scholarly journals EFECTOS DE LA DENSIDAD DE PLANTACIÓN Y LA ALTURA DE PODA SOBRE LA PRODUCCION DE Pinus taeda L. A LOS 5 AÑOS DE EDAD

FLORESTA ◽  
2003 ◽  
Vol 33 (1) ◽  
Author(s):  
Ruben Costas ◽  
Patricio Mac Donagh ◽  
Elizabeth Weber ◽  
Pedro Irschick ◽  
José Palavecino
Keyword(s):  
Pinus Taeda ◽  
Basal Area ◽  
Stand Density ◽  
Tree Height ◽  
High Density ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Pinus Taeda L

En un ensayo con 3 niveles de densidad y 11 niveles de altura de poda, se evaluaron los efectos de la densidad, la altura de poda y la interacción entre ambas sobre la producción de la masa de Pinus taeda L. a los 5 años de edad. Las variables sobre las cuales se analizó la producción fueron el volumen por unidad de superficie, el área basal, el volumen individual, el diámetro a la altura de pecho y la altura.Se observaron mayores volumen por unidad de superficie y área basal y menores volúmenes individuales y los diámetros a la altura de pecho en los tratamientos con mayor densidad. Para todas las variables respuestas, excepto la altura, se observó que en general a mayor altura de poda se produjeron valores medios menores y viceversa.La interacción entre densidad y altura de poda no fue significativa para ninguna de las variables respuestas. STAND DENSITY AND PRUNE HEIGTH EFFECTS OVER FIVE YEAR OLD YIELD PLANTATION OF Pinus taeda L. Abstract The effects of the stand density and prune height, and the interaction between them, have been evaluated over the yield of five years old Pinus taeda plantation. There were three density levels and eleven prune heights. There were analyzed volume per hectare, basal area, tree volume, diameter at breast height (dbh) and height. It were found higher volume and basal area per hectare, and lower tree volume and dbh for the high density treatments. Except tree height, all the others variables showed lower average values with the increasing of the prune height. The interaction between stand density and prune height was not significant for all analyzed variables.

Sapwood and heartwood taper in Scots pine stems

1995 ◽  
Vol 25 (12) ◽  
pp. 1928-1943 ◽  
Author(s):  
Risto Ojansuu ◽  
Matti Maltamo
Keyword(s):  
Relative Size ◽  
Basal Area ◽  
Stand Density ◽  
Tree Height ◽  
Sapwood Area ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Independent Variable ◽  
Tree Stem ◽  
Taper Models

The heartwood and sapwood of Pinussylvestris L. were analysed using simultaneous taper models for stem without bark and for heartwood. Sapwood area tapered monotonically from the base to the top of the stem. Below crown base the stem tapered more slowly than in the crown. The proportion of heartwood in the tree stem was higher in dense sample plots than in sparse ones and also decreased significantly with increasing relative size of a tree in a plot. Height at crown base correlated significantly with the proportion of heartwood, stand density, and relative size. Height at crown base was the most effective additional independent variable for predicting sapwood basal area at crown base when diameter at breast height and tree height were measured. Connected with diameter at breast height and tree height measurements, width of the sapwood at breast height explained significantly better sapwood and heartwood volumes than height at crown base.

scholarly journals EFICIÊNCIA DE DUAS VARIAÇÕES ESTRUTURAIS DO MÉTODO DE AMOSTRAGEM DE ÁREA FIXA EM PLANTAÇÕES DE Pinus taeda

FLORESTA ◽  
2013 ◽  
Vol 43 (4) ◽  
pp. 621
Author(s):  
João Paulo Druszcz ◽  
Nelson Yoshihiro Nakajima ◽  
Sylvio Pellico Netto ◽  
Sebastião do Amaral Machado ◽  
Nelson Carlos Rosot ◽  
...  
Keyword(s):  
Pinus Taeda ◽  
Relative Efficiency ◽  
Block Design ◽  
Basal Area ◽  
Average Diameter ◽  
Breast Height ◽  
Variable Diameter ◽  
Randomized Block Design ◽  
Fixed Area ◽  
Pinus Taeda L

Este estudo foi conduzido em três diferentes condições de plantações de Pinus taeda L., sem desbastes, com 10, 9 e 7 anos de idade, 2.000 árvores por hectare e diferentes inclinações no terreno, localizados no Estado do Paraná. O objetivo foi avaliar a eficiência do inventário florestal, utilizando-se a amostragem de área fixa com a estrutura de parcela circular (PC) e conglomerado em cruz (CC), através da análise do comportamento quanto às precisões e eficiências relativas nas estimativas das seguintes variáveis: diâmetro médio (cm), número de árvores por ha, área basal (m2/ha) e volume total (m3/ha). Para isso, utilizou-se o delineamento em blocos casualizados com 40 unidades amostrais para a PC e 10 unidades para o CC, sendo este composto por 4 subunidades circulares. Concluiu-se que, para as variáveis diâmetro médio (cm), número de árvores (N/ha), área basal (m2/ha) e volume total (m3/ha), indica-se a utilização do método de área fixa com PC, tendo em vista a maior eficiência no levantamento dessas variáveis.Palavras-chave: Eficiência relativa; precisão; reflorestamento. AbstractStructural efficiency of two variations of method of sampling of fixed area in plantations of Pinus taeda. This study was carried out in three different stands of Pinus taeda L., unthinned and aged 10, 9 and 7 years. The stands have 2.000 trees per hectare and are located in Parana State. The aim was to evaluate the efficiency of inventories using circular plot (PC) and cross cluster (CC) by analyses of behavior towards accuracies and relative efficiencies for estimation of the following variables: average diameter at breast height, number of trees, basal area and total volume per hectare. For this study, it was taken a sample of 40 units to the PC structure and 10 units for the CC structure, which is composed of four circular subunits, and it was used the randomized block design. It was concluded that for the variable diameter (cm), number of trees (ha), basal area (m2/ha) and total volume (m3/ha) it is indicated the use of PC, since its greater efficiency in the survey of these variables.Keywords: Relative efficiency; accuracy; reforestation.

Crown efficiency in a loblolly pine (Pinus taeda) spacing experiment

1998 ◽  
Vol 28 (9) ◽  
pp. 1344-1351 ◽  
Author(s):  
Hubert Sterba ◽  
Ralph L Amateis
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Basal Area ◽  
Tree Height ◽  
Projection Area ◽  
Individual Tree ◽  
Dominant Height ◽  
Crown Projection Area ◽  
Pinus Taeda L ◽  
Crown Closure

Crown efficiency was first defined by Assmann (1961. Waldertragskunde. BLV, München) as individual tree volume increment per unit of crown projection area. He hypothesized that within a given crown class, smaller crowns are more efficient because their ratio between crown surface and horizontal crown projection is higher. Data from a loblolly pine (Pinus taeda L.) spacing experiment were used to test if this hypothesis also holds in young loblolly pine stands and, if so, to determine if it explains the increment differences between spacings in the spacing experiment. Using individual tree height relative to plot dominant height to describe crown class, within-plot regression showed that crown efficiency decreased with crown size for trees below dominant height. This relationship was much less pronounced than indicated from Assmann's examples, although the crown surface to crown projection ratio behaved in the same way as Assmann had hypothesized. Crown efficiency as well as the crown surface to crown projection area ratio decreased with increasing density. Basal area increment per hectare increased until total crown closure approached 130% and then stayed constant. This major impact of total crown coverage brings into question the usefullness of crown efficiency as an indicator for unit area growth.

scholarly journals Stand Density Index for Loblolly Pine Plantations in North Louisiana

1996 ◽  
Vol 20 (2) ◽  
pp. 110-113 ◽  
Author(s):  
Roger A. Williams
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Basal Area ◽  
Stand Density ◽  
Pine Plantations ◽  
Density Index ◽  
Pinus Taeda L ◽  
Stand Density Index ◽  
North Louisiana

Abstract Stand Density Index (SDI) equations and diagrams were developed and presented for loblolly pine (Pinus taeda L.) plantations in north Louisiana. Two different SDI diagrams are presented—one that utilizes the number of trees per acre and average stand diameter, and a second that uses the number of trees per acre and the basal (ft²) per acre. Basal area is presented as a second alternative to average stand diameter since many practicing foresters commonly use basal area for density management. South. J. Appl. For. 20(2):110-113.

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 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.

Long-term effects of stand density management and genotype on wood properties of loblolly pine (Pinus taeda L.) in the mid-South USA

2021 ◽  
Vol 491 ◽  
pp. 119176
Author(s):  
Michael A. Blazier ◽  
Thomas Hennessey ◽  
Laurence Schimleck ◽  
Scott Abbey ◽  
Ryan Holbrook ◽  
...  
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Stand Density ◽  
Wood Properties ◽  
Long Term Effects ◽  
Stand Density Management ◽  
Pinus Taeda L

scholarly journals Seemingly Unrelated Mixed-Effects Biomass Models for Black Locust in West Poland

Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 380
Author(s):  
Karol Bronisz ◽  
Szymon Bijak ◽  
Rafał Wojtan ◽  
Robert Tomusiak ◽  
Agnieszka Bronisz ◽  
...  
Keyword(s):  
Black Locust ◽  
Random Effect ◽  
Tree Height ◽  
Cross Model ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Dependent Variables ◽  
Dry Biomass ◽  
Biomass Components ◽  
Independent Variable

Information about tree biomass is important not only in the assessment of wood resources but also in the process of preparing forest management plans, as well as for estimating carbon stocks and their flow in forest ecosystems. The study aimed to develop empirical models for determining the dry mass of the aboveground parts of black locust trees and their components (stem, branches, and leaves). The research was carried out based on data collected in 13 stands (a total of 38 sample trees) of black locust located in western Poland. The model system was developed based on multivariate mixed-effect models using two approaches. In the first approach, biomass components and tree height were defined as dependent variables, while diameter at breast height was used as an independent variable. In the second approach, biomass components and diameter at breast height were dependent variables and tree height was defined as the independent variable. Both approaches enable the fixed-effect and cross-model random-effect prediction of aboveground dry biomass components of black locust. Cross-model random-effect prediction was obtained using additional measurements of two extreme trees, defined as trees characterized by the smallest and largest diameter at breast height in sample plot. This type of prediction is more precise (root mean square error for stem dry biomass for both approaches equals 77.603 and 188.139, respectively) than that of fixed-effects prediction (root mean square error for stem dry biomass for both approaches equals 238.716 and 206.933, respectively). The use of height as an independent variable increases the possibility of the practical application of the proposed solutions using remote data sources.

scholarly journals Field Evaluation of Populus deltoides Bartr. ex Marsh. at Two Sites in Indo-gangetic Plains of India

2010 ◽  
Vol 59 (1-6) ◽  
pp. 1-7 ◽  
Author(s):  
G. P. S. Dhillon ◽  
Avtar Singh ◽  
Pritpal Singh ◽  
D. S. Sidhu
Keyword(s):  
Populus Deltoides ◽  
Growth Traits ◽  
Tree Height ◽  
Field Evaluation ◽  
Site Conditions ◽  
Genetic Advance ◽  
Gangetic Plains ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Northwestern India

Abstract Results from clonal trials of Populus deltoides conducted in two distinct agroclimatic regions of Punjab in northwestern India are reported and discussed. Sixteen clones were evaluated at Hambran and Bathinda where commonly grown clone ‘G-48’ was considered as control. Significant differences among clones (P < 0.001) were observed for diameter at breast height (DBH), tree height and volume at the age of four and six years under both the site conditions. Clone ‘L-48’ ranked first for volume at six year age at both sites and was followed by clone ‘Ranikhet’. The respective superiority for volume of these clones over control was 44.8 and 23.2 per cent at Hambran and 72.5 and 30.7 per cent at Bathinda. All growth traits registered significantly higher values at Hambran in comparison to those at Bathinda. Clone x site interaction was also significant (P < 0.001). The clones ‘L-168’, ‘154/86’, ‘Solan-z’ and ‘170/88’ experienced huge fluctuation in ranking between sites for volume at 6-year age. The DBH and height showed significant and positive correlation with each other and with tree volume at all the age combinations. The clonal mean heritability was quite high both at Hambran (0.73-0.86) and Bathinda (0.80-0.95). The genetic advance were the highest for volume (33.34-64.26%) and the lowest (10.65-22.79%) in case of height.

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