Influence of Progeny and Initial Stand Density on the Relationship between Diameter at Breast Height and Knot Diameter of Picea abies

1999 ◽  
Vol 14 (5) ◽  
pp. 470-480 ◽  
Author(s):  
Geir Isak Vestøl ◽  
Francis Colin ◽  
Michel Loubère
Keyword(s):  
Picea Abies ◽  
Stand Density ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
The Relationship

scholarly journals PENAKSIRAN VOLUME POHON KOMERSIL MELALUI METODE PENARIKAN ACAK BERLAPIS (STRATIFIED RANDOM SAMPLING) BERDASARKAN KELAS LERENG DAN KERAPATAN TEGAKAN DI PT. LIMBANG GANECA

2018 ◽  
Vol 2 (2) ◽  
Author(s):  
Gunawan Wibisono
Keyword(s):  
Random Sampling ◽  
Stand Density ◽  
Stratified Random Sampling ◽  
Class Iii ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Two Factors ◽  
Interaction Factors ◽  
Vegetation Maps ◽  
Slope Class

This study aims to estimate the volume of commercial trees at PT. Limbang Ganeca based on Stratified Random Sampling carried out on the RKL VII area of the HPH with an area of 16,101 hectares with a forested area of 15,215 hectares. The area of the study area is 76.08 hectares which is divided into strata based on the slope class and stand density. Based on the results of stratification of topographic maps and vegetation maps, there is a combination of slope I class, slope II class, slope class III and three forest stratum with a combination of 9 forest strata. From this combination the diameter at breast height is measured to assess the volume of the tree.Based on the results of data analysis, slope class factors can be used in estimating volume, while stand density and interaction factors for these two factors cannot be used in estimating tree volume. From the results of measuring the diameter at breast height and calculating tree volume, the average volume of the area was 109,9898 m3 / hectare or around 108,309 to 111,487 m3 / hectare. While the overall volume of the RKL VII area ranges from 1,647,950,462 to 1,696,304,584 m3.

scholarly journals Model of mixed effects of height dependence on tree diameters in pine stands

2021 ◽  
Author(s):  
Н.Н. Дубенок ◽  
В.В. Кузьмичев ◽  
А.В. Лебедев
Keyword(s):  
Fixed Effects ◽  
Mixed Effects ◽  
Mixed Effects Model ◽  
Fixed Effects Model ◽  
Permanent Sample Plots ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Russian State ◽  
Pine Stands ◽  
The Relationship

Основными исходными данными для определения запаса служат результаты обмеров диаметров и высот деревьев. Но обмеры диаметров деревьев на высоте груди выполнить намного проще, чем обмеры высот, поэтому ограничиваются замерами высот 15–25 деревьев. Цель исследования – по материалам измерения модельных деревьев в сосновых древостоях выбрать наиболее адекватную простую модель, которая передает зависимость между высотой деревьев и диаметром на высоте груди. Объектом исследования послужили сосновые древостои искусственного происхождения на постоянных пробных площадях в Лесной опытной даче Российского государственного агарного университета – МСХА имени К.А. Тимирязева. В работе используются данные обмеров деревьев на 17 постоянных пробных площадях с 1934 по 2005 гг. Возраст древостоев на момент проведения измерений от 50 до 125 лет. По итогам проведения 77 перечетов массив данных составил 1157 наблюдений. И модель фиксированных эффектов, и модель смешанных эффектов адекватно описали зависимость между высотами и диаметрами деревьев в культурах сосны. Но, как и ожидалось, первая модель имеет худшие значения метрик качества по сравнению со второй. Модель со смешанными эффектами более точно предсказывает значения высот по сравнению с моделью фиксированных эффектов. Недостающие значения высот большого количества деревьев на участке можно вычислить более точно с помощью модели смешанных эффектов, а не применения модели фиксированных эффектов или использования только фиксированной части (средний отклик) модели смешанных эффектов. Применение разработанной модели должно ограничиваться только в тех условиях, к которым относятся экспериментальные материалы The main data for the stock of research results is the diameter of measurements and heights of trees. But measurements of the diameter at breast height are much easier to perform than measurements of heights, therefore, they are limited to measuring the heights of 15–25 trees. The aim of the study is to select the most adequate simple model based on the measurements of model trees in pine antiquities, which conveys the relationship between the height of trees and the diameter at breast height. The object of the study was pine stands of artificial origin on permanent test plots in the Forest Experimental Station Russian State Agararian University – Moscow Timiriazev Agricultural Academy. The work uses data from tree measurements on 17 permanent sample plots from 1934 to 2005. The age of the stands at the time of measurements was from 50 to 125 years. As a result of 77 enumerations, the data array amounted to 1157 observations. Both the fixed effects model and the mixed effects model adequately describe the relationship between heights and diameters of trees in pine stumps. But, as expected, the first model has worse quality metrics than the second. The mixed effects model more accurately predicts heights from the fixed effects model. The missing heights of a large number of trees on a site can be calculated accurately using mixed effects models, rather than using fixed effects models or using only a fixed portion (mean response) of the mixed effects model. The application of the developed model should be limited only in those conditions to which the experimental materials are applied.

scholarly journals Development and Evaluation of Models for the Relationship between Tree Height and Diameter at Breast Height for Chinese-Fir Plantations in Subtropical China

PLoS ONE ◽  
2015 ◽  
Vol 10 (4) ◽  
pp. e0125118 ◽  
Author(s):  
Yan-qiong Li ◽  
Xiang-wen Deng ◽  
Zhi-hong Huang ◽  
Wen-hua Xiang ◽  
Wen-de Yan ◽  
...  
Keyword(s):  
Tree Height ◽  
Chinese Fir ◽  
Subtropical China ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
The Relationship

scholarly journals Fitting Linear and Non Linear Growth Models for Selected Plantations in Omo Forest Reserve Southwestern Nigeria

2020 ◽  
pp. 19-29
Author(s):  
E. T. Adedeji ◽  
A. S. Akinbowale ◽  
O. A. Akinbode
Keyword(s):  
Linear Models ◽  
Tectona Grandis ◽  
Pinus Caribaea ◽  
Southwestern Nigeria ◽  
Forest Reserve ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Non Linear ◽  
Nauclea Diderrichii ◽  
The Relationship

This study was conducted to assess the suitability of forest models in Tectona grandis, Pinus caribaea and Nauclea diderrichii stands at Omo forest reserve, Ijebu East, Ogun State, Southwestern Nigeria. Temporary sample plots of equal size (25 m x 25 m) were laid while complete enumeration were carried out in each sampled plot and tree growth variables such as diameter at breast height (dbh), diameter at the top (dt), diameter at the middle (dm) and diameter at the base (db) as well as total height of all trees were measured. Simple linear models and six non linear models were developed and assessed for the selected plantation. The linear model developed _ R-squared ranged from 77% to 93%. The least R- square was obtained in Tectona grandis plantation and the highest was obtained in 93% Pinus caribaea. All the models have high F values ranging from 234.71 to 2965.40. In Tectona grandis plantation, Logistic power model, gave a good fit in describing the relationship between diameter at breast height and volume with AICC values of -2368.92, 0.22 each. The Sigmond models that gave a good fit in describing the relationship between the diameter at breast height and volume in Pinus caribaea were Weibull model (-719.19, 0.09) while Gompertz relation is the best for Nauclea diderrichii, respectively. The various models generated in the study are highly recommended for use in estimating the growth characteristics of the plantation in the future.

scholarly journals Competition in Abies kawakamii forests at subtropical high mountain in Taiwan

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254791
Author(s):  
Wei Wang ◽  
Min-Chun Liao ◽  
Hsy-Yu Tzeng
Keyword(s):  
Plant Species ◽  
Spatial Patterns ◽  
Subtropical High ◽  
High Mountain ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Dominant Component ◽  
Understory Composition ◽  
The Relationship ◽  
Competition Indices

The spatial patterns of plant species reflect the competitive pressures on individuals. To generate Competition indices (CI), we measured the diameter at breast height (DBH), crown volumes (CV) and the distances between trees. In this study, Abies kawakamii were divided based on the dominant component of the understory (moss or bamboo) to (1) investigate the relationship between the CI and stand structural attributes (SSAs); (2) compare the inter- and intraspecies; CIs as well as living and dead individual CIs; and (3) examine the relationship between the DBH and CI. The current findings indicate that the understory composition affected the CI and SSAs. The interspecies CI was larger than the intraspecies CI when bamboo-dominated the understory. In contrast, the intraspecies CI was larger than the interspecies CI when the understory was dominated by moss. The CI of dead individuals was higher than that of live individuals due to the biological characteristics and regeneration needs of Abies. Additionally, sensitivity to the environment and available resources may exert more pressure on young individuals than mature individuals.

Planting density and tree-size relations in coast Douglas-fir

1998 ◽  
Vol 28 (1) ◽  
pp. 74-78 ◽  
Author(s):  
William Scott ◽  
Rodney Meade ◽  
Richard Leon ◽  
David Hyink ◽  
Richard Miller
Keyword(s):  
Tree Growth ◽  
Stand Density ◽  
Average Diameter ◽  
Douglas Fir ◽  
Planting Density ◽  
Practical Significance ◽  
Average Height ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Initial Spacing

Test plantations were established in western Washington and Oregon to compare tree growth at six initial planting densities ranging from 300 to 2960 trees/ha (120 to 1200/acre). A size-density relation was visually apparent 3 to 4 years after planting. Inventory data from the oldest 11 trials (5 or 6 years after planting) showed that initial spacing strongly influenced early growth of coast Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii). Average height and diameter at breast height were progressively larger as planting density increased; at the widest spacing (lowest stand density), average height was 75% and average diameter at breast height was 67% of that at the closest spacing. We have no firm explanation for the early faster tree growth at close spacings. Trees planted at 2960 trees/ha (1200 trees/acre) attained breast height (1.3 m) 2 years earlier than trees planted at a density of 300/ha (120/acre). This finding has practical significance to current efforts to achieve early establishment of plantations.

The effects of ring width, stem position, and stand density on the relationship between foliage biomass and sapwood area in Scots pine (Pinussylvestris)

1995 ◽  
Vol 25 (6) ◽  
pp. 970-977 ◽  
Author(s):  
Annikki Mäkelä ◽  
Katri Virtanen ◽  
Eero Nikinmaa
Keyword(s):  
Scots Pine ◽  
Ring Width ◽  
Stand Density ◽  
Relative Height ◽  
Data Set ◽  
Measuring Point ◽  
Sapwood Area ◽  
Breast Height ◽  
The Relationship ◽  
Stem Position

The effects of the average ring width of sapwood, bole length, and stand density on the relationship between foliage biomass and sapwood area at four different stem positions were studied in a data set comprising 20 ca. 35-year-old Scots pine (Pinussylvestris L.) trees in southern Finland. The average ring width within sapwood had no effect on the foliagersapwood ratio inside the crown, but a correlation was found when sapwood was measured at breast height or 20% relative height. The distance of the measuring point from the crown base provided a bigger improvement of foliage biomass prediction from sapwood, a finding emphasizing the significance of the taper of sapwood along the bole. After accounting for the sapwood taper, no differences could be detected between thinned and unthinned stands, nor between breast height and 20% relative height.

scholarly journals Norway Spruce Stem Parameters in Sites with Different Stand Densities in Lithuanian Hemiboreal Forest

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 201
Author(s):  
Lina Beniušienė ◽  
Edmundas Petrauskas ◽  
Marius Aleinikovas ◽  
Iveta Varnagirytė-Kabašinskienė ◽  
Ričardas Beniušis ◽  
...  
Keyword(s):  
Norway Spruce ◽  
Stand Density ◽  
Tree Height ◽  
Linear Regression Models ◽  
Forest Zone ◽  
Branch Diameter ◽  
Stem Wood ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Stem Quality

Background and Objectives: The study aimed to determine the changes of the main stem and branch parameters of Norway spruce (Picea abies (L.) H. Karst) trees under different stand densities. More specifically, the objective was to develop the models for the determination of branch diameter in 0–6 m log from root collar, taken as one of the parameters directly influencing the stem quality. The study continues a piece of research on stem and branch parameters’ responses to different stand density (SD) in the plantations of coniferous tree species in Lithuania. Materials and Methods: The following key parameters were measured in this study: total tree height, diameter at breast height, height to the lowest live branch, height to the lowest dead branch, and diameter of all branches in 0–6 m log. The linear regression models to predict branch diameter in 0–6 m log were developed based on stand density (SD), tree characteristics (tree diameter at breast height, DBH; and tree height, H) and other related stem and branch parameters. Results and Conclusions: Directly measured tree DBH, branch diameters and number of branches in 0–6 m log decreased significantly with the increasing SD. In the 0–6 m log, the branch diameter and the diameter of the thickest branch were identified as the main parameters related to stem quality. The best fitted models, developed including SD, tree DBH, branch diameter, and diameter of the thickest branch in 0–3 m log, can be proposed as a predictor for stem-wood quality for Norway spruce in hemiboreal forest zone.

scholarly journals Performance Analysis of Log Extraction by a Small Shovel Operation in Steep Forests of South Korea

Forests ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 585 ◽  
Author(s):  
Eunjai Lee ◽  
Sang-Kyun Han ◽  
Sangjun Im
Keyword(s):  
South Korea ◽  
Predictive Ability ◽  
Stand Density ◽  
Production Costs ◽  
Mixed Stands ◽  
Forest Road ◽  
Stem Size ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
The Impact

In South Korea, logs for low-value products, such as pulpwood and fuelwood, are primarily extracted from harvest sites and transported to roadside or landing areas using small shovels. Previous studies on log extraction, however, have focused on cable yarding operations with the goal of improving productivity on steep slopes and inaccessible sites, leaving small-shovel operations relatively unexamined. Therefore, the main objectives were to determine small-shovel extraction productivity and costs and to evaluate the impact of related variables on productivity. In addition, we developed a model to estimate productivity under various site conditions. The study took place in 30 case study areas; each area has trees with stems at a diameter at breast height ranging from 18 to 32 cm and a steep slope (greater than 15%). The areas ranged from 241 to 1129 trees per hectare, with conifer, deciduous, and mixed stands. Small-shovel drives ranged from 36 to 72 m per extraction cycle from stump to landing. The results indicated that the mean extraction productivity of small-shovel operations ranged between 2.44 to 9.85 m3 per scheduled machine hour (including all delays). At the forest level, the estimated average stump-to-forest road log production costs were US $4.37 to 17.66/m3. Small-shovel productivity was significantly correlated with stem size (diameter at breast height and tree volume) and total travelled distance (TTD). However, a Pearson’s correlation analysis indicated that stand density and slope did not have a significant effect on productivity. Our findings provide insights into how stem size and TTD influence small shovel performance and the predictive ability of productivity. Further, this information may be a valuable asset to forest planners and managers.

scholarly journals PENAKSIRAN VOLUME POHON KOMERSIL MELALUI METODE PENARIKAN ACAK BERLAPIS (STRATIFIED RANDOM SAMPLING) BERDASARKAN KELAS LERENG DAN KERAPATAN TEGAKAN DI PT. LIMBANG GANECA

2018 ◽  
Vol 2 (2) ◽  
Author(s):  
Gunawan Wibisono
Keyword(s):  
Random Sampling ◽  
Stand Density ◽  
Stratified Random Sampling ◽  
Class Iii ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Two Factors ◽  
Interaction Factors ◽  
Vegetation Maps ◽  
Slope Class

This study aims to estimate the volume of commercial trees at PT. Limbang Ganeca based on Stratified Random Sampling carried out on the RKL VII area of the HPH with an area of 16,101 hectares with a forested area of 15,215 hectares. The area of the study area is 76.08 hectares which is divided into strata based on the slope class and stand density. Based on the results of stratification of topographic maps and vegetation maps, there is a combination of slope I class, slope II class, slope class III and three forest stratum with a combination of 9 forest strata. From this combination the diameter at breast height is measured to assess the volume of the tree.Based on the results of data analysis, slope class factors can be used in estimating volume, while stand density and interaction factors for these two factors cannot be used in estimating tree volume. From the results of measuring the diameter at breast height and calculating tree volume, the average volume of the area was 109,9898 m3 / hectare or around 108,309 to 111,487 m3 / hectare. While the overall volume of the RKL VII area ranges from 1,647,950,462 to 1,696,304,584 m3.

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