scholarly journals Determining Harvester Productivity Curves of Thinning Operations in Birch Stands of Central Europe

2021 ◽  
Vol 43 (1) ◽  
Author(s):  
Martyna Rosińska ◽  
Mariusz Bembenek ◽  
Rodolfo Picchio ◽  
Zbigniew Karazzewski ◽  
Andreja Đuka ◽  
...  
Keyword(s):  
Pinus Sylvestris ◽  
Central Europe ◽  
Tree Species ◽  
Betula Pendula ◽  
North West ◽  
Breast Height ◽  
Thinning Operation ◽  
Mean Diameter ◽  
Thinning Operations ◽  
The Mean

Silver birch (Betula pendula Roth) is a popular tree species forming stands in nearly the whole of Europe. In Poland, birch is one of the most representative broadleaved species growing on rather poor soils, very often as a mix species with Scots pine (Pinus sylvestris L.). In Central Europe, birch forms trunk often with sweeps, and at the older age with thick branches. Due to that, a harvester thinning operation in birch stands can be challengeable when trying to process logs from the top part of trees, which can finally impact on productivity. The objective of this research was to determine harvester productivity for birch with particular attention to production of logs from the top part of a tree. The research was carried out in stands of North and North-West Poland. All together 21 tests were completed in 16 stands, in which 9 harvesters were used (8 different models). The mean diameter of harvested trees was 23.7 cm with the mean height of 21.7 m. Obtained productivity without delays was on average 21.98 m3 h-1 and varied from as low as 5.14 to maximum 44.66 m3 h-1, and depended mainly on harvested tree size. It was also confirmed that top diameter of the last log depended on diameter at breast height (DBH). The model developed based on that relationship can be used for prediction of biomass volume from birch stands when harvesters are used for thinning.

scholarly journals Modelling Bark Thickness of Norway Spruce (Picea abies Karst)

2019 ◽  
Vol 10 (2) ◽  
pp. 125-135
Author(s):  
Jusuf Musić ◽  
Velid Halilović ◽  
Jelena Knežević ◽  
Admir Avdagić ◽  
Aida Ibrahimspahić ◽  
...  
Keyword(s):  
Norway Spruce ◽  
Bosnia And Herzegovina ◽  
Timber Harvesting ◽  
Bark Thickness ◽  
Optimal Model ◽  
Breast Height ◽  
Starting Point ◽  
Mean Diameter ◽  
The Mean ◽  
Actual Method

Background and Purpose: Bark thickness and its share in the volume of roundwood are the most important characteristics of the bark, particularly in the process of timber harvesting, and during scaling of processed logs. Therefore it is very important to have at disposal relatively accurate data regarding these characteristics of bark for particular tree species. The main goal of this paper is to investigate the thickness of the bark and its share in the volume of roundwood of Norway spruce. Materials and Methods: The research was carried out in the area of the Canton 10 of the Federation of Bosnia and Herzegovina and it encompassed 393 trees of Norway spruce from 10 cm to 115 cm of thickness at breast height. Measuring of the mean diameter and double thickness of bark was conducted by section method. In total, 4,647 diameters and bark thicknesses were measured in different relative lengths of stems or in average 10.6 measurements per one stem. Results: As an optimal model for the evaluation of double thickness of the bark of Norway spruce depending on mean diameter of roundwood the function with designated determination coefficient of 0.7142 was selected. The obtained results have confirmed the previously defined relations of investigate characteristics, which are as following: a) with the increase of mean diameter of roundwood (section) double bark thickness is increased from 9.26 mm (thickness class 12.5 cm) to 31.65 mm (thickness class 92.5 cm); b) with the increase of mean diameter of roundwood the share of bark in its volume decreased from 14.26% (thickness class 12.5 cm) to 6.73% (thickness class 92.5 cm). Conclusions: By the actual method of estimating bark thickness or the share of bark in the volume of roundwood of Norway spruce in the forestry of the Federation of Bosnia and Herzegovina a significant error was created which increases with the increase of mean diameter. The obtained results point to the necessity of investigation of these bark characteristics in Bosnia and Herzegovina and represent an inevitable starting point for making adequate tables of bark thickness and its percentage share in the volume of roundwood of Norway spruce.

Effects of shading and humus fertility on growth, competition, and ectomycorrhizal colonization of boreal forest tree seedlings

2004 ◽  
Vol 34 (12) ◽  
pp. 2573-2586 ◽  
Author(s):  
Helena Dehlin ◽  
Marie-Charlotte Nilsson ◽  
David A Wardle ◽  
Anna Shevtsova
Keyword(s):  
Picea Abies ◽  
Pinus Sylvestris ◽  
Boreal Forest ◽  
Interspecific Competition ◽  
Tree Species ◽  
Betula Pendula ◽  
Low Fertility ◽  
Tree Seedlings ◽  
High Fertility ◽  
Ectomycorrhizal Colonization

We performed a pot experiment to study the effects of varying levels of vegetation shade and humus fertility, simulating natural conditions of the boreal forest, on growth, interspecific competition, and ectomycorrhizal colonization of seedlings of three coexisting tree species: Pinus sylvestris L., Picea abies (L.) Karst., and Betula pendula Roth. In contrast to late-successional Picea abies, early-successional species Pinus sylvestris and particularly B. pendula responded to shade with an increase in stem height and with some changes in biomass, especially in the high-fertility humus. Humus fertility had greater effects on biomass of seedlings than did shade treatments. Interspecific competition among pairwise combinations of the three species was greatest in the high-fertility humus, but was not affected by shade. Betula pendula was the strongest competitor among species; it was not affected by the presence of coexisting species and strongly suppressed coniferous seedlings, especially in the high-fertility humus. Generally, ectomycorrhizal colonization was not affected by shade treatments, but was highest in the low-fertility humus. These results show that effects of light, humus fertility, and presence of neighbours are species specific, and these differences are important for the competitive and recruitment abilities of seedlings of coexisting tree species and ultimately for the species composition of developing forests.

scholarly journals Effect of prior tree marking, thinning method and topping diameter on harvester performance in a first thinning operation – a field experiment

Silva Fennica ◽  
2019 ◽  
Vol 53 (3) ◽  
Author(s):  
Franz Holzleitner ◽  
Magdalena Langmaier ◽  
Eduard Hochbichler ◽  
Bernhardt Obermayer ◽  
Karl Stampfer ◽  
...  
Keyword(s):  
Average Diameter ◽  
Stem Volume ◽  
Major Influence ◽  
Video Technology ◽  
Stem Number ◽  
Breast Height ◽  
Thinning Operation ◽  
Thinning Operations ◽  
And Performance ◽  
Machine Operator

The effect of harvester operator tree selection or prior tree marking in thinning operations on satisfactory results and performance has been widely discussed. In harvester operator tree selection, the machine operator decides on the fly which trees are selected to remain or cut. The objective of the study was to analyze the effect of prior tree marking, thinning method and topping diameter on harvester performance in low-diameter thinning operations. The entire thinning operation was captured using video technology. Overall, 2.36 ha divided into 48 plots with 5202 trees were thinned with an average diameter at breast height (dbh) over bark for all plots of between 12.5 and 14.7 cm. In total, 3122 trees were harvested, resulting in 60% removal of stem number over all plots. The harvester achieved a mean productivity of 7.38 m PMH with 1.48 m PMH SEM, with stem volume having the major influence on harvesting productivity. Prior tree marking, topping and thinning method did not significantly affect productivity. Without prior tree marking by the foresters, harvesting removal was shifted toward lower diameters. Within the unmarked plots, 7.0% of the residual trees were damaged compared with 3.2% in marked plots.30–130–1

The Rate of Forest Tree Growth and a Forest Ordination at Xumeni, Natal

Bothalia ◽  
1971 ◽  
Vol 10 (3) ◽  
pp. 451-460 ◽  
Author(s):  
E. J. Moll ◽  
D. B. Woods
Keyword(s):  
South Africa ◽  
Tree Growth ◽  
Tree Species ◽  
Forest Tree ◽  
Moist Soil ◽  
Breast Height ◽  
Canopy Tree ◽  
Ordination Analysis ◽  
The Mean ◽  
Canopy Tree Species

The rate of increment in circumference at breast height of canopy tree species in the southern temperate, Mist-belt forest at Xumeni, Natal, South Africa, is very slow. The mean for all trees calculated from measurements in 1929 and 1966 is 0.201 ± 0.015 inches per year. Results from an ordination analysis of 39 plots were interpreted in terms of a successional gradient from serai sites on steep ground, characterized by  Kiggelaria africana, Xymalos monospora and  Fagara davyi,  to climax sites on flatter ground with  Podocarpus spp. Two climax types are indicated, with  P. henkelli on moist soil and  P. falcatus on drier soils.

Stable carbon and oxygen isotope variability of modern pollen from nine abundant European tree species.

2020 ◽  
Author(s):  
Carolina Müller ◽  
Manja Hethke ◽  
Frank Riedel ◽  
Gerhard Helle
Keyword(s):  
Pinus Sylvestris ◽  
Oxygen Isotope ◽  
Tree Species ◽  
Betula Pendula ◽  
Isotope Ratios ◽  
Early Summer ◽  
Acer Pseudoplatanus ◽  
Climate Conditions ◽  
Modern Pollen ◽  
Carbon And Oxygen Isotope

<p>A detailed understanding of the carbon and oxygen isotope ratios of modern pollen is crucial for the interpretation of fossil δ<sup>13</sup>C<em><sub>pollen</sub></em> and δ<sup>18</sup>O<sub><em>pollen</em> </sub>values. To broaden our knowledge of pollen-isotope ratios we investigated the isotope ranges of nine abundant tree species from central and northern Europe (vegetation periods 2015 and 2016).</p><p>In general, the isotope values of modern pollen are highly species-specific and yield site-specific patterns. Trees of different locations revealed distinct δ<sup>13</sup>C<em><sub>pollen</sub></em> and δ<sup>18</sup>O<em><sub>pollen</sub></em> patterns for maritime and continental growing conditions and for high and low altitudes. Furthermore, pollen-isotope ratios reflect the time of blossoming. δ<sup>13</sup>C<em><sub>pollen</sub></em> values of broad-leaved species flowering before leaf proliferation (Janurary to March; <em>Alnus glutinosa</em> and <em>Corylus avellana</em>) are on average 2.6‰ lower in comparison to broad-leaved and coniferous trees flowering during late spring and early summer (April to June; <em>Acer pseudoplatanus</em>, <em>Betula pendula</em>, <em>Carpinus betulus</em>, <em>Fagus sylvatica</em>, <em>Picea abies</em>, <em>Pinus sylvestris</em> and <em>Quercus robur</em>). δ<sup>18</sup>O<em><sub>pollen</sub></em> values yielded similar results, which are on average 3.1‰ lower for species flowering early in the year. An intra-annual analysis of Betula pendula and Pinus sylvestris pollen revealed increased δ<sup>18</sup>O<em><sub>pollen</sub></em> values during the last stages of pollen-maturation, whereas δ<sup>13</sup>C<em><sub>pollen </sub></em>values of both species remain consistent during late pollen development. Additionally, pollen-isotope values vary markedly within individual trees. Circumferential and height-dependent variations within single trees can be as high as 3.5‰ for δ<sup>13</sup>C<em><sub>pollen</sub></em> and 2.1‰ for δ<sup>18</sup>O<em><sub>pollen</sub></em>.</p><p>Our results suggest that local environmental conditions are generally reflected in the carbon and oxygen pollen-isotopes, but some species seem to reflect the conditions more closely than others. The data indicate that it may even be feasible to reconstruct intra-annual climate conditions by analysing isotopes of species whose pollen develop during different seasons throughout the year.</p>

Development of blue stain in mechanically harvested Scots pine (Pinus sylvestris) logs during storage

2020 ◽  
Vol 50 (1) ◽  
pp. 42-50
Author(s):  
Grzegorz Szewczyk ◽  
Robert Jankowiak ◽  
Bartosz Mitka ◽  
Piotr Bożek ◽  
Piotr Bilański ◽  
...  
Keyword(s):  
Pinus Sylvestris ◽  
Scots Pine ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Age Class ◽  
Duration Of Storage ◽  
Blue Stain ◽  
Microclimatic Conditions ◽  
The Mean ◽  
The Aesthetic

Blue stain is a type of discoloration that considerably lowers the aesthetic qualities of wood. During harvesting, fungal inoculum finds its way into the wood through places of cutting, delimbing, and damage to the tree stem. The development of peripheral blue stain in the logs of Scots pine (Pinus sylvestris L.) due to damage by a harvester head was investigated, using logs felled and delimbed with a chainsaw as reference. The development of blue stain was related to the age class of the stand, the date of felling, and the microclimatic conditions of the wood storage place. The mean surface area of blue stain in logs produced with the harvester was almost 35 cm2, approximately 30% larger than that of the reference logs. In stands of the fourth age class (diameter at breast height 32 cm), the surface of blue stain was more than two times larger than that of stands of the third age class (diameter at breast height 24 cm). The mean area of blue stain in wood stored after spring felling (19.3 cm2) was about 50% of that after summer felling (38.2 cm2). In particular, the development of blue stain in logs obtained with a harvester was visible between weeks 6 and 9 after spring felling and between weeks 3 and 6 after summer felling. For both felling dates, the range of blue stain depended less on air temperature around the wood stack and depended more on the duration of storage.

scholarly journals Floristic Structure of Fire Experimental Plots of Olokemeji Forest Reserve, Ogun State, Nigeria

2020 ◽  
Vol 24 (11) ◽  
pp. 1861-1865
Author(s):  
DM Taiwo ◽  
OR Olatidoye ◽  
OR Jeminiwa ◽  
TO Oyebola ◽  
C Omonu
Keyword(s):  
Tree Species ◽  
Basal Area ◽  
Relative Importance ◽  
Importance Value ◽  
Forest Reserve ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Ogun State ◽  
Mean Diameter ◽  
Floristic Structure

Total enumeration of tree species was carried out fire experimental plot of Olokemeji forest reserve for relative importance value (RIV) mean heights, mean diameter at breast height and mean basal area. Three investigative plot (Plot A, B and C) were established. Plot A which represents Early Burn is burnt annually during the dry season while Plot B was burnt annually during the rainy season when the trees are still wet and Plot C serves as the protected area. Gmelina arborea had the highest relative importance value (28.31), this is followed by Dalbergia sissoo which had RIV of 10.94. Plot C recorded the highest frequency of trees with the highest tree heights, this is closely followed by Plot A and Plot B being the plot with the lowest mean height. Plot C has the highest mean diameter at breast height (DBH) of trees and it is followed by Plot B and Plot A with very close mean DBH. The highest mean basal area was also recorded in Plot C, the highest total basal area and tree volume was also recorded at Plot C as 32.2 m2 ha-1 and 188.8 m3. The size distribution of tree species depicts that Plot C has been protected just as expected Keywords: Forest, Structure, Flora, Dynamics, Fire

scholarly journals Natural reforestation of Kuzbass dumps

2021 ◽  
Vol 31 ◽  
pp. 00012
Author(s):  
Olga Klimova ◽  
Andrei Kupriyanov
Keyword(s):  
Pinus Sylvestris ◽  
Coal Mining ◽  
Environmental Conditions ◽  
Tree Species ◽  
Betula Pendula ◽  
Steppe Zone ◽  
Populus Tremula ◽  
Forest Steppe ◽  
Forest Stands ◽  
Invasion Species

We study the restoration of coal mining dumps through reforestation in the forest-steppe zone of Kuzbass. 3 main forest-forming species (Betula pendula, Pinus sylvestris and Populus tremula) and 11 accompanying tree species were involved in the formation of forest stands. The main forest-forming species was Betula pendula. The amount of renewal was found to be 10.7, 3.1 and 1.0 thousand pcs/ha in sites with favourable, moderate favourable and unfavourable environmental conditions, respectively. The level of natural reforestation on dumps in the southern forest-steppe zone can be described as weak. The renewal of the Acer negundo invasion species was determined by a continuous drift of seeds on the dumps; however, its seedlings and young undergrowth did not reach a generative age.

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