Mechanical stability of black spruce in the clay belt region of northern Ontario

1987 ◽  
Vol 17 (9) ◽  
pp. 1080-1091 ◽  
Author(s):  
V. G. Smith ◽  
M. Watts ◽  
D. F. James
Keyword(s):  
Mechanical Stability ◽  
Black Spruce ◽  
Stand Density ◽  
Tree Height ◽  
Static Force ◽  
Northern Ontario ◽  
Wind Speeds ◽  
Spruce Stands ◽  
Stand Height ◽  
The Stability

Black spruce (Piceamariana (Mill.) B.S.P.) is an important pulpwood species that grows on peatland sites in the clay belt region of northern Ontario. The mechanical stability of spruce found on these sites is crucial in determining how tall a stand can grow before losses due to windthrow become excessive. In this study, the stability of a sample of 58 black spruce trees, in stands of various height and density classes, was measured by winching them over and determining their critical turning moment. Regression analysis was used to express critical turning moment as a function of tree height, dominant stand height, and stand stocking. An analysis was carried out to estimate turning moments due to static wind action on the sample trees and predicting the wind speeds required to produce the static force needed to cause windthrow. A comparison of the measured critical turning moments to the estimated wind-generated critical turning moments was used to identify the wind speeds that have enough static force to cause windthrow. A table of critical wind speeds, based on a reference wind, is given for black spruce stands of various heights and densities. Based on these wind speeds and winds associated with periodic storms, black spruce stands can be expected to become susceptible to windthrow once dominant stand height reaches 20 to 21 m. Stand stability increases with stand density owing to the greater ability of dense stands to dissipate incoming winds and the added stability of interlocking root systems. These results suggest that the black spruce stands growing on peatland sites in the clay belt should be harvested before dominant stand height reaches a maximum of 20 to 21 m to avoid excessive losses due to windthrow.

Stand density management diagram for managed black spruce stands

1994 ◽  
Vol 70 (1) ◽  
pp. 65-74 ◽  
Author(s):  
P. F. Newton ◽  
G. F. Weetman
Keyword(s):  
Black Spruce ◽  
Stand Density ◽  
Northern Ontario ◽  
Site Class ◽  
Permanent Sample Plots ◽  
Kalmia Angustifolia ◽  
Initial Spacing ◽  
Stand Density Management ◽  
Crown Closure ◽  
Stand Density Management Diagram

A stand density management diagram for managed black spruce (Picea mariana (Mill.) B.S.P.) stands was developed using data derived from 37 variable-size temporary and permanent sample plots, and 257 open-grown sample trees. The plots were situated within 15 plantations and 4 precommercially thinned stands located throughout central and western Newfoundland, north-western New Brunswick and northern Ontario. The basic components of the diagram included: (1) an approximate crown closure line (2) the self-thinning rule (3) expected size-density trajectories and (4) isolines for dominant height, relative density index, quadratic mean diameter and merchantability ratio. The utility of the diagram was demonstrated by deriving yields for various initial spacings by site class and subsequently evaluating various outcomes in terms of operability criteria. In addition, the potential of estimating the time of crown closure by initial spacing and site class is discussed in relation to minimizing the adverse effects of Kalmia angustifolia (L.) on black spruce growth and development. Key words: stand density management diagram, initial spacing, black spruce, operability, Kalmia angustifolia (L.)

Testing the Lake States variant of FVS (Forest Vegetation Simulator) for the main forest types of northern Ontario

2004 ◽  
Vol 80 (4) ◽  
pp. 495-506 ◽  
Author(s):  
V. Lacerte ◽  
G R Larocque ◽  
M. Woods ◽  
W J Parton ◽  
M. Penner
Keyword(s):  
Black Spruce ◽  
Basal Area ◽  
Stand Density ◽  
Site Index ◽  
Forest Vegetation ◽  
Forest Vegetation Simulator ◽  
Consistency Analysis ◽  
Northern Ontario ◽  
Individual Tree ◽  
Stand Basal Area

The Lake States variant of the FVS (Forest Vegetation Simulator) model (LS-FVS), also known as the LS-TWIGS variant of FVS, was validated for black spruce (Picea mariana (Mill.) BSP), white spruce (Picea glauca (Moench) Voss), jack pine (Pinus banksiana Lamb.) and trembling aspen (Populus tremuloides Michx.) forests in northern Ontario. Individual-tree data from 537 remeasured sample plots were used. This dataset included different combinations of site index, stand density and age. It was possible to compare observations and predictions for different projection length periods. The validation exercise included a biological consistency analysis, the computation of mean percent difference (MPD) for stand density, stand basal area, top height and quadratic mean diameter (QMD) and the comparison of observed and predicted individual-tree dbh. The biological consistency analysis indicated that LS-FVS logically predicted the effect of site index on top height, stand basal area and QMD for black spruce and jack pine. However, the decrease in stand basal area at young ages was inconsistent with the normal development pattern of the forest stands under study and was attributed to deficiencies in the prediction of mortality. LS-FVS was found to underpredict stand density, stand basal area and top height and to over-predict QMD. Even though there were large errors in the prediction of change in stand density, LS-FVS was nevertheless consistent in the prediction of the shape of the dbh size distribution. Key words: FVS, Forest Vegetation Simulator, validation, biological consistency analysis

An assessment of the structural method of deriving a black spruce site equation

1987 ◽  
Vol 17 (10) ◽  
pp. 1181-1189 ◽  
Author(s):  
Victor G. Smith ◽  
Martin Watts
Keyword(s):  
Black Spruce ◽  
Nonlinear Models ◽  
Site Index ◽  
Stand Age ◽  
Structural Method ◽  
Northern Ontario ◽  
Data Set ◽  
Permanent Sample Plots ◽  
Stochastic Error ◽  
Stand Height

To date, methods of deriving site index (S) equations assume that stochastic error is only present in the regressor. This paper develops a method, termed the "structural method," which recognizes that both dominant stand height (H) and S measurements contain stochastic error. To achieve this, the structural method utilizes the structural relationship that exists between H and S to derive an S equation. S equations are derived for black spruce, Piceamariana (Mill.) B.S.P., using the structural method and various other methods, with linear and nonlinear models that are currently in use. Data used in the study consist of 56 black spruce permanent sample plots, containing a total of 382 observations, from north central Ontario and the Clay Belt Region of northern Ontario. This data set is split into 36 plots (260 observations) for deriving S equations and 20 plots (122 observations) for testing the equations for accuracy in predicting H, S, and future H. The equations are also examined for bias over stand age. Results show that height development of black spruce is not asymptotic and is best described by a linear model. Overall, the structural method provides the most accurate S equation within the range of the data. It predicted 90% of the H test observations with an error of 0.4 m or less, 89% of the S test observations with an error of 0.4 m or less, and 90% of the future H test observations with an error of 0.7 m or less. The structural method also has the advantage of producing only one equation for predicting both H and S. This enables estimates of both H and S to be made from one graph of H over age by S classes.

The effect of advance regeneration height on future yield of black spruce stands

1995 ◽  
Vol 25 (4) ◽  
pp. 536-544 ◽  
Author(s):  
David Pothier ◽  
René Doucet ◽  
Jocelyn Boily
Keyword(s):  
Black Spruce ◽  
Site Index ◽  
Site Quality ◽  
Management Tools ◽  
Clear Cutting ◽  
Advance Regeneration ◽  
Short Period ◽  
Index Site ◽  
Spruce Stands ◽  
Stand Height

The advance regeneration often present following clear-cutting in black spruce (Piceamariana (Mill.) B.S.P.) stands is generally composed of individuals of various heights. This initial height difference is hypothesized to affect the yield of the future stand. Height of the advance regeneration at time of release was determined on several black spruce trees within 33 stands distributed across the boreal forest of the province of Quebec, Canada. From these data, a regeneration structure index was developed and used to explain a part of the variation in subsequent stand yield. Dominant trees of stands developing for 38 to 65 years since clear-cutting generally originated from the tallest advance regeneration at time of release. Stands with the tallest regeneration at time of release produced the largest yields for a given site quality and number of years since harvesting. A 3-m increase in advance-regeneration height resulted in a similar yield gain as a 3-m increase in site index. Site indices calculated from age-height relationships of dominant trees originating from tall advance regeneration were less than those calculated from trees that have undergone a relatively short period of suppression. These results suggest that traditional management tools developed for fire-origin black spruce stands, i.e., stands mainly composed of seed-origin trees established after perturbation, should be adjusted for clearcut-origin stands that largely develop from advance regeneration.

scholarly journals A Site Index Formula for Peatland Black Spruce in Ontario

1978 ◽  
Vol 54 (1) ◽  
pp. 39-41 ◽  
Author(s):  
Bijan Payandeh
Keyword(s):  
Black Spruce ◽  
Growth Function ◽  
Site Index ◽  
Index Formula ◽  
Stand Age ◽  
Northern Ontario ◽  
Analysis Of Results ◽  
Stand Height ◽  
A Site ◽  
Index Formulas

Site index formulas were derived for peatland black spruce (Picea mariana [Mill.] B.S.P.) in northern Ontario based on stem analysis of 60 dominant and codominant trees. Nonlinear regression analysis and a biological growth function were employed to express both height as a function of site index and stand age and also site index as a function of stand height and age. Analysis of results indicates that peatland black spruce has a different pattern of height growth than that shown by Plonski's site index curves, particularly for site indices less than 8 m and stands older than 80 years.

Croissance juvénile de marcottes d'épinette noire en régénération après récolte du couvert dominant

1993 ◽  
Vol 23 (7) ◽  
pp. 1396-1401 ◽  
Author(s):  
Jocelyn Boily ◽  
René Doucet
Keyword(s):  
Growth Rates ◽  
Natural Regeneration ◽  
Black Spruce ◽  
Height Growth ◽  
Management Unit ◽  
Site Quality ◽  
Clear Cutting ◽  
Ecological Regions ◽  
Spruce Stands ◽  
Stand Height

Annual height growth of natural regeneration was measured in 18- to 21-year-old clear-cuts of black spruce stands growing on sites of contrasted drainage, in two ecological regions of the Haute-Gatineau-et-Cabonga management unit in western Quebec. Most regeneration was established by layering and was growing slowly on all sites at time of release by clear-cutting of the main stand. Height growth rates increased rapidly thereafter on mesic sites: about 7 to 8 years after release, it reached 15 cm or more per year, and 32 to 45 cm per year 20 years after harvest. On moist sites, growth rates of 15 cm per year were attained only 10 to 15 years after release, and did not exceed 25 cm at age 20. These results show that growth of black spruce natural regeneration is controlled more by site quality than by the mechanism responsible for reproduction.

scholarly journals The mechanical stability of the world’s tallest broadleaf trees

2019 ◽  
Author(s):  
T. Jackson ◽  
A. Shenkin ◽  
N. Majalap ◽  
J. bin Jami ◽  
A. bin Sailim ◽  
...  
Keyword(s):  
Mechanical Stability ◽  
Tree Height ◽  
Wind Loading ◽  
Maximum Height ◽  
Wind Speeds ◽  
Extreme Wind ◽  
North Borneo ◽  
Relative Rarity ◽  
Extreme Wind Speeds ◽  
The Tropics

AbstractThe factors that limit the maximum height of trees, whether ecophysiological or mechanical, are the subject of longstanding debate. Here we examine the role of mechanical stability in limiting tree height and focus on trees from the tallest tropical forests on Earth, in Sabah, Malaysian Borneo, including the recently discovered tallest tropical tree, a 100.8 mShorea faguetiana. We use terrestrial laser scans,in situstrain gauge data and finite-element simulations to map the architecture of tall broadleaf trees and monitor their response to wind loading. We demonstrate that a tree’s risk of breaking due to gravity or self-weight decreases with tree height and is much more strongly affected by tree architecture than by material properties. In contrast, wind damage risk increases with tree height despite the larger diameters of tall trees, resulting in a U-shaped curve of mechanical risk with tree height. The relative rarity of extreme wind speeds in north Borneo may be the reason it is home to the tallest trees in the tropics.

scholarly journals Alternate Strip Clearcutting in Upland Black Spruce: IV. Projected Nutrient Removals Associated with Harvesting

1987 ◽  
Vol 63 (6) ◽  
pp. 451-456 ◽  
Author(s):  
Neil W. Foster ◽  
Ian K. Morrison
Keyword(s):  
Forest Floor ◽  
Black Spruce ◽  
Northern Ontario ◽  
Preparation Methods ◽  
Rooting Zone ◽  
N Removal ◽  
Spruce Stands ◽  
Post Harvesting ◽  
Whole Tree Harvesting ◽  
Tree Harvesting

Nutrient removals associated with conventional, full-tree, and whole-tree harvesting on 100-year rotations in an upland boreal black spruce stand in northern Ontario were estimated. Conventional (stems only) logging would remove 219 kgha−1 of Ca, 62 of N, 36 of K, 18 of Mg and 9 of P from the site. Increased utilization of phytomass during full-tree harvesting, in comparison with conventional logging, could result in as much as a 400% increase in N removal and a 60% increase in Ca removal. Estimates of projected N and K removals by full-tree harvesting may be conservative, relative to those in other black spruce stands because of the low foliar mass of this forest. The forest floor contained 51% to 72% of the soil's reserves of nutrients, except for P, within the effective rooting zone. Post-harvesting site preparation methods should be restricted to those that ensure that forest floor nutrient reserves are retained on site.

scholarly journals A Height Growth Model and Associated Growth Intercept Models for Estimating Site Index in Black Spruce (Picea mariana Mill. B.S.P.) Plantations in Northern Ontario, Canada

2011 ◽  
Vol 28 (3) ◽  
pp. 129-137
Author(s):  
Martin M. Kwiaton ◽  
Jian R. Wang ◽  
Douglas E.B. Reid
Keyword(s):  
Picea Mariana ◽  
Black Spruce ◽  
Site Index ◽  
Height Growth ◽  
Growth And Yield ◽  
Site Quality ◽  
Northern Ontario ◽  
Spruce Stands ◽  
Growth Intercept

Abstract Site quality is a key component of growth and yield models because height growth rates are known to be influenced by available site resources. Accurate prediction of future growth and yield requires site quality information for both plantations and natural stands. The forest industry in northern Ontario relies on high-quality wood and fiber from black spruce (Picea mariana Mill. B.S.P.); therefore, these tools are essential to ensure sustainable forest management. Although there are site index (SI) models for natural-origin black spruce stands in northern Ontario, models for estimating site quality of young black spruce plantations have not been developed. We used stem analysis data collected from 62 plantations (>40 years of age) of pure black spruce across northern Ontario to develop height growth, SI, and variable growth intercept models. The distinct height growth patterns we observed may be attributed to early silvicultural treatments (site preparation and herbicide) in plantations allowing black spruce trees to attain breast height (1.3 m) faster than in fire-origin stands in northern Ontario. Our models can be used to estimate site quality of black spruce plantations, a key consideration for silviculture and forest management planning. We also compare our managed stand SI model to one we developed from a comparable subset of data from black spruce growing in unmanaged stands and propose a method to assign an SI with a common base age to pure upland black spruce stands regardless of origin.

scholarly journals Sensitivity of vegetation indices in relation to parameters of Norway spruce stands

2017 ◽  
Vol 59 (2) ◽  
pp. 85-98 ◽  
Author(s):  
Aneta Modzelewska ◽  
Krzysztof Stereńczak ◽  
Monika Mierczyk ◽  
Sylwia Maciuk ◽  
Radomir Bałazy ◽  
...  
Keyword(s):  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Dynamic Range ◽  
Vegetation Indices ◽  
Stand Density ◽  
Spatial Changes ◽  
Spruce Stands ◽  
Stand Height ◽  
Stable Index ◽  
Stand Characteristics

AbstractThe main goal of this research is to shed further light on the sensitivity of the vegetation indices to spatial changes of stand parameters. The analysis was done within mountain forests in the Sudetes and the Beskids in southern Poland. Some 1327 stands were analysed with more than 70 percent of spruce contribution in the species composition. The response of selected vegetation indices was verified in relation to the alterations of spruce participation, stand height, volume, stand density and diameter. The following indices were analysed: Normalized Difference Vegetation Index, Normalized Difference Red Edge Index, Green Normalized Difference Vegetation Index and Wide Dynamic Range Vegetation Index. Indices were calculated based on the Rapid Eye (Black Bridge) images. All the analysed stand characteristics influence the values of vegetation indices. In general: mean height, diameter at breast height, volume and spruce participation are the most negatively correlated with the indices. Density is a variable that, in general, cannot directly be used for indices correction, because it is hard to find any stable trend. NDRE is the most stable index for the analysis of stand characteristics.

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