scholarly journals Wedge prism as a tool for diameter and distance measurement

2008 ◽  
Vol 54 (No. 3) ◽  
pp. 121-124 ◽  
Author(s):  
L. Šálek ◽  
D. Zahradník
Keyword(s):  
Basal Area ◽  
Distance Measurement ◽  
Stem Volume ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Standing Trees ◽  
Wedge Prism ◽  
Non Destructive

The wedge prism, which is generally used for the measurement of basal area in diameter at breast height, is also a tool for the measurement of distance as well as for the measurement of diameters at a certain height of the stem, in the upper stem. Measurements using the wedge prism are based on the same principle as measurements using Bitterlich mirror relascope. This method is appropriate for non-destructive determination of stem volume. Moreover, the wedge prism can be used for the sorting of logs in standing trees when the small end of expectant assortment has to be known. As the wedge prism is a common tool for foresters, its usage seems to be larger than only the measurement of basal area.

scholarly journals The results of an 18–year old beech trees (Fagus sylvatica L.) provenance trial in the Łobez Forest District

2013 ◽  
Vol 74 (3) ◽  
pp. 197-203
Author(s):  
Wojciech Kowalkowski
Keyword(s):  
Block Design ◽  
Basal Area ◽  
Experimental Plot ◽  
Site Location ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Natural Range ◽  
Fagus Sylvatica L ◽  
Forest District

Abstract The experimental area is located in the Węgorzyno Forest Sub-District, Łobez Forest District. 29 Polish provenances of beech from their natural range were growth in a completely randomised block design with four replications. In 2010, after the end of the growing season, measurements were carried out on the experimental plot, including: determination of the survival rate and the diameter at breast height, and height of trees. Moreover, the total basal area and the total volume were calculated. Using ANOVA, statistically significant differences between provenances were apparent for four of the five traits measured; all except diameter at breast height. Provenances characterised by high values for the analysed traits were considered the best adapted to the habitat conditions in the experimental plot, while provenances reaching low values were considered unsuitable for use under the conditions similar to those at the trial site location

scholarly journals Estimation of Genetic Parameters and Wood Yield Selection Index in a Clonal Trial of Korean Pine (Pinus koraiensis) in Northeastern China

2021 ◽  
Vol 13 (8) ◽  
pp. 4167
Author(s):  
David Kombi Kaviriri ◽  
Huan-Zhen Liu ◽  
Xi-Yang Zhao
Keyword(s):  
Selection Index ◽  
Tree Height ◽  
Stem Volume ◽  
Korean Pine ◽  
Branch Number ◽  
Basal Diameter ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Stem Straightness ◽  
Clonal Trial

In order to determine suitable traits for selecting high-wood-yield Korean pine materials, eleven morphological characteristics (tree height, basal diameter, diameter at breast height, diameter at 3 meter height, stem straightness degree, crown breadth, crown height, branch angle, branch number per node, bark thickness, and stem volume) were investigated in a 38-year-old Korean pine clonal trial at Naozhi orchard. A statistical approach combining variance and regression analysis was used to extract appropriate traits for selecting elite clones. Results of variance analysis showed significant difference in variance sources in most of the traits, except for the stem straightness degree, which had a p-value of 0.94. Moderate to high coefficients of variation and clonal repeatability ranged from 10.73% to 35.45% and from 0.06% to 0.78%, respectively. Strong significant correlations on the phenotypic and genotypic levels were observed between the straightness traits and tree volume, but crown breadth was weakly correlated to the volume. Four principal components retaining up to 80% of the total variation were extracted, and stem volume, basal diameter, diameter at breast height, diameter at 3 meter height, tree height, and crown height displayed high correlation to these components (r ranged from 0.76 to 0.98). Based on the Type III sum of squares, tree height, diameter at breast height, and branch number showed significant information to explain the clonal variability based on stem volume. Using the extracted characteristics as the selection index, six clones (PK105, PK59, PK104, PK36, PK28, and K101) displayed the highest Qi values, with a selection rate of 5% corresponding to the genetic gain of 42.96% in stem volume. This study provides beneficial information for the selection of multiple traits for genetically improved genotypes of Korean pine.

Response of Nine-Year-Old Plantation Sweetgum to Nitrogen Fertilization in Mississippi

1992 ◽  
Vol 16 (3) ◽  
pp. 146-150
Author(s):  
L. E. Nelson ◽  
G. L. Switzer
Keyword(s):  
Nitrogen Fertilization ◽  
Basal Area ◽  
Woody Biomass ◽  
Growing Season ◽  
Maximum Growth ◽  
Liquidambar Styraciflua ◽  
Stem Volume ◽  
Breast Height ◽  
Seed Sources ◽  
N Rates

Abstract Nine-year-old planted sweetgum (Liquidambar styraciflua L.) consisting of four half-sib seed sources were refertilized with nitrogen in 1981 at the beginning of the tenth field-growing season. Increases in periodic annual height, diameter at breast height, basal area, stem volume (ob),and woody biomass increments of all four half-sib seed sources from applied nitrogen were observed during the 9 years following application. Periodic annual stem volume (ob) increments averaged over all half-sib seed sources were 120, 152, 192, and 266 ft³/ac/yr for the 0, 89, 178, and356 lb/ac N rates, respectively. The half-sib seed sources from alluvial sites were superior to those from upland sites in terms of productivity and response to N. The response of all half-sibs to N was immediate, occurring during the year of application; however, the increased growth ratesdue to N persisted for only 3 years. This suggests that on responsive sites, applications of N may be necessary every fourth year to maintain maximum growth rates. South. J. Appl. For. 16(3):146-150.

scholarly journals Unexplained Relationships of Height-Diameter of Three Tree Species in a Tropical Forest.

2013 ◽  
Vol 6 (3) ◽  
pp. 196-204
Keyword(s):  
Tree Species ◽  
Coefficient Of Determination ◽  
Multivariate Models ◽  
Forest Reserve ◽  
Permanent Sample Plots ◽  
Tree Distance ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Bivariate Models

Associations between bivariate variables relative to the unexplained relationships of height-Dbh (diameter at breast height) models were investigated. Seven permanent sample plots measuring 40m by 250m at Omo Forest Reserve were used to assess the relationships between height and diameter at breast height of three tree species as affected by the variables of neighbouring trees. The result showed differences in the coefficient of determination of the bivariate models and multivariate models. The models arrived at for each of the species and for the bivariate models are: Scottelia coriaceae: Ht = 2.59 + 0.473D+ 0.0012D2 for 5cm ≤ D ≤100cm (R2 = 0.70) Sterculia rhinopetala: Ht = 5.96 + 0.467D+ 0.00296D2 for 5cm ≤ D ≤100cm (R2 = 0.77) Strombosia pustulata: Ht = 2.02 + 0.722D+ 0.00581D2 for 5cm ≤ D ≤ 60cm (R2 = 0.81) Where both Ht and D are height and Diameter at breast height. While on the other hand the multivariate models that considered the effect of neighbouring trees are: Scottelia coriaceae: 2 1 2 3 4 Ht = 3.74 + 0.41x −1.14x + 0.205x +1.278x (R = 0.723) Sterculia rhnopetala: 2 1 2 3 4 Ht = 6.18 + 0.2601x +1.163x + 0.438x − 0.442x (R = 0.608) Strombosia pustalata: 2 1 2 3 4 Ht = 6.84 + 0.399x − 0.318x − 0.138x − 0.838x (R = 0.650) x1 = diameter at breast height, x2 = Mean neighbouring tree distance, x3 = Frequency of the neighbouring tree and x4 = Position of the crown.

scholarly journals ESTIMATION OF PRODUCTIVITY AND PRIME COST OF LOGSET 5HP GT HARVESTER IN THINNING

2018 ◽  
Author(s):  
Guna PETAJA ◽  
Aldis BUTLERS ◽  
Modris OKMANIS ◽  
Agris ZIMELIS
Keyword(s):  
Production Cost ◽  
Stem Volume ◽  
Time Study ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Prime Cost ◽  
Commercial Thinning ◽  
Study Results ◽  
Work Hour ◽  
Increase Production Cost

Productivity of a harvester significantly affects costs of mechanized felling, which in turn determines, if commercial thinning will be profitable. The objective of this study is to estimate productivity and prime cost of Logset 5HP GT harvester with increased boom length (11 m), equipped with the TH45 felling head, in thinning. Trials are conducted in Latvia, eastern Vidzeme, in coniferous stands. To evaluate productivity of Logset 5HP GT, a time study was carried out. Influence of small trees (diameter at breast height < 8 cm) on productivity and harvesting cost was also determined. During the trials 2379 trees are harvested with the total stem volume of 400 m3. The diameter at breast height of an average harvested tree is 14 cm and volume of a stem – 0.171 m3. Duration of time study is 33.5 h. Obtained productivity rates of Logset 5HP GT are compared with those of John Deere 1070 D harvester. According to the study results average productivity of Logset 5HP GT harvester in thinning of coniferous stands is 13.85 m3 per productive work hour. Prime cost of harvesting of the Logset 5HP GT in thinning is 8.02 € m-3. Increased boom length allows to decrease the total time spent for driving in a stand by 71%. Harvesting of small trees reduces productivity by 6.9% and increase production cost by 2.1% in the experimental stands. Difference between productivity of Logset 5HP GT and John Deere 1070 D in similar conditions is statistically insignificant.

Modeling of aboveground tree stand-level biomass in Erukot Forest of Oban Division, Cross River National Park, Nigeria

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
S.E. Bassey ◽  
S. Ajayi
Keyword(s):  
Carbon Dioxide ◽  
Aboveground Biomass ◽  
National Park ◽  
Basal Area ◽  
Tree Stand ◽  
Diameter At Breast Height ◽  
Total Height ◽  
Breast Height ◽  
Dry Biomass ◽  
Individual Trees

This research estimated aboveground tree stand level Biomass in Erukot Forest of Oban Division, Cross River National Park. A total of 872 individual trees were identified and measured for diameter at breast height and total height (dbh ≥ 5cm). The 872 individual trees spread across 51 species belonging to 25 different tree families. Simple random sampling was used with sampling intensity of 0.3% to lay 15 nested plots (7m x 7m, 25m x 25m and 35m x 35m). Diameter at breast height, total height and specific density of each wood species were used to determine aboveground biomass for each tree. Conversion factors were applied to estimate stand level green and dry biomass, sequestered carbon and carbon dioxide (CO2) emission in the study area. Simple linear regression models were fitted into the stand level growth data for the forest (basal area and volume). The mean diameter at breast height and mean total height were 38.5cm and 18.5m respectively. Mean basal area of 39.8 m2 ha-1 was obtained with a mean volume of 177.3 m3 ha-1 . Average green biomass, dry biomass, carbon stock and carbon-dioxide emission of 521.8113 ton ha-1 , 341.5880 ton ha-1 , 183.196 ton ha-1 and 694.2067 ton ha-1 respectively were obtained in the study area. Stand level biomass model developed for the forest showed that common logarithm of volume per hectare is significantly related to common logarithm of stand biomass (R2 = 58%). The actual and predicted biomasses were not significantly different (Paired T-test at p ˂ 0.05). Estimated bias of 0.10% for the stand biomass model means that the developed model can be used to predict the aboveground biomass of the study area without any adjustment. The research has provided easy to use regression model for determining aboveground biomass at stand level. This is very useful for carbon trade and assessment of carbon-dioxide emissions through deforestation in the study area. The model is also a tool for assessing the wood productivity of the study area and for better management of the park. Keyword: Sequestered carbon, aboveground biomass, dry biomass, conversion factor

Modelling survival probability of individual trees in Norway spruce stands under different thinning regimes

2005 ◽  
Vol 35 (1) ◽  
pp. 113-121 ◽  
Author(s):  
Kjell Karlsson ◽  
Lennart Norell
Keyword(s):  
Norway Spruce ◽  
Goodness Of Fit ◽  
Basal Area ◽  
Site Index ◽  
Stand Age ◽  
Goodness Of Fit Test ◽  
Individual Tree ◽  
Thinning Intensity ◽  
Diameter At Breast Height ◽  
Breast Height

The probability that an individual tree will remain in even-aged Norway spruce (Picea abies (L.) Karst.) stands subjected to different thinning programmes was modelled, using data from a thinning experiment established in 25 localities in southern Sweden. A logistic regression approach was used to predict the probability and the Hosmer–Lemeshow goodness-of-fit test to evaluate the fit. Diameter at breast height (DBH), quadratic mean DBH, thinning intensity, thinning quotient, basal area, number of stems per hectare, stand age, number of thinnings, and site index were used as explanatory variables. Separate analyses for stands thinned from below, stands thinned from above, and unthinned stands were performed. The modelled probability graphs for trees not being removed, plotted against their diameter at breast height, had clear S-shapes for both unthinned stands and stands thinned from below. The graph for stands thinned from above was bell-shaped.

scholarly journals Relative effects of dendrometers on the estimation of diameter at breast height, stand basal area and stand volume in uneven-aged northern hardwoods

2009 ◽  
Vol 85 (3) ◽  
pp. 446-452 ◽  
Author(s):  
François Guillemette ◽  
Marie-Claude Lambert
Keyword(s):  
Basal Area ◽  
Major Axis ◽  
Minor Axis ◽  
Northern Hardwoods ◽  
Parameter Estimates ◽  
Betula Alleghaniensis ◽  
Stand Volume ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Stand Basal Area

Four methods of estimating diameter at breast height (DBH) were used on 558 northern hardwood stems, located in 6, 0.25-ha plots, to compare their effects. The first method was a diameter tape reading and the second was a systematic reading, along a predefined axis, taken with a calliper. The last 2 methods were both obtained from the arithmetic mean of 2 different pairs of calliper readings taken at right angles. The first pair was directed along the major bole axis and the other pair along the minor axis. The 4 methods were compared in terms of mean tree diameter, plot basal area and plot volume. There were significant differences (p < 0.05) in parameter estimates among methods, and the differences varied according to species (Acer saccharum Marsh. and Betula alleghaniensis Britt.) and tree size class. Differences among methods were more evident for larger DBH classes, which contribute most to the significant differences observed for both the plot and stand basal area and volume. Overall, tree DBH, plot basal area and plot volume provided by these 4 methods ranked in this ascending order: mean calliper reading directed along the minor axis, systematic calliper reading, mean calliper reading directed along the major axis, and diameter tape. The difference in stand basal area or volume between the estimates obtained with a systematic calliper reading and a diameter tape was 1.1 m2/ha with a mean basal area of about 21 m2/ha, or 10.5 m3/ha with a mean stand volume of 169 m3/ha. Because of the magnitude of these differences, it is recommended the method of DBH estimation be specified in studies, to be careful when crossing databases or models using different methods of DBH estimation, and to always maintain the same method of DBH estimation when remeasuring a plot. Key words: northern hardwoods, dendrometer, diameter tape, calliper, caliper, DBH measurement, basal area, volume

scholarly journals Linear Regression Model to Identify the Factors Associated with Carbon Stock in Chure Forest of Nepal

Scientifica ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Ira Sharma ◽  
Sampurna Kakchapati
Keyword(s):  
Linear Regression ◽  
Regression Model ◽  
Linear Regression Model ◽  
Carbon Stock ◽  
Multiple Linear Regression Model ◽  
Greenhouse Gas Mitigation ◽  
Stem Volume ◽  
Diameter At Breast Height ◽  
Factors Associated ◽  
Breast Height

Use of woody plants for greenhouse gas mitigation has led to the demand for rapid cost-effective estimation of forest carbon stock and related factors. This study aims to assess the factors associated with carbon stock in Chure forest of Nepal. The data were obtained from Department of Forest Research and Survey (DFRS) of Nepal. A multiple linear regression model and then sum contrasts were used to observe the association between variables such as stem volume, diameter at breast height, altitude, districts, number of trees per plot, and ownership of the forest. 95% confidence interval (CI) plots were drawn for comparing the adjusted carbon stocks with each of the factors and with the overall carbon stock. The linear regression showed a good fit of the model (adjusted R2 = 83.75%) with the results that the stem volume (sv), diameter at breast height (dbh), and the number of trees per plot showed statistically significant (p value ≤ 0.05) positive association with carbon stock. The highest carbon stock was associated with sv more than 199 m3/ha, average dbh more than 43.3 cm/plot, and number of trees more than 20/plot, whereas the altitude, geographical location, and ownership had no statistical associations at all. The results can be of use to the government for enhancing carbon stock in Chure that supports both natural resource conservation and United Nations-Reducing Emission from Deforestation and Forest Degradation program to mitigate carbon emission issues.

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