Predicting branch angle and branch diameter of Scots pine from usual tree measurements and stand structural information

1998 ◽  
Vol 28 (11) ◽  
pp. 1686-1696 ◽  
Author(s):  
Harri Mäkinen ◽  
Francis Colin
Keyword(s):  
Scots Pine ◽  
Structural Information ◽  
Stand Density ◽  
Random Tree ◽  
Tree Level ◽  
Variance Component Model ◽  
Detailed Knowledge ◽  
Branch Diameter ◽  
Branch Angle ◽  
Tree Effect

A total of 19 thinning experiments were performed in southern and central Finland to study branchiness of Scots pine (Pinus sylvestris L.). Data were collected from 229 trees of different ages and canopy positions growing on sites of different fertility and thinned to different stand densities. They were used to construct models for predicting vertical trends of branch angle and branch diameter along the stem. By using the variance component model, it was possible to separate the stand-, plot-, and tree-level variations of the dependent variables. However, as the random stand and plot effects were small, they were ignored. The random tree effect of the branch angle model was slightly higher compared with the random tree effect of the branch diameter model. Branch angle increased rapidly in the upper part of the crown, but the increase levelled off in the lower part of the stem. Branch diameter increased from the stem apex to the lower part of the crown and then decreased again towards the base of the tree. Stand density measures were significant variables in the models of branch angle and branch diameter. However, they could be excluded without loss of accuracy if variables describing dimensions of the tree were used as independent variables. Relative crown length and stem diameter were adequate tree-level variables for describing branch characteristics. Validation of the models constructed without variables describing stand density revealed no biased behaviour with respect to stand density. It was concluded that branch characteristics can be predicted from the measurement of some tree-level variables without detailed knowledge of the stand history.

scholarly journals Scots Pine Stem Parameters in Sites with Different Stand Densities in Lithuania

Forests ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 716
Author(s):  
Lina Beniušienė ◽  
Benas Šilinskas ◽  
Ričardas Beniušis ◽  
Marius Aleinikovas ◽  
Edmundas Petrauskas ◽  
...  
Keyword(s):  
Forest Management ◽  
Scots Pine ◽  
Management Practices ◽  
Stand Density ◽  
Management Tool ◽  
Stem Height ◽  
Bottom Part ◽  
Branch Diameter ◽  
Stem Wood ◽  
Stem Quality

Background and Objectives: The aim of this study was to determine the effects of different stand densities and thinning regimes on stem quality parameters, mainly branch characteristics, of Scots pine (Pinus sylvestris L.) trees. The study provides some input to the discussion about Scots pine stem quality responses to different forest management practices in relatively young stands. Materials and Methods: Total tree height, height to the lowest live and dead branch, diameter at breast height (DBH), and diameter of all branches from the whorls located up to 6 m from the ground were measured. The linear regression models to predict branch diameter, as the main parameter for the stem quality assessment, were developed based on stand density and stem parameters. Results and Conclusions: DBH, branch diameter and number of branches up to 6-m stem height were significantly higher in the stands with the lowest density. These stem parameters showed a relatively clear downward trend from the lowest to the highest stand densities. The main identified variables which significantly affected stem quality, were branch diameter and diameter of the thickest branch in the bottom part of the stem, at least up to 3-m stem height. For practical use, the best fitted model was estimated when stand density, DBH, and branch diameter up to 3-m height were included in a single equation. The developed model for branch diameter could be used as a forest management tool for managing stem-wood quality.

Growth, suppression, death, and self-pruning of branches of Scots pine in southern and central Finland

1999 ◽  
Vol 29 (5) ◽  
pp. 585-594 ◽  
Author(s):  
Harri Mäkinen
Keyword(s):  
Scots Pine ◽  
Radial Growth ◽  
Stand Density ◽  
Diameter Growth ◽  
High Quality ◽  
Branch Diameter ◽  
Growth Cessation ◽  
Canopy Position ◽  
Branch Development ◽  
Stand Characteristics

Branch development of Scots pine (Pinus sylvestris L.) was studied in 19 thinning experiments in southern and central Finland. Data were collected from 229 trees on sites of different fertility with different stand density, age, and canopy position. Stem sections that included the thickest branch or knot of the whorl were sawn out from the whorls below the lowest living and dead whorl. The stem sections were dissected and the years of birth, suppression, death, and occlusion of the branches were determined. Diameter growth of the branches continued for a longer time in older trees. Branch growth was also prolonged by rapid radial growth of the stem. On average, branches died 7 years after their growth cessation. The number of years that branches stayed alive after growth cessation was independent of the tree or stand characteristics. After the death of a branch, more than 40 years elapsed before the branch was occluded. Large branch diameter and rapid radial growth of the stem increased the width of the loose knot zone in the stem. The results showed that there are limited possibilities of using delayed thinnings to reduce the knottiness of timber, and artificial pruning is needed to produce timber of high quality.

Predicting the number, death, and self-pruning of branches in Scots pine

1999 ◽  
Vol 29 (8) ◽  
pp. 1225-1236 ◽  
Author(s):  
Harri Mäkinen ◽  
Francis Colin
Keyword(s):  
Scots Pine ◽  
Stand Density ◽  
Spatial Arrangement ◽  
Tree Age ◽  
Tree Level ◽  
Sample Tree ◽  
Large Trees ◽  
Dependent Variables ◽  
Variance Component Models ◽  
Component Models

Branchiness of Scots pine (Pinus sylvestris L.) was studied in 19 thinning experiments in southern and central Finland. Data were collected from 229 trees growing on sites of different fertility, stand densities, ages, and canopy positions. The data were used to construct models for (i) the number of new branches on the stem apex, (ii) the probability of a branch being alive, and (iii) the proportion of the actual number of dead branches out of the predicted initial number of branches on the whorls below the crown base. Generalized variance component models were used to separate the stand-, plot-, and tree-level variation in the dependent variables. The number of new branches was closely connected to the height increment of the current year, slightly modified by the height/diameter at breast height ratio (h/DBH). The probability of a branch being alive was connected to its age, tree age, h/DBH, and its relative diameter within the branch whorl. Self-pruning of branches was faster on large trees with long crowns than on thin trees with short crowns. The indices describing the stand density and spatial arrangement of the neighbouring trees around the sample tree reduced the residuals only slightly.

scholarly journals Tree Biomass Equations for Naturally Regenerated Shortleaf Pine

2008 ◽  
Vol 32 (4) ◽  
pp. 163-167 ◽  
Author(s):  
Charles O. Sabatia ◽  
Thomas B. Lynch ◽  
Rodney E. Will
Keyword(s):  
Stand Density ◽  
Seemingly Unrelated Regression ◽  
Tree Level ◽  
Parameter Estimates ◽  
Pinus Echinata ◽  
Shortleaf Pine ◽  
Tree Biomass ◽  
Biomass Component ◽  
Tree Component ◽  
Old Trees

Abstract Aboveground tree-level and branch-level biomass component equations were fitted by nonlinear seemingly unrelated regression, for even-aged naturally regenerated shortleaf pine (Pinus echinata Mill.) in southeastern Oklahoma. Data were obtained from 46- to 53-year-old trees growing in stands that had previously been thinned to densities ranging from 50% of full stocking to overstocked unthinned stands. Stand density affected some of the parameter estimates for trees growing in thinned stands versus unthinned stands. Equations based on dbh alone gave biomass estimates that were not significantly different from those obtained with equations based on dbh, height, and/or crown width. The fitted tree-level biomass component equations were additive in the sense that predictions for biomass components were constrained by the estimation process to sum to total tree biomass. These equations can be used to estimate aboveground tree or tree component biomass for naturally regenerated shortleaf pine in the dbh range of 7–40 cm in southeastern Oklahoma and have potential for application in other shortleaf pine growing areas.

scholarly journals Implications of Reduced Stand Density on Tree Growth and Drought Susceptibility: A Study of Three Species under Varying Climate

Forests ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 627
Author(s):  
Mathias Steckel ◽  
W. Keith Moser ◽  
Miren del Río ◽  
Hans Pretzsch
Keyword(s):  
Scots Pine ◽  
Tree Growth ◽  
Water Availability ◽  
Ponderosa Pine ◽  
Stand Density ◽  
Stand Age ◽  
Short Term ◽  
Sessile Oak ◽  
Site Water ◽  
Positive Effect

A higher frequency of increasingly severe droughts highlights the need for short-term measures to adapt existing forests to climate change. The maintenance of reduced stand densities has been proposed as a promising silvicultural tool for mitigating drought stress. However, the relationship between stand density and tree drought susceptibility remains poorly understood, especially across ecological gradients. Here, we analysed the effect of reduced stand density on tree growth and growth sensitivity, as well as on short-term drought responses (resistance, recovery, and resilience) of Scots pine (Pinus sylvestris L.), sessile oak (Quercus petraea (Matt.) Liebl.), and ponderosa pine (Pinus ponderosa Douglas ex C. Lawson). Tree ring series from 409 trees, growing in stands of varying stand density, were analysed at sites with different water availability. For all species, mean tree growth was significantly higher under low compared with maximum stand density. Mean tree growth sensitivity of Scots pine was significantly higher under low compared with moderate and maximum stand density, while growth sensitivity of ponderosa pine peaked under maximum stand density. Recovery and resilience of Scots pine, as well as recovery of sessile oak and ponderosa pine, decreased with increasing stand density. In contrast, resistance and resilience of ponderosa pine significantly increased with increasing stand density. Higher site water availability was associated with significantly reduced drought response indices of Scots pine and sessile oak in general, except for resistance of oak. In ponderosa pine, higher site water availability significantly lessened recovery. Higher site water availability significantly moderated the positive effect of reduced stand density on drought responses. Stand age had a significantly positive effect on the resistance of Scots pine and a negative effect on recovery of sessile oak. We discuss potential causes for the observed response patterns, derive implications for adaptive forest management, and make recommendations for further research in this field.

scholarly journals Long-Term Effect of Lophodermium Needle Cast on The Growth of Scots Pine and Implications for Financial Outcomes

Forests ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 718 ◽  
Author(s):  
Āris Jansons ◽  
Pauls Zeltiņš ◽  
Jānis Donis ◽  
Una Neimane
Keyword(s):  
Scots Pine ◽  
Stand Density ◽  
Resistance Breeding ◽  
Financial Loss ◽  
Management Scenarios ◽  
Early Management ◽  
Needle Cast ◽  
Stand Management ◽  
Negative Effect

In Northern Europe, climate change may facilitate the prevalence of Scots pine, yet also promote the spread of pathogens attacking this species. A common biotic risk for Scots pine in nurseries and young stands is Lophodermium needle cast, primarily caused by Lophodermium seditiosum, which negatively affects the survival and growth of saplings. Reduced tree growth has been observed several years after damage by Lophodermium needle cast. However, for decision-making in protection or resistance breeding, an estimate of financial loss is important. Thus, the study aimed to assess the long-term influence of Lophodermium needle cast on the growth and financial value of Scots pine stands. The effect of needle cast damage during the sixth growing season on growth at the age of 17 years was evaluated in a control-crossed Scots pine progeny trial, and the results indicated a significantly negative effect on the height and diameter of the trees. A significant family effect also existed on the severity of the needle cast damage. Long-term simulations indicated that severely damaged Scots pines had a reduced equivalent annual annuity (EAA) of almost 100% at the final harvest. More intensive early management to reduce stand density could partly compensate for losses caused by needle cast. A higher EAA for the most resistant group of trees regardless of the stand management scenarios suggests an economically justified potential for improved resistance. Strong negative (−0.62 to −0.70) correlations of height and survival with the proportion of severely affected trees at the family mean level implies that resistant genotypes can be selected along with improved growth in progeny trials, which are affected by needle cast.

On the economics of optimal timber production in boreal Scots pine stands

2013 ◽  
Vol 43 (8) ◽  
pp. 719-730 ◽  
Author(s):  
Olli Tahvonen ◽  
Sampo Pihlainen ◽  
Sami Niinimäki
Keyword(s):  
Interest Rates ◽  
Scots Pine ◽  
Rotation Period ◽  
Stand Density ◽  
Optimization Methods ◽  
Growth Conditions ◽  
Maximum Sustainable Yield ◽  
Pattern Search ◽  
Stand Management ◽  
Volume Yield

This study analyzes the optimal management of Scots pine (Pinus sylvestris L.) stands by applying recent developments in numerical optimization methods and forest production ecology. Our approach integrates a process-based, stand-level growth model and a detailed economic description of stand management. The variables optimized include the initial stand density, the number, timing, type, and intensity of thinnings, and the rotation period. A generalized pattern search is used to maximize the present value of net timber revenue over an infinite time horizon. The model adopts quality pricing, which takes branch size and quality into account, to differentiate among five different timber assortments. The analysis also covers five different site types. The results demonstrate the necessity of optimizing all of the management variables simultaneously. Given a low interest rate, optimized thinning significantly increases the rotation period, volume yield, and economic outcome. At higher interest rates, optimal rotation may be shortest under the least fertile growth conditions. The inclusion of a detailed price structure reveals that previous results concerning sensitivity to timber price and the relationship between maximum sustainable yield and economic solutions do not hold true in models that provide a more realistic description of forest management.

Corrigendum to: Assessing canopy fuel stratum characteristics in crown fire prone fuel types of western North America

2010 ◽  
Vol 19 (1) ◽  
pp. iii ◽  
Author(s):  
Miguel G. Cruz ◽  
Martin E. Alexander ◽  
Ronald H. Wakimoto
Keyword(s):  
Ponderosa Pine ◽  
Fire Management ◽  
Linear Regression Analysis ◽  
Basal Area ◽  
Stand Density ◽  
Fuel Load ◽  
Tree Level ◽  
Management Decision ◽  
Crown Fire ◽  
In Fire

Application of crown fire behavior models in fire management decision-making have been limited by the difficulty of quantitatively describing fuel complexes, specifically characteristics of the canopy fuel stratum. To estimate canopy fuel stratum characteristics of four broad fuel types found in the western United States and adjacent areas of Canada, namely Douglas-fir, ponderosa pine, mixed conifer, and lodgepole pine forest stands, data from the USDA Forest Service's Forest Inventory and Analysis (FIA) database were analysed and linked with tree-level foliage dry weight equations. Models to predict canopy base height (CBH), canopy fuel load (CFL) and canopy bulk density (CBD) were developed through linear regression analysis and using common stand descriptors (e.g. stand density, basal area, stand height) as explanatory variables. The models developed were fuel type specific and coefficients of determination ranged from 0.90 to 0.95 for CFL, between 0.84 and 0.92 for CBD and from 0.64 to 0.88 for CBH. Although not formally evaluated, the models seem to give a reasonable characterization of the canopy fuel stratum for use in fire management applications.

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