Development and evaluation of ecoregion-based jack pine height-diameter models for Ontario

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

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.


2008 ◽  
Vol 38 (11) ◽  
pp. 2746-2761 ◽  
Author(s):  
L. Chasmer ◽  
N. Kljun ◽  
A. Barr ◽  
A. Black ◽  
C. Hopkinson ◽  
...  

Carbon dioxide, water vapour, and energy fluxes vary spatially and temporally within forested environments. However, it is not clear to what extent they vary as a result of variability in the spatial distribution of biomass and elevation. The following study presents a new methodology for extracting changes in the structural characteristics of vegetation and elevation within footprint areas, for direct comparison with eddy covariance (EC) CO2 flux concentrations. The purpose was to determine whether within-site canopy structure and local elevation influenced CO2 fluxes in a mature jack pine ( Pinus banksiana Lamb.) forest located in Saskatchewan, Canada. Airborne light detection and ranging (lidar) was used to extract tree height, canopy depth, foliage cover, and elevation within 30 min flux footprints. Within-footprint mean structural components and elevation were related to 30 min mean net ecosystem productivity (NEP) and gross ecosystem production (GEP). NEP and GEP were modeled using multiple regression, and when compared with measured fluxes, almost all periods showed improvements in the prediction of flux concentration when canopy structure and elevation were included. Increased biomass was related to increased NEP and GEP in June and August when the ecosystem was not limited by soil moisture. On a daily basis, fractional cover and elevation had varying but significant influences on CO2 fluxes.


1976 ◽  
Vol 54 (5-6) ◽  
pp. 446-455 ◽  
Author(s):  
V. Chalupa ◽  
D. J. Durzan ◽  
C. Vithayasai

Jack pine (Pinus banksiana Lamb.) calluses from hypocotyls and radicles of 5-day-old seedlings were established when the yield of callus from the donor was greatest compared with other stages of germination. Effects of macroelements, organic nitrogen sources, growth regulators, temperature, light, and carbon dioxide on the fresh and dry weights of callus indicated that the medium formulated was optimal. Although tissues assimilated exogenous sources of N, they also depended upon the food reserves that were mobilized during germination as the density (dry weight per cubic centimetre) of calluses gradually fell.Initially, the proliferation and release of cells from their neighbors was mainly on the outer surface of tissue. Eventually all cells appeared to divide to yield a friable, green callus with cell clumps that were easily dissociated from one another. Some clumps, especially those below the surface and near vascular tissues, were filamentous and exhibited polarity resembling the early stages of pine embryogeny.The growth form of hypocotyl callus was autocatalytic, whereas radicle callus was exponential for both dry weight and volume. Final size was greater in hypocotyl callus. In both systems, the relative growth rates of weight and volume correlated negatively but significantly to water intake. Average parameters of growth rates were calculated using Richards's comprehensive growth function.


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.


2014 ◽  
Vol 44 (1) ◽  
pp. 82-91 ◽  
Author(s):  
Manon Vincent ◽  
Isabelle Duchesne

Mixed models combining random coefficient effect and covariance patterns were used to investigate mechanical property variations in jack pine (Pinus banksiana Lamb.) and white spruce (Picea glauca (Moench) Voss) trees. Modulus of elasticity (MOE) and modulus of rupture (MOR) were measured by conducting three-point bending tests on small defect-free samples selected from different radial positions and at a height of 2.5 m above ground within the stems. The objective of the paper was to build statistical predictive models describing the radial variations in stems for wood mechanical properties using easily measurable explanatory variables that are typically available in the wood manufacturing industry: distance from pith, tree height and diameter, and spacing. The explanatory variables integrated into the models explained MOE adequately, whereas MOR appeared harder to predict with only these variables and at this resolution. For white spruce, the best mixed-effects models explained 80% and 61% of the variation in MOE and MOR, respectively. For jack pine, it was 51% and 33% for the same response variables. These results are a step toward models that could be used in sawing simulation software designed to estimate the internal properties of sawlogs and, as a result, better predict lumber and pulp chip quality.


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.


2013 ◽  
Vol 43 (3) ◽  
pp. 266-277 ◽  
Author(s):  
E. Duchateau ◽  
F. Longuetaud ◽  
F. Mothe ◽  
C. Ung ◽  
D. Auty ◽  
...  

Existing models for describing knot morphology are typically based on polynomial functions with parameters that are often not biologically interpretable. Hence, they are difficult to integrate into tree growth simulators due to the limited possibilities for linking knot shape to external branch and tree characteristics. X-ray computed tomography (CT) images taken along the stems of 16 jack pine (Pinus banksiana Lamb.) trees and 32 black spruce (Picea mariana (Mill.) B.S.P.) trees were used to extract the three-dimensional shape of 3450 and 11 276 knots from each species, respectively. Using a nonlinear approach, we firstly fitted a model of knot geometry adapted from a Weibull function. Separate equations were used to describe both the curvature and the diameter of the knot along its pith. Combining these two equations gave an accurate representation of knot shape using only five parameters. Secondly, to facilitate the integration of the resulting model into a tree growth simulator, we extracted the parameters obtained for each knot and modelled them as functions of external branch and tree characteristics (e.g., branch diameter, insertion angle, position in the stem, tree height, and stem diameter). When fitted to a separate data set, the model residuals of the black spruce knot curvature equation were less than 2.9 mm in any part of the knot profile for 75% of the observations. The corresponding value from the diameter equation was 2.8 mm. In jack pine, these statistics increased to 5.4 mm and 3.2 mm, respectively. Overall, the ability to predict knot attributes from external tree- and branch-level variables has the potential to improve the simulation of internal stem properties.


2020 ◽  
Vol 3 (1) ◽  
pp. 93
Author(s):  
Iulian Constantin Dănilă

Short rotation forestry (SRF) provides an important supply of biomass for investors in this area. In the NE (North-East) part of Romania at the present time are installed over 800 Ha of this kind of crops. The SRF enjoys the support through environmental policies, in relation to climate change and the provisions of the Kyoto Protocol to reduce the concentration of CO2 in the atmosphere. A precise estimate of biomass production is necessary for the sustainable planning of forest resources and for the exchange of energy in ecosystems. The use of the terrestrial laser scanner (TLS) in estimating the production of above ground wood biomass (AGWB) of short rotation forestry (SRF) brings an important technological leap among indirect (non-destructive) methods. TLS technology is justified when destructive methods become difficult to implement, and allometric equations do not provide accurate information. The main purpose of the research is to estimate the biomass productivity on tree parts in short rotation forestry with TLS technology. Measuring the hybrid poplars crops by TLS may have the following consequences: (1) Higher accuracy of the estimate of biomass production in the SRF; (2) cost and time effective measurements over the biomass of tree parts; (3) new and validated allometric equations for SRF in NE Romania; (4) solid instrument for industry to estimate biomass. TLS technology gives accurate estimates for DBH, tree height and location, as much as the volume on segments, commercial volume or crown volume can be determined. The accuracy of these values depends on the original scan data and their co-registration. The research will contribute to the development of knowledge in the field of hybrid crops.


Forests ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 59
Author(s):  
Olivier Fradette ◽  
Charles Marty ◽  
Pascal Tremblay ◽  
Daniel Lord ◽  
Jean-François Boucher

Allometric equations use easily measurable biometric variables to determine the aboveground and belowground biomasses of trees. Equations produced for estimating the biomass within Canadian forests at a large scale have not yet been validated for eastern Canadian boreal open woodlands (OWs), where trees experience particular environmental conditions. In this study, we harvested 167 trees from seven boreal OWs in Quebec, Canada for biomass and allometric measurements. These data show that Canadian national equations accurately predict the whole aboveground biomass for both black spruce and jack pine trees, but underestimated branches biomass, possibly owing to a particular tree morphology in OWs relative to closed-canopy stands. We therefore developed ad hoc allometric equations based on three power models including diameter at breast height (DBH) alone or in combination with tree height (H) as allometric variables. Our results show that although the inclusion of H in the model yields better fits for most tree compartments in both species, the difference is minor and does not markedly affect biomass C stocks at the stand level. Using these newly developed equations, we found that carbon stocks in afforested OWs varied markedly among sites owing to differences in tree growth and species. Nine years after afforestation, jack pine plantations had accumulated about five times more carbon than black spruce plantations (0.14 vs. 0.80 t C·ha−1), highlighting the much larger potential of jack pine for OW afforestation projects in this environment.


Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 370
Author(s):  
Holly D. Deighton ◽  
Frederick Wayne Bell ◽  
Nelson Thiffault ◽  
Eric B. Searle ◽  
Mathew Leitch ◽  
...  

We assessed 27 indicators of plant diversity, stand yield and individual crop tree responses 25 years post-treatment to determine long-term trade-offs among conifer release treatments in boreal and sub-boreal forests. This research addresses the lack of longer-term data needed by forest managers to implement more integrated vegetation management programs, supporting more informed decisions about release treatment choice. Four treatments (untreated control, motor-manual brushsaw, single aerial spray, and complete competition removal) were established at two jack pine (Pinus banksiana Lamb.) sites in Ontario, Canada. Our results suggest that plant diversity and productivity in boreal jack pine forests are significantly influenced by vegetation management treatments. Overall, release treatments did not cause a loss of diversity but benefitted stand-scale yield and individual crop tree growth, with maximum benefits occurring in more intensive release treatments. However, none of the treatments maximized all 27 indicators studied; thus, forest managers are faced with trade-offs when choosing treatments. Research on longer term effects, ideally through at least one rotation, is essential to fully understand outcomes of different vegetation management on forest diversity, stand yield, and individual crop tree responses.


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