Application of Generalized Taper Model of Norway Spruce Tree in Forestry Practice

U radu je prikazan jedinstveni model oblika debla smreke, razvijen primjenom modificirane Brinkove funkcije, za područje Bosne i zapadne Srbije. Cilj istraživanja je izvršiti prilagođavanje jedinstvenih modela (Model 1 i Model 2) oblika debla prikazanih u radu Matovića, i dr.(2007) za jednostavnu praktičnu primjenu u šumarstvu. Jedinstveni model dobiven u ovome radu (Model 3) pokazuje nešto manju preciznost procjene promjera duž debla i volumena stabla od jedinstvenih Modela 1 i 2, ali je još uvijek dovoljno precizan, pa se uspješno može rabiti u šumarskoj praksi. U radu je izvršeno i uspoređenje jedinstvenih modela oblika debla s klasičnim dvoulaznim volumnim tablicama. Model 3 ima značajnu praktičnu primjenu i može se koristiti za procjenu volumena cijelog ili dijelova debla, promjera na bilo kojemu dijelu debla i neposredno visina stabla na kojima se nalaze karakteristični (traženi) promjeri.By applying modified Brink’s function, this paper presents the unique generalized taper model of Norway spruce tree, developed for the area of Bosnia and west Serbia. The objective of this research is adapt generalized taper models (Models 1 and 2) for trees presented in the paper Matović, et al. (2007), for practical use in forestry. The significant quality of the modified Brink’s function is the correlation of the characteristics of individual trees and stands and the function parameters, so in this way generalized taper models can be calculated for the use in a definite geographic region. The study of Norway spruce taper is based on the data collected from 86 even-aged stands in the region of Bosnia and west Serbia, which is adjacent to Bosnia. The total number of model trees is 156, and the number of data pairs (diameter-height) is 2028. The original parameters i, p and q of the modified Brink’s function were first calculated for all model trees by the optimisation method - equations (1). By applying the multiple regression method, a link has been established between original values of parameters i, p and q, and characteristics of individual trees (diameter at breast height and tree height), i.e. Model 3 has been obtained. Model 3 is consisted of three functions used for determining the parameters of generalized taper model i, p and q. Unknown parameters of the three functions a1, a2, a3,...,.a15 are determined on the basis of available data, by applying multiple regression – equations (2), (3) and (4). In order to test the estimation of taper volume, on the material used for the development of generalized taper models of spruce trees by applying multiple regression, dual input volume tables were created. For that purpose Näslund and Schumacher-Hall functions were used – equations (6) and (7). This research confirms that Model 3 shows less accuracy in estimating the diameter along the taper and volume than Models 1 and 2, which besides using the diameter at breast height and tree height, also require using the stand quadratic mean diameter. However, such difference, from the aspect of practical use, is not important, so Model 3 that applies only the diameter at breast height and tree height (in fact, reduced to the level of dual input volume tables) can be successfully used in forestry practice. Obtained Model 3 is the superior substitute for conventional dual input volume tables, because besides the total volume it enables the volume estimation for particular parts of the standing tree, and also estimation of the diameter along the taper. Model 3 indirectly enables the calculation of tree heights with some diameters characteristic for forestry practice. Model 3, with all above mentioned practical possibilities, can be very simply used by applying one EXCEL application. Because of the dimensions of trees used for Model 3 design, it can be reliably used in practice for Norway spruce trees with diameters at breast height of 10 to 60 cm and height of 6 to 37 m

Usporedba strukture sastojina gospodarenih i prašumskih bukovih šuma Srbije

This study presents results of the comparison of structural and production characteristics of managed and virgin European beech forests in Serbia. Five managed and three virgin European beech stands were studied. The aim of this research was to determine the impact of the previous forest management on the structural diversity and production characteristics of managed European beech high forests in Serbia. The observed stands are located in the mountainous range of 400 to 1200 meters above sea level in the areas with the most productive beech forests in Serbia. Structural characteristics were compared using the following parameters: Height curves, Diameter distribution, Gini index, Coefficient of variation, Slenderness coefficient and maximum dimensions of standing living and dead trees. Stand density and productive characteristics were studied using the following forest estimation elements: number of trees, basal area, volume, biomass, carbon stock, stand quadratic mean diameter, Lorey’s mean height and volume of dead wood. The greatest differences were found in the dimensions of the largest trees in managed and virgin beech forests (diameters at breast height and heights). Certain differences were found in the shape of Height curves and Diameter distribution and in the values of Slenderness coefficient. However, the Gini index and the Coefficient of variation show that these managed beech forests in Serbia substantially preserve the primeval structural diversity. The differences in the average value of most forest estimation elements of managed beech high forests in Serbia compared to virgin beech forests are statistically significant, which tells us that the previous management had a significant impact on the changes in the production characteristics of these forests in Serbia.U radu se prikazuju rezultati usporedbe strukturnih i proizvodnih karakteristika bukovih sastojina gospodarskog i  prašumskog tipa u Srbiji. Istraživano je pet sastojina gospodarskog  i tri sastojine prašumskog tipa. Cilj ovog istraži­va­nja bio je utvrditi utjecaj prethodnog gospodarenja šumama na strukturnu raznolikost i proizvodne osobine visokih bukovih šuma u Srbiji. Istraživane sastojine nalaze se u planinskom rasponu od 400 do 1200 metara nadmorske visine u područjima gdje se nalaze najproduktivnije bukove šume u Srbiji (slika 1 i tablica 1). Strukturne karakteristike uspore­đe­ne su pomoću sljedećih parametara: visinske krivulje, debljinska struktura, Gini indeks, koeficijent varijacije, koeficijent vitkosti i maksimalne dimenzije dubećih živih i mrtvih stabla. Sastojinsku gustoću i produktivne osobine  proučavane su pomoću sljedećih procijenenih taksacijskih elemenata: broj stabala, temeljnica, volumen, biomasa, zaliha ugljika, srednji promjer po temeljnici, Lorajeva srednja visina i volumen mrtvog drveta. Najveće razlike pronađene su u dimenzijama najvećih stabala u bukovim sasatojinama gospodarskog i prašumskog tipa (tablica 4). Određene razlike pro­na­đene su u obliku visinskih krivulja i debljinskoj strukturi, i vrijednostima koeficijenta vitkosti (slike 2, 3, 4 i 5, i tablica 3).  Međutim, Ginijev indeks i koeficijent varijacije pokazuju da su bukove sastojine gospodarskog tipa u Srbiji u velikoj mjeri sačuvale iskonsku strukturnu raznolikost (tablica 2 i slika 6). Razlike u prosječnim vrijednostima taksacijskih elemenata sastojina gospodarskog tipa visokih bukovih šumama u Srbiji u odnosu na sastojine prašumskog tipa su statistički značajne, što nam govori da je prethodno gospodarenje imalo značajan utjecaj na promjene u proizvodnim karakteristikama ovih šuma u Srbiji (tablica 5)

Quality and Assortment Structure of Beech High Forests in Serbia

The paper presents research results on quality and assortment structure of uneven-agedbeech high forests in Central Serbia. Eleven representative stands of submontane beech forest(Fagenion moesiacae submontanum B. Jov. 1976 ) and montane beech forest (Fagenion moesiacaemontanum B. Jov. 1976) were selected. Their altitude ranges from 450 m to 1350 m. Site class rangesfrom I/II to III/IV, canopy closure from 0.7 to 0.9 and volume from 290 m3/ha to 522 m3/ha. Total areaof the stands is 241.9 ha. Sample plots of 500 m2 were established in a systematic grid of 100 x 100 m.From silvicultural aspect, 16% of the standing volume (384 m3/ha) is class one, 39% is class two and45% is class three. From the aspect of forest utilization 37% of the volume is class one, 34% is classtwo, 19% is class three, and 10% is class four. In the assortment structure of the average stand volume,industrial wood accounts for 42%, cordwood 48% and waste 10%. It has been concluded that beechhigh forests in Serbia have unfavourable quality and assortment structure. This situation should beimproved in future by taking adequate management measures

Relationship Between Some Structural Elements of Macedonian Pine (Pinus peuce Gris.) in Different Elevations in National Park Pelister in North Macedonia

The influence of elevation on the forest development and also on more structural elements is evident. The aim of this paper is to research the impact of elevation on the relationship between diameter at breast height (DBH), tree height (H), crown length (L) and stem volume (V). In the area of the Pelister National Park in North Macedonia, 22 experimental plots (EPs) were established in the even-age Pinus peuce Gris. stands with an average age of 90 years. The EPs were of a circular form and covered an area of 500 m2 each; 6 of them were established at 1150 meter above sea level (m asl), 7 at 1350 m asl and 9 at 1550 m asl. DBH, tree height, and crown length of 481 trees were measured in all EPs. The DBH – H model was prepared in accordance with Prodan, as well as nonlinear (polynomial) regression for the relation between DBH and L and nonlinear (power) regression for the relation between DBH and V. The stem volume was calculated with a formula by Parishko for Pinus peuce Gris. The quadratic mean of DBH, average Loray height, average crown ratio, and the density of the stands were also calculated. The relationship between DBH and H, L, and V was examined with Pearson correlation and root mean square deviation (RMSE). The differences between averages of H, L, and V from the EPs were tested with analysis of variance (ANOVA) with an elevation class (1150, 1350 and 1550 m asl) as single factor. The density of stands was 490, 429 and 409 trees per ha on 1150 m, 1350 m and 1550 m asl, respectively. The average DBH was 39.8 cm, 46.5 cm and 45.5 cm, and Loray height was 23.9 m, 24.1 m and 22.6 m at 1150 m, 1350 m and 1550 m asl, respectively. Crown ratio (CR) pointed out different results on the different elevations, with the average value of 40.5%, 43.7%, and 39.3% at 1150 m, 1350 m, and 1550 m asl, respectively. Differences between average structural elements at different elevations can be confirmed with ANOVA with a significance of p<0.05 and F of 3.4 for H, the significance of p<0.05 and F 3.2 for L data and p<0.05 and F of 9.7 for the value of V. In that way, the regression model for H is higher at a lower elevation, the tree has a longer crown length at lower elevation and also has a bigger volume at lower elevation. From the results, it can be concluded that the elevation has an influence on the relationship between DBH on the one hand and H, L and V as structural elements on the other hand. It can be said that at higher elevation trees have a smaller average height, DBH, and volume and have longer crown length than trees at lower elevation

Application of Generalized Taper Model of Norway Spruce Tree in Forestry Practice

U radu je prikazan jedinstveni model oblika debla smreke, razvijen primjenom modificirane Brinkove funkcije, za područje Bosne i zapadne Srbije. Cilj istraživanja je izvršiti prilagođavanje jedinstvenih modela (Model 1 i Model 2) oblika debla prikazanih u radu Matovića, i dr.(2007) za jednostavnu praktičnu primjenu u šumarstvu. Jedinstveni model dobiven u ovome radu (Model 3) pokazuje nešto manju preciznost procjene promjera duž debla i volumena stabla od jedinstvenih Modela 1 i 2, ali je još uvijek dovoljno precizan, pa se uspješno može rabiti u šumarskoj praksi. U radu je izvršeno i uspoređenje jedinstvenih modela oblika debla s klasičnim dvoulaznim volumnim tablicama. Model 3 ima značajnu praktičnu primjenu i može se koristiti za procjenu volumena cijelog ili dijelova debla, promjera na bilo kojemu dijelu debla i neposredno visina stabla na kojima se nalaze karakteristični (traženi) promjeri.By applying modified Brink’s function, this paper presents the unique generalized taper model of Norway spruce tree, developed for the area of Bosnia and west Serbia. The objective of this research is adapt generalized taper models (Models 1 and 2) for trees presented in the paper Matović, et al. (2007), for practical use in forestry. The significant quality of the modified Brink’s function is the correlation of the characteristics of individual trees and stands and the function parameters, so in this way generalized taper models can be calculated for the use in a definite geographic region. The study of Norway spruce taper is based on the data collected from 86 even-aged stands in the region of Bosnia and west Serbia, which is adjacent to Bosnia. The total number of model trees is 156, and the number of data pairs (diameter-height) is 2028. The original parameters i, p and q of the modified Brink’s function were first calculated for all model trees by the optimisation method - equations (1). By applying the multiple regression method, a link has been established between original values of parameters i, p and q, and characteristics of individual trees (diameter at breast height and tree height), i.e. Model 3 has been obtained. Model 3 is consisted of three functions used for determining the parameters of generalized taper model i, p and q. Unknown parameters of the three functions a1, a2, a3,...,.a15 are determined on the basis of available data, by applying multiple regression – equations (2), (3) and (4). In order to test the estimation of taper volume, on the material used for the development of generalized taper models of spruce trees by applying multiple regression, dual input volume tables were created. For that purpose Näslund and Schumacher-Hall functions were used – equations (6) and (7). This research confirms that Model 3 shows less accuracy in estimating the diameter along the taper and volume than Models 1 and 2, which besides using the diameter at breast height and tree height, also require using the stand quadratic mean diameter. However, such difference, from the aspect of practical use, is not important, so Model 3 that applies only the diameter at breast height and tree height (in fact, reduced to the level of dual input volume tables) can be successfully used in forestry practice. Obtained Model 3 is the superior substitute for conventional dual input volume tables, because besides the total volume it enables the volume estimation for particular parts of the standing tree, and also estimation of the diameter along the taper. Model 3 indirectly enables the calculation of tree heights with some diameters characteristic for forestry practice. Model 3, with all above mentioned practical possibilities, can be very simply used by applying one EXCEL application. Because of the dimensions of trees used for Model 3 design, it can be reliably used in practice for Norway spruce trees with diameters at breast height of 10 to 60 cm and height of 6 to 37 m

Prirast i vitalnost hrasta lužnjaka u Sremu sa aspekta promene vodostaja Save

The decline in vitality and dieback of oak forests is increasingly present Vojvodina. This is old challenge for forestry, which again became actual. The paper used dendrochronological methods with the intention to describe trends in growth of pedunculate oak forests in Srem and trends of the water level of the Sava River and air temperature, which are defined as critical to the vitality of these forests. Predicted were water levels of Sava River in the 21st century with overview of its implications on the oak forests growth. Samples were taken from three stands in Srem (Stara Vratična, Smogva and Blate). Flows of Sava river were taken according to five climate scenarios for the periods 2012-2040 and 2042-2070, and converted into the water levels. A trend of decrease in growth in all three stands in last 30 years was observed, together with decrease in water level and temperature rise. Predicted future water levels of the Sava River were in general lower than those in the period 1951-1981, and higher than in the period 1982-2012. The differences between the various scenarios, as well as the impossibility of adequate simulations of extreme events, leavs space for further considerations.Opadanje vitalnosti i sušenje šuma je sve više prisutno u šumama hrasta lužnjaka u Vojvodini. Stari izazov za šumarstvo koji ponovo postaje aktuelan. U radu su korišćene dendrohronološke metode sa namerom da se prikažu trendovi prirasta hrasta lužnjaka u Sremu i trendovi vodostaja reke Save i temperature koji su definisani kao kritični za vitalnost ovih šuma. Izvršeno je predviđanje vodostaja Save u 21. veku i dat osvrt na njen uticaj na šume lužnjaka. Uzorci su uzeti iz tri sastojine u Sremu (Stara Vratična, Smogva i Blate). Razmatrano je pet klimatskih scenarija budućih protoka reke Save za period 2012-2040 i 2042-2070, koji su preračunati u vodostaje. Uočen je trend smanjenje prirasta u sve tri istraživane sastojine u proteklih 30 godina, kao i trend smanjenja vodostaja i porasta temperature. Projekcije budućih vodostaja reke Save su u većini slučajeva bile niže od onih u periodu 1951-1981, a više od onih u period 1982-2012. Razlike između različitih scenarija, kao i nemogućnost verodostojne simulacije ekstremnih voda, ostavlja prostora za dalja razmatranja

Climate change impact on a mixed lowland oak stand in Serbia

Climatic changes and bad environmental conditions may lead to forests vitality loss and even mortality. This is the reason why increased sanitary felling operations were performed in mixed oak forests in northern Serbia in 2013 in order to solve the severe dieback which affected some Pedunculate oak (Quercus robur L.) and Turkey oak (Quercus cerris L.) stands, after the very dry years 2011 and 2012.Dendrochronological techniques were applied to both these oak species collected in a stand, to examine the impact of temperature, precipitation and ground water level on forest growth and investigate the potential causes of the dieback.Differences in tree-ring patterns between surviving and dead trees were not significant according to t-value (from 5.68 to 14.20) and Gleichläufigkeit coefficient (from 76% to 82%), this meaning no distinctive responses of the two ecologically different oak species. As for radial increment, pedunculate and Turkey oak trees showed a similar response to environmental variables in this mixed stand. The Simple Pearson’s correlation analysis, which was conducted, showed that among three basic environmental variables (the mean monthly air temperature, the monthly sum of precipitation and the mean monthly water level, proxy of ground water level), the water level of Danube river in May and the temperature in April were statistically related to the growth of the four tree groups: (i) pedunculate oak vital, (ii) pedunculate oak dead, (iii) Turkey oak vital and (iv) Turkey oak dead trees, for the period 1961-2010 (p<0.05, n=60). Similar phenomena had already been observed in the Sava River basin for the growth of pure pedunculate oak forests. The long-term decline of the Danube River water level may be related to climate variations and to the changes of water management, river bed, as well as land-use. Together with the increase of temperature, this decline of the water level, and its potential unavailability in the soil, represents a serious challenge for the mixed oak forests silviculture in the Danube basin

Future of the Main Important Forest Tree Species in Serbia from the Climate Change Perspective

Background and Purpose: Climate change is possibly the biggest 21st century challenge for the European forestry. Serbia is also under pressure, since the regions of South Europe and Mediterranean are expected to suffer the most. Main purpose of this study was to predict how distribution of several tree species in Serbia may change in the future. Materials and Methods: Our study integrates climate change scenarios for the region of Serbia together with the current distribution of forest tree species. Evaluation was performed using forest aridity index which takes into account mean temperatures and sums of precipitation of the critical months during the growing season. Distribution data of the nine most abundant tree species in Serbia (European beech, Turkey oak, Sessile oak, Hungarian oak, Pedunculate oak, Norway spruce, Silver fir, Black and Scots pine) were taken from the National Forest Inventory. Results: Significant change of bioclimatic niches is expected for the majority of the studied tree species. The most endangered will be Pedunculate oak due to the extreme change of its habitats, while drought prone species (like pines and Hungarian oak) will be less endangered. Sessile oak, Turkey oak, Silver fir, Norway spruce and European beech will be out of their 20th century bioclimatic niches before the end of 21st century according to A2 scenario. Conclusion: Our results suggest that some of the most important tree species in Serbia (Sessile oak, Turkey oak, Silver fir, Norway spruce and European beech) will be endangered by the end of 21st century. General adaption options and specific measurements for forestry sector have to be made for the region of southeast Europe due to the expected extreme change in climate

Synthesis and characterization of high-entropy A2B2O7 pyrochlore with multiple elements at A and B sites

Single nano high-entropy pyrochlore-type compound (A2B2O7) with 7 different rare-earth cations at site A and 3 different metal cations at site B with equiatomic amounts (7A1/7)2(3B1/3)2O7 is successfully obtained. The powder with nominal composition (La1/7Sm1/7Nd1/7Pr1/7Y1/7Gd1/7Yb1/7)2(Sn1/3Hf1/3Zr1/3)2O7 was fabricated by reacting metal nitrates (site A) and metal chlorides (site B) with glycine during the combustion reaction. The XRD analysis revealed that the powder attained during synthesis is in an amorphous state. To induce crystallization of the obtained pyrochlore structure, the post-calcination process at 600-1500 °C was conducted and studied. Results of this study showed that the monophase pyrochlore (A2B2O7) structure is obtained during the calcination at 900 °C. The high-density ceramic pellet with 97% of theoretical density and free of any additives was obtained through pressureless sintering at 1650 °C for 4 h in the air using the powder calcined at 900 °C

Damage to a tube of output reheater due to gas corrosion

IMEC2022 - 1st International Conference on Innovative Materials in Extreme Conditions, 22-23 March 2022, Belgrade, Serbi