bluuebunny/crossref_metadata_2025 huggingface dataset:
Cytogenetic evidence of nucleolar dominance in allotetraploid species ofBrachypodium
Authors: Idziak Dominika , Hasterok Robert
Published: April 2008

Sequential silver staining and fluorescence in situ hybridization (FISH) were used to establish activity and number of 45S rDNA sites in meristematic root tip cells of 6 ecotypes of allotetraploid (2n = 4x = 30) species of Brachypodium and their putative ancestors, B. distachyon (2n = 2x = 10) and ABR114 (2n = 2x = 20). Using either total nuclear DNA of ABR114 or the ABR1-63-E6 BAC clone from a B. distachyon genomic library as an auxiliary probe, it was possible to distinguish by FISH between the two genomes composing the ecotypes of allotetraploid Brachypodium species and to determine unambiguously the parentage of both dominant and suppressed rRNA genes. Each of the diploid species possessed two rDNA loci, both transcriptionally active. The number of 45S rDNA sites in 6 ecotypes of allotetraploid Brachypodium species was always equal to the sum of loci present in their putative diploid parents. Two smaller sites were located in chromosomes corresponding to the ABR114 chromosomal set, and two larger ones in the chromosomes of B. distachyon origin. In all analyzed allotetraploid ecotypes, only rRNA genes belonging to the B. distachyon–like genome were transcriptionally active, while rDNA from the other parental genome was always suppressed. Thus the occurrence of nucleolar dominance in the allotetraploid (2n = 4x = 30) species of Brachypodium is demonstrated for the first time.
Effects of diameter distribution on the growth of simulated uneven-aged sugar maple stands
Authors: Hansen Gerald D. , Nyland Ralph D.
Published: April 2008

Effects of diameter distribution on the growth of simulated uneven-aged sugar maple (Acersaccharum Marsh.) stands are described using output from a computer simulation model. Results indicate that the combination of q ratio (a constant ratio between the numbers of trees present in adjacent diameters over the entire range of size classes present), maximum tree size, and basal area should vary depending on management objectives and cutting cycle length. A ratio of 1.2 appears best for describing a diameter distribution to maximize growth of large sawtimber, but larger q ratios are needed in the sapling and pole size classes to insure sufficient numbers of trees to sustain the distribution through the end of a cutting cycle. Retaining trees larger than a 40 cm diameter at breast height offers no advantage when objectives stress maximum volume production. A 50 cm maximum tree size appears better suited for maximizing large sawtimber volume and value growth, but a 40 cm maximum will yield a better compound rate of return on initial stand value. Under all options, longer cutting cycles require lower initial basal area levels.
Estimating tree-quality potential in a managed white oak stand by Markov Chain analysis
Authors: Brisbin Robert L. , Dale Martin E.
Published: April 2008

In many central hardwood stands, forest managers should be concerned about maintaining or improving the potential quality of future crop trees as well as increasing growth. Thinning practices have been shown to increase diameter and volume growth but there have been few studies on the effects of thinning on product potential. The effect of thinning to various basal area levels on the limb-related defect development of 80-year-old white oak (Quercusalba L.) is analyzed by Markov Chain analysis. The transition probabilities from the Markov Chain analysis were used to predict the expected number of limb-related defects by 5-year intervals for 40 years after treatment. At this age, the average tree in the untreated plots and the standard thinning had a probability of 0.81 of attaining grade 1. The average tree in the heavy and severe thinning had only a probability of about 0.25 of attaining grade 1. Generally, severe thinnings may result in a decrease of tree quality, particularly in white oak. Managers must balance this with increased growth potential and the inherent quality potential of the stand before making decisions.
A moisture strain index for loblolly pine
Authors: Byrne Stephen V. , Wentworth Thomas R. , Nusser Sarah M.
Published: April 2008

Seedlings of Pinustaeda L. were planted in 1982 on a clear-cut site in the northeastern Piedmont of North Carolina. Two intensities of site preparation (chopping and shear–pile–disk) were applied in the previous year, and seedlings were maintained under three intensities of cultural practice (no treatment, application of herbicides, and hand weeding) for control of successional vegetation regrowth. Both site preparation and cultural practice significantly affected pine performance (relative growth rate) and predawn leaf water potentials. Soil water potentials showed no significant treatment effects, even during a severe drought in the summer of 1983. An index of moisture strain for the pine seedlings was developed by regressing predawn leaf water potentials of individual pines against the mean leaf water potentials of all pines using data collected on 5 days in the summer of 1983. This index accounted for 55% of the variation in pine performance. The predictive value of the index resulted from its integration of a variety of stress factors and was probably enhanced by its application during a dry growing season.
Comparison of eight Pisolithustinctorius isolates for growth rate, enzyme activity, and phytohormone production
Authors: Ho Iwan
Published: April 2008

Eight isolates of Pisolithustinctorius (Pers.) Coker and Couch (three each from Georgia and northern California and one each from Oregon and Washington) were compared invitro for growth rate, for alkaline and acid phosphatase and nitrate reductase activities, for acid phosphatase isozyme patterns, and for cytokinin, indoleacetic acid, and gibberellin production. Significant differences appeared between isolates for each parameter examined. All isolates showed relatively low phosphatase and nitrate reductase activities. Isolate S-359 from northern California grew the slowest in culture and produced significantly more indoleacetic acid than all other isolates and more cytokinin than six of the other seven isolates; this isolate was also the only one of the eight that did not share at least one acid phosphatase allele with the others in the isozyme analysis.
Indolebutyric acid and ectomycorrhizal inoculation increase lateral root initiation and development of container-grown black oak seedlings
Authors: Baser C. M. , Garrett H. E. , Mitchell R. J. , Cox G. S. , Starbuck C. J.
Published: April 2008

Containerized black oak seedlings in which the growth medium was inoculated with Pisolithustinctorius (Pers.) Coker Couch or left uninoculated were grown for 16 weeks with or without a polyacrylic starch containing 1000 μg indolebutyric acid per gram mixed throughout the growth medium. Seedlings treated with indolebutyric acid developed more than twice as many lateral roots as control seedlings which did not receive indolebutyric acid. Indolebutyric acid reduced the percentage of primary laterals colonized by P. tinctorius; however, the total number of colonized lateral roots was not affected. The combination of ectomycorrhizal inoculation with the indolebutyric acid treatment significantly increased the growth and development of black oak seedlings.
Undercutting conifer seedlings: effect on morphology and field performance on droughty sites
Authors: Hobbs S. D. , Stafford S. G. , Slagle R. L.
Published: April 2008

Bareroot 2-0 Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) and ponderosa pine (Pinusponderosa Dougl. ex Laws.) seedlings were subjected to five undercutting treatments, which varied by number and depth of undercut and seedling phenology at time of treatment, so that morphological characteristics at lifting and field performance 4 years after planting on droughty south slopes in southwest Oregon could be evaluated. All undercutting treatments significantly reduced seedling top growth, but changes in root system morphology depended upon treatment severity and species. Treatment effects were generally more pronounced in ponderosa pine than Douglas-fir. Multivariate analysis of variance showed significant treatment effects for both species based on seedling morphology at lifting, but discriminant analyses revealed that these differences existed primarily between undercut seedlings, regardless of undercutting treatment, and controls. In Douglas-fir this separation was largely due to differences in seedling height and in ponderosa pine it was due to differences in tap root biomass. However, no treatment effects were detectable 4 years after outplanting for either species despite record high air temperatures during the first growing season, suggesting that morphological differences at lifting were probably not of sufficient magnitude to affect field performance.
Relationships among soil microsite, ectomycorrhizae, and natural conifer regeneration of old-growth forests in western Montana
Authors: Harvey A. E. , Jurgensen M. F. , Larsen M. J. , Graham R. T.
Published: April 2008

Successful establishment, root distribution, growth, and ectomycorrhizal development of conifer regeneration in three old-growth forests in western Montana showed site-specific associations with soil microsites containing organic matter. A positive association between decayed wood in the soil and establishment of seedlings occurred on the two drier sites. In general, organic soil components supported most of the root system and ectomycorrhizae on all three sites. Associations between soil organic components and occurrence (establishment) and between organic components and performance (growth) were site specific. No observable evidence of feeder root mortality attributable to soil-inhabiting pathogens was present in any soil component. Roots of competing understory species were notably absent in decayed soil wood.
Test of the first-in, first-in pollination hypothesis in coastal Douglas-fir
Authors: Webber J. E. , Yeh F. C. H.
Published: April 2008

The hypothesis that pollen arriving first to receptive seed-cone buds has an advantage over pollen arriving later (first-on, first-in) was tested in Douglas-fir using two reciprocal pollination experiments. In the first test, one each of two outcross-pollen parents was applied first followed by the other 5 min or 24 h later. In the second test, self- and outcross-pollen parents were compared in a similar reciprocal arrangement 5 min, 6 h, and 24 h apart. Electrophoretic analysis of isocitrate dehydrogenase alleles was used to distinguish between the two pollen parents in resultant seeds. When a second pollen parent arrived within 5 min of the first, both contributed to the seed produced. However, when the second pollen parent arrived 6 or 24 h later, its contribution to the resultant seed was less. Pollen fertility potential interacted with arrival time and affected both seed yields and parental composition. When pollen of lower fertility was applied first followed by a higher fertility pollen, seed yields were lower; as the time interval for the arrival of the second pollen parent increased to 24 h, the percent contribution of the first pollen increased. However, when the higher fertility pollen was applied first, there was little effect of the lower fertility pollen arriving within 5 min or 24 h.
Evaluating growth response to fertilization: Discussion
Authors: Doucet René , Veilleux Jean-Marc
Published: April 2008

not available
Relation between air water potential and cambial electrical resistance of balsam fir and white spruce after budbreak
Authors: Gagnon Robert R. , Bauce Eric , Pineau Marius
Published: April 2008

Cambial electrical resistance in 10 balsam fir (Abiesbalsamea (L.) Mill.) and 10 white spruce (Piceaglauca (Moench) Voss) trees in Québec was measured 42 times during July and August 1985. Simultaneous measurements of relative humidity and temperature were also taken so that water potential in air (ψa) could be determined. In both species, cambial electrical resistance, corrected to a constant temperature of 15 °C (CERCOR), was negatively correlated with ψa. On the other hand, 10 measurements on 14 balsam fir trees that had been severely defoliated by the spruce budworm (Choristoneurafumiferana (Clem.)) in 1983 and 1984, and 12 measurements on 14 protected trees showed that the correlation was stronger for sprayed trees than for those that had been defoliated. We propose that the correlation coefficient between cercor and ψa may be a useful index of tree vigor. However, in situations where plots can be visited only once during the season, cambial electrical resistance measurements should be made in the morning when the relative humidity is high.
Decomposition of boreal forest litters from central Alberta under laboratory conditions
Authors: Fyles J. W. , McGill W. B.
Published: April 2008

Decomposition of foliage litter from jack pine (Pinusbanksiana Lamb.), white spruce (Piceaglauca (Moench) Voss), balsam fir (Abiesbalsamea (L.) Mill.), green alder (Alnuscrispa (Ait.) Pursh.), two feathermosses (Hylocomiumsplendens (Hedw.) B.S.G., Pleuroziumschreberi (Brid.) Mitt.), and a lichen (Cladinamitis (Sandst.) Hale & W. Culb.) was examined by measuring weight loss at 5-week intervals during a 35-week laboratory incubation (constant moisture, 23 °C). Weight loss by most litter types was more precisely described by a two-component than a one-component exponential decay model. Decomposition of lichen was best described by a one-component model as is consistent with the chemical and structural homogeneity of this litter. Decay rate was not correlated with concentration of C, N, soluble tannin or lignin, C:N ratio, or lignin:N ratio, although weight loss and lignin:N ratio were correlated in a combined data set that included data from published literature. Cutting pine needles into 1-cm lengths doubled initial decomposition rates, indicating that physical constraints associated with litter structure exert a strong influence on decomposition. Such structural controls limit the use of litter chemistry to predict decomposition rates. Relative differences in decomposition rates among litter types appeared to be reflected in forest floor properties, suggesting that plant species play different roles in the control of decomposition-related ecosystem processes.
Evaluation of four techniques to assess vigor of water-stressed ponderosa pine
Authors: McCullough Deborah G. , Wagner Michael R.
Published: April 2008

Four techniques of vigor estimation were evaluated on root-trenched, watered, and untreated ponderosa pine (Pinusponderosa Doug, ex Laws.) in northern Arizona. Trenching and watering were initiated in August 1983. Vigor measurements were taken in summer and fall of 1983 and 1984 and summer of 1985. Correlations among the four vigor indices as well as tree age, diameter, and height were developed for each measurement period. Trenched trees consistently had higher moisture stress readings (based on the Scholander pressure chamber) than watered trees. The ability to measure differences in xylem water potential among treatments with the pressure chamber was affected by the season of measurement. The Waring vigor index was calculated for 2-year and 5-year growth increments in June 1983 and August 1985. Trenched trees had significantly lower 2-year vigor ratings following treatment than watered or untreated trees, and all ratings were correlated with tree age and size. A shoot starch content rating was significantly higher for watered trees than for trenched trees only during the final measurement period. Electrical resistance readings were consistently higher for trenched trees than for watered or control trees. Season and tree diameter were consistently correlated with electrical resistance readings.
Feeding preference and its relation to herbivore repellent studies
Authors: Gillingham Michael P. , Speyer Menno R. , Northway Steve , McLaughlin Ron
Published: April 2008

Two testing procedures were used to evaluate the effectiveness of gaseous selenium compounds emitted from a packaged solid as black-tailed deer (Odocoileushemionuscolumbianus Richardson) browsing repellents: (i) pen bioassay trials with simultaneous access to all treatments, and (ii) tests with controlled access to only one treatment at a time. The two testing procedures yielded different results. Bioassay trials indicated that there was a significant difference (p = 0.049) in the browsing damage that occurred between treated and untreated seedlings. There was no difference (p = 0.444) in the browsing damage, however, when all seedlings in the enclosure were identically treated. The dependence of the results on the experimental design used and the implications of using measures of herbivore preference to test potential browse repellents are discussed.
Fifth-year responses of Douglas-fir to crowding and nonconiferous competition
Authors: Cole Elizabeth C. , Newton Michael
Published: April 2008

Growth responses from crowding and interspecific competition were examined in 5-year-old plantations of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco var. menziesii) spaced 17 to 123 cm apart, alone or with either grass or red alder (Alnusrubra Bong.) on three site types in the Oregon Coast Range. Grass and red alder competition and crowding adversely affected growth and standing biomass on a per tree basis. Basal area per hectare and volume per hectare were higher at high densities but these relations are expected to change with time as the larger trees at low densities form fully stocked stands. Grass competition showed greatest effects on growth at the driest site. Although the presence of red alder decreased growth on all sites, the effect was most significant at the coastal site where light is most limiting and moisture is least limiting. If the production of maximum tree size is the primary objective, then low stocking with control of competing vegetation will produce larger trees faster than will other management alternatives.
Incidence of pinewood nematode dauerlarvae and phoretic mites associated with long-horned beetles in central Louisiana
Authors: Kinn D. N.
Published: April 2008

In central Louisiana, Monochamustitillator and M. carolinensis are the principle vectors of dauerlarvae of the pinewood nematode. Although proportionally more M. carolinensis carry the nematode, M. titillator is the more abundant species. Neacanthocinusobsoletus, a common long-horned beetle found in dead pines, seldom carries the pinewood nematode. Twelve species of mites are found to have instars phoretic on these cerambycids. More species of mites are associated with M. titillator than with N. obsoletus and, with the exception of Histiogasterarborsignis, mites are more numerous on M. titillator. Longoseiuscuniculus, Trichouropodalamellosa, T. hirsuta, and Histiogaster spp. are the most common mite species. Deutonymphs of the two Trichouropoda spp. and Dendrolaelapsvaripunctatus were observed to prey upon the pinewood nematode under laboratory conditions.
Sources of variation in soil solution collected by tension plate lysimeters
Authors: David Mark B. , Gertner George Z.
Published: April 2008

Soil solutions were collected at hardwood and conifer sites located on Typic Haplorthods using tension plate lysimeters and examined for random variation effects due to differences in pits, individual lysimeters, and period of collection. Analysis of variance using a partially nested design indicated that for solution volume, H+, specific conductance, and base cations, a large part of the random variation (>55%) in solution characteristics was due to differences within sampling periods. Differences between pits or lysimeters were generally significant for total S and [Formula: see text] only. These data indicate that the lysimeter sampling design used in this study (two lysimeters per horizon, two pits per site) was adequate in collecting representative solution concentrations for the fraction of soil water collected. For total S and [Formula: see text] concentrations, measurements could be improved by increasing the number of pits and lysimeters per pit for sample collection, whereas for other characteristics increased sampling frequency (greater than weekly) would be needed to reduce random variation.
Physical and chemical response of understory vegetation to deer use in southeastern Alaska
Authors: Hanley Thomas A.
Published: April 2008

Biomass of understory vegetation was sampled inside and outside four 19- to 21-year-old deer enclosures in the Alexander Archipelago of southeastern Alaska. Three sites were old-growth forests of western hemlock (Tsugaheterophylla (Raf.) Sarg.) –Sitka spruce (Piceasitchensis (Bong.) Carr.) and one site was an even-aged spruce–hemlock stand. In vitro dry-matter digestibility, fiber, nitrogen, and phosphorus concentrations of western hemlock seedlings and Alaska blueberry (Vacciniumalaskensis How.) inside and outside each exclosure also were compared. Analysis of variance indicated that Alaska blueberry and trailing bramble (Rubuspedatus Sm.) had greater biomass inside than outside the exclosures. No differences in chemical composition or digestibility of blueberry or hemlock inside and outside the exclosures occurred across sites. Results indicated that although deer may exert moderate to strong influence on the species composition and biomass of forest understories, their effect on dry-matter digestibility, fiber, nitrogen, and phosphorus concentrations of individual species may be negligible.
Phenotypic variation in predetermined and free growth in sapling size western larch
Authors: Joyce Dennis G.
Published: April 2008

Phenotypic variation in the proportions of annual shoot growth attributable to predetermined and free growth were assessed using upper crown lateral branches of sapling size western larch (Larixoccidentalis Nutt.) from five stands. Significant differences in predetermined and total annual shoot needle complement were detected among stands. Although stands were elevationally diverse, no significant differences in free growth were detected among stands. Substantial variation in predetermined, free growth, and total annual shoot needle complements were present within stands. An average of 17% of the annual shoot needle complement was attributable to free growth, but the percentage varied from 0 to 94% for individual trees. Although predetermined needle complement was negatively correlated with free growth needle complement, some trees had above-average values for both modes of shoot growth.
Leaf area – sapwood cross-sectional area relationships in repressed stands of lodgepole pine
Authors: Keane M. G. , Weetman G. F.
Published: April 2008

To better understand the phenomenon of growth "stagnation" in high-density lodgepole pine (Pinuscontorta Dougl. ex Loud.), leaf area and its relationship with sapwood cross-sectional area were examined on both an individual tree and stand basis. Leaf areas of individual trees in a 22-year-old stand varied from 30.8 m2 (dominants in stands of low stocking) to 0.05 m2 (suppressed trees in stands of high stocking). Leaf area indices ranged from 13.4 to 2.3 m2 m−2 between low and high stocking levels, respectively. Over the same stocking range, the ratio of leaf area to sapwood cross-sectional area was reduced from 0.3 to 0.15 m2 cm−2. Intraring wood density profiles showed that ovendry density increased from 0.52 to 0.7 g cm−3 and the proportion of early wood decreased over a stocking level range of 6500–109 000 trees/ha. A reduction in hydraulic conductivity in the stems of stagnant trees, suggested by the greater proportion of narrow-diameter tracheids present, may lead to a greater resistance to water transport within the boles of trees from stagnant stands, leading to low leaf areas.
Genetic differentiation among 22 mature populations of green alder (Alnuscrispa) in central Quebec
Authors: Bousquet J. , Cheliak W. M. , Lalonde M.
Published: April 2008

Electrophoretically demonstrable diversity of 11 enzymes encoded by a total of 16 structural loci was analyzed in 22 sexually mature populations of Alnuscrispa (Ait.) Pursh (green alder, Betulaceae) in central Quebec. On average, 45% of the loci per population were polymorphic, with a mean of 2.39 alleles per polymorphic locus. Approximately 5% of the total genetic diversity resided among populations, with a mean genetic distance between populations of 0.01. Most populations thus appeared homogeneous, likely linked by high gene flow, as demonstrated by analysis of conditional average frequencies of alleles. Geoclimatic similarity among sites was also considered as a possible contributing factor to this apparent homogeneity. Heterogeneity of allele frequencies among populations was noted at seven loci. However, the presence of four populations that appeared to be more differentiated accounted for much of the observed heterogeneity. The early successional nature of this species and the partial isolation of these four populations seemed the most likely factors causing the observed differentiation.
Equations for predicting sapwood area at crown base in southwestern Oregon Douglas-fir
Authors: Maguire Douglas A. , Hann David W.
Published: April 2008

Two basic taper models were analyzed for their ability to predict sapwood area at crown base. Sapwood areas were estimated on stem cross sections by measuring sapwood radii on the longest and perpendicular to longest axes and by assuming conformity to an ellipse. These data were collected on 2 to 14 points along the stems of 72 Douglas-fir trees in southwestern Oregon. Across the range in diameter at breast height, total height, and height to crown base, quadratic–quadratic segmented polynomials (T. A. Max and H. E. Burkhart. 1976. For. Sci. 25: 283–289) provided more consistent monotonie taper from breast height to crown base than F. A. Bennett and B. F. Swindel models (1972. USDA For. Serv. Res. Note SE-179). A model for predicting breast height sapwood area from only diameter at breast height, total height, and height to crown base is also presented.
A volume and taper prediction system for bald cypress
Authors: Parresol Bernard R. , Hotvedt James E. , Cao Quang V.
Published: April 2008

A volume and taper prediction system based on d10 and consisting of a total volume equation, two volume ratio equations (one for diameter limits, the other for height limits), and a taper equation was developed for bald cypress using sample tree data collected in Louisiana. Normal diameter (dn), a subjective variable-height measure applied to bald cypress (Taxodiumdistichum (L.) Rich.) in place of diameter at breast height (dbh), was found to be inferior to five different fixed-height diameter measurement points in terms of predicting total volume. Diameter measured at 10 ft (3.0 m) above the ground, termed d10 is recommended as a better diameter measurement point for bald cypress. A number of "goodness-of-fit" statistics were employed to evaluate alternative functions for predicting volume and taper. Two statistics, bias and sum of squared relative residuals, provided the best discrimination between functions.
Effect of pH, aluminum, and sulfate on a high-elevation Armillaria isolate cultured in vitro
Authors: Entry James A. , Cromack Jr. Kermit
Published: April 2008

An Armillaria (Ft.) isolate compatible with Armillaria biological species II according to haploid tester challenge, was taken from a dying high-elevation red spruce (Picearubens Sarg.) tree in New York and cultured in unbuffered Melin–Norkrans medium containing 0, 50, 100, or 200 mg/L of Al3+ as Al2(SO4)3 at pH 3, 4, or 5. Total fungal weight and hyphal extension increased significantly as pH rose yet increased only slightly when aluminum was added to the medium. The pH of the medium decreased as fungal weight increased. Weight was linearly correlated with hyphal extension (r2 = 0.87) at all aluminum concentrations and pH values tested. Fungal weight and hyphal extension significantly decreased when Armillaria II was cultured in a duplicate experiment with 0, 395, 790, or 1580 mg/L of [Formula: see text] as MgSO4, indicating that increasing [Formula: see text] concentrations were harmful to fungal growth. Field studies demonstrating predisturbance distribution of Armillaria functioning as a stress pathogen of P. rubens are needed to help determine whether soil conditions created by acid deposition are inhibiting Armillaria growth.
Expected decrease in diameter growth of even-aged red spruce
Authors: Federer C. Anthony , Hornbeck James W.
Published: April 2008

Weibull functions provide close least square fits to tables for stand basal area and density versus age in even-aged, second-growth red spruce as reported by W. H. Meyer (USDA Tech. Bull. No. 142. 1929). The annual mean radial and basal area increments of the trees can be calculated from the two Weibull functions. For a stand following Meyer's tables and reaching breast height in 1915, mean tree basal area increment increases steadily to a maximum in the early 1960's and then declines; mean radial increment is constant from 1925 to 1955 and then declines rapidly. This behavior matches very closely the results from 3001 red spruce increment cores in New England and New York, which suggests that forest aging is an important cause of decreasing red spruce diameter growth.
The architectural significance of interfoliar branches in Pinus subsection Balfourianae
Authors: Connor Kristina F. , Lanner Ronald M.
Published: April 2008

In pines, branches of interfoliar origin (IFBs) often occur in response to injury. However, in all three species of Pinus subsection Balfourianae we observed in Utah, Nevada, and California, IFBs are common and of nontraumatic origin. They comprise 41 and 51% of the first-order branches in foxtail pine (Pinusbalfouriana Grev. & Balf.) and Great Basin bristlecone pine (P. longaeva D. K. Bailey), respectively. Second-order IFBs are frequent in Rocky Mountain bristlecone pine (P. aristata Engelm.) (45%) and Great Basin bristlecone pine (47%). All species of subsection Balfourianae produce exceptionally low numbers of long-shoot lateral branches (LSLBs). Growth and morphological data suggest that the IFBs function similarly to LSLBs.
Tenure effects on forest management investment
Authors: Nautiyal J. C. , Rawat J. K.
Published: April 2008

Study of the investment behaviour of a tenure-holding forestry firm in Canada has policy implications and is, therefore, important. Investment by a firm in establishing a plant was analyzed in an earlier issue (June 1986) of this journal. In this paper, the firm's investment in the management of Crown forest lands is investigated. The impacts of tenure conditions, taxation, and technological progress have been analyzed. Tenure insecurity has been found to be only partly responsible for a firm's less than enthusiastic behaviour regarding investment in forest management. Long rotation is by far the single most important factor inhibiting expenditure on forest management inputs. A judicious mixture of tenure and taxation regulations can be used as a policy instrument for encouraging intensive forest management. Anticipation of even very modest secular increases in profits due to technological progress can make intensive forestry a desirable economic activity.
Estimation of foliage area in dense Montana lodgepole pine stands
Authors: Hungerford Roger D.
Published: April 2008

Six stands of lodgepole pine, Pinuscontorta ssp. latifolia (Engelm.) Critchfield, in Montana were sampled to evaluate sapwood area (at 1.37 m and the crown base), basal area (at 1.37 m), tree height, and crown length as predictors of foliage area. Densities of the six stands ranged from 2900 to 17 800 stems/ha. This density range was picked to determine how stand density affects the ratio of foliage area to basal sapwood area. Regression estimates of foliage area using basal area and sapwood area at 1.37 m and the crown base were equally good. Within the sampled range of stand densities, differences in the foliage area to sapwood area ratio were not significant. The amount of foliage area served per unit of sapwood area (at 1.37 m) averaged 0.25 m2/cm2 for all 54 trees sampled. This value of foliage area per unit of sapwood area in dense stands was smaller than most other published values.
Soil CO2 evolution in Florida slash pine plantations. II. Importance of root respiration
Authors: Ewel Katherine C. , Cropper.Jr. Wendell P. , Gholz Henry L.
Published: April 2008

Respiration of live roots was the single largest contributor to soil CO2 evolution in two mature slash pine (Pinuselliottii) plantations. Root respiration accounted for 51% of soil CO2 evolution at the 9-year-old plantation and 62% at the 29-year-old plantation. Additional estimates, calculated from data recorded from two small trenched plot sites at the 29-year-old plantation and based on possible variations in initial root biomass and subsequent decomposition rates, also averaged 62% of soil CO2 evolution. Specific root respiration averaged 0.40 g•g−1•year−1, varying from 0.34 to 1.70 g•g−1•year−1. Plots with larger proportions of fine roots had faster soil CO2 evolution rates.
Evaluation of planting sites common to a southeast Alaska clear-cut. III. Effects of microsite type and ectomycorrhizal inoculation on growth and survival of Sitka spruce seedlings
Authors: Shaw III Charles G. , Sidle Roy C. , Harris Arland S.
Published: April 2008

Hebelomacrustuliniforme (Bull. ex St. Amans) Quel., Laccarialaccata (Scoop. ex Fr.) Berk and Br., and Cenococcumgeophilum (L. ex Fr.) Pers. ex Hooker were established as ectomycorrhizae on container-grown Sitka spruce seedlings. These seedlings and noninoculated controls were planted in rotten wood, exposed mineral soil, undisturbed duff, and undisturbed duff on the north side of large stumps on one clear-cut site in southeast Alaska. At planting, seedling heights differed significantly among fungal treatments: the tallest were those inoculated with C. geophilum, the shortest with H. crustuliniforme. Some height differences persisted after planting, but 3-year height and diameter increments did not differ significantly among fungal treatments and controls. As a percentage of their initial height, seedlings inoculated with L. laccata increased the least in size after 3 years (70%), significantly less than for seedlings with H. crustuliniforme (126%). All test fungi survived for 2 years, but most seedlings were further colonized by one or more on-site ectomycorrhizal fungi, frequently C. geophilum. Regardless of fungal treatment, seedlings in rotten wood had the least percentage increase in height after 3 years (69%), significantly less than the 121% increase for seedlings in undisturbed duff on the north side of stumps. Seedling survival after 3 years was over 92% and did not differ by microsite or fungal treatment. At another clear-cut site, survival of noninoculated seedlings after 3 years was 86% in exposed mineral soil, significantly less than the 98% on all other microsites. Frost heave was the primary cause of mortality. These data suggest that prior colonization by these ectomycorrhizal fungi provides little survival or growth benefit after out planting Sitka spruce seedlings on various microsites in southeast Alaskan clear-cuts. Some improvement in early height growth and survival may be obtained, however, by planting in undisturbed duff, particularly near stumps, and by avoiding exposed mineral soil.
Evaluation of planting sites common to a southeast Alaska clear-cut. IV. Nutrient levels in ectomycorrhizal Sitka spruce seedlings
Authors: Sidle Roy C. , Shaw III Charles G.
Published: April 2008

Sitka spruce (Piceasitchensis (Bong.) Carr.) seedlings colonized by the ectomycorrhizal fungi Laccarialaccata (Scop. ex Fr.) Berk and Br., Hebelomacrustuliniforme (Bull, ex St. Amans) Quel., or Cenococcumgeophilum Fr. and a noninoculated control were planted on rotten wood, undisturbed duff, undisturbed duff on the north side of large stumps, and exposed mineral soil in an area recently clear-cut on Chichagof Island, southeast Alaska. Uptake and concentrations of N, P, K, Ca, Mg, and several micronutrients in foliage, stems, and roots were determined 2 years after outplanting. There were no significant interactions between fungal treatments and microsite types for uptake or concentration of any nutrient. Uptake and concentrations of N and P in foliage and roots did not differ significantly among fungal treatments. Foliar K and Cu concentrations were significantly higher in control seedlings than in those with L. laccata ectomycorrhizae. Calcium was the only nutrient analyzed that was present in higher concentrations in seedlings inoculated with H. crustuliniforme than in controls. Concentrations of foliar P, Mn, and Zn were significantly greater in seedlings grown on undisturbed duff (protected north side) than in seedlings grown on exposed mineral soil. However, foliar concentrations of all nutrients tested were not significantly different between seedlings grown on undisturbed duff (unprotected sites) and those grown on mineral soil. Seedlings grown on rotten wood had significantly greater concentrations of foliar Ca than seedlings grown on either exposed mineral soil or undisturbed duff. The on-site colonization of control seedlings after outplanting indicates that resident ectomycorrhizal fungi readily establish and appear to provide equal if not improved nutrient benefits compared to inoculated seedlings. Greater nutritional benefits were derived by planting on certain microsite types (duff and protected duff) than by inoculating with specific ectomycorrhizal fungi.
Resin acid variation in sun and shade needles of Scots pine (Pinussylvestris L.)
Authors: Gref Rolf , Tenow Olle
Published: April 2008

Bioclimatic and physiological differences between sun and shade needles suggest that their chemical composition should differ. An analysis of resin acid content demonstrated that although the same resin acids were found (i.e., levopimaric/palustric, dehydroabietic, abietic, neoabietic, 4-epiimbricatolic, pinifolic, and isopimaric acids), both individual and total resin concentrations were significantly higher in sun than in shade needles. These relationships were true for a dense 40-year-old pine stand in southern Sweden as well as for a dense 12-year-old stand in northern Sweden. The role of resin acids in defence against needle-eating insects and the relative susceptibilities of shade and sun needles to needle-attacking organisms are discussed. Variation in resin acid concentration in sun and shade needles should be considered when such acids are used as genetic markers.
Propagation of mature western white pine (Pinusmonticola Dougl.) by cuttings
Authors: Williams F.
Published: April 2008

A technique enabling the rooting of cuttings from mature (25–29 years old) western white pines (Pinusmonticola Dougl.) is described. A number of treatment and planting media combinations were tested, but these factors had no significant effect on rooting success. More significant were the length of time required (29 weeks) for root formation and between tree variation in survival and rooting success. Overall rooting success was 37%, with donor-tree success ranging from a low of 10% to a high of 87%.
The influence of moose on the composition and structure of Isle Royale forests
Authors: Risenhoover Kenneth L. , Maass Steven A.
Published: April 2008

The long-term influence of moose (Alcesalces) on the structure and species composition of three forest types in Isle Royale National Park, Michigan was evaluated using four moose-proof exclosures established in 1949–1950. Results obtained during the present study were compared with the original vegetation at each study site and with data collected by Krefting (1974) in order to discriminate between the effects of moose browsing and forest community succession. In the spruce–birch–fir climax and aspen–birch–conifer forest study sites, self-thinning and reduced light availability reduced the density of woody plant stems in exclosure areas. In the adjacent control areas, moose browsing has slowed the rate of succession. Repeated browsing by moose on palatable species has retarded vertical growth and has prevented stems from growing beyond reach. Effects of moose browsing on succession in the aspen–birch study sites in the 1936 burn were less clear. In all three forest types, stem densities of most species were higher in control areas than in exclosures. Species diversity was also greater in control areas. American yew (Taxuscanadensis) and red-osier dogwood (Cornusstolonifera) were the only species that declined in abundance as a result of browsing by moose.
The mating system in a black spruce clonal seed orchard
Authors: Barrett J. W. , Knowles P. , Cheliak W. M.
Published: April 2008

Isozyme markers were used to study the mating system, estimate the effective population size, and determine the effective gene pool composition in a black spruce clonal seed orchard. Ten seeds per family were electrophoretically analyzed by embryo and megagametophytic pairs to determine their allelic and genotypic frequencies at five polymorphic loci. Single-locus estimates of outcrossing ranged from 0.682 to 1.087 (mean, 0.942), while the multilocus estimate was 0.837. The variance effective population size was calculated to be 17 individuals, comprising 13 receptive females and 4 effective males. Evidence of gene pool heterogeneity suggested a small, nonrandomly mating population within the clonal seed orchard.
Abscisic acid concentration in Douglas-fir needles in relation to lifting date, cold storage, and postplanting vigor of seedlings
Authors: Puttonen Pasi
Published: April 2008

Spring-lifted seedlings were grown in pots in the field and, after a natural fall photoperiod, exposed to three 25-day cold (+4 °C) storage treatments and two lifting times, mid-November and mid-January. The storage treatments were light storage in pots, dark storage in pots, and bareroot storage in polyethylene bags in the dark. In a second experiment, an extended fall photoperiod treatment was applied to seedlings that were then stored in pots and subjected to the same light and dark treatments above. In both experiments, needle samples were taken four times during and after the treatments for abscisic acid assay. Abscisic acid concentrations were determined using gas liquid chromatography after purification with high performance liquid chromatography. Lifting times and storage treatments did not result in statistically significant differences in abscisic acid concentrations. However, there were treatment differences in characteristics of postplanting performance. Mid-November lifting resulted in reduced survival and a greater number of days to bud flush compared with the mid-January lifting results. The extended fall photoperiod material produced similar results to the natural fall photoperiod material. The failure to detect a relationship between needle abscisic acid concentration and seedling vigor may have been due to a transitory role of abscisic acid in the storage conditions studied. The quantification method for abscisic acid is insensitive and laborious for practical seedling testing.
A logistic model for predicting daily people-caused forest fire occurrence in Ontario
Authors: Martell D. L. , Otukol S. , Stocks B. J.
Published: April 2008

The authors describe the development of a procedure that can be used to predict daily people-caused forest fire occurrence in the Northern Region of the province of Ontario. The procedure is based on the use of logistic regression analysis techniques to predict the probability of a fire day and the assumption that a Poisson probability distribution can be used to model daily people-caused forest fire occurrence. The results of a field test that was conducted during the summer portion of the 1984 fire season indicate the procedure works well during relatively wet periods.
Expression of a gene in Pinusstrobus ovules associated with fertilization and early embryo development
Authors: Whitmore F. W. , Kriebel H. B.
Published: April 2008

Total cellular messenger ribonucleic acid (mRNA) was extracted from whole ovules of Pinusstrobus L. before and after fertilization and during embryo development. Invitro translation of the mRNA showed that a messenger coding for a protein of about 23 000 Da appeared as a prominent component about the time of fertilization, remained present for several days, then disappeared. No protein appeared in the array of extant or invivo labeled proteins with the same periodicity as the messenger. The translation product does not, therefore, appear to be a storage protein but may be a protein that undergoes rapid turnover. Freeze-dried ovules were divided into (i) prothallium and (ii) integuments and nucellus for mRNA extraction. The transient mRNA was found in the integument and nucellar tissue but not in the prothallium, which contains the archegonia and subsequent embryo. This mRNA is of interest because it may be the result of gene expression activated by fertilization.
The hybrid white × Sitka spruce: species crossability
Authors: Fowler D. P.
Published: April 2008

The cross white spruce, Piceaglauca (Moench) Voss, × Sitka spruce, Piceasitchensis (Bong.) Carr., was attempted on over 18 000 ovulate strobili on 29 clones of white spruce with pollens from 45 clones of Sitka spruce. All 300 single pair matings and 18 polycross matings were successful in that they produced one or more full seeds per cone. The cross white × white spruce was simultaneously attempted on over 3500 strobili on the same 29 clones. Crossability estimates, determined on an individual cross basis or on a year basis, were highly variable. Average crossability, based on data acquired over 7 years, is 54 to 55% and indicates a close relationship between white and Sitka spruce. White, Sitka, and Engelmann spruce, P. engelmannii (Parry) Engelm., should be assigned to section Omorika, subsection Glaucoides of the genus Picea.
On the error of estimates from successive forest inventories with SPR
Authors: Cunia Tiberius
Published: April 2008

The approach used by Cunia to combine the error from sample plots with the error from volume or biomass tables when Continuous Forest Inventory (CFI) estimates of current values and growth are calculated is extended to the CFI systems using Sampling with Partial Replacement (SPR). The formulae are derived for the case of SPR on two measurement occasions when (i) volume or biomass tables are constructed from linear regressions for which an estimate of the covariance matrix of the regression coefficients is known, and (ii) the sample plots or points are selected by random sampling independently of the given volume or biomass regression functions.
Restricted distribution of a virulent race of the white pine blister rust pathogen in the western United States
Authors: Kinloch Jr. Bohun B. , Dupper Gayle E.
Published: April 2008

A race of Cronartiumribicola virulent to a major gene for resistance to blister rust in sugar pine appears to be limited to the site where first discovered on resistant genotypes in 1978. It was not detected in inocula surveyed extensively throughout a large part of the range of blister rust in the western United States and detected only rarely in inocula surrounding the discovery site. Nor was it found attacking resistant genotypes in other test plantings either nearby or remote from this site. Rate of spread of the virulent race from the discovery site was too slow to be measured during 6 years of observation. These results imply that major gene resistance may be usable for at least one rotation of improved planting stock, while other resistance mechanisms are being developed.