scholarly journals A Mathematically Tractable Stem Profile Model for Jack Pine in Ontario

1999 ◽  
Vol 16 (3) ◽  
pp. 138-143 ◽  
Author(s):  
W. T. Zakrzewski

Abstract A new model was derived to describe the inside bark cross-sectional area of tree stems. It is a rational function. The inputs required by the model are outside bark tree diameter at breast height (DBH) and total tree height (H). Knowledge of a species-specific bark thickness at 1.3 m expressed in terms of input variables is also needed. Defining the model involves estimating two regression coefficients using either nonlinear or linear regression (after linearization of the model). The formula is analytically integrable and thus provides analytical inside bark volume estimates for any stem section defined by height limits. The model is analytically solvable for a stem height location at any given inside bark diameter, so that stem sections can be defined by the required inside bark diameter limits. The new model can be calibrated using either section diameter or section volume data. It is suggested that involving the ratio H/DBH in the model accounts for the influence of stand density on stem profile. The formula was calibrated for jack pine (Pinus banksiana Lamb.) in Ontario. Wider applicability of the model is supported by results obtained for sugar maple (Acer saccharum Marsh.) in Ontario and Scots pine (Pinus silvestris L.) in Finland. Comparing volume estimates from the new model with those generated by Honer's formula confirms the advantages of the new model. North. J. Appl. For. 16(3):138-143.

1998 ◽  
Vol 28 (12) ◽  
pp. 1784-1793 ◽  
Author(s):  
W Jan A Volney

The fate of jack pine (Pinus banksiana Lamb.) trees growing in a variety of stand conditions was assessed annually for a decade following an outbreak of jack pine budworm (Choristoneura pinus Freeman) in central Saskatchewan. Mortality was clearly associated with the severity and damage sustained by the trees during the second year of the defoliation episode. The pattern of mortality was remarkably similar among stands that originated in decades that spanned 60 years. Mortality rates were highest in stands that originated in the 1890s and were lowest in stands of the most recent origin (1940s). Defoliation severity, the length of dead top, diameter at breast height, and relative tree height expressed as a standard normal variable accounted for 94% of the variability in survival time. A nonparametric proportional hazards model was developed to evaluate the relative risk of individual trees dying. Defoliation is an important process in determining stand density, basal area, and volume after juvenile stand development is complete. The results presented suggest a novel method to determine the hazard of trees in stands and thus assess the vulnerability of stands to future budworm attack.


2010 ◽  
Vol 86 (6) ◽  
pp. 775-779 ◽  
Author(s):  
Alice Verrez ◽  
Dan Quiring ◽  
Thibaut Leinekugel Le Cocq ◽  
Greg Adams ◽  
Yill Sung Park

White pine weevil (Pissodes strobi Peck) damage was evaluated in one white pine (Pinus strobus L.) and four jack pine(Pinus banksiana Lamb) half-sib family test sites to determine the role of tree genotype in resistance to the weevil. Halfsibfamily explained a significant proportion of the variation in weevil attack at all sites. Estimates of family (0.16-0.54)and individual (0.09-0.24) heritabilities of jack pine resistance to white pine weevil were moderate. Estimates of family(0.37) and individual (0.22) heritability of resistance of white pine to the weevil were also moderate when the percentageof test trees damaged by the weevil was relatively low, but were insignificant four years later when more than three-quartersof trees were damaged. Significant positive correlations between mean tree height and mean incidence of trees damagedby the weevil were observed for four of seven site-years but relationships were weak, suggesting that any cost, withrespect to height growth, to breeding weevil resistant trees may be small.Key words: Pinus, Pissodes strobi, trade-offs, tree improvement, tree resistance, white pine weevil.


1963 ◽  
Vol 41 (2) ◽  
pp. 227-235 ◽  
Author(s):  
L. C. O'Neil

An investigation of the radial growth of jack pine (Pinus banksiana Lamb.) defoliated by the Swaine jack-pine sawfly (Neodiprion swainei Midd.) disclosed that growth rings were discontinuous and missing in cross-sectional disks from severely damaged trees. In young and open-grown trees with dead tops, the incidence of such deficiencies in radial growth was especially high in disks from upper regions of the stems, in the vicinity of the dead tops; radial growth was suspended for 1 year and subsequently resumed in disks from the lower regions of some stems. Cambial inactivity was more generalized in trees from an old and dense stand and it was detected in disks representing major portions of some of the stems sampled; the death of some trees followed 2 to 6 years of cambial inactivity in disks cut at various heights along their entire stems. Growth deficiencies in the young stand were clearly effects of severe sawfly defoliation. Data from the old, dense stand indicated that sawfly defoliation had perhaps merely hastened the gradual deterioration of the stand in which intertree competition was intense.


2011 ◽  
Vol 28 (2) ◽  
pp. 84-91 ◽  
Author(s):  
Matthew B. Russell ◽  
Aaron R. Weiskittel

Abstract An extensive statewide data set for seven conifer and eight hardwood species commonly occurring in Maine was used in the development of maximum and largest crown width equations. To establish the characteristics of open-grown trees, quantile regression was used to estimate the biological maximum crown width for a species at a given diameter. To predict crown widths of trees in forested settings, a constrained nonlinear equation was used, using the predicted maximum crown width, tree diameter, and crown ratio. The models performed well across the wide range of stand conditions present in the data set and improved predictions over the currently used crown width equations for most species (reduction of mean absolute error ranged from 1 to 23%). In general, predictions of largest crown width were not greatly improved with the inclusion of crown ratio, and there was a high amount of unexplained variation for shade-tolerant hardwood species, such as American beech (Fagus grandifolia) and sugar maple (Acer saccharum). The equations presented herein can be used in examining tree crown profiles, computing measurements of stand density, and investigating canopy dynamics for species common to the forests of Maine.


Forests ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 605
Author(s):  
Peter F. Newton

The objective of this study was to specify, parameterize, and evaluate an acoustic-based inferential framework for estimating commercially-relevant wood attributes within standing jack pine (Pinus banksiana Lamb) trees. The analytical framework consisted of a suite of models for predicting the dynamic modulus of elasticity (me), microfibril angle (ma), oven-dried wood density (wd), tracheid wall thickness (wt), radial and tangential tracheid diameters (dr and dt, respectively), fibre coarseness (co), and specific surface area (sa), from dilatational stress wave velocity (vd). Data acquisition consisted of (1) in-forest collection of acoustic velocity measurements on 61 sample trees situated within 10 variable-sized plots that were established in four mature jack pine stands situated in boreal Canada followed by the removal of breast-height cross-sectional disk samples, and (2) given (1), in-laboratory extraction of radial-based transverse xylem samples from the 61 disks and subsequent attribute determination via Silviscan-3. Statistically, attribute-specific acoustic prediction models were specified, parameterized, and, subsequently, evaluated on their goodness-of-fit, lack-of-fit, and predictive ability. The results indicated that significant (p ≤ 0.05) and unbiased relationships could be established for all attributes but dt. The models explained 71%, 66%, 61%, 42%, 30%, 19%, and 13% of the variation in me, wt, sa, co, wd, ma, and dr, respectively. Simulated model performance when deploying an acoustic-based wood density estimate indicated that the expected magnitude of the error arising from predicting dt, co, sa, wt, me, and ma prediction would be in the order of ±8%, ±12%, ±12%, ±13%, ±20%, and ±39% of their true values, respectively. Assessment of the utility of predicting the prerequisite wd estimate using micro-drill resistance measures revealed that the amplitude-based wd estimate was inconsequentially more precise than that obtained from vd (≈ <2%). A discourse regarding the potential utility and limitations of the acoustic-based computational suite for forecasting jack pine end-product potential was also articulated.


2013 ◽  
Vol 43 (7) ◽  
pp. 649-657 ◽  
Author(s):  
Sharad Kumar Baral ◽  
Robert Schneider ◽  
David Pothier ◽  
Frank Berninger

The presence of wound (strain) initiated discoloured wood columns in the core of sugar maple (Acer saccharum Marshall) stems reduces the proportion of white-coloured wood and, thus, lowers its commercial value. This study aimed to assess the relationship between tree characteristics and the extent and proportion of discoloured wood in sugar maple tree stems. Using 109 trees from three different sites in southern Quebec, we found that the proportion of discoloured wood increased with decreasing sapwood volume and increasing tree age. Younger trees showed a significantly lower proportion of discoloured wood volume. Discoloured wood volume increases disproportionately with tree diameter, while varying among sites. The third important factor affecting the amount of discolored wood was tree vigour as measured by crown characteristics and growth rate changes. A nonlinear mixed-effects model was used to predict discoloured wood taper. Height along the stem was used as a predictor, along with diameter at 1.3 m (DBH), the ratio of live crown length to tree height, and tree height. Although observed injury surface area was positively correlated to discoloured wood volume, injury information did not explain a large share of discoloured wood proportion variation. Overall, older and larger trees with many injuries on less productive sites are likely to have more discoloured wood.


1964 ◽  
Vol 40 (4) ◽  
pp. 474-481 ◽  
Author(s):  
P. E. Vezina

The concept of stand density in relation to thinning is examined and its development over the years is discussed. Present difficulties of objectively measuring stand density are recognized and probable future trends towards the development of better formulae to express stand density are outlined. Researchers should continue to collect information on interrelationships among stand variables. Certain merits accrue from description of stand density in terms of variables, such as crown closure, that can be measured with some precision from aerial photographs. Conversely, valid estimates of crown closure which are often difficult to obtain by means of devices from the ground, could be predicted from stand density. Three stand variables, used as expressions of stand density, were tested in crown closure simple regressions in even-aged, unmanaged stands of balsam fir (Abies balsamea (L.) Mill.) and jack pine (Pinus banksiana Lamb.). These are: total number of trees, number of trees 4 inches and up, and basal area per acre. The strongest relationship found was the one where crown closure is compared with basal area; it was stronger for jack pine than for balsam fir. This was explained by differences in tolerance among the two species. The significance of these relationships for the stand development, and the feasibility of using height-and diameter-based indices as measures of growing stock in studies of yield are discussed.


1994 ◽  
Vol 70 (6) ◽  
pp. 788-794 ◽  
Author(s):  
S. C. Hills ◽  
D. M. Morris ◽  
C. Bowling

Jack pine (Pinus banksiana Lamb.) is one of the most important commercial species in northwestern Ontario and is the principal host of one of the most serious stem rusts, western gall rust (WGR) caused by Endocronartium harknessii (J.P. Moore) Y. Hirat. In 1986 a trial was established to determine, in part, effects of precommercial thinning on the distribution and occurrence of WGR in jack pine. A 9 year-old aerially seeded jack pine stand was thinned to square spacings of 1 m, 1.5 m, 2 m, 2.5 m, 3 m and a control. Fifth-year results indicated that a significant quadratic trend (p = 0.014) existed between spacing and stem gall infection rate. The incidence of WGR (stem galls) increased as stand density decreased to a maximum at 1.5 m spacing, and then declined to roughly the infection rate of the control at the lowest density (3 m). A significant relationship (0.084) between crown class and the rate of branch gall infection rate was also detected. The branch gall infection rate decreased from 6.2% year−1 for dominant trees to 2.8% year−1 for trees categorized as suppressed. Based on these results, pre-commercial thinning operations should target those trees with main stem galls and/or numerous branch galls, regardless of size and crown position, and then focus on the removal of suppressed trees to meet the desired density target. This strategy should not only enhance growth of the remaining trees, but also reduce WGR inoculum levels and reduce future WGR-related mortality. Key words: jack pine (Pinus banksiana Lamb.), western gall rust (Endocronartium harknessii (J.R Moore) Y. Hirat.), pre-commercial thinning, white pine weevil (Pissodes strobi Peck.)


2002 ◽  
Vol 78 (4) ◽  
pp. 530-538 ◽  
Author(s):  
Lianjun Zhang ◽  
Changhui Peng ◽  
Shongming Huang ◽  
Xiaolu Zhou

The Chapman-Richards growth function is used to model jack pine (Pinus banksiana Lamb.) tree height-diameter relationships at provincial, regional, and ecoregional levels. The results suggest that the tree height-diameter relationships of jack pine are significantly different among the geographic regions of Ontario, depending on local climatic, soil, and ecological conditions. In light of this study, the provincial and regional height-diameter models are not appropriate for predicting tree heights at the ecoregional level. Further, applying a specific ecoregional model to other ecoregions will also result in significant biases for predicting local tree heights. The ecoregion-based height-diameter models developed in this study may provide more accurate information on tree growth and development to forest resource managers and planners. Key words: Chapman-Richards growth function, permanent sample plot, non-linear extra sum of square method, forest management


2008 ◽  
Vol 38 (10) ◽  
pp. 2566-2578 ◽  
Author(s):  
Robert Schneider ◽  
Frank Berninger ◽  
Chhun-Huor Ung ◽  
Pierre Y. Bernier ◽  
D. Edwin Swift ◽  
...  

Allometric equations for estimating foliage biomass, sapwood area, and branch basal area from tree diameters and crown lengths for jack pine ( Pinus banksiana Lamb.) in eastern Canada were calibrated using mixed models. A first model is presented that relates branch foliage biomass to branch diameter and relative position within the crown. These results show that a branch’s foliage biomass is inversely proportional to its depth within the crown. At the tree level, foliage biomass was found to be proportional to crown length and to vary with stem age and slenderness. Pipe model parameters (sapwood area and branch basal area to foliage biomass) were also calculated. The sapwood area to foliage biomass parameter is proportional to stand density, whereas branch basal area to foliage biomass is constant. The tree-level allometeric models were calibrated using a mixed-effects seemingly unrelated regression to account for between-model correlations.


Sign in / Sign up

Export Citation Format

Share Document