scholarly journals Scaling Approach for Estimating Stand Sapwood Area from Leaf Area Index in Five Boreal Species

Forests ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 829 ◽  
Author(s):  
Quiñonez-Piñón ◽  
Valeo

This paper presents a scaling approach for estimating sapwood area at the stand level using knowledge obtained for individual trees of five boreal species: Populus tremuloides (Michx.), Pinus contorta (Doug. ex Loud. var. latifolia Engelm.), Pinus banksiana (Lamb.), Picea mariana (Mill.) BSP, and Picea glauca (Moench) Voss. Previously developed allometric models for sapwood depth and diameter at breast height for individual tree species were used to build stand level sapwood area estimates as well as stand level leaf area estimates, in pure and mixed vascular vegetation stands. A stand’s vegetation heterogeneity is considered in the scaling approach by proposing regression models for each species. The new combined scaling approach drew strong linear correlations at the stand scale between sapwood area and leaf area using observations taken in mixed stands of Southern Alberta, Canada. This last outcome suggests a good linear relationship between stand sapwood area and stand leaf area. The accuracy of the results was tested by observing each regression model’s adequacy and by estimating the error propagated through the whole scaling process.

2011 ◽  
Vol 26 (2) ◽  
pp. 82-90 ◽  
Author(s):  
Richard D. Kabzems ◽  
George Harper ◽  
Peter Fielder

Abstract Managing boreal mixed stands of trembling aspen (Populus tremuloides Michx.) and white spruce (Picea glauca [Moench] Voss) is more likely to sustain a diversity of values and has the potential to increase productivity at both the site and landscape levels compared with pure broadleaf or conifer management. In this study, we examine growth of white spruce and aspen after 11 growing seasons over a range of aspen densities created by spot and broadcast treatment of broadleaves using manual and chemical means, aspen spacing, and an untreated control. Results indicate that survival and growth of both spruce and aspen were similar across the range of treatments. Spruce groundline diameter was greater, and height to groundline diameter ratio was lower, for the treatments in which aspen was chemically controlled or uniformly spaced compared with the control. Light measurements at the individual tree level suggested that increased light availability improved white spruce diameter growth. Spruce height growth did not vary by treatment. The status of these experimental mixedwoods was compared with current conifer and mixedwood regeneration evaluations, as well as the preharvest composition of the original stand. After 11 growing seasons, growth of aspen and white spruce indicated that opportunities exist to further modify aspen density to enhance treatment longevity and effectiveness to produce a greater range of boreal mixedwood stand types.


2019 ◽  
Author(s):  
Marina Caselli ◽  
Gabriel Ángel Loguercio ◽  
María Florencia Urretavizcaya ◽  
Guillermo Emilio Defossé

Abstract Leaf area is an important ecophysiological and silvicultural variable for quantifying the potential production of trees, since it can represent growing space occupancy. At the stand level in mixed forests, productivity is conditioned on how growing space is distributed among different components structure, such as species and strata. In complex structures, traditional forest variables (i.e., basal area) do not allow a good representation of the occupied growing space, whereas leaf area appears as a better indicator. Andean cypress and coihue beech are species of the Andean-Patagonian forests that grow in either pure or mixed stands, presenting high productive potential. The aim of this study was to develop, for each species, leaf area prediction functions through allometric relations and to evaluate the relation between leaf area, volume increment and growing space occupancy. For this purpose, we carried out destructive sampling of individuals of both species in mixed Andean cypress-coihue forests. Results for these species show that leaf area can be reliably estimated by using the models developed in this study. These models, based on sapwood area, tree diameter, and/or height measurements, explain at least 90 percent of variation in leaf area. The functions fitted are a fundamental tool to study the distribution of growth and to formulate management guidelines for mixed forests through the control of growing space occupancy using leaf area index.


Forests ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 686 ◽  
Author(s):  
M. Quiñonez-Piñón ◽  
Caterina Valeo

The translucence and color change in wood methods, which are commonly used to differentiate sapwood from heartwood in tree cores, are compared against the microscopic analysis of wood anatomy method for determining sapwood depth. The translucence method was tested on collected wood cores of White Spruce (Picea glauca (Moench) Voss) and Jack Pine (Pinus banksiana Lamb.). The color change in wood method was tested on Trembling Aspen (Populus tremuloides Michx.). For every statistical comparison, sapwood depth values obtained with the translucence or color-change methods were significantly different from those obtained using the microscopic analysis. Using the sapwood depth values obtained with microscopy as a reference, the bias associated with the translucence or color-change methods used on Picea glauca, Pinus banksiana and Populus tremuloides constantly under- or overestimated sapwood depths within −0.3 cm to 1.6 cm; −4.9 cm to 0.5 cm; and 0 to 1.8 cm, respectively. The different ranges of over- and underestimation arise from species-specific anatomical characteristics. Estimates for the errors in sapwood depth, when the depth is measured using either the translucence or color-change methods, are presented. These relationships and research outcomes will lead to more efficient forest monitoring and improved estimates of forest water balance, which in turn will lead to improved forest management in the face of climate change.


2007 ◽  
Vol 22 (3) ◽  
pp. 163-170 ◽  
Author(s):  
Ryan J. Klos ◽  
G. Geoff Wang ◽  
Qing-Lai Dang ◽  
Ed W. East

Abstract Kozak's variable exponent taper equation was fitted for balsam poplar (Populus balsamifera L.), trembling aspen (Populus tremuloides Michx.), white spruce (Picea glauca [Moench] Voss), black spruce (Picea mariana [Mill.] B.S.P.), and jack pine (Pinus banksiana Lamb.) in Manitoba. Stem taper variability between two ecozones (i.e., Boreal Shield and Boreal Plains) were tested using the F-test. Regional differences were observed for trembling aspen, white spruce, and jack pine, and for those species, separate ecozone-specific taper equations were developed. However, the gross total volume estimates using the ecozone-specific equations were different from those of the provincial equations by only 2 percent. Although the regional difference in stem form was marginal within a province, a difference of approximately 7 percent of gross total volume estimation was found when our provincial taper equations were compared with those developed in Alberta and Saskatchewan. These results suggest that stem form variation increases with spatial scale and that a single taper equation for each species may be sufficient for each province.


1991 ◽  
Vol 71 (4) ◽  
pp. 397-410 ◽  
Author(s):  
X. J. Xiao ◽  
D. W. Anderson ◽  
J. R. Bettany

Pedogenesis and its effect on calcium (Ca), magnesium (Mg) and phosphorus (P) was studied on a sequence of seven Gray Luvisol soils in central Saskatchewan. The soils were formed on calcareous glacial till under trembling aspen (Populus tremuloides Michx), mixedwood (aspen and white spruce) (Picea glauca (Moench) Voss)) and coniferous (black spruce and jack pine) (Picea mariana (Mill) BSP and Pinus banksiana Lamb) forests. Soils under aspen had the highest concentration of total and exchangeable Ca and Mg in litter layers and Ae horizons, and had Ae and Bt horizons that were least acidic. The most acidic Ae and Bt horizons and lowest amounts of Ca and Mg occurred under coniferous forests, whereas the soils under mixedwood stands were intermediate. The thickness of eluvial (Ae and AB) horizons increased along the aspen to coniferous sequence. All soils had about 40% less P in their A and B horizons than was calculated to have been present at the start of soil formation. The greatest decrease in P was observed in the thickest and most acidic soil under coniferous forest. The present litter layers and vegetation make up only a small proportion of the P removed from the mineral soil. Unusually large amounts of P appear to have been translocated from A and B horizons during development of Gray Luvisols, in comparison to Chernozemic or even Podzolic soils. Our hypothesis proposes that P is ineffectively retained in the solum as P-clay-humus, or iron-P complexes and that organic P moves along with the soil water, laterally and downslope through permeable Ae horizon over less permeable Bt horizons, or vertically through macropores. Key words: Boreal forest, nutrient cycling, phosphorus losses, weathering, soil formation


2008 ◽  
Vol 38 (7) ◽  
pp. 1817-1828 ◽  
Author(s):  
Cosmin D. Man ◽  
Philip G. Comeau ◽  
Douglas G. Pitt

The influence of aspen ( Populus tremuloides Michx.) and herbaceous (forb and grass) vegetation on resource availability and white spruce ( Picea glauca (Moench) Voss) growth were examined as part of a long-term experiment established in 2002 near Whitecourt, Alberta, Canada. During the 2005 growing season, we examined the effects of herbicide treatments designed to control only woody (triclopyr ester) or both woody and herbaceous (glyphosate) vegetation on leaf area index (LAI) of both the woody and herbaceous components and relationships among LAI and light, soil moisture, air temperature, soil temperature, nitrogen availability, and spruce growth. Treatments reduced LAI and increased light, soil nitrogen availability, and white spruce growth. There were no apparent effects of the treatments on soil moisture in 2005. Both the woody and herb–grass layers appear to be competing for light and soil nitrogen in this young plantation. Controlling only woody vegetation resulted in an increase in herbaceous and total LAI (dominated by the grass Calamagrostis canadensis (Michx.) Beauv.). Spot treatment, involving control of vegetation within a 2 m radius of spruce seedlings while leaving 1 m of untreated ground between treated spots, may be a promising alternative to classical broadcast treatments for establishing spruce in a mixedwood stand. Spot treatments provided good growing conditions and reduced exposure of spruce seedlings to summer and winter frost injury during the first 3 years after planting.


1984 ◽  
Vol 60 (5) ◽  
pp. 283-287 ◽  
Author(s):  
R. F. Sutton

One manual and two chemical (mist-blown foliar spray of glyphosate and hexazinone) methods of vegetation control were applied in two 17.1 m × 17.1 m plots per treatment in a 1969 boreal cutover in Forest Section B7 where natural jack pine (Pinus banksiana Lamb.) regeneration, mostly about 1 m tall, was overtopped by post-harvest deciduous growth, including sapling aspen (Populus tremuloides Michx.). Season of application(fall = September 1976; summer = July 1977) and, for the chemical treatments, rate of application (0. 1, 2, and 4 kg ai/ha) were evaluated for their effect on (a) deciduous competition, (b) natural jack pine regeneration, and (c) white spruce (picea glauca [Moench] Voss) outplanted as bare-root 2 + 2 stock in June 1978. Annual or more frequent assessments were made through 1983. With (a), manual treatment was more effective in summer than in fall but did not effect sustained control. Of the fall-applied herbicide treatments, only glyphosate at 2 and 4 kg ai/ha was efficacious. Sustained control over several years was obtained with summer-applied glyphosate and, to a lesser degree, hexazinone. With (b), jack pine was not benefited by any treatment. With (c), frost and browsing obscured treatment effects, but the "best" control of deciduous vegetation was probably silviculturally detrimental to the spruce.


2019 ◽  
pp. 297-307
Author(s):  
Yuqing Yang ◽  
Shongming Huang ◽  
Robert Vassov ◽  
Brad Pinno ◽  
Sophan Chhin

Climate-sensitive height–age models were developed for top height trees of trembling aspen (Populus tremuloides Michx.), jack pine (Pinus banksiana Lamb.), and white spruce (Picea glauca (Moench) Voss) in natural and reclaimed oil sands stands. We used stem analysis data collected from the Athabasca oil sands region in northern Alberta, Canada, and climate data generated by the ClimateWNA model. Height–age trajectories differed between top height trees in natural and reclaimed stands for jack pine and white spruce, but not for trembling aspen. At a given age, white spruce top height trees were taller and jack pine top height trees were shorter in reclaimed stands than those in natural stands, suggesting that it is easier to achieve similar forest productivity for oil sands sites reclaimed with white spruce stands than for sites reclaimed with jack pine stands. The principal climate variables were growing season (May to September) precipitation averaged over the previous 10 years for trembling aspen and jack pine and summer (June to August) precipitation averaged over the previous 10 years for white spruce. These variables had positive effects on the height–age trajectories.


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