedeutung verschiedener kernformen bei der buche (Fagus silvaticaL.). Schweizerische Zeitschrift für Forstwesen 142: 391–406. Wernsdörfer,H., T.Constant,F.Mothe, M.A. Badia, G.Nepveu, U.Seeling2005: Detailed analysis of the geometric relationship between external traits and the shape of red heartwood in beech trees (Fagus sylvaticaL.). Trees-Structure and Function 19: 482–491. Ziegler, H.1968: Biological aspects of heartwood formation. Holz als Roh und Werkstoff 26: 61–68. Zycha, H.1948:Über die kernbildung und verwandte vorgänge im holz der rotbuche. ForswissenschaftlichesZentrablatt 67: 80–109. SAŽETAK: Neprava srž (crveno srce) i poremećaji u rastu debla bukovih stabala glavni su fenomeni koji značajno utječu na kvalitetu sirovog drva, a time značajno smanjuju financijsku vrijednost izrađenih sortimenata (Bec ker et al 2005). U posljednje vrijeme velik broj autora istražuje utjecaj uzgajivačkih metoda (njege i obnove sastojina) na kvalitetu drvnih sortimenata s gledišta pojavnosti neprave srži. (Knoke 2003, Kudra et al. 2003, Prka 2003, Schmidt et al. 2005, Kadunc 2006). Ranija istraživanja pokazala su da dob sastojine, promjer debla i sastojinski oblik (Mahler a Höwecke 1991) imaju značajan utjecaj na veličinu i učestalost pojavnosti neprave srži. Održavanje aktivnog parenhima u stanju visoke vlažnosti na presjeku bukovog debla ovisno je o volumenu krošnje stabla. Intenzivne visoke prorede utječu na manju |
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V. Račko, M. Saniga, I. Čunderlík: THE IMPACT OF SILVICULTURALTREATMENTS ON THE STRUCTURE ...Šumarski list br. 9–10, CXXXV (2011), 437-448 učestalost pojavnosti neprave srži, ako promatramo ciljani prsni promjer od 40 do 50 cm (Kudra et al. 2003, Kadunc 2006). Intenzivne visoke prorede utječu na ranije dostizanje ciljanog promjera debla. Postoji mnogo čimbenika koji utječu na nastanak i dinamiku širenja neprave srži u bukovim sastojinama. Zbog toga je cilj ovoga rada procijeniti utjecaj različitih šumskouzgojnih zahvata koji utječu na razvoj krošanja stabala, te tako i na pojavnost i raširenost neprave srži uz homogenost sljedećih čimbenika (vrsta sastojine, tip tla, dob, nagib terena, nadmorska visina i sl.). Kako bi se otklonio utjecaj navedenih čimbenika, odabrane su dvije sastojine koje se nalaze u neposrednoj blizini, dok su uzgojni zahvati u njima bili različiti. U sastojini na istraživačkoj plohi (CMT 513) 1980. godine postavljene su dvije trajne plohe (SPPs). Do 1980. godine bila je njegovana visokom proredom. Godine 1986. i 1991. u sastojini je izvršena selektivna proreda, a od 1991. do 2009. god. dva puta je izvršena preborna sječa u iznosu od 70–80 m3ha-1. Druga sastojina 514 b ima četiri trajne plohe (SPPs) koje su osnovane 1966. godine visokom proredom usmjerenom na maksimalno oslobađanje prostora krošanja odabranih stabala. Intenzitet proreda za razdoblje od 5 godina do 1991. godine bio je na razini 16–18 %. U toj je godini izvršena posljednja proreda s intenzitetom 24–26 % drvne zalihe. Dendrometrijske značajke stabala mjerene su 1986, 1991,1997, 2001. i 2009. godine. Iz obje je sastojine odabrano po 14 stabala starosti u rasponu od 93 do 111 godina (tablice 1 i 2). Nakon rušenja i rezanja kolutova (sekcioniranja debla) na čelima je izmjerena širina neprave srži (RH) i piravosti (DZ). Iz tablice 3 vidljivo je da se srednje vrijednosti volumena krošanja na istraživanim plohama značajno razlikuju s obzirom na različite metode prorede koje su provedene u protekle 23 godine. Iznimka je posljednje desetljeću 2001–2009. Srednja vrijednost volumena krošnje (razdoblje 1986–2001) za plohu CMT 513 23–35 % je veća nego na plohi CMT 514 b. Daljnje produkcijske značajke istraživanih sastojina vide se iz korelacijskih odnosa između visine stabla i prsnog promjera (slika 3) i između prsnog promjera i volumena krošnje (slika 4). S obzirom na veće srednje vrijednosti volumena krošanja tijekom razvoja, istraživačka ploha CMT 513 (tablica 3) imala je značajno niži stupanj pojavnosti neprave srži (RH) od pojavnosti na plohi 514b (slika 5). Isti faktor (tablica 3) nije značajno utjecao na udjel neprave srži (RH) (tablica 4). Iz tablice 4 također se može vidjeti da je razvoj krošnje utjecao na srednje vrijednosti udjela piravosti (DZ) (tablica 3). Niže vrijednosti veličine piravosti na istraživačkoj plohi CMT 513 prema plohi CMT 514 b (tablica 4) posljedica su prevencije oštećivanja debla, što je dovelo i do smanjenja pojavnosti neprave srži (RH). Starenjem kambija širina piravosti i bijelji na stablima na obje se istraživačke plohe linearno povećavala (tablica 5). Suprotno tomu, rastom debla (H) oba su se faktora smanjivali (tablica 5). Statistički značajne korelacijske zavisnosti također ukazuju na jak utjecaj navedenih faktora. Analizom kvalitete izrađenih sortimenata (slika 7) potvrđena je viša kvaliteta sortimenata s istraživačke plohe CMT 513 u klasama A i B (STN EN1316-1). Suprotno tomu, udjel klase C bio je značajno niži nego li u sastojini 514 b. Rezultati istraživanja potvrdili su da stablimično i dugotrajno uzgajanje bukve s krošnjom većom od polovice visine stabla u gornjoj etaži stvara preduvjete za postizanje željenog prsnog promjera od 45 do 50 cm (starost 100 do 110 godina) s vrlo malom pojavnosti neprave srži (RH). Stoga je uzgojne zahvate potrebno usmjeriti na formiranje kvalitetne donje trećine debla, koja prema Bachmanna (1990) predstavlja tek 60 % njegovog volumena, ali 90 % vrijednosti produkcije. Istraživana sastojina CMT 513 imala je značajno nižu učestalost pojavnosti neprave srži (RH) (slika 5). U usporedbi s literaturnim |