Impact of the thinning regime on the mean diameter of the largest stems by diameter at breast height in even-agedPicea abiesstands

2006 ◽  
Vol 21 (1) ◽  
pp. 20-31 ◽  
Author(s):  
Kjell Karlsson
Keyword(s):  
Diameter At Breast Height ◽  
Breast Height ◽  
Mean Diameter ◽  
The Mean

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.

Biogenic Imprint on Hillslopes in the Sudety Mts. — Origin and Consequences of the Tree Uprooting Process

2014 ◽  
Vol 48 (1) ◽  
Author(s):  
Łukasz Pawlik
Keyword(s):  
National Park ◽  
Qualitative Description ◽  
Main Subject ◽  
Diameter At Breast Height ◽  
Geomorphological Mapping ◽  
Breast Height ◽  
The World ◽  
The Mean ◽  
Tree Uprooting ◽  
Root Plate

AbstractThe main subject of this article is the tree uprooting process and its effects on forested hillslopes in the Sudety Mts. The research has been carried out between 2010 and 2012 in the Karkonosze National Park (KNP), Stołowe Mountains National Park (SMNP) and Suche Mts. The methods included: detailed geomorphological mapping and measurements of root plates of recently fallen trees and relict treethrow mounds and pits (called pit-and-mound microtopography), their qualitative description and measurements of diameter at breast height (dbh) of uprooted tree trunks.The mean root plate volume was 0.3-1.4 mIt has been shown that tree uprooting can contribute to the evolution of regolith and soils and it is an important factor of their disturbances. This reflects results from other sites in the World. However, in the Sudety Mts. the significance of tree uprooting has been validated only locally and it is suggested that its importance decreases proportionally to the area under consideration. Here, biogenic transport is limited to treethrow pits on gentle hillslopes but can be much more effective at steeper sites.

Local competition in a naturally established jack pine stand

1989 ◽  
Vol 67 (9) ◽  
pp. 2630-2635 ◽  
Author(s):  
N. C. Kenkel ◽  
J. A. Hoskins ◽  
W. D. Hoskins
Keyword(s):  
Spatial Pattern ◽  
Jack Pine ◽  
Differential Mortality ◽  
Time Interval ◽  
Local Competition ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Dead Trees ◽  
Standing Dead ◽  
The Mean

The spatial pattern of 1375 jack pine individuals (459 live, 257 standing dead, and 659 stumps) in a pure, even-aged, naturally established stand was mapped. Three maps corresponding to different stages of stand development were recognized: live + dead (initial pattern, n = 1375), live (following self-thinning, n = 459), and live + standing dead (survivors plus most recent mortality, n = 716). The Dirichlet-Thiessen tessellations of these maps indicated that the distribution of tile areas (area potentially available) becomes increasingly equitable over time. A significant positive correlation between diameter at breast height of surviving trees and their area potentially available was found for each map; this correlation was highest for the live tessellation. In the live + dead and live + standing dead tessellations, the mean tile area of dead trees was significandy smaller than that of survivors. The spatial pattern of diameter at breast height values of survivors revealed a positive autocorrelation: larger trees tend to have large neighbours and smaller trees have small ones. These results suggest a model of differential mortality in which the smaller individuals in a stand, particularly those surrounded by larger individuals, are most likely to die over a given time interval.

Modeling relative error in stem basal area estimates

1990 ◽  
Vol 20 (5) ◽  
pp. 496-502 ◽  
Author(s):  
T. G. Gregoire ◽  
S. M. Zedaker ◽  
N. S. Nicholas
Keyword(s):  
Basal Area ◽  
Field Measurements ◽  
Mean Square ◽  
Interval Estimates ◽  
Tree Diameter ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
The Mean ◽  
The Difference ◽  
Relative Errors

The computed estimate of basal area was the focus of this investigation into the accuracy of tree diameter measurements. Diameter at breast height was measured on 101 trees, the breast height disc was removed from the stem, and each disc outline was then digitized to determine its actual area. Actual areas were compared with the basal areas computed with the field measurements of diameter by expressing the deviations as a proportion of the actual areas. These relative errors averaged 3.1% when basal area was computed with a taped diameter at breast height, and they averaged −2.5% when the mean of two calipered, perpendicular diameter at breast height measurements were used. Noncircularity accounted for about 2.6% of the bias, on average, in basal areas from taped diameters. Root mean square error of relative basal area errors ranged from 7.3 to 7.9% among these methods. The difference between basal areas computed with a taped diameter at breast height and with calipered diameter at breast height was computed and expressed as a proportion of the actual basal area. On average, a difference of 5% was observed. Interval estimates for these differences are presented.

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.

Nesting Requirements of the Yellow-Tailed Black-Cockatoo, Calyptorhynchus Funereus, in Eucalyptus Regnans Forest, and Implications for Forest Management.

1994 ◽  
Vol 21 (3) ◽  
pp. 267 ◽  
Author(s):  
JL Nelson ◽  
BJ Morris
Keyword(s):  
Forest Management ◽  
Forest Stand ◽  
Agonistic Behaviour ◽  
Wildlife Corridors ◽  
Eucalyptus Regnans ◽  
Diameter At Breast Height ◽  
Crown Diameter ◽  
Breast Height ◽  
Rotation Time ◽  
Mean Diameter

The nesting requirements of the yellow-tailed black-cockatoo (Calyptorhynchus funereus) were studied at 68 sites in Eucalyptus regnans forest in the Strzelecki Ranges, South Gippsland, Victoria. Nest trees were located and their characteristics related to forest stand variables. Eighteen nest hollows were found. Nest trees had a mean diameter at breast height of 2.5 m, a mean estimated age of 221 years, a mean height of 58 m and for live nest trees a mean crown diameter of 22 m. The currently proposed rotation time for silvicultural systems of 80-150 years will reduce the number of hollow-bearing trees suitable for nesting yellow-tailed black-cockatoos. Adequate numbers of trees must be retained in logged areas and wildlife corridors and reserves, and protected to ensure a continual supply for yellow-tailed black-cockatoos and other hollow-dependent species. If agonistic behaviour is operating between female yellow-tailed black-cockatoos, nesting potential may be enhanced if trees retained on coupes are evenly distributed rather than clumped. Silvicultural systems that facilitate the protection of trees retained on coupes would benefit the conservation of the yellow-tailed black-cockatoo.

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 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.

Comparaison de différentes approches, modèles et tailles d'échantillons pour l'établissement de relations hauteur-diamètre locales

1995 ◽  
Vol 25 (8) ◽  
pp. 1303-1312 ◽  
Author(s):  
Jean Bégin ◽  
Frédéric Raulier
Keyword(s):  
Sample Size ◽  
Residual Variance ◽  
Sample Plot ◽  
Sample Sizes ◽  
Total Height ◽  
Breast Height ◽  
Mean Diameter ◽  
The Mean ◽  
The Individual ◽  
Model Approach

This study compares the predictability of 3 approaches, 4 models, and 10 different sample sizes to determine local relationships between total height and diameter at breast height in balsam fir stands less than 50 years old. The results show that a system of height–diameter curves based on the mean diameter and mean height of the sampled trees (approach 3) gives the most precise estimations in comparison with curves resulting from pooling all sampled trees in a single height–diameter model (approach 1) and with those resulting from the application of a height–diameter model for each of the combinations of sample plot–measurement periods (approach 2). Depending on the sample size, the residual variance of the total height or the total volume is reduced 2 to 2.5 times for the individual stems and 2 to 15 times for the mean stem, when using approach 3 instead of approach 1. Approach 3 is more precise than approach 2 for sample sizes that vary between three and five sampled trees per plot. However, this gain in precision becomes negligible when the sample size approaches 10 sampled trees per plot.

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