How well can we select undamaged site trees for estimating site index?

1999 ◽  
Vol 29 (12) ◽  
pp. 1989-1992 ◽  
Author(s):  
Gordon D Nigh ◽  
Bobby A Love

The best estimates of site index, an indicator of site productivity, are obtained from site trees. Undamaged site trees should be sampled to obtain unbiased estimates of site index. Two juvenile height growth modelling projects provided us with sufficient data to assess our ability to select undamaged lodgepole pine (Pinus contorta var. latifolia Dougl.) and white spruce (Picea glauca (Moench) Voss) site trees. The sample trees were split open to measure height growth from the terminal bud scars. Splitting the stems also revealed damage that was not visible from the outside of the tree. Over 50% of the lodgepole pine trees and 75% of the white spruce trees had damage, which was much higher than expected. Possible causes of damage are frost and insects. The damage does not significantly reduce the height of the spruce trees, but there is evidence that the heights of the lodgepole pine trees are reduced.

1997 ◽  
Vol 12 (1) ◽  
pp. 5-8
Author(s):  
Gordon D. Nigh

Abstract The objective of this study was to determine whether the relationship between site index and early height growth of lodgepole pine (Pinus contorta var. latifolia) is the same on wet and dry sites. If the height growth/site index relationship is the same for different site types, then only one growth intercept model is required to estimate site index. Indicator variables in nonlinear regression were used to incorporate soil moisture availability into a growth intercept model. One set of parameters in a site index/early height growth model was adequate for both wet and dry sites. This result was supported graphically. Therefore, only one growth intercept model is necessary for the sites examined in this study. West. J. Appl. For. 12(1):5-8.


2005 ◽  
Vol 54 (1-6) ◽  
pp. 138-144 ◽  
Author(s):  
Jodie Krakowski ◽  
Y. A. El-Kassaby

Abstract The effects of seed pre-treatment (stratification/prechilling) and simulated aging on germination parameters (germination capacity, speed and value and peak value) were evaluated for several seedlots originating from seed orchard clones of lodgepole pine (Pinus contorta var. latifolia DOUGL. ex LOUD.) and white spruce (Picea glauca (MOENCH) VOSS). Region of origin and stratification had little effect on white spruce, while stratification enhanced germination speed and completeness of lodgepole pine. Broad-sense heritability for germination parameters ranged from 70 to 97% (unstratified) and from 81 to 96% (stratified) for pine, and from 95 to 97% (unstratified) and from 93 to 97% (stratified) for spruce. Simulated aging (short-term storage at high temperature and relative humidity, approximating the physiological effects of long-term storage) resulted in rapid deterioration of white spruce, with very little germination after six days of aging. Lodgepole pine germination increased during the first several aging treatments relative to the control, but germination capacity decreased following twelve days of aging, and was very low after 18 days. White spruce was nondormant and responded primarily to moisture conditions, whereas pine was strongly influenced by maternal effects. These results can be incorporated for more efficacious nursery production practices for commercial reforestation seedling production as well as ex-situ gene conservation strategies.


1963 ◽  
Vol 39 (4) ◽  
pp. 436-445 ◽  
Author(s):  
J. W. Bruce Wagg

Cage feeding of deer mice, Peromyscus maniculatus, and red-backed mice, Clethrionomys gapperi, showed a daily maximum seed consumption of lodgepole pine, Pinus contorta var. latifolia, of about 1,000 seeds and of white spruce, Picea glauca, of 2,000 seeds. There was no difference in the amount of seed consumed by the two species of mice. Lodgepole pine seed was preferred over white spruce.Meadow voles, Microtus spp., readily ate lodgepole pine and white spruce seedlings following germination. Red-backed mice also ate seedlings but not to the same degree as the meadow voles. The deer mouse was not tested.


1979 ◽  
Vol 55 (3) ◽  
pp. 102-105 ◽  
Author(s):  
D. G. Blackmore ◽  
Wm. G. Corns

Perennial herbaceous vegetation, mainly marsh reed grass, (Calamagrostis canadensis (Michx) Beauv.), was sprayed with glyphosate on the day before planting one-year-old plugs of lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) and white spruce (Picea glauca (Moench) Voss) on cutover forest land north of Edson, Alberta. Spraying at 4.5 kg ai/ha, included spot and strip applications in June 1976, compared with unsprayed scalps and controls. At the same time, all treatments were repeated plus a 9 g, 22-8-2 fertilizer tablet for each seedling. Another experiment at the same site, begun on August 1, 1976, compared scalp, unfertilized control and glyphosate strip treatments, followed by planting of pine seedlings the day after spraying 4.5 kg ai/ha glyphosate. An adjacent experiment, also commenced on August 1, included dosages of 1.1 to 5.6 kg ai/ha with planting of pine seedlings in 4.5 kg/ha and in control plots in May 1977. August application of 2.2 kg/ha provided excellent initial vegetation control, as effective as the larger amounts applied at that time, and was superior during the first 12 months to 4.5 kg/ha applied in June. Twenty-six months after the spring planting new shoot growth of fertilized pine in the glyphosate strips was statistically significantly greater than that for all other treatments and growth in fertilized scalps was also very good. At the same time leader growth of spruce in fertilized scalps was significantly greater than that for other treatments but growth in glyphosate strips did not exceed that of unfertilized controls. Contrary to results of spring planting, there was marked injury and mortality of pine planted in August in glyphosate plots which had been sprayed on the preceding day. Seedlings planted in glyphosate-treated strips nine months after the August spraying exceeded the growth of control plants but not until the year after they were planted.


2001 ◽  
Vol 31 (9) ◽  
pp. 1650-1653 ◽  
Author(s):  
Sarah M Lieffers ◽  
Victor J Lieffers ◽  
U Silins ◽  
L Bach

Twigs from lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) and white spruce (Picea glauca (Moench) Voss) trees were bent at a range of temperatures below 0°C using a two-point bending test. This was done to determine how cold temperatures might affect twig breakage and potential shoot and foliage loss in maturing conifer stands. The bending angle necessary to cause 50% twig breakage decreased linearly with decreasing temperatures for both species. No difference in the relationship between temperature and twig breakage was evident among species. Below –13°C, all breakage was on the tension side; at warmer temperatures there was compression damage to many twigs.


2000 ◽  
Vol 17 (2) ◽  
pp. 71-79 ◽  
Author(s):  
Sam K. Takyi ◽  
Graham R. Hillman

Abstract Artificial reforestation experiments compared survival and growth of five species of coniferous containerized seedlings, and seedling browsing by ungulates on a clearcut, drained, and mounded peatland in the boreal forest. Six to seven growing seasons after planting, 91% of all seedlings had survived. Height and diameter growth in five species were ranked as follows: Siberian latch (Larix sibirica Ledeb.) > lodgepole pine (Pinus contorta var. latifolia Engelm.) > tamarack (Larix laricina [Du Roi] K. Koch) > black spruce (Picea mariana [Mill.] B.S.P.) = white spruce(Picea glauca [Moench] Voss). Overall, tamarack height and diameter growth was twice that of either spruce species. Height and diameter growth of tamarack, black spruce, and white spruce planted in the spring was 65% to 97% greater than that of the more robust seedlings for the same species planted in the fall of the same year. Repeated winter browsing by ungulates did not affect survival and growth of the five species. In an experiment where survival and growth of tamarack and black spruce seedlings planted on the mounds were compared with that of seedlings planted on the flat areas between mounds, there were no differences in survival, height, or root collar diameter growth between the two planting sites. In the event that suitable peatlands are used to augment existing timber supplies, lowering the water table through ditching, combined with mound-planting, is a feasible method of reforesting timber-harvested, boreal wet sites with Siberian latch, lodgepole pine, and white spruce. Tamarack and black spruce, however, survive and grow well on drained peatlands without mound-planting. North. J. Appl. For. 17(2):71-79.


1998 ◽  
Vol 28 (3) ◽  
pp. 489-493 ◽  
Author(s):  
L B Nadeau ◽  
D J Pluth ◽  
P V Blenis

Seedlings of lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) and white spruce (Picea glauca (Moench) Voss) were grown for 8 years under five different levels of deep tillage. These were, in increasing order of disturbance: control, vibration ripping, deep plowing, deep plowing plus residue, and Marttiini plowing. Five-year growth curves of each tree were partitioned into three orthogonal components: mean, linear, and quadratic trends. Nitrogen and phosphorus concentrations and mass of the current-year needles were analyzed. Deep plowing plus residue significantly reduced pine heights relative to both vibration ripping and the control, whereas spruce heights were less in the control treatment than in the vibration-ripped treatment. Tillage treatments did not affect nitrogen or phosphorus concentrations of current-year pine or spruce needles. In pine, deep plowing plus residue treatment resulted in the lightest needles, and Marttiini plowing, deep plowing and control treatments resulted in the heaviest needles. In spruce, needle mass was lowest for the deep plowing plus residue treatment and similar among the other treatments. Vibration ripping of medium-textured, well to imperfectly drained Gray Luvisols may be recommended to increase spruce seedling height growth, but any of the deep-tillage treatments used cannot be recommended for pine.


2013 ◽  
Vol 43 (2) ◽  
pp. 139-148 ◽  
Author(s):  
Diana E. Osika ◽  
Kenneth J. Stadt ◽  
Philip G. Comeau ◽  
Daniel A. MacIsaac

In the boreal plains of western Canada, white spruce (Picea glauca (Moench) Voss) height−age and site index (SI) curves have been developed and applied to assess site productivity for white spruce without fully considering the competition that usually occurs between the spruce and taller deciduous trees. In this study, we evaluated the effects of deciduous removal on white spruce height growth potential using stem analysis on typical control spruce grown with deciduous neighbours and spruce that were released from deciduous competition ∼60 years prior. Due to the late application of the release treatments (at stand ages of 20–60 years), the observed site index of spruce was not affected by treatment. However, height growth in the 50 years following treatment was increased by 2.1 m. We present a height−age model to specifically estimate the change in SI required to achieve the observed height response following late release. The model indicated that the post-release SI estimate of white spruce would need to be on average 4.2 m higher than control SI to track the height response. This model is useful for estimating the true, competition-free SI for white spruce from the observed SI in natural mixed stands.


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