bluuebunny/crossref_metadata_2025 huggingface dataset:
Syllepsis in Larixlaricina: occurrence and distribution of sylleptic long shoots and their relationships with age and vigour in young plantation-grown trees
Authors: Powell G. R. , Vescio Shelley A.
Published: February 2008

Production of sylleptic long shoots by 102 young Larixlaricina (Du Roi) K. Koch growing in three plantations was monitored for 5 successive years. Sylleptic long shoots were readily discernible both during development and in subsequent years because of their location, growth pattern, and distinctive morphology. Percentages of trees with current-year syllepsis increased from 67% at age 3 years to 90% at age 6 years. Mean numbers of sylleptic long shoots per sylleptic leader also increased as trees aged. Leaders with heavy syllepsis (21–39 shoots) elongated at a mean rate of 14 mm/day for 60 days; whereas, leaders without syllepsis elongated at 12 mm/day for 60 days. The former then continued elongating for a longer period. Distribution of elongation along the leaders also differed. More segments of equal initial length were marked on sylleptic than on nonsylleptic elongating leaders. Early segments elongated more on the latter than on the former. Sylleptic shoots became evident in late June and more formed acropetally until late July on some trees. They elongated at rates up to 10 mm/day and some continued elongating for as long as did their parent leaders. Syllepsis gives trees apparent advantage as they have greater capacity for foliage production.
The impact of misspecification of the negative binomial shape parameter in sequential sampling plans
Authors: Warren W. G. , Chen Pin Whei
Published: February 2008

Standard sequential sampling plans for determining whether infestations of forest pests have attained critical levels are commonly based on the assumption that the counts follow a negative binomial distribution for which the shape parameter, k, which must be specified, may be difficult to estimate and may well be unstable. This paper studies the effect of misspecification of this parameter on the operating characteristic and average sample number functions of a sequential sampling plan. It appears that slight underestimation of the shape parameter can improve the operating characteristic at little cost, i.e., with only small increase in the average sample number.
Inoculation of Douglas-fir roots with isolates of Phellinusweirii on sites differing in root rot severity
Authors: Hansen E. M.
Published: February 2008

Dougls-fir (Pseudotsugamenziesii (Mirb.) Franco) trees 12–32 years old were inoculated with four isolates of the fungus Phellinusweirii (Murr.) Gilb in 20 plantations in western Oregon. Mycelium grew onto roots from inoculum blocks in 54% of 759 inoculations, but the fungus appeared to be alive on only 32% of the roots after 2 years. The average maximum extent of ectotrophic growth on successfully inoculated roots was 13.2 cm. Inoculation success and mycelial growth were greater for the two isolates originating from an area of severe root rot than for the two isolates from an area with light damage. Mycelial growth on roots differed among plantations, but there was no correlation between naturally occurring root rot damage and inoculation success or mycelial growth.
Soil temperature regime in a forested Appalachian watershed
Authors: Tajchman S. J. , Minton C. M.
Published: February 2008

Daily and seasonal variations in soil temperature at various topographic positions in a forested catchment are compared. The experimental sites were designed as ridgetop, north-facing lower slope, south-facing lower slope, and southwest-facing slope. On sunny days during the growing season, the surface temperature had the greatest amplitude (7.8 °C) at the south-facing upper slope and the smallest amplitude (4.0 °C) at the north-facing slope; the remaining sites were intermediate. The maximum surface temperature was observed in the afternoon at all sites. With increasing depth, daily soil temperature ranges diminished and, below 10 cm depth, they were less than 1 °C. Under overcast conditions, daily soil temperature fluctations lessened. For individual months, the mean temperatures of the 2–30 cm soil layer generally varied among all sites by less than 1 °C and never the difference exceeded 1.8 °C. The surface temperature variations and their differences among sites appear to be the most distinguished feature of the soil thermal regime and they seem to be aspect related.
Successional changes in Pinuselliottii plantations following two regeneration treatments
Authors: Swindel Benee F. , Conde Louis F. , Smith Joel E.
Published: February 2008

In the intensively managed forests of the Lower Coastal Plain of the southeastern United States, clear-cutting and intensive regeneration methods may pose a threat to the existing flora. To assess this danger, our objective was to quantify and describe the changes in community structure and composition following conversion of second-growth pine forests in northern Florida to plantations of slash pine (Pinuselliottii Engelm.). Plantations were established by two different regeneration regimes: a minimum regime effecting little dislocation of the forest floor and the soil and a maximum regime effecting severe dislocation of logging slash, the forest floor, and the soil together with much greater destruction of residual understory. Statistically independent surveys of the crown cover and foliage biomass of all plant species were conducted before harvesting and at plantation age 1, 2, 3, and 5 years. Reductions of woody species during regeneration were more pronounced following maximum treatment, but subsequent response in cover and biomass were similar. Herbaceous species generally increased markedly following forest operations, with differences in magnitude and pattern of response attributable to difference in treatment. However, similarity indices indicate that herbs are not regaining pretreatment composition. Plant species richness generally increased following regeneration; forb species were especially numerous after harvests. Shannon diversity, especially foliage biomass diversity also increased substantially after harvests. Twelve scarce species were identified as plants worthy of special concern in managed flat woods forests.
Rapid micropropagation of Calabrian pine from primary and secondary buds on shoot explants
Authors: Abdullah Anwar A. , Grace John , Yeoman Michael M.
Published: February 2008

Axillary shoot production was achieved in 6 weeks using excised shoot explants of Pinusbrutia Ten. on a modified Schenk and Hildebrandt medium containing cytokinin. Primary shoots arose from existing axillary buds and secondary buds arose from bases of the primary shoots. Their production could be increased by regulating the cytokinin level and by surgical removal of apical buds from the cultured explants. However, the best performance was achieved with a low level of 6-benzylaminopurine (3 × 10−6 M) or a mixture of 6-benzylaminopurine and kinetin (10−6 M of each). Subsequent transfer to a cytokinin-free medium resulted on average in the production of 43 shoots per cultured explant and up to 67 shoots per clone within 12 weeks. When the primary shoots, which had already produced one crop of secondary shoots, were maintained under conditions favourable for shoot production, a doubling in number was obtained within 4–6 weeks. To encourage further elongation, newly formed shoots were incubated for 2 weeks on a cytokinin-free medium to which 1% activated charcoal was added. The time taken with this method was much shorter than with other published methods and is, therefore, likely to be important for the vegetative propagation and multiplication of selected seedlings of this species.
Impact of feeding damage by the porcupine on western hemlock – Sitka spruce forests of north-coastal British Columbia
Authors: Sullivan Thomas P. , Jackson William T. , Pojar James , Banner Allen
Published: February 2008

This study measured the incidence of feeding damage by porcupines (Erethizondorsatum Allen) within the second-growth western hemlock (Tsugaheterophylla Raf. (Sarg.)) – Sitka spruce (Piceasitchensis (Bong.) Carr.) forest of Khutzeymateen Inlet, 45 km northeast of Prince Rupert, British Columbia. Tree mensuration and damage assessments were conducted in 69 sample plots located on four transects. Western hemlock, which composed 67% of sampled stands, was the most severely (52.7% of trees, of which 5.1% were newly attacked) damaged species followed by Sitka spruce with minor (7.8%) damage. The less frequent amabilis fir (Abiesamabilis (Dougl.) Forbes) and western red cedar Thujaplicata Donn.) were not attacked. The total percentage of girdled (mortality) hemlock stems was 30.9%. Hemlock trees with a dbh > 27.4 cm had 55.9% of stems girdled. Porcupines attacked and girdled a significantly greater proportion of large than small diameter hemlock trees. Stems smaller than 125.5 cm dbh had little (3.7%) damage. Significantly more damage wounds were recorded in the middle and upper thirds of hemlock stems than in the lower bole. Dominant and codominant hemlock were preferred by porcupines in their feeding attacks. In combination with porcupine control measures, these stands clearly require some form of silvicultural treatment, such as sanitation spacing, conducted initially as an operational trial on at least a 20-ha block.
Terminal leader failure in white spruce plantations in northern Minnesota
Authors: Harding R. Bruce
Published: February 2008

Terminal leader failure from bud mortality occurred in 46% of plantation white spruce (Piceaglauca (Moench) Voss) trees, 19–43 years old. Frost damage was identified as the causal factor of bud mortality, with all plantations being established from seed sources of local origin. Large differences in terminal bud failure rates were noted between year of observation, tree size class, and stand age-class. Dominant trees, 33–43 years old, had a 3 year failure rate ranging from 16 to 51 %. For dominant trees, an 18% (9 cm) height growth reduction per year of incidence was noted. The lateral replacement process could account for greater than a 2 m height reduction for dominants at age 50 years, confounding estimates of potential site quality. The height growth of overtopped trees responded differently to frost damage than dominants, with replacement laterals averaging 38% (8 cm) greater height growth than apical terminals of undamaged trees.
Elemental profiles for Douglas-fir seeds: evidence of genetic control
Authors: McLean John A. , El-Kassaby Yousry A.
Published: February 2008

Seeds from four ramets in each of six clones of 17-year-old Douglas-fir, Pseudotsugamenziesii (Mirb.) Franco, grown in a Saanichton, B.C., seed orchard on common rootstock were examined by X-ray energy-dispersive spectrometry to determine variations in trace element profiles. These profiles were analysed by discriminant function analysis and shown to be specific for each clone with 80.4% of seeds being correctly classified to original clone. Since the ramets were all grown in a similar orchard environment, these results support the hypothesis that elemental uptake by seeds of Douglas-fir is under genetic control.
Effects of madrone, chinkapin, and tanoak sprouts on light intensity, soil moisture, and soil temperature
Authors: Minore Don
Published: February 2008

Light, moisture, and temperature measurements beneath sprout clumps were compared with similar measurements outside the clumps on eight clear-cuttings in southwestern Oregon. Light intensity was higher beneath madrone than beneath tanoak or chinkapin. Soil moisture was higher beneath the clumps and soil temperature was lower than outside them during the cool moist summer of 1983. Soil temperature remained lower beneath the clumps during the warm dry summer of 1985, but moisture conditions were similar beneath and outside the clumps after the prolonged 1985 drought.
The effect of dwarf mistletoe on starch concentrations in the twigs and needles of lodgepole pine
Authors: Broshot Nancy E. , Tinnin Robert O.
Published: February 2008

The effect of Arceuthobiumamericanum on starch concentrations in the needles and twigs of Pinuscontorta was analyzed at two study sites. We found that the starch concentration of needles from systemically infected branches was significantly higher than that of those from locally infected branches and that the concentration in needles from locally infected branches was significantly higher than that of those from uninfected branches. We also found that the starch concentration of twigs from locally infected branches was significantly higher than that of twigs from uninfected branches. Our results collectively suggest a trend in starch concentrations form 1% of dry mass or less in needles from uninfected branches to 1–2% in needles from branches with local infections to greater than 2% in needles from systemically infected branches.
Direct seeding techniques to regenerate white spruce in interior Alaska
Authors: Putman William E. , Zasada John C.
Published: February 2008

Direct seeding techniques for regenerating white spruce (Piceaglauca (Moench) Voss) were tested on 12 logged areas near Fairbanks, AK. Techniques examined included spot seeding on scarified seed spots with and without plastic cone shelters and spot seeding on nonscarified seed spots with and without plastic funnel shelters, all at three sowing times. After the second growing season, scarified treatments produced greater seedling survival. Cone shelters usually produced greater survival than unsheltered seeding on scarified seed spots and funnel shelters usually produced greater survival than unsheltered seeding on non-scarified seed spots. Sowing time had little effect on survival.
Embryolike structures from cotyledons and ripe embryos of Norway spruce (Piceaabies)
Authors: Krogstrup P.
Published: February 2008

Embryos from imbibed ripe seeds and cotyledon expiants of 7-day-old Norway spruce (Piceaabies (L.) Karst.) seedlings produced the early stages of somatic embryogenesis. Using a modified Murashige and Skoog medium, a whitish, glossy callus was induced consisting of translucent cells embedded in a mucilaginous cloudy matrix. This embryogenic callus formed on the surface of explants treated first with N-6-benzyladenine followed by 2,4-dichlorophenoxyacetic acid + 6-furfurylaminopurine (kinetin) + N-6-benzyladenine. Transfer of this callus to media lacking growth regulators resulted in the formation of numerous bipolar embryoids with suspensorlike structures. These embryoids strongly resembled repressed embryos in polyembryonic seeds.
First- and second-year survival of containerized Engelmann spruce in relation to initialseedling size
Authors: Hines Franklin D. , Long James N.
Published: February 2008

Drought during the first growing season following outplanting and damage by rodents and snow during the 2nd year were the principle causes of mortality in a test of containerized Engelmann spruce (Piceaengelmannii Parry) planting stock. Stem caliper at planting is an important indicator of 1st- and 2nd-year survival. The increased survival of seedlings with large initial caliper reflect improved root regeneration and decreased susceptibility to bending and breaking by snow.
Selection of weights for a weighted regression of tree volume
Authors: Meng C. H. , Tsai W. Y.
Published: February 2008

The construction of regression equations for predicting tree volumes requires the assumption of homogeneity of variance that can be achieved by the method of weighted least squares. Some of the weights have the form (1/DλH)2 or (1/Dλ)2 (where D represents tree diameter at breast height and H represents tree height). Traditionally, λ has been assigned a value of 2. This paper suggests a method to estimate the exponent λ. This is accomplished by finding a maximum log likelihood function for a transformed tree volume regression equation. A proper value of λ is chosen within the confidence interval of λ. The confidence interval is established from the maximum log likelihood function.
Aryl esters of indolebutyric acid increase root regeneration in 3-0 red oak seedlings
Authors: Struve Daniel K. , Arnold Michael A.
Published: February 2008

Dormant 3-0 red oak seedlings (Quercusrubra L.) were given a 3-s basal dip in 20 mM solutions of indole-3-butyric acid (IBA), the potassium salt of IBA (K-IBA), N-phenyl indolyl-3-butyramide (NP-IBA), phenyl indole-3-thiolobutyrate (P-ITB), or phenyl indolyl-3-butyrate (P-IBA). Seedlings dipped in water or 95% ethanol served as controls. Fifty-six days after treatment, seedlings treated with NP-IBA and P-ITB regenerated up to 3 times more roots (48.7 and 40.0 roots, respectively) than did ethanol-treated control seedlings, which regenerated 14.3 roots. Seedlings treated with P-IBA regenerated 26 roots per seedling. Seedlings treated with NP-IBA and P-ITB had smaller leaves than IBA- and K-IBA treated seedlings. NP-IBA treated seedlings had more leaves than IBA- or K-IBA treated seedlings (155.3 vs. 59 and 53.3, respectively), but had similar leaf surface area. P-ITB-treated seedlings had similar numbers of leaves as IBA- and K-IBA-treated seedlings, but leaves were smaller in size, resulting in less total leaf area. P-IBA-treated seedlings had the greatest total leaf surface area, 1509 cm2; water- and ethanol-treated seedlings had total leaf surface areas of 1271 and 866 cm2, repectively.
Twig weight–diameter relationships for selected browse species on the Duck Mountain Forest Reserve, Manitoba
Authors: Schewe A. M. , Stewart J. M.
Published: February 2008

Estimates of twig weight from twig diameter of 10 plant species browsed by moose (Alcesalces L.), elk (Cervuselaphus L.), and white-tailed deer (Odocoileusvirginianus Zimmerman) were obtained from one site along the edge of the Duck Mountain Forest Reserve, Manitoba. Seasonal variation in the twig weight–diameter relationships was great, as shown by differences in the correlation coefficient for the seasons. The highest correlations occurred in midwinter. Collection of twigs during their dormancy in winter or during their period of growth cessation in late summer produced the highest correlations between twig weight and twig diameter. In addition, red osier dogwood (Cornusstolonifera Michx.) was collected at three other sites and revealed that between-site differences in twig weight predicted from mean diameter were less than 20% for all test sites.
Seed quality and germination characteristics of tamarack in northwestern Ontario
Authors: Farmer Jr. Robert E. , Reinholt Ronald W.
Published: February 2008

Tamarack seed from provenances in northwestern Ontario were incubated in light and dark under a range of alternating temperature regimes (5–15, 10–20, and 20–30 °C) before and after 33 days stratification. Unstratified sound seed germinated completely in light at all incubation temperatures. Partial germination of unstratified seed took place in the dark at 20–30 °C, but stratification was required for dark germination at lower temperatures. Wide variation in dark germination was noted among seed lots from individual trees, but stand and provenance differences were nonsignificant. Much of the variation in seed quality among tree lots was related to differences in the degree of embryo failure.
Relationship between jack pine growth and site variables in New Brunswick plantations
Authors: Hamilton W. N. , Krause H. H.
Published: February 2008

not available
Detection of hiddon morphology of wood by magnetic resonance imaging
Authors: Hall Laurance D. , Rajanayagam Vasanthan , Stewart Wendy A. , Steiner Paul R. , Chow Suezone
Published: February 2008

Hidden knots and regions of decay in aspen (Populustremuloides Michx.) sample are highlighted using the nuclear magnetic resonance imaging technique. The images were obtained on a whole-body nuclear magnetic resonance scanner that operates at 0.14 T for protons. The water in different regions of the sample responds differently, thereby imparting this useful information.
An indirect method for determining the order of expected thinning response among overstocked lodgepole pine stands
Authors: Cole Dennis M.
Published: February 2008

Relationships for representing relative thinning response potential among overstocked lodgepole pine stands were investigated with data from 31 stands in four National Forests of Idaho. The common logarithm of mean 10-year cross-sectional increment of dominant and codominant trees on stand edges created by clearing was the dependent variable selected for examining relationships with a large number of tree, stand, and site variables. A linear regression model explained nearly 60% of the variance in the response variable. The model included variables representing mean 10-year periodic cross-sectional increment prior to clearing, site index, and quadratic mean stand diameter. As a predictor of edge-tree response to clearing, the model represents relative thinning response differences to be expected among overstocked lodgepole pine stands and thus reflects relative stand vigor.
An analysis of the separable costs – remaining benefits method of joint cost allocation
Authors: Rideout Doug , Wagner John E.
Published: February 2008

The separable costs – remaining benefits (SCRB) incremental cost-allocation technique, preferred for United States Department of Agriculture Forest Service use, is critically analyzed. The paper mathematically specifies the SCRB model and demonstrates that the long-standing reasons for its wide appeal are not always valid. The analysis focuses on three fundamental reasons associated with the appeal of SCRB: (1) the ability of SCRB allocations to cover separable costs, (2) the claim that SCRB allocations will not make an efficient project purpose appear inefficient, and (3) the equity criteria often associated with SCRB. The paper shows that SCRB allocations will not always cover separable costs and suggests replacing the SCRB tests for purpose efficiency. The paper also shows that current SCRB formulations incorrectly define remaining benefits and, hence, the equity relation often associated with SCRB is defined incorrectly. The paper also suggests a general interpretation of the opportunity-cost concept that defines remaining benefits.
Development patterns in two hemlock–hardwood stands in southern New England
Authors: Kelty Matthew J.
Published: February 2008

Two forest stands, composed primarily of northern red oak (Quercusrubra L.), red maple (Acerrubrum L.), and eastern hemlock (Tsugacanadensis (L.) Carr.), were studied by stand-reconstruction techniques to determine the pattern of development of canopy structure. One stand had originated following clear-cutting 87 years ago; the other, following catastrophic windthrow 44 years ago. Juvenile height growth of the hardwood species was much greater than that of hemlock and a stratified canopy developed by age 30 years, with hardwoods forming an overstory canopy above hemlock. Hemlocks maintained overstory positions only if they were 3 m or more in height immediately following canopy disturbance. In the older stand, hardwood height growth was about twice that of the tallest understory hemlocks during the first 30 years. The hardwood overstory slowed after that and grew at the same rate as the tallest understory hemlocks, which maintained a constant rate of height growth, and a constant to accelerating rate of basal area growth for much of the 87-year measurement period. The height growth of the tallest understory hemlocks was apparently limited in part by breakage of terminal shoots, caused by abrasion against branches of overstory hardwood crowns.
Effect of aluminum on the growth of sugar maple in solution culture
Authors: Thornton F. C. , Schaedle M. , Raynal D. J.
Published: February 2008

The effect of aluminum (Al) on the growth of sugar maple (Acersaccharum Marsh.) was studied in two experiments in nutrient solution containing from 0 to 2000 μM Al at pH 4. Visible symptoms of injury to shoots or roots were not observed in either experiment. Reductions in seedling shoot size at the 1000, 1500, and 2000 μM concentrations were readily apparent; however, root biomass for these same concentrations did not differ significantly from the pH 4 controls. A plot of the relative total dry matter accumulation versus Al in solution showed that above 600 μM Al total seedling biomass declined exponentially. Of the mineral elements examined in these experiments, Ca was the most severely affected by increasing Al in solution. Even at 100 μM Al reductions in leaf, stem, and root Ca content were 17, 13, and 50% of the pH 4 controls, respectively. Some stimulation of growth and slightly higher P and K tissue concentrations were observed at low (100–500 μM) Al concentrations. At higher Al levels, P, K, and Mg were also reduced below the tissue content of the controls. The Al critical toxicity level for a 20% reduction in total seedling biomass was found to be 137 μg Al g dry weight−1 for newly expanded leaves.
Carbon and nitrogen allocation patterns of Douglas-fir seedlings fertilized with nitrogen in autumn. I. Overwinter metabolism
Authors: Margolis H. A. , Waring R. H.
Published: February 2008

Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedlings at a western Oregon nursery were fertilized in October 1983 with ammonium nitrate and harvested for biochemical analyses on four dates over autumn and winter 1983–1984. Free amino acid and total nitrogen concentrations in the needles of fertilized seedlings showed a pronounced increase 1 month after fertilization. Free amino acid concentrations of fertilized seedlings decreased in needles during winter but remained stable in stems and fine roots. Just before budbreak in mid-March, free amino acid concentrations increased significantly in stems and fine roots. Total nitrogen concentrations increased 1 month after fertilization, remained stable throughout winter, and tended to decrease or remain stable just before budbreak. Starch and total nonstructural carbohydrate concentrations of needles and stems of fertilized seedlings were lower just before budbreak and sugar concentrations of fine roots of fertilized seedlings were lower when data from all harvests were combined. The reduction in carbohydrate reserves following fertilization probably reflects increased respiration associated with the synthesis and maintenance of higher levels of enzymes.
Carbon and nitrogen allocation patterns of Douglas-fir seedlings fertilized with nitrogen in autumn. II. Field performance
Authors: Margolis H. A. , Waring R. H.
Published: February 2008

October-fertilized and unfertilized 2-0 Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedlings were outplanted the following February. Half of each planting block was seeded with grass to induce water stress during the typical summer drought. Sucrose was applied to soil around each seedling to limit availability of nitrogen to tree roots. Fertilized seedlings broke bud 9–10 days earlier, produced more shoot growth, and, as shown in later harvests, had higher relative growth rates than unfertilized seedlings. However, initial differences in growth response were due primarily to the earlier budbreak. Seedlings growing with grass had predawn water potentials of −1.5 MPa by early August; by September 3, unfertilized seedlings growing with grass were significantly more stressed than any others. Although free amino acid and total nitrogen concentrations were higher in fertilized than unfertilized seedlings when planted, they became equal by the end of one growing season. However, fertilized seedlings contained more free amino acids and nitrogen because of their greater size. Grass competition affected both seedling nitrogen and carbohydrate chemistry. After one growing season, fertilized seedlings had greater height increment, shoot growth, leaf area, relative growth rate, and production per unit nitrogen. Although autumn fertilization benefited these Douglas-fir seedlings, negative effects could result from carbohydrate depletion because of increased respiration or from frost damage because of earlier budbreak.
Comparative effects of three nitrogen fertilizers applied in fall and spring to a 29-year-old Douglas-fir plantation
Authors: Miller Richard E. , Atherton Mark V. , Wilcox James E.
Published: February 2008

Stand growth and mortality were monitored for 13 years after six fertilizer treatments were applied in a 29-year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) medium site quality plantation on Vancouver Island. The equivalent of 224 kg N/ha was added in either fall or spring as ammonium nitrate, urea, or urea – ammonium sulfate, which additionally supplied 56 kg S/ha. These treatments and a control were replicated three times. Foliar analyses indicated insufficient available N initially and increased available N after fertilization. Average, adjusted gross and net cubic volume growth in fertilized plots, however, did not differ from that of controls in any of the intermediate periods or in the total measurement period. This field experiment was not sensitive enough to detect real differences in 13-year growth among the seven treatments. Based on the experimental error measured in this study, seven replications would have been necessary to detect a 20% response in 13-year gross growth at the 10% confidence level; with seven replications, this 20% response would be detected in 90% of all experiments. Suggestions for improving field trials are included.
Distance methods and density estimators
Authors: Payandeh Bijan , Ek Alan R.
Published: February 2008

The relative performance of five distance–density estimators was evaluated for the n-tree circular, semicircular, and strip plots on several simulated and natural tree populations. Results indicate that for the n-tree circular plot, the ratio estimator performed very well for most populations examined and for n > 10. The performance of both the maximum likelihood and first moment estimators was affected to a great degree by the spatial pattern of the populations, but they performed satisfactorily for the random and uniform populations and for large n values (i.e., n > 10). Smaltschinski's estimator resulted in nearly bias-free estimates for nonaggregated populations and for all n, but performed poorly otherwise. The generalized Prodan estimator performed well for the random population, but overestimated the density otherwise. The relative performance of all estimators for the n-tree semicircular plot was quite similar to that of estimators for the n-tree circular plot, except that the former tended to produce lower density estimates. For n-tree strip plots, the generalized Prodan and the ratio estimator performed very well for the nonaggregated populations and for n > 10. All other estimators resulted in density estimates lower than those for n-tree circular and semicircular plots.
Clonal testing efficiency: the trade-offs between clones tested and ramets per clone
Authors: Russell J. H. , Libby W. J.
Published: February 2008

Three contrasting simulation models were developed to investigate testing efficiencies in a clonal selection program. The variables investigated were number of total plants tested, number of candidate clones tested, number of ramets per clone, number of clones selected, selection intensity, and broad-sense heritability. The model deemed appropriate to most clonal forestry situations selected a fixed number of clones in an experiment with the total number of plants in the test held constant. In this model, as the number of ramets per clone was varied, the number of candidate clones tested and the selection intensity necessarily also varied. This model indicates that cloning individuals for testing is useful when selection is based on a characteristic or index with broad-sense heritability less than about 0.6. At the lower heritabilities, two to six ramets per clone per site usually produces the optimum level of cloning, the exact number depending upon the selection intensity and heritability. Predictions generated by this fixed number of selected clones model were compared with average phenotypic values of selections using different subsamples of data for 8-year height and for 8-year diameter in a radiata pine (Pinusradiata D. Don) clonal experiment. Agreement between predictions and average phenotypic values in both these two comparisons was close.
Regression methodology for estimating model prediction error
Authors: Reynolds Jr. Marion R. , Chung Jain
Published: February 2008

The process of validating a stochastic simulation model involves the comparison of data generated by the model with corresponding data from the real system. Instead of applying statistical tests to determine whether the model adequately represents the real system, an alternate approach is to estimate the error that will result when the model is used to draw inferences about the real system. Regression methodology is proposed for estimating this error as a function of the levels of the input variables of the model. Confidence intervals for expected error and prediction intervals for actual error are given. An example of estimating the error in the volume predictions of a stochastic forest stand simulator is given.
Derivation of Sirococcusstrobilinus specific monoclonal antibodies
Authors: Mitchell Leslie Ann
Published: February 2008

Cloned hydridoma cell lines producing monoclonal antibodies to Sirococcusstrobilinus (a seed-borne fungus causing shoot blight in pine, spruce, and fir seedlings) have been prepared by immunizing BALB/c mice with whole mycelium and fusing their spleen cells with SP2/0-Ag14 myeloma cells. Specificity for S. strobilinus was ascertained by testing the monoclonal antibodies in enzyme-linked immunosorbent assays and by indirect surface immunofluorescence tests against a panel of seven nonrelated commensal fungi obtained from the same seed lot as the Sirococcus isolate used in the derivation of the monoclonal antibodies. The monoclonal antibodies produced by these selected hydridoma cell lines also recognize antigens from other S. strobilinus isolates from diverse host species and tissues. The monoclonal reagents will thus be useful as diagnostic probes for locating S. strobilinus in or on seed and other plant tissues. Preliminary characterization of the morphologic distribution of antigens recognized by the monoclonal antibodies is discussed.
The effect of moderate moisture and nutrient stress on bud formation and growth of container-grown white spruce seedlings
Authors: Macey D. E. , Arnott J. T.
Published: February 2008

Piceaglauca (Moench) Voss seedlings were grown in controlled environment rooms following germination with a combination of fluorescent and incandescent lamps (ratio, 1.4:1) providing 390 μmol s−1 m−2 of photosynthetically active radiation over a 24-h photoperiod. Moderate moisture and nutrient stress treatments were applied to separate seedling groups (10 weeks from germination) for a 2-week period during the initial free growth phase when mean seedling shoot length had reached 12 cm. Photoperiod was then reduced to 8 h. Both periodic moisture stress (reaching −1.72 MPa) and nutrient withdrawal (N, P, K) were effective in inducing terminal bud formation in container-grown white spruce seedlings under nonlimiting photoperiod and the number of needle primordia subsequently formed in the terminal bud under short days was significantly reduced. However, decreased needle complements in the stressed seedlings did not result in reduced shoot growth in the second growing season. Free growth following extension of the preformed shoot compensated for the reduced amount of predetermined foliage.
Pollen from conifers native to British Columbia
Authors: Owens John N. , Simpson Sheila
Published: February 2008

In most coniferous seed orchards for several conifers in British Columbia some form of pollen management is required. This involves collection, storing, application, monitoring, and identification of pollen. Pollen from all 25 native British Columbia conifers is described in simplified terms with regard to size, morphology, exine sculpturing, stage of pollen development in overwintering pollen cones, primary storage products of pollen, and time of pollen shedding in natural stands. Each species is illustrated by light and scanning electron micrographs. Similarities between species and genera and common contaminating pollen from nonseed orchard sources are discussed.
Effect of the energy crisis on the elasticities of demand for forest products in OECD countries
Authors: Buongiorno Joseph , Chang Ham Shee
Published: February 2008

The purpose of this paper was to test if there had been systematic changes in the income and price elasticities of demand for forest products after the first oil embargo of 1973. The test used pooled data from 10 OECD (Organization for Economic Cooperation and Development) countries between 1961 and 1981. Eight commodity groups were considered: coniferous sawn wood, nonconiferous sawn wood, plywood, particleboard, fibreboard, newsprint, other printing and writing paper, and other paper and paperboard. The demand models used were distributed lags on first logarithmic differences of income and price in each country and year. The hypothesis that the long-term elasticities of demand with respect to gross domestic product were the same from 1963 to 1981 as from 1974 to 1981 was rejected for coniferous sawn wood and printing and writing paper. Long-term price elasticities had also changed for the same commodities. A negative trend in the demand of coniferous sawn wood and particleboard, independent of prices or gross domestic product, appeared to have set in after 1973.
Forest fire monitoring using NOAA satellite AVHRR
Authors: Flannigan M. D. , Haar T. H. Vonder
Published: February 2008

The feasibility of using the advanced very high resolution radiometer (AVHRR) carried by the National Oceanic and Atmospheric Administration (NOAA) series of satellites to monitor forest fires was tested during a severe fire outbreak in north central Alberta between June 12 and June 21, 1982. A multispectral technique used AVHRR channels 3 and 4 to identify fires and estimate fire size. This multispectral approach enabled identification of subpixel-sized fires as small as 1 ha. During the study, fires were obscured from satellite view by the presence of cloud and smoke 59% of the time. In the remaining time, 80% of the fires listed by the Alberta Forest Service were identified by satellite. Satellite observations of forest fires are not sufficiently accurate to replace existing monitoring methods, but they are of value in providing a rapid, inexpensive supplement, especially in remote forested areas.
Effects and importance of indigenous earthworms on decomposition and nutrient cycling in coastal forest ecosystems
Authors: Spiers G. A. , Gagnon D. , Nason G. E. , Packee E. C. , Lousier J. D.
Published: February 2008

The general ecology of an undescribed indigenous earthworm species in the Megascolecidae, found in the organic horizons of Podzolic soils under mixed stands of Tsugaheterophylla, Abiesamabilis, Thujaplicata, and Pseudotsugamenziesii, is described. The earthworm is a member of the genus Arctiostrotus. Over a range of sites, population numbers of earthworms were correlated to rooting concentration in and immediately below the mor humus. By micromorphological examination, earthworm casts were found to account for up to 60% by volume of the constituent solids of the organic horizons. The abundance of both fine roots and fungal hyphae in the worm casts suggested high nutrient availability. Analysis of fresh faecal material showed a marked increase in most important nutrients (N, P, K, Mg, Fe, Na) relative to levels in noningested litter. Observations indicate that this earthworm species, whose population density may reach 200 m−2, has a major role in the decomposer subsystem of these ecosystems.
A model of stand allometry and biomass allocation during the self-thinning process
Authors: Smith N. J.
Published: February 2008

A growth model is developed to describe the relationship between any measure of size and number of stems in even-aged, monospecific plant populations during self-thinning. The model is tested on red alder (Alnusrubra Bong.) seedlings and red pine (Pinusresinosa Ait.) stands grown over a range of site qualities and initial spacings. Allometric relationships between plant dimensions are shown to change over time, finally approaching a stable value defined by a generalized self-thinning rule. Because of unique intraspecific plant geometry, allometric relationships appear to be more consistent within than between species. The priorisation for red alder biomass allocation with stand development was as follows (P < 0.05): branches > stem ≥ leaves ≥ root ≥ 2 nodules. For red pine the slope and intercept of the maximum size–density line were greater (P < 0.05) for merchantable versus total stem volume. A new approach for constructing stand density programs is presented.
Black-stain root disease on lodgepole pine in British Columbia
Authors: Hunt R. S. , Morrison D. J.
Published: February 2008

Surveys were made for incidence and damage by black-stain root disease (Ceratocystiswageneri) on Pinuscontorta in British Columbia. Incidence surveys indicated the hard pine pathotype to be largely restricted to the west Kootenays, northern Okanagan, and southern Cariboo. Damage surveys of 177 ha in 12 stands revealed severe damage in pure, dense stands, 80 years and older, at elevations above 1000 m. In one-half of the stands, C. wageneri was associated with Armillariaobscura; in one-third, some trees in C. wageneri centres were currently infested with Dendroctonusponderosae. Most disease centres were small, but sometimes there were many per stand, so that up to 46% of a stand was affected. The pattern of disease centres suggested that unknown vectors were responsible for initiating disease centres. Isolations from excavated stumps indicated little survival of C. wageneri after 1 year and none after2 years. Infested stands can be clear-cut and regenerated to P. contorta without risk of infection from the previous stand.
The economics of containerized forest tree seedling research in the United States
Authors: Westgate Robert A.
Published: February 2008

There is extensive evidence that research has a significant effect on increases in productivity, which in turn has a positive effect on economic growth and development. This study examines the economic impacts of research that led to a forestry innovation, containerized forest tree seedlings. Economic benefits resulting from the development of this method of reforestation are attributable to numerous sources, although only benefits measurable in terms of savings to consumers are considered in this analysis to ensure a conservative estimate of benefits. An economic surplus model is utilized to estimate research benefits. Public and private research expenditures are estimated using screened publication counts and by contacting firms who have undertaken or who are conducting containerized seedling research. Average internal rates of return from investment in containerized seedling research range from 37 to 111%, depending on assumptions concerning the percentage price differential between containerized and bare-root seedlings, and research cost estimates. A sensitivity analysis shows that the rate of return is insensitive to estimates of future production. Results from research evaluations such as this can supply background information for decision making, provide support for decisions already made (or provide impetus for changing decisions), and give verification or refutation of ideas.
Genetic variation in allozymes of western larch
Authors: Fins Lauren , Seeb Lisa W.
Published: February 2008

Seed samples from 19 stands of Larixoccidentalis Nutt. were analyzed for electrophoretic variation at 23 loci. Because sample sizes consisted of only 9 or 10 trees per stand (18–20 alleles per locus per stand), samples were grouped by geographic proximity into four larger samples. For all measures of variation, this species scored lower than most, but within the range observed for other western conifers. Most of the variation was found within rather than between the population groups. The single southern sample appeared to be genetically distinct from the others. Although some variation was observed between individual stand samples in expected heterozygosity, the consistently low values for all samples suggest that genetic drift has played a major role in the genetic history of the species in the Inland Empire, both through its glacial history in postulated refugia and through fire history in recent times.
The influence of temperature, nutrient status, and short drought on seasonal initiation of primordia and shoot elongation in Pinusradiata
Authors: Bollmann M. P. , Sweet G. B. , Rook D. A. , Halligan E. A.
Published: February 2008

Effects of temperature-related conditions on primordial initiation and shoot elongation were studied using rooted cuttings of mature Pinusradiata D. Don grown for 12 months in two field locations and three controlled environments. In two of the controlled environments, mean monthly temperatures of the respective field sites were simulated and in the third, a constant day–night temperature regime was set up. For each of the controlled environments there were four subtreatments: (i) frost, (ii) water deficit, (iii) supplementary nutrients, and (iv) control. Plants in relatively warm environments, both field and laboratory, produced more primordia, elongated more, and showed greater apical dominance than those in cool conditions. In the cooler environments, formation of lateral shoots tended to occur later in the growing season. Water deficit and supplementary nutrient subtreatments did not significantly affect growth. Exposure to light frosts reduced internode elongation of the leading shoots of plants grown at relatively warm temperatures. Quantitatively there were significant differences between field- and laboratory-grown plants. Annual primordial production in the field and shoot elongation were 2 and 3 times that obtained under controlled conditions, respectively. Apical dominance in the field was much more pronounced than in the controlled environment. However, the types and patterns of morphological response to temperature were similar in both field and laboratory plants.
Bucking tree-length stems optimally
Authors: Eng G. , Daellenbach H. G. , Whyte A. G. D.
Published: February 2008

The aim of this paper is to describe a methodology that has been used to assist in formulating sound production and marketing plans for a forest enterprise by relating information on stem frequency, size, and defect collected in routine inventories of forest resources to the projected demand for various log types. Emphasis is given to efficient bucking on landings of resources that are to be felled within a planning period as a whole, rather than efficient prescriptions for either each stand or each individual stem. The central model is a Dantzig–Wolfe decomposition procedure with a linear programming master and dynamic programming subproblems. The dynamic programming algorithm is used to maximize return from bucking a sequence of logs from single stems. From a set of alternative bucking patterns for different stem classes, the linear program selects those that maximize overall financial return, subject to satisfying constraints on resource availability and for a mix of log types from which end-use product demands can be met. Informational requirements for and applications of the model are presented with reference to a plantation resource of Caribbean pine belonging to the Fiji Pine Commission.
Carbohydrate allocation and mountain pine beetle attack in girdled lodgepole pines
Authors: Miller R. H. , Berryman A. A.
Published: February 2008

Healthy lodgepole pine trees (Pinuscontorta Dougl. var. latifolia Engelm.) were girdled on the lower trunk in patterns designed to selectively eliminate the influence of materials transported from the roots, lateral tissues, and crown. Titres of soluble sugars and starch observed in areas isolated by girdling were significantly lower than those observed in areas open to the upper bole and crown. Corresponding decreases were observed in the numbers of Dendroctonusponderosae Hopkins attacking those areas.