scholarly journals Modeliranje višinske in debelinske rasti dominantnih dreves ter ocenjevanje indeksov produkcijske sposobnosti gozdnih rastišč

2021 ◽  
Vol 125 ◽  
pp. 1-12
Author(s):  
Andrej Bončina ◽  
Vasilije Trifković ◽  
Živa Bončina

Modeling the height and diameter growth of trees is an important part of forest management. Growth models provide the basis for determining the thinning regime, target tree dimensions and optimal proportions of developmental phases of forest stands. We developed individual height growth models for dominant Norway spruce (Picea abies (L.) Karst) and European beech (Fagus sylvatica L.) in two forest types (sessile oak-European beech forests and pre-Alpine silver fir-European beech forests). Based on the models, the site productivity index (SPI), defined as the dominant tree height at a diameter of 45 cm, was determined for spruce and beech in both forest types. Based on the diameter increment of the dominant trees, the age of trees in regard to their diameter was calculated, which was the basis for Height-Age modeling. The site productivity index (SPI) of spruce in sessile oak-beech forests and pre-Alpine silver fir-European beech forests is higher than that of beech: 31.3 and 29.7 vs 28.7 and 27.9, respectively. Estimated site indices (SI; dominant tree height at the age of 100 years) in sessile oak- European beech forests and pre-Alpine silver fir-European beech forests were 33.4 and 32.0 for spruce, and 29.0 and 27.0 for beech, respectively. Using the described procedure, it is possible to determine indices of site productivity of spruce and beech (SI and SPI) in the selected forest habitat types. Testing the procedure in other forest types and for other tree species is suggested.

2017 ◽  
Vol 45 (2) ◽  
pp. 639-645
Author(s):  
Diana VASILE ◽  
Any Mary PETRITAN ◽  
Nicu Constantin TUDOSE ◽  
Florin Lucian TOIU ◽  
Virgil SCARLATESCU ◽  
...  

Old-growth forests are often looked at as reference for close to nature silviculture, which aims to manage forests in a natural way. An important component of these forests is the large amount of deadwood they possess; the role of dead wood in the forest ecosystem has been well recognised. A detailed investigation of dead wood characteristics (the amount per stand, species, dead wood type, decay class, size and spatial distribution) was performed in two Romanian old-growth European mixed beech forests: Runcu Grosi Reserve (sessile oak-beech) and Sinca (silver fir-beech). Dead wood pieces were classified as belonging to one of seven dead wood types and one of five decay classes. The total amount of the dead wood was greater in Runcu Grosi (240.8 m3 ha-1) than in Sinca Forest (135.5 m3 ha-1). The majority of the dead wood in Runcu Grosi was composed of sessile oak (91.7%), whereas in Sinca Forest, the main dead wood species was silver fir (67.0%); both species exhibited higher values of probability density than beech, the second most important species. The dead wood exhibited much variation in tree size and in dead wood type, and covered the entire spectrum of decomposition classes. The main spatial pattern of all standing dead trees was random in both forests (over 55%), with a reduced participation of regularity and aggregation. The results of this investigation could be used as key values derived from natural conditions to enhance the biodiversity related to dead wood in managed temperate beech mixed forests.


Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 823
Author(s):  
Anna Zielonka ◽  
Marek Drewnik ◽  
Łukasz Musielok ◽  
Marcin K. Dyderski ◽  
Dariusz Struzik ◽  
...  

Forest ecosystems significantly contribute to the global organic carbon (OC) pool, exhibiting high spatial heterogeneity in this respect. Some of the components of the OC pool in a forest (woody aboveground biomass (wAGB), coarse root biomass (CRB)) can be relatively easily estimated using readily available data from land observation and forest inventories, while some of the components of the OC pool are very difficult to determine (fine root biomass (FRB) and soil organic matter (SOM) stock). The main objectives of our study were to: (1) estimate the SOM stock; (2) estimate FRB; and (3) assess the relationship between both biotic (wAGB, forest age, foliage, stand density) and abiotic factors (climatic conditions, relief, soil properties) and SOM stocks and FRB in temperate forests in the Western Carpathians consisting of European beech, Norway spruce, and silver fir (32 forest inventory plots in total). We uncovered the highest wAGB in beech forests and highest SOM stocks under beech forest. FRB was the highest under fir forest. We noted a considerable impact of stand density on SOM stocks, particularly in beech and spruce forests. FRB content was mostly impacted by stand density only in beech forests without any discernible effects on other forest characteristics. We discovered significant impacts of relief-dependent factors and SOM stocks at all the studied sites. Our biomass and carbon models informed by more detailed environmental data led to reduce the uncertainty in over- and underestimation in Cambisols under beech, spruce, and fir forests for mountain temperate forest carbon pools.


2020 ◽  
Author(s):  
Jing-Zhong Lu ◽  
Stefan Scheu

AbstractTree - soil interactions depend on environmental context. Plantations of trees may impact soil microorganisms more strongly under unfavorable environmental conditions, compromising long-term ecosystem services. To contextually understand the effects of tree species composition on soil microorganisms, we quantified structural and functional responses of soil microorganisms to forest types across environmental gradients using substrate-induced respiration and phospholipid fatty acid analyses. Five forest types were studied including pure stands of native European beech (Fagus sylvatica), range expanding Norway spruce (Picea abies), and non-native Douglas-fir (Pseudotsuga menziesii), as well as the two conifer - beech mixtures. We found that microbial functioning strongly depends on environmental conditions, in particular on soil nutrients. At nutrient-poor sites, both pure and mixed coniferous forests, but especially Douglas-fir forests, stressed soil microorganisms compared to beech forests. By contrast, microbial structure and functional indicators in beech forests varied little with site conditions, likely because beech provided high amounts of root-derived resources for microbial growth. The results indicate that, at nutrient-poor sites, long-term effects of planting exotic Douglas-fir on ecosystem functioning need further attention, but planting Douglas-fir at nutrient-rich sites may be of little concern from the perspective of microbial communities. Overall, the results point to the importance of root-derived resources in determining the structure and functioning of soil microbial communities, and document the sensitivity of soil microorganisms to planting tree species that may differ in the provisioning of these resources.


2019 ◽  
Vol 65 (No. 9) ◽  
pp. 331-345 ◽  
Author(s):  
Stanislav Vacek ◽  
Anna Prokůpková ◽  
Zdeněk Vacek ◽  
Daniel Bulušek ◽  
Václav Šimůnek ◽  
...  

The growth, structure and production of mixed beech (Fagus sylvatica L.) forests were analysed  in the Broumovsko Protected Landscape Area, Czech Republic. The objective of the paper was to evaluate stand structure, timber production and dynamics of forests with historically different silvicultural practices in relation to climate conditions, management and game damage. The results indicate that scree forests (coppices and coppices with standards) were stands with high-rich species diversity and structure compared to herb-rich beech forests (high forests) with higher timber production. The Norway spruce (Picea abies [L.] Karst.) was the most sensitive tree species compared to low growth variability in European beech. The climate factors had the highest effect on radial growth from June to August. Natural regeneration showed great density potential (13,880–186,462 recruits·ha<sup>–1</sup>), especially in expansion of maples and European ash (Fraxinus excelsior L.). However, recruits were seriously limiting by damage caused by hoofed game, especially in silver fir (Abies alba Mill.; 53% browsing damage), wych elm (Ulmus glabra Hudson; 51%) and rowan (Sorbus aucuparia L.; 50%).


2014 ◽  
Vol 56 (2) ◽  
pp. 93-104 ◽  
Author(s):  
Rudolf Petráš ◽  
Michal Bošeľa ◽  
Julian Mecko ◽  
Julius Oszlányi ◽  
Ionel Popa

AbstractHeight-diameter models define the general relationship between the tree height and diameter at each growth stage of the forest stand. This paper presents generalized height-diameter models for mixed-species forest stands consisting of Norway spruce (Picea abies Karst.), Silver fir (Abies alba L.), and European beech (Fagus sylvatica L.) from Slovakia. The models were derived using two growth functions from the exponential family: the two-parameter Michailoff and three-parameter Korf functions. Generalized height-diameter functions must normally be constrained to pass through the mean stand diameter and height, and then the final growth model has only one or two parameters to be estimated. These “free” parameters are then expressed over the quadratic mean diameter, height and stand age and the final mathematical form of the model is obtained. The study material included 50 long-term experimental plots located in the Western Carpathians. The plots were established 40-50 years ago and have been repeatedly measured at 5 to 10-year intervals. The dataset includes 7,950 height measurements of spruce, 21,661 of fir and 5,794 of beech. As many as 9 regression models were derived for each species. Although the “goodness of fit” of all models showed that they were generally well suited for the data, the best results were obtained for silver fir. The coefficient of determination ranged from 0.946 to 0.948, RMSE (m) was in the interval 1.94-1.97 and the bias (m) was -0.031 to 0.063. Although slightly imprecise parameter estimation was established for spruce, the estimations of the regression parameters obtained for beech were quite less precise. The coefficient of determination for beech was 0.854-0.860, RMSE (m) 2.67-2.72, and the bias (m) ranged from -0.144 to -0.056. The majority of models using Korf’s formula produced slightly better estimations than Michailoff’s, and it proved immaterial which estimated parameter was fixed and which parameters were free


2018 ◽  
Vol 29 (4) ◽  
pp. 775-787 ◽  
Author(s):  
Marco Mina ◽  
Miren del Río ◽  
Markus O. Huber ◽  
Esther Thürig ◽  
Brigitte Rohner

2016 ◽  
Vol 222 ◽  
pp. 21-31 ◽  
Author(s):  
Michal Bosela ◽  
Igor Štefančík ◽  
Rudolf Petráš ◽  
Stanislav Vacek

2009 ◽  
Vol 160 (5) ◽  
pp. 114-123 ◽  
Author(s):  
Daniel Otto ◽  
Sven Wagner ◽  
Peter Brang

The competitive pressure of naturally regenerated European beech (Fagus sylvatica) saplings on planted pedunculate oak (Quercus robur) was investigated on two 1.8 ha permanent plots near Habsburg and Murten (Switzerland). The plots were established with the aim to test methods of artificial oak regeneration after large-scale windthrow. On both plots, 80 oaks exposed to varying levels of competitive pressure from at most 10 neighbouring beech trees were selected. The height of each oak as well as stem and branch diameters were measured. The competitive pressure was assessed using Schütz's competition index, which is based on relative tree height, crown overlap and distance from competing neighbours. Oak trees growing without or with only slight competition from beech were equally tall, while oaks exposed to moderate to strong competition were smaller. A threshold value for the competition index was found above which oak height decreased strongly. The stem and branch diameters of the oaks started to decrease even if the competition from beech was slight, and decreased much further with more competition. The oak stems started to become more slender even with only slight competition from beech. On the moderately acid beech sites studied here, beech grow taller faster than oak. Thus where beech is competing with oak and the aim is to maintain the oak, competitive pressure on the oak must be reduced at an early stage. The degree of the intervention should, however, take the individual competitive interaction into account, with more intervention if the competition is strong.


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