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.

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 The Effects of Tree and Stand Traits on the Specific Leaf Area in Managed Scots Pine Forests of Different Ages

Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 396
Author(s):  
Agnieszka Błasiak ◽  
Andrzej Węgiel ◽  
Adrian Łukowski ◽  
Sławomir Sułkowski ◽  
Mieczysław Turski
Keyword(s):  
Leaf Area ◽  
Scots Pine ◽  
Specific Leaf Area ◽  
Stand Structure ◽  
Light Exposure ◽  
Direct Method ◽  
Stand Density ◽  
Tree Age ◽  
Structure Tree ◽  
Northwestern Poland

The purpose of this study was to understand the relationships between stand structure (tree size, volume, biomass, social position, stand density) and the variability of specific leaf area (SLA) at the stand level, which could improve forest management modeling. The study was carried out on 100 trees selected from 10 stands of Scots pine located in northwestern Poland. The stands had been established in a similar way and were similarly managed. Five mid-aged (51–60 years) and five mature (81–90 years) pure Scots pine stands were selected. To obtain the SLA index, we used the direct method, which involves scanning ca. 50 needles from each part of the tree crown. The average SLA was from 4.65 to 6.62 m2·kg−1 and differed significantly according to the part of the crown measured (p < 0.0001) and the tree age (p < 0.0001). The smallest SLA was in the upper part of the crown and the largest in the lower part of the crown, which is in line with the known relation to the light exposure of needles. Mid-aged stands of Scots pine have higher SLA values than mature ones. Dominant trees in mid-aged stands have a lower SLA than more shaded intermediate ones, which is probably due to the different lighting conditions within the canopy. No clear relationship is observed between the stand density and the SLA.

ASSESSMENT OF PINE CROPS GROWTH IN BAIMAK FORESTRY

2020 ◽  
Vol 37 (3) ◽  
pp. 83-90
Author(s):  
T.Z. Mutallapov ◽  
Keyword(s):  
Scots Pine ◽  
Forest Ecosystem ◽  
Distribution Curve ◽  
Comparative Assessment ◽  
Tree Distribution ◽  
Entire Structure ◽  
Structure Changes ◽  
Large Trees ◽  
Different Types ◽  
The Stability

The article presents the results of evaluating the growth of Scots pine in the Baymak forest area. The analysis of forestry and taxation indicators of Scots pine crops on the studied sample areas is carried out, and a comparative assessment of the growth of forest crops growing in different types of forest is given. Increased competition in plantings leads to the natural decline of stunted trees, which is the result of differentiation in the stand. As a result, its structure changes, the number of large trees increases, and, accordingly, the stability of the forest ecosystem increases. In this regard, the appearance of the tree distribution curve by thickness levels also changes. It becomes more "flat", and its competitive load is more evenly distributed over the entire structure of the stand, and competition is weakened.

The Analytic Identification of Variance Component Models Common to Behavior Genetics

2021 ◽  
Author(s):  
Michael D. Hunter ◽  
S. Mason Garrison ◽  
S. Alexandra Burt ◽  
Joseph L. Rodgers
Keyword(s):  
Variance Component ◽  
Behavior Genetics ◽  
Variance Component Models ◽  
Component Models

scholarly journals Selected physical and mechanical properties of Scots pine (Pinus sylvestris L.) wood from stands of younger age classes as criteria for rational utilization of timber

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Przemysław Marcin Pikiński ◽  
Jaroslav Szaban ◽  
Gerda Šilingienė ◽  
Robert Korzeniewicz ◽  
Witold Pazdrowski
Keyword(s):  
Mechanical Properties ◽  
Pinus Sylvestris ◽  
Scots Pine ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Growth Conditions ◽  
Tree Age ◽  
Coniferous Forests ◽  
Forest Site ◽  
Quality Coefficient

The aim of this study was to assess the quality of Scots pine (Pinus sylvestris L.) wood depending on the age of trees, forest site conditions and social class of tree position in the stand. Analyses were based on the determination of specific density and static bending strength, as well as the strength quality coefficient. It was to determine changes in physical and mechanical properties of timber depending on tree age as well as growth conditions reflected in the forest site such as fresh mixed coniferous forests and fresh mixed broadleaved forests. Experimental plots were established in 6 localities with 30, 40 and 60-year-old trees. In each of the stands, a 1-hectare experimental plot was established. Based on the measured DBH and tree height, dimensions of three mean sample trees were calculated, while the classification of social class of tree position in the stand developed by Kraft (1884) was also applied. Analyses were conducted on wood samples with 12% moisture content. Strength tests on wood samples were performed on an Instron 33RH204 universal strength testing machine. A detailed analysis showed properties of pine wood are improved with an increase of tree age in both forest sites. Statistically significant differences were observed for wood density and static bending strength. More advantageous properties were observed for wood of pines from the less fertile forest site, i.e., fresh mixed coniferous forests. Density and static bending strength were markedly determined by tree age and growth conditions. The static bending strength quality coefficient from pines growing in the fresh mixed coniferous forests increased between 30 and 40 years, similarly as it was for the fresh mixed broadleaved forests, while between 40 and 60 years, it deteriorated for the fresh mixed coniferous forests. Wood density from the fresh mixed coniferous forests was by 3% to 7% greater than pines growing in fresh mixed broadleaved forests. In turn, static bending strength of wood from pines growing in fresh mixed coniferous forests was by 4% to 10% greater than trees from the fresh mixed broadleaved forests.  Keywords: Scots pine, wood properties, forest site, Poland

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 Tree height explains mortality risk during an intense drought

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Atticus E. L. Stovall ◽  
Herman Shugart ◽  
Xi Yang
Keyword(s):  
Environmental Gradients ◽  
Tree Height ◽  
Mortality Rates ◽  
Airborne Lidar ◽  
Optical Data ◽  
Social Benefits ◽  
Tree Level ◽  
Large Trees ◽  
Persistent Drought ◽  
Temperature Water

Abstract Forest mortality is accelerating due to climate change and the largest trees may be at the greatest risk, threatening critical ecological, economic, and social benefits. Here, we combine high-resolution airborne LiDAR and optical data to track tree-level mortality rates for ~2 million trees in California over 8 years, showing that tree height is the strongest predictor of mortality during extreme drought. Large trees die at twice the rate of small trees and environmental gradients of temperature, water, and competition control the intensity of the height-mortality relationship. These findings suggest that future persistent drought may cause widespread mortality of the largest trees on Earth.

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