scholarly journals Influence of Stem Taper on the Yield of Black Spruce Stands and Trees Following Commercial Thinning

Forests ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 1024 ◽  
Author(s):  
Manon Vincent ◽  
Cornelia Krause ◽  
Ahmed Koubaa
Keyword(s):  
Treatment Effect ◽  
Black Spruce ◽  
Growth Increment ◽  
Tree Level ◽  
Stem Volume ◽  
Stand Volume ◽  
Commercial Thinning ◽  
Volume Increment ◽  
Individual Trees ◽  
Stem Shape

In this work, we examine the effects of commercial thinning on stand volume and individual stem form in nine naturally regenerated black spruce (Picea mariana (Mill.) B.S.P.) stands. We compared these study sites with controls in the commercial boreal forest of northern Quebec, Canada. At stand level, dendrochronological data provided insight into changes in stand volume ten years after thinning. Analysis of a subsample of six individual trees from each commercially thinned stand and three individual trees from the controls illustrated the role of thinning on stem shape development. Although average volume increased for residual stems in thinned stands slightly more than in the controls (110% versus 106%), the treatment effect stand-level volume increment or stand-level total volume harvested (ten years after treatment) was not statistically significant. Moreover, at tree level, thinning did not significantly affect stem volume increment. However, radial growth increment significantly increased after treatment. Trees from commercially thinned stands showed a significantly higher growth increment along the lower first two-thirds of the stem. Response to thinning at tree level correlated strongly with the size and number of harvested competitors around a residual stem. We conclude that commercial thinning modified wood allocation rather than wood volume and did not affect taper and stem shape. These patterns of post-cutting growth are explained by wood allocation following thinning. After commercial thinning, growth increment is favored at the expense of height growth. As the treatment effect was found at the stem scale rather than at the stand scale, further research is needed in regard to commercial thinning treatments to investigate how to increase productivity at the stand scale.

Growth and foliar nutrition of juvenile western hemlock and western redcedar plantations on low- and medium-productivity sites on northern Vancouver Island: response to fertilization and planting density

2007 ◽  
Vol 37 (12) ◽  
pp. 2587-2599 ◽  
Author(s):  
R. W. Negrave ◽  
C. E. Prescott ◽  
J. E. Barker
Keyword(s):  
Volume Growth ◽  
Western Hemlock ◽  
Planting Density ◽  
Stem Volume ◽  
Thuja Plicata ◽  
Limiting Factor ◽  
Western Redcedar ◽  
Stand Volume ◽  
Reduced Height ◽  
Volume Increment

A factorial trial was established to examine the effects of planting density and fertilization on the growth of western redcedar ( Thuja plicata Donn ex D. Don) and western hemlock ( Tsuga heterophylla (Raf.) Sarg.) on nutrient-poor (CH) sites and nutrient-medium (HA) sites. Two levels of NPK fertilization were crossed with three levels of planting density (500, 1500, and 2500 stems/ha). Fifteen years after establishment and 10 years after the last fertilizer application, height, individual stem volume increment, stand volume, 5 year periodic annual increment (PAI), and 5 year periodic height increment were all increased by fertilization. Fertilization of CH sites increased annual stand volume increment by 753%–2552% and 122%–209% for hemlock and cedar, respectively; fertilization of HA sites increased PAI by 94%–264%. Volume growth response to fertilization was greater on HA than on CH sites. Increasing stand density reduced height growth on CH sites but not on HA sites. These results suggest that competition for nutrients can be a significant growth-limiting factor even before canopy closure occurs and that treatment of ericaceous sites may not be justified by productivity increases.

An Equation for Estimating Total Volume of Both Stands and Single Trees of Black Spruce

1983 ◽  
Vol 59 (1) ◽  
pp. 26-29 ◽  
Author(s):  
F. Evert
Keyword(s):  
Picea Mariana ◽  
Black Spruce ◽  
Direct Reference ◽  
Individual Tree ◽  
Stand Volume ◽  
Volume Equation ◽  
The Individual ◽  
Individual Trees

A stand volume equation is presented for black spruce (Picea mariana (Mill.)B.S.P.), based on a sample of 785 felled trees. To ensure that the equation will provide accurate estimates of the volume of both variously stocked stands and of individual trees, stand volume was expressed as the sum of individual tree volumes without direct reference to the size of the area that the trees occupy. The equation will reduce the problem of forecasting stand volume to the simpler problem of forecasting separately the individual components in the stand-volume equation.

scholarly journals Comparison of Backpack, Handheld, Under-Canopy UAV, and Above-Canopy UAV Laser Scanning for Field Reference Data Collection in Boreal Forests

2020 ◽  
Vol 12 (20) ◽  
pp. 3327 ◽  
Author(s):  
Eric Hyyppä ◽  
Xiaowei Yu ◽  
Harri Kaartinen ◽  
Teemu Hakala ◽  
Antero Kukko ◽  
...  
Keyword(s):  
Data Collection ◽  
Point Cloud ◽  
Laser Scanning ◽  
Reference Data ◽  
Tree Height ◽  
Tree Level ◽  
Stem Volume ◽  
Point Cloud Data ◽  
Cloud Data ◽  
Individual Trees

In this work, we compared six emerging mobile laser scanning (MLS) technologies for field reference data collection at the individual tree level in boreal forest conditions. The systems under study were an in-house developed AKHKA-R3 backpack laser scanner, a handheld Zeb-Horizon laser scanner, an under-canopy UAV (Unmanned Aircraft Vehicle) laser scanning system, and three above-canopy UAV laser scanning systems providing point clouds with varying point densities. To assess the performance of the methods for automated measurements of diameter at breast height (DBH), stem curve, tree height and stem volume, we utilized all of the six systems to collect point cloud data on two 32 m-by-32 m test sites classified as sparse (n = 42 trees) and obstructed (n = 43 trees). To analyze the data collected with the two ground-based MLS systems and the under-canopy UAV system, we used a workflow based on our recent work featuring simultaneous localization and mapping (SLAM) technology, a stem arc detection algorithm, and an iterative arc matching algorithm. This workflow enabled us to obtain accurate stem diameter estimates from the point cloud data despite a small but relevant time-dependent drift in the SLAM-corrected trajectory of the scanner. We found out that the ground-based MLS systems and the under-canopy UAV system could be used to measure the stem diameter (DBH) with a root mean square error (RMSE) of 2–8%, whereas the stem curve measurements had an RMSE of 2–15% that depended on the system and the measurement height. Furthermore, the backpack and handheld scanners could be employed for sufficiently accurate tree height measurements (RMSE = 2–10%) in order to estimate the stem volumes of individual trees with an RMSE of approximately 10%. A similar accuracy was obtained when combining stem curves estimated with the under-canopy UAV system and tree heights extracted with an above-canopy flying laser scanning unit. Importantly, the volume estimation error of these three MLS systems was found to be of the same level as the error corresponding to manual field measurements on the two test sites. To analyze point cloud data collected with the three above-canopy flying UAV systems, we used a random forest model trained on field reference data collected from nearby plots. Using the random forest model, we were able to estimate the DBH of individual trees with an RMSE of 10–20%, the tree height with an RMSE of 2–8%, and the stem volume with an RMSE of 20–50%. Our results indicate that ground-based and under-canopy MLS systems provide a promising approach for field reference data collection at the individual tree level, whereas the accuracy of above-canopy UAV laser scanning systems is not yet sufficient for predicting stem attributes of individual trees for field reference data with a high accuracy.

Vertical patterns in specific volume increment along stems of dominant jack pine (Pinus banksiana) and black spruce (Picea mariana) after thinning

2012 ◽  
Vol 42 (4) ◽  
pp. 733-748 ◽  
Author(s):  
Venceslas Goudiaby ◽  
Suzanne Brais ◽  
Frank Berninger ◽  
Robert Schneider
Keyword(s):  
Picea Mariana ◽  
Specific Volume ◽  
Pinus Banksiana ◽  
Black Spruce ◽  
Mass Density ◽  
Volume Growth ◽  
Jack Pine ◽  
Stem Volume ◽  
Volume Increment ◽  
Foliage Density

Jack pine ( Pinus banksiana Lamb.) and black spruce ( Picea mariana (Mill.) B.S.P.) total stem volume increment and vertical growth distribution after thinning were quantified and related to foliage biomass, foliage density, and growth efficiency (GE) (stem to foliage biomass ratio). Significant positive stem volume increments were observed following thinning for jack pine (3 years after) and black spruce (4 years after). Both species reacted differently in terms of the distribution in specific volume increments (SVI) (annual stem volume increment to cambial surface ratio): (i) for jack pine, an increase in SVI was first observed at the base of the tree, with the increase moving upwards, showing that the taper was likely to increase following thinning and (ii) for black spruce, the vertical distribution of SVI was constant, leading to no modifications in stem taper. For jack pine, total stem volume growth was related to an increase in GE and a greater foliage biomass at midcrown, with foliage density staying constant. For black spruce, however, no changes in GE, foliage biomass, and foliage mass density were observed.

scholarly journals Growth and form responses to pre-commercial thinning regimes in aerially seeded jack pine stands: 5th year results

1994 ◽  
Vol 70 (6) ◽  
pp. 780-787 ◽  
Author(s):  
D. M. Morris ◽  
S. C. Hills ◽  
C. Bowling
Keyword(s):  
Block Design ◽  
Volume Growth ◽  
Jack Pine ◽  
Reduced Form ◽  
Stem Volume ◽  
Stem Taper ◽  
Commercial Thinning ◽  
Four Blocks ◽  
Individual Trees ◽  
Crown Dimensions

In 1986, a thinning trial was established in a 9-year-old jack pine stand near Dryden, Ontario. Four blocks consisting of five thinning regimes (1 m × 1 m, 1.5 m × 1.5 m, 2 m × 2 m, 2.5 m × 2.5 m, 3 m × 3 m) and a control plot were established using a randomized complete block design. Once thinned, a series of measurements were taken in 1986 and repeated in 1991 to determine growth and form responses. Results identified highly significant responses for DBH growth and individual stem volume growth. Height response did not vary among the spacing levels. Changes in crown dimensions and stem taper were used to evaluate form responses to thinning. A highly significant decline in all form variables was found in response to increased spacing. Although the increased growth in individual trees provides an opportunity to produce a wider array of products, it appears to be at a cost of reduced form characteristics. Specific management implications for the Dryden Crown Forest are discussed. Key words: jack pine, pre-commercial thinning, growth and form responses

scholarly journals Equations for predicting tree height, total volume, and product recovery for black spruce (Picea mariana) plantations in northeastern Quebec

2005 ◽  
Vol 81 (6) ◽  
pp. 808-814 ◽  
Author(s):  
Chuangmin Liu ◽  
S Y Zhang
Keyword(s):  
Black Spruce ◽  
Management Strategies ◽  
Tree Height ◽  
Product Recovery ◽  
Tree Level ◽  
Stem Volume ◽  
Model Parameters ◽  
Total Product ◽  
Tree Product ◽  
Tree Characteristics

Several regression models with different independent variables were studied for their ability to predict total tree height, total stem volume, and product recoveries (lumber volume, chip volume, lumber value, and total product value) from a sawing simulator. A sample of 172 trees from black spruce plantations was used to fit model parameters and another independent sample of 139 trees was used for model evaluation. The sample encompassed large variations in tree characteristics and tree product recovery. All the fitted models were suitable for predicting their corresponding response variables. Model validation through actual product recovery data from a real stud mill further indicated that the general tree-level models for the product recovery were able to accurately predict product recovery, especially from small- and medium-sized trees, using measured tree characteristics. These models provide a valuable tool for forest managers in determining appropriate management strategies (e.g., stand volume and optimizing stand value). Key words: black spruce, regression analysis, tree characteristics, product recovery, sawing simulation

Clonal and nonclonal genetic structure of subarctic black spruce (Picea mariana) populations in Yukon territory

Botany ◽  
2011 ◽  
Vol 89 (2) ◽  
pp. 133-140 ◽  
Author(s):  
Marios Viktora ◽  
Rodney A. Savidge ◽  
Om P. Rajora
Keyword(s):  
Genetic Structure ◽  
Picea Mariana ◽  
Black Spruce ◽  
A Priori ◽  
Nuclear Genome ◽  
Yukon Territory ◽  
Fire Disturbance ◽  
Clone Size ◽  
Flat Terrain ◽  
Individual Trees

Black spruce (Picea mariana) reproduces sexually from seeds and asexually by layering. There is a prevalent concept that clonal reproduction maintains populations of this species in the subarctic and arctic regions. We used microsatellite DNA markers of the nuclear genome to investigate the genetic structure of montane and subalpine black spruce populations from the Western Yukon Plateau in relation to this concept. Sixty individual trees at a minimum distance of 4 m from each other were sampled from each of four populations and individual trees were genotyped for eight microsatellite loci. Each of the 60 individuals from three montane pure black spruce populations growing on flat terrain at relatively low elevations had unique multilocus genotypes, indicating an absence of clonal structure in those populations. However, in an anthropologically undisturbed climax white spruce-dominated subalpine black spruce population on a northwest slope near Mount Nansen, the majority of the sampled individuals belonged to eight genetically distinct clones (genets). Clone size differed by altitude, the dominant genet being nearest the timberline–tundra ecotone. The results indicate that black spruce reproduction is variable and adaptive, being primarily sexual in flat-terrain montane populations previously subjected to fire disturbance, but mixed vegetative–sexual in the anthropogenically undisturbed subalpine population. This study is the first to employ molecular markers a priori to examine the mode of reproduction in natural black spruce populations.

scholarly journals Spatial Models With Inter-Tree Competition From Airborne Laser Scanning Improve Estimates of Genetic Variance

2021 ◽  
Vol 11 ◽  
Author(s):  
David Pont ◽  
Heidi S. Dungey ◽  
Mari Suontama ◽  
Grahame T. Stovold
Keyword(s):  
Laser Scanning ◽  
Management Practices ◽  
Spatial Models ◽  
Airborne Laser Scanning ◽  
Tree Level ◽  
Residual Variance ◽  
Spatial Effects ◽  
Individual Tree ◽  
Airborne Laser ◽  
Individual Trees

Phenotyping individual trees to quantify interactions among genotype, environment, and management practices is critical to the development of precision forestry and to maximize the opportunity of improved tree breeds. In this study we utilized airborne laser scanning (ALS) data to detect and characterize individual trees in order to generate tree-level phenotypes and tree-to-tree competition metrics. To examine our ability to account for environmental variation and its relative importance on individual-tree traits, we investigated the use of spatial models using ALS-derived competition metrics and conventional autoregressive spatial techniques. Models utilizing competition covariate terms were found to quantify previously unexplained phenotypic variation compared with standard models, substantially reducing residual variance and improving estimates of heritabilities for a set of operationally relevant traits. Models including terms for spatial autocorrelation and competition performed the best and were labelled ACE (autocorrelation-competition-error) models. The best ACE models provided statistically significant reductions in residuals ranging from −65.48% for tree height (H) to −21.03% for wood stiffness (A), and improvements in narrow sense heritabilities from 38.64% for H to 14.01% for A. Individual tree phenotyping using an ACE approach is therefore recommended for analyses of research trials where traits are susceptible to spatial effects.

scholarly journals Comprehensive yield model for plantation teak in Panama

Silva Fennica ◽  
2020 ◽  
Vol 54 (5) ◽  
Author(s):  
Petteri Seppänen ◽  
Antti Mäkinen
Keyword(s):  
Input Parameter ◽  
Large Diameter ◽  
Measurement Data ◽  
Growth And Yield ◽  
Tree Level ◽  
Stem Volume ◽  
Yield Model ◽  
Individual Tree ◽  
Support Tool ◽  
Volume Models

The purpose of this study was to prepare a comprehensive, computerized teak ( L.f) plantation yield model system that can be used to describe the forest dynamics, predict growth and yield and support forest planning and decision-making. Extensive individual tree and permanent sample plot data were used to develop tree-level volume models, taper curve models and stand-level yield models for teak plantations in Panama. Tree volume models were satisfactorily validated against independent measurement data and other published models. Tree height as input parameter improved the stem volume model marginally. Stand level yield models produced comparable harvest volumes with models published in the literature. Stand level volume product outputs were found like actual harvests with an exception that the models marginally underestimate the share of logs in very large diameter classes. The kind of comprehensive model developed in this study and implemented in an easy to use software package provides a very powerful decision support tool. Optimal forest management regimes can be found by simulating different planting densities, thinning regimes and final harvest ages. Forest practitioners can apply growth and yield models in the appropriate stand level inventory data and perform long term harvest scheduling at property level or even at an entire timberland portfolio level. Harvest schedules can be optimized using the applicable financial parameters (silviculture costs, harvesting costs, wood prices and discount rates) and constraints (market size and operational capacity).Tectona grandis

Sampling methods for estimating stem volume and volume increment

1987 ◽  
Vol 21 (3-4) ◽  
pp. 311-323 ◽  
Author(s):  
Timothy G. Gregoire ◽  
Harry T. Valentine ◽  
George M. Furnival
Keyword(s):  
Sampling Methods ◽  
Stem Volume ◽  
Volume Increment
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