The use of multiple measurement techniques to refine estimates of conifer needle geometry

2003 ◽  
Vol 33 (1) ◽  
pp. 101-105 ◽  
Author(s):  
B Bond-Lamberty ◽  
C Wang ◽  
S T Gower

Knowledge of foliar surface area is important in many fields, but estimating the area of nonflat conifer needles is difficult. The primary goal of this study was to use optical scanning and immersion methods to test and refine the standard cross-sectional geometries assumed for black spruce (Picea mariana (Mill.) BSP) and jack pine (Pinus banksiana Lamb.) needles. Projected leaf area (PLA, measured using a flatbed scanner), and hemisurface leaf area (HSLA, estimated from water immersion) were compared for conifer samples from a 37-year-old even-aged stand in northern Manitoba, Canada. The HSLA–PLA relationship was used to infer information about needle cross-sectional geometry after assuming a basic form (rhombus for black spruce and hemiellipse for jack pine). The cross section of black spruce needles was best approximated as a rhombus with a major/minor diagonal ratio of 1.35. Jack pine needles were best described by a hemiellipse with major/minor axis ratio of 1.30. Minor but incorrect assumptions of needle cross-sectional geometry resulted in foliar area errors of 6–8% using scanning methods and 1–2% using immersion methods. Simple equations are presented to calculate hemisurface needle area from volume or projected needle area based on these refined parameters.

1987 ◽  
Vol 63 (6) ◽  
pp. 446-450 ◽  
Author(s):  
James E. Wood ◽  
Richard Raper

In the alternate strip clearcutting system, first-cut strips are regenerated by seed produced by black spruce (Picea mariana [Mill.] B.S.P.) in the forested leave strips. However, after the second cut, such a seed source is not available for regenerating the leave strips. Therefore, the forest manager must consider a number of alternative regeneration options. The selection of the most appropriate regeneration option is dependent upon several economic and biological criteria. These include future costs of delivered wood, site productivity, post-harvest site condition, future alternative sources of supply, and future demand for industrial wood. Regeneration options such as preservation of advance growth and direct seeding are recommended for sites on which the manager is concerned primarily with regenerating first cut strips and is willing to accept a lower level of stocking in leave strips. Planting, the most intensive option discussed, should be reserved for sites offering the highest potential return or greatest future cost savings. Direct seeding of jack pine (Pinus banksiana Lamb.) should be considered on the upland portions of this patterned site type. Mixing jack pine and black spruce is a suggested regeneration option if the site contains both upland and lowland topographic positions. Other seeding options include the use of semi-transparent plastic seed shelters. The manager might consider combining two or more of these options to meet management objectives.


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.


2017 ◽  
Vol 47 (8) ◽  
pp. 1116-1122 ◽  
Author(s):  
Rongzhou Man ◽  
Pengxin Lu ◽  
Qing-Lai Dang

Conifer winter damage results primarily from loss of cold hardiness during unseasonably warm days in late winter and early spring, and such damage may increase in frequency and severity under a warming climate. In this study, the dehardening dynamics of lodgepole pine (Pinus contorta Dougl. ex. Loud), jack pine (Pinus banksiana Lamb.), white spruce (Picea glauca (Moench) Voss), and black spruce (Picea mariana (Mill.) B.S.P.) were examined in relation to thermal accumulation during artificial dehardening in winter (December) and spring (March) using relative electrolyte leakage and visual assessment of pine needles and spruce shoots. Results indicated that all four species dehardened at a similar rate and to a similar extent, despite considerably different thermal accumulation requirements. Spring dehardening was comparatively faster, with black spruce slightly hardier than the other conifers at the late stage of spring dehardening. The difference, however, was relatively small and did not afford black spruce significant protection during seedling freezing tests prior to budbreak in late March and early May. The dehardening curves and models developed in this study may serve as a tool to predict cold hardiness by temperature and to understand the potential risks of conifer cold injury during warming–freezing events prior to budbreak.


1998 ◽  
Vol 78 (1) ◽  
pp. 77-83 ◽  
Author(s):  
Helmut Krause

The purpose of this study was to determine whether change of forest cover had an effect on the development of the organic surface horizons, particularly on those variables that influence nutrient cycling and forest productivity. Jack pine (Pinus banksiana Lamb.) and black spruce (Picea mariana [Mill.] B.S.P.) plantations were selected from among the youngest to oldest (2–16 yr) within a 100 km2 area in southeastern New Brunswick. Natural forests were also included as benchmark sites. The forest floor and tree foliage was sampled and trees measured on 0.05-ha plots. The forest floor samples were used to determine organic mass, nutrient contents and pH. In pine plantations, organic matter accumulated rapidly during the period of exponential tree growth, but leveled off at about 45 Mg ha–1. This was within the range of benchmark sites with mixed conifer-hardwood cover. In spruce plantations, the forest floor mass ranged upward to 77 Mg ha–1. Development was strongly influenced by the nature of the previous forest. Spruce forest floors were on average more acid and had lower nutrient concentrations, particularly N and Ca. The observed differences suggest that nutrients are recycled more rapidly in the pine plantations, partly explaining the superior growth of the latter. Key words: Forest floor, Kalmia angustifolia L., Picea mariana (Mill.) B.S.P., Pinus banksiana Lamb., nutrient cycling, plantation forest


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.


2004 ◽  
Vol 34 (9) ◽  
pp. 1938-1945 ◽  
Author(s):  
Isobel Waters ◽  
Steven W Kembel ◽  
Jean-François Gingras ◽  
Jennifer M Shay

This study compares the effects of full-tree versus cut-to-length forest harvesting methods on tree regeneration in jack pine (Pinus banksiana Lamb.), mixedwood (Picea glauca (Moench) Voss – Populus tremuloides Michx. – Abies balsamea (L.) Mill.), and black spruce (Picea mariana (Mill.) BSP) sites in southeastern Manitoba, Canada. We surveyed tree regeneration densities, disturbance characteristics, and understorey vegetation in replicated control and harvested plots in each site type preharvest (1993) and 1 and 3 years postharvest (1994, 1996). In jack pine sites, the full-tree harvest method promoted regeneration of Pinus banksiana through increased disturbance of soil and the moss layer, and decreased slash deposition relative to the cut-to-length method. Conversely, in mixedwood sites the cut-to-length method resulted in less damage to advance regeneration and proved better at promoting postharvest regeneration of Abies balsamea and Picea glauca relative to the full-tree method. In black spruce sites, there were few differences in the impact of the two harvesting methods on regeneration of Picea mariana, which increased in frequency and density after both types of harvesting.


1988 ◽  
Vol 64 (4) ◽  
pp. 315-319 ◽  
Author(s):  
Z. Chrosciewicz

An experimental burn in conjunction with a seed-tree system was successful in regenerating jack pine (Pinus banksiana Lamb.) on a fresh to somewhat moist upland, loamy till, cutover site in central Saskatchewan. About 20 well-formed, uniformly spaced seed trees per hectare were left standing during timber harvest. The ignition of logging slash was carried out under preselected weather and fuel conditions so that favorable seedbeds and adequate seed dispersal from the seed trees were produced. Four growing seasons after burning, jack pine stocking by 4-m2 quadrats was 90% with 12 195 seedlings/ha. Aspen (Populus tremuloides Michx.), to a lesser degree black spruce (Picea mariana [Mill.] B.S.P.), and other companion tree species also regenerated with the pine. Various seedbed and regeneration characteristics as well as height growth rates are discussed. Key words: Pinus banksiana, slash burning, seed-tree system, forest regeneration, growth rates, central Saskatchewan.


2010 ◽  
Vol 40 (1) ◽  
pp. 37-47 ◽  
Author(s):  
Xavier Cavard ◽  
Yves Bergeron ◽  
Han Y.H. Chen ◽  
David Paré

This study investigates the potential of mixed forest stands as better aboveground carbon sinks than pure stands. According to the facilitation and niche complementarity hypotheses, we predict higher carbon sequestration in mature boreal mixedwoods. Aboveground carbon contents of black spruce ( Picea mariana (Mill.) Britton, Sterns, Poggenb.) and trembling aspen ( Populus tremuloides Michx.) mixtures were investigated in the eastern boreal forest, whereas jack pine ( Pinus banksiana Lamb.) and trembling aspen were used in the central boreal forest. No carbon gain was found in species mixtures; nearly pure trembling aspen stands contained the greatest amount of aboveground carbon, black spruce stands had the least, and mixtures were intermediate with amounts that could generally be predicted by linear interpolation with stem proportions. These results suggest that for aspen, the potentially detrimental effect of spruce on soils observed in other studies may be offset by greater light availability in mixtures. On the other hand, for black spruce, the potentially beneficial effects of aspen on soils could be offset by greater competition by aspen for nutrients and light. The mixture of jack pine and trembling aspen did not benefit any of these species while inducing a loss in trembling aspen carbon at the stand level.


2005 ◽  
Vol 81 (1) ◽  
pp. 104-113 ◽  
Author(s):  
Daniel Mailly ◽  
Mélanie Gaudreault

The objective of this study was to develop variable growth intercept models for coniferous species of major importance in Quebec using Nigh's (1997a) modelling technique. Eighty-three, 68, and 70 stem analysis plots of black spruce (Picea mariana [Mill.] BSP), jack pine (Pinus banksiana Lamb.) and balsam fir (Abies balsamea (L.) Mill) were used, respectively. The growth intercept models for black spruce were the most precise, followed by those for jack pine and finally by those for balsam fir, based on the root mean square errors. Results indicated that the accuracy of the models was good, relative to those previously published for other species in Canada. Interim testing of the models revealed a low mean error for all three species that may not be of practical significance for site index determination, although more data should be obtained to further test the models. Key words: balsam fir, black spruce, growth intercept, jack pine, model, nonlinear regression, site index


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