bluuebunny/crossref_metadata_2025 huggingface dataset:
Succession des micro-organismes à la suite de blessures artificielles au tronc chez le bouleau jaune (Betulaalleghaniensis Britt.) et l'érable à sucre (Acersaccharum Marsh.)
Authors: Lavallée André , Bard Alain
Published: July 2007

Xylem of sugar maple and yellow birch trees were exposed to natural infection by making axe blazes to simulate mechanical injuries. After 8, 21, and 34 months, dissection and isolations made from the discolored wood permitted the localization of certain microorganisms in three arbitrarily determined zones. Longitudinal and radial development of discoloration associated with wounds was more rapid in yellow birch than in sugar maple. There was evidence of a succession of organisms in the colonization of the wounds which was subsequent to the first discoloration process and involved different organisms in the two hosts. In general, decay fungi did not appear until after 21 months. Cytosporadecipiens occurred exclusively in discolored wood of sugar maple while Phialophora spp. and Cephalosporium sp. dominated the discolored wood of yellow birch. Bacteria were more frequent in yellow birch than in sugar maple. Relationships between size of injuries, linear extent of the discoloration produced, and identity of the various organisms involved are also presented.
Mortality and Annual Changes in Distribution of Above-Ground Biomass in an Aspen Sucker Stand
Authors: Pollard D. F. W.
Published: July 2007

Biomass (stems and branches) increased from 17 000 kg h−1 in the 4th year to 34 000 kg h−1 in the 7th year of development of an aspen sucker stand. The bulk of the biomass was distributed in the middle and upper diameter classes of shoots; net annual increases only occurred in the upper classes. About 80% of shoots dying in the 3 years of study were less than 2 cm dbh; the biomass lost in these amounted to 200 kg h−1 or less each year. The remaining 20% mortality occurred in the 7th year among shoots 2–5 cm dbh infected with Diplodiatumefaciens. Biomass lost in these larger shoots amounted to 4 900 kg h−1; this was close to the discrepancy between net production (stems and branches) in the 7th year (2600 kg h−1 per annum) and net production in the 5th and 6th years (about 7000 kg h−1 per annum.) Results suggest that although high rates of net annual production are obtainable in short rotations, the mean annual production is strongly influenced by disease because of insufficient time for enhanced growth of survivors.
Range as a Measure of Dispersion in Forest Sampling
Authors: Heger L.
Published: July 2007

The assumption of randomness, underlying the use of range as an estimator of the standard deviation in a normal parent population, was deliberately violated in order to assess how restrictive is this assumption in sampling tree diameters and heights. In only four, out of 34 non-random samples, were the estimates of population standard deviation using range significantly lower than the corresponding root-mean-square estimates. These underestimates were reduced by randomizing the collected data.
Tree Volume Estimates as Affected by Errors Due to Sampling, Volume Equation and Grouping
Authors: Meng C. H.
Published: July 2007

In this paper estimates of tree volume, volume by DBH classes, mean volume per plot and their estimated variances are studied. It is suggested that there are three sources of error. These arise from sampling, the volume equation, and grouping. To illustrate the possible effects of these errors on volume estimates, formulae are presented and an example is calculated. A proposed method of volume estimation which combines and accounts for these errors is recommended.
Effects of Water Deficits on First Periderm and Xylem Development in Fraxinuspennsylvanica
Authors: Borger G. A. , Kozlowski T. T.
Published: July 2007

Three-day-old seedlings of Fraxinuspennsylvanica were transferred to soil undergoing periodic drying or continuous subirrigation. Seedlings were harvested after 24 days. Germinating seeds of F. pennsylvanica were exposed to 1, 10, 20, or 30% polyethylene glycol (PEG) for 35 days and 1-day-old seedlings were exposed to 1, 10, or 20% PEG for 35 days. Seedlings grown on drying cycles or in 20% PEG had smaller periderm and xylem increments than seedlings grown in continuously subirrigated soil or 1 or 10% PEG, respectively. Xylem increment was affected more than periderm increment by water deficits. Germinating seeds exposed to 10 or 20% PEG did not develop periderm or secondary xylem and did not expand foliage. Thirty per cent PEG caused desiccation and death of germinating seeds. Seeds exposed to 1% PEG germinated and developed normally. When water deficits occurred during germination the foliage failed to expand and periderm formation was thereby prevented. Water deficits subsequent to seed germination reduced periderm increment less than they reduced xylem increment, indicating difference in physiological controls.
A Tree Platform for Crown Sampling
Authors: L'Armee M. Talmon-De
Published: July 2007

To facilitate foliage sampling in a physiological study, a portable, inexpensive, and easily constructable tree platform was designed that minimized damage to the tree while providing a solid work base. The design and construction of the platform is described.
Effects of Temperature on First Periderm and Xylem Development in Fraxinuspennsylvanica, Robiniapseudoacacia, and Ailanthusaltissima
Authors: Borger G. A. , Kozlowski T. T.
Published: July 2007

Effects of temperature over the range 10–30 °C were studied on first periderm and xylem development in Fraxinuspennsylvanica, Robiniapseudoacacia, and Ailanthusaltissima. Thirty-five days after germination, phellogen activity in F. pennsylvanica seedlings increased significantly with each temperature increase except from 15 to 20 °C. Periderm was absent in A. altissima seedlings grown for 35 days at 10 °C; phellogen activity increased with each temperature increase from 15 to 25 °C, then declined as temperature was raised from 25 to 30 °C. Phellogen activity of R. pseudoacacia seedlings could not be quantified because outer phellem cells often were crushed, but it depended on temperature in the same general way as in A. altissima. With each increase in temperature from 10 to 25 °C, xylem increments in 35-day-old A. altissima and R. pseudoacacia seedlings increased significantly. As temperature was raised from 25 to 30 °C, xylem increments in these two species decreased significantly. In 35-day-old F. pennsylvanica seedlings, xylem increment increased significantly as temperature was raised from 10 to 15 °C and from 20 to 25 °C. Raising temperature from 15 to 20 °C did not increase xylem production, nor did raising temperature from 25 to 30 °C decrease xylem production. Optimum temperature for periderm development was not necessarily the same as that for xylem production and varied among species, indicating differences in physiological controls.
Cone and Seed Production of One-Year-Old Rooted Cuttings of Western Hemlock
Authors: Piesch R. F.
Published: July 2007

Reproductive buds were initiated concurrently with the development of roots on cuttings of western hemlock (Tsugaheterophylla) set in a rooting bed. The ovulate cones were pollinated the following spring and cones from most cuttings produced viable seeds. The subsequent growth of the seedlings was good.
The Relationship Between Leaf Area and Leaf Dry Weight of Three Conifer Species Grown on Three Sources of Nitrogen
Authors: Mellor G. E. , Tregunna E. B.
Published: July 2007

Western hemlock, Douglas-fir and lodgepole pine were grown on three different sources of nitrogen. At 18 weeks the relationship between leaf area and leaf dry weight was determined for each species. A linear relationship was found between leaf area and leaf dry weight for all three species. Different nitrogen treatments had no effect on this relationship.
Enhancement of Twig Abscission in White Oak by Ethephon
Authors: Chaney William R. , Leopold A. Carl
Published: July 2007

Abscission of twigs from a mature Quercusalba L. was stimulated by 1 and 2% ethephon (2-chloroethylphosphonic acid) in lanolin applied to the base of twigs in the fall. The greatest stimulation resulted from treatment on September 11. Two percent ethephon enhanced twig abscission approximately 122%. The current shoot of abscised twigs was shorter than the current shoot of twigs retained on the tree, suggesting that the less vigorous twigs were shed. Twigs of juvenile trees did not abscise naturally and were not induced to abscise by ethephon.
Effect of Index Age on the Precision of Site Index
Authors: Heger L.
Published: July 2007

Effect of index age on the probable size of random error in site index was evaluated by comparing the 95% confidence interval for site index by curves based on index age 50 years at breast height (BH) with that by curves based on index age 100 years at BH. The curves were constructed using the regression method and stem analyses of 181 dominant white spruce trees (Piceaglauca (Moench) Voss). Using curves based on index age 100, a 10-ft index class could not be identified with 95% confidence for BH ages below about 50 years even if these curves were entered with sample averages of 50 dominant heights. Using curves based on index age 50, a 10-ft index class could be identified with 95% confidence for BH ages 20–100 years if these curves were entered with sample averages of at least 15 dominant heights. Effect of index age on the outcome of curve shape comparisons was discussed.
The Use of Branches as a Basis for the Estimation of the Copper, Zinc, Lead, and Nickel Status of a Forest Stand
Authors: Fortescue J. A. C.
Published: July 2007

An experiment is described which was carried out to examine the feasibility of using 10 years of growth of tree branches as the basis for an estimate of the trace element status of forest trees and stands. The experiment was undertaken to obtain an estimate of trace element status of forest trees (or stands) independent of 'within season' or 'season to season' variations in the chemical composition of the branches. Thirty-six trees, twelve of each of three species (Betulapapyrifera, Populusgrandidentata, Populustremuloides), growing together in a 50 year old mixed wood stand at Chalk River, Ontario were included in the experiment. On the basis of tree growth data and measurements of the content of two micronutrient elements (copper and zinc) and two nonnutrient elements (lead and nickel) in 360 samples of branch material it was concluded that the proposed method of determination of the element status of forest trees (or stands) shows promise, but requires more detailed study before its importance as a method of trace element status estimation can be fully evaluated.
Effects of Fertilization of a Black Spruce Stand on Nitrogen Contents of Stemflow, Throughfall, and Litterfall
Authors: Mahendrappa M. K. , Ogden E. D.
Published: July 2007

The nitrogen (N) contents of stemflow, throughfall, litter, and rain were investigated in a black spruce stand with 95% crown closure treated with three levels each of nitrogen and phosphorus fertilizers in a factorial design. Throughfall and rain were collected in standard rain gauges. Stemflow was collected using lead collars coated with an inert plastic and fixed on the tree trunks. Litter samples were collected with fiberglass screens. In all samples, NH4+-N and total-N were determined.During this study, 18–20% of the rainfall was lost through interception and evaporation, 80% was throughfall, and less than 0.5% reached the ground as stemflow. Average concentrations of NH4+-N for all fertilized plots in stemflow, throughfall, and rain were 0.15, 0.23, and 0.09 p.p.m. N, respectively, and the total-N in these samples was 1.69, 0.63, and 0.37 p.p.m. N in the same sequence. Quantities of nitrogen in the throughfall were highest in the fertilized plots, i.e. fertilization increased the concentration of NH4+-N and total-N in throughfall but not in stemflow. In both stemflow and throughfall, highest concentrations of nitrogen were recorded in June. The estimated nitrogen returned to the ground by litterfall, throughfall, stemflow, and unintercepted rain was 16.00, 4.33, 0.04, and 2.62 kg N/ha/year.
Some Histological Features of Acersaccharum Wood Formed after Wounding
Authors: Sharon Edward M.
Published: July 2007

A pattern of chemical and morphological changes occurred in sugar maple wood that formed after wounding, resulting in a distinct tissue. After normal wood formation resumed, this wound-associated tissue separated wood formed subsequently from wood that formed before wounding. Discoloration associated with the wound developed in the wood extant prior to wounding.
Increased Mortality of the Swaine Jack-pine Sawfly, and Foliar Nitrogen Concentrations After Urea Fertilization
Authors: Smirnoff W. A. , Bernier B.
Published: July 2007

Mortality of the Swaine jack-pine sawfly larvae (Neodiprionswainei Midd.) introduced as colonies on jack-pine (Pinusbanksiana Lamb.) foliage was measured in untreated and urea-treated plots of natural forest. Following applications of urea (400 kg N/ha) repeated in two successive years, natural mortality increased from 40 to 70% after 4 weeks, from 33 to 51% after 6 weeks, and from 18 to 36% after 4 weeks for larvae introduced as 1st instar, 2nd instar, and 3rd instar, respectively. This was accompanied by a marked reduction in foliage consumption as revealed by direct measurements or by the weight of frass collected. With 3rd-instar larvae sprayed with a suspension of the virus Borrelinavirusswainei (Smirnoff), viral infection developed much more rapidly in larvae placed on fertilized trees, mortality reaching 100%, double that measured on unfertilized trees. Single applications of urea at lower rates (100 and 200 kg N/ha) revealed a trend of increasing mortality for both unsprayed and virus-sprayed larvae with increasing urea application rate and increasing nitrogen concentration in the needles. Changes in the nitrogenous composition of needle tissue are considered an important factor in the increased larval mortality.
Effects of Different Foliar-applied Nitrogen Fertilizers on Balsam Woolly Aphid
Authors: Carrow J. Roderick , Betts Robert E.
Published: July 2007

Balsam woolly aphids were reared on young grand fir trees maintained in controlled environment or outdoors. Solutions of various nitrogen fertilizers were applied repeatedly to the trees and the effects on aphids and bark amino acids were studied. On trees fertilized with ammonium nitrate or a sequence of compounds, aphid population growth was less than on trees fertilized with urea or potassium ammonium nitrate. On urea-fertilized trees, populations multiplied 16.5 times in five generations, compared with a 5.7-fold increase on unfertilized trees and a 1.4-fold increase on ammonium nitrate-fertilized trees. These differences resulted from effects of these nutrients on aphid life history. Urea promoted aphid establishment and reproduction, whereas ammonium nitrate affected these processes, as well as survival, adversely. The highest establishment and survival rates resulted from potassium ammonium nitrate.These differences may be related to fertilizer-induced changes in the amino acid diet of the aphid. Thin layer electrophoresis and chromatography revealed that urea, ammonium nitrate, and calcium nitrate each increased arginine concentrations in the bark, the highest levels resulting from ammonium nitrate. Traces of phenylalanine and asparagine, found in other treatments, were absent from trees fertilized with ammonium nitrate during June.
Micro-organismes dans les tissus colorés et cariés du peuplier faux-tremble
Authors: Laflamme Gaston , Lortie Marcel
Published: July 2007

Trees in two 45-year old stands of aspen were sampled for microorganisms in discolored and decayed wood. The main genera of fungi imperfecti isolated were Phialophora, Libertella and Ascocoryne. The commonest decay organism was Corticiumpolygonium followed in decreasing order of frequency by Fomesigniarius, Phlebiastrigoso-zonata and Pleurotusostreatus. Trichocladiumcanadense was usually found in the wood near the stump as was Armillariamellea. Bacteria and yeasts were common, especially in colored wood. From the location of the main organisms recorded, a succession of organisms is apparent. The presence of F. igniarius apparently is influenced by aspen clonal characteristics.
Short-term Progeny Tests and Second Generation Breeding in Slash Pine
Authors: Franklin E. C. , Squillace A. E.
Published: July 2007

Progeny testing is the most widely used method for intensive genetic evaluation of selected forest trees, but its major disadvantage is the length of time needed to get results. To circumvent this problem in selection for a multiproduct strain of slash pine (Pinuselliottii Engelm.), a system for short-term (3-year) progeny testing was developed. Oleoresin yields of selected second-generation 19-year-old parent trees were compared with yields of their 3-year-old offspring. Both parents and offspring showed little variation and a low offspring–parent correlation (r = 0.18), but other traits based on the same parent trees when they were 25 years old and their 3-year-old offspring showed relatively large amounts of variation and moderate to strong offspring-parent correlations: height, r =.56; volume, r = 0.43; turpentine, r = 0.71; ethanol–benzene extractives, r = 0.38; specific gravity, r = 0.43; moisture content, r = 0.34. Thus, indications are that additional gains could be made in the first generation by selecting among parent trees on a progeny performance basis in all traits except oleoresin yield. Original mass selection for oleoresin yield achieved gains of 100% improvement and apparently exploited almost all of the genetic variation in the base population. In second generation selection, progeny testing will be used primarily in screening for fusiform rust resistance. Between-family plus within-family selection will be used for other traits.
Distribution of Elements in Aerial Components of Several Natural Jack Pine Stands in Northern Ontario
Authors: Morrison I. K.
Published: July 2007

Concentrations of N, P, K, Ca, and Mg were determined in aerial components of jack pine [Pinitsbanksiana Lamb.] trees growing in 12 stands, representing three age classes, two site classes, and two stocking intensities, all in close proximity on a coarse glacio-fluvial soil deposit, in northern Ontario. Element contents were estimated from these values in conjunction with dry matter functions. Regression equations relating logarithms of element content with logarithms of diameter at breast height were calculated. These were used in association with individual plot stand tables to give total weight per hectare of each element in the aerial parts of each stand. Converted to normal stocking, contents of all elements increased with increasing stand age. Over half of the aboveground N and P, but somewhat less than half of the aboveground K, Ca, and Mg occurred in crowns as opposed to stems in 65-year-old stands.
Développement hivernal de semis de Douglas
Authors: Andre P. , Weerts J.
Published: July 2007

The authors studied the winter behavior of Douglas-fir seedlings and the influence of a complete fertilization. Under normal climatological conditions, the seedlings showed a winter development increased by the addition of fertilizers.Among the several variations of aerial and underground parts of the vegetal, the growth of the root system is very important since a lengthening of the tap root and an increase in both the number of lateral roots, and total weight were observed.
Field Test of the Effectiveness of Chitinase Additive to Bacillusthuringiensis Berliner Against Choristoneurafumiferana (Clem.)
Authors: Smirnoff W. A. , Randall A. P. , Martineau R. , Haliburton W. , Juneau A.
Published: July 2007

In a field trial two 100 acre (40 ha) plots of balsam fir heavily infested with spruce budworm were sprayed with a water-based formulation of a liquid concentrate containing 25% commercial Bacillusthuringiensis Berliner and 25% non-volatile additive. The spray formulation used on one plot contained 5.5 g of the enzyme chitinase added to the 200 gal (757 l) of material. The spray was applied at 2 gal/acre (G.P.A.) (18.6 l/ha) by a Stearman aircraft equipped with 4 Micronair® AU 3000 rotary atomizers. Spray deposits were sampled with paper cards and plates of nutrient medium. A dry dye treatment was used to enhance drop trace visibility on deposit sample cards.Larval mortality was higher on the chitinase treatment plot, and better foliage protection resulted. Biochemical tests indicated some differences in physiological responses in larvae and pupae from the two treatments. It is concluded that, given suitably equipped aircraft, and a guidance system that would ensure uniform coverage, the addition of chitinase should make it practicable as one of the methods of control of the spruce budworm.
Role of Carbohydrate Reserves in the Development of Root Suckers in Populustremuloides
Authors: Schier George A. , Zasada John C.
Published: July 2007

The role of carbohydrate reserves in initial sucker growth from excised roots of Alaskan and Utahan aspen (Popnlustremuloides Michx.) was investigated by correlating the seasonal variation in sucker production in darkness with the concentration of total nonstructural carbohydrates (T.N.C.) in the roots. Sucker numbers were not correlated with T.N.C. content. Dry weight of suckers per cutting (D.W./C) was a function of T.N.C. percentage and the number of suckers per cutting (No./C). In the additive model, D.W./C = b0 + b1 (No./C) + b2 (T.N.C), T.N.C. was a significant contributor to sucker dry weight. Although dry weight per cutting increased as the number of suckers became larger, dry weight per sucker decreased. Within geographic area, number and dry weight of suckers and T.N.C. percentage were related to both date of collection and clone of origin. Seasonal trends in T.N.C. content were similar in the Utahan and Alaskan roots studied.
Domestication Strategies for Forest Trees
Authors: Libby W. J.
Published: July 2007

This paper is based in large part on recent reviews of tree breeding programs in the southeastern United States, the Pacific Northwest, New Zealand, southeastern Australia, and Taiwan. Domestication, which here includes tree breeding, is discussed generally in terms of original species variability, the processes of selection and packaging, and the returns via a more useful renewable resource. Six reasons why forest geneticists and tree breeders plant trees are given, along with the different requirements for site, planting design, number of trees, and number of entry genotypes or lines for each reason. A flow chart is presented, showing the various kinds of plantations and forests established during a domestication program, and the physical movement of gene packages between such plantations and forests. The information flow within the scheme is also discussed.
A Stochastic Model for the Occurrence of Man-caused Forest Fires
Authors: Cunningham A. A. , Martell D. L.
Published: July 2007

This paper discusses the occurrence of man-caused forest fires during the summer fire season in a section of northwestern Ontario. Fire occurrence is viewed as being a chance process and a stochastic model is developed to describe it. The results of this study indicate that a Poisson model with the average number of fires per day depending on the Fine Fuel Moisture Code is appropriate.
Stand Equations for Estimating Aerial Biomass, Net Productivity, and Stem Survival of Young Aspen Suckers on Good Sites
Authors: Perala Donald A.
Published: July 2007

Equations were developed from single and repeated stem counts, diameter and height measurements to predict leafless aerial biomass, net productivity, and stem survival in young trembling aspen sucker stands on good to excellent sites. Although the most dense stands studied reached maximum periodic annual productivity at age 16, maximum mean annual productivity will not be reached until after 20 years of age.
New Form-class Equations Improve Volume Estimates
Authors: Evert F.
Published: July 2007

Three form-class volume equations involving the upper stem diameter at 19.5 ft (5.94 m) above ground level and three standard volume equations based on d.b.h. and height were tested for accuracy in estimating both tree and stand volume in different stands of red pine (Pinusresinosa Ait.). All three form-class equations met the required 10% accuracy in estimating individual tree volumes; the three standard volume equations failed to meet this accuracy. All three form-class equations also met the required 5% accuracy in estimating stand volume, but none of the standard equations did.
Concentrations of Manganese and Microorganisms in Discolored and Decayed Wood in Sugar Maple
Authors: Shortle Walter C. , Shigo Alex L.
Published: July 2007

Columns of discolored and decayed wood associated with 8-year-old wounds and contiguous clear wood in five sugar maple trees, Acersaccharum Marsh., were mapped systematically for microorganisms and concentrations of manganese. Numbers of wood chips yielding microorganisms decreased as the vertical distance above and below the wounds increased. Bacteria and nonhymenomycetous fungi were isolated from the discolored wood at the distal margins of the columns, Hymenomycetes were not. In columns of discolored wood alone, without decayed wood, the concentrations of manganese were the same as in the contiguous clear wood. In columns of discolored and decayed wood, but where few Hymenomycetes were isolated from the decayed wood, the concentrations of manganese were the same as in the contiguous clear wood. The concentrations of manganese were higher in those tissues at the interface between discolored wood, and decayed wood that yielded Hymenomycetes frequently in culture, than contiguous clear tissues. Changes in ash, moisture, and pH may be more related to the tree response to wounding while manganese concentrations may be more related to the concentration and species of microorganisms in the tissues.
A Markov Chain Approach to the Prediction of Diameter Distributions in Uneven-aged Forest Stands
Authors: Bruner Harold D. , Moser Jr John W.
Published: July 2007

A simple stochastic model to predict future diameter distributions, number of survivor trees, number of mortality trees, and number of harvested trees is developed from conventional continuous forest inventory data over two measurement periods. The length of the prediction period is limited to multiples of the remeasurement period. Data used to construct the model and test its predictive ability came from 19 consecutive years of C.F.I, measurements collected in Washington County, Wisconsin. Results indicate that number of survivor trees can be predicted with very good accuracy; predictions of diameter distributions, number of mortality trees, and number of harvested trees are less accurate.
Chemosystematic Studies in the Genus Pseudotsuga. III: Population Differences in British Columbia as Determined by Volatile Leaf Oil Analysis
Authors: Rudolff E. von
Published: July 2007

Detailed analysis of the volatile leaf oil terpenes of different Douglas-fir populations and provenances growing in British Columbia confirmed the previous classification into the following terpene types: three coastal (A, B, and C), coastal intermediate, intermediate, interior intermediate, and Rocky Mountain. In areas of overlap of the coastal and Rocky Mountain varieties a continuous gradation of terpene types may be encountered. Differences in elevation or soil sites within homogeneous populations do not affect the terpene patterns noticeably. The major area of overlap occurs in the Cascade Mountains of southern British Columbia. Further inland either interior intermediate or Rocky Mountain types are found. However, at wet sites there is a noticeable increase of the typical coastal terpenes. Conversely, at drier sites in the southern coastal regions, including southeastern Vancouver Island, a distinct increase of the typical Rocky Mountain variety terpenes was recorded. Somewhat unexpectedly, this was also found at Cowichan-Skutz, which is a typical wet coastal site. Equally unexpected was the finding of many trees with the coastal C terpene pattern in three locations near D'Arcy; no noticeable increase in the typical Rocky Mountain variety terpenes was recorded at D'Arcy.A simplified gas chromatographic technique was developed which reduces the cost of analysis by a factor of ten, yet allows differentiation between the seven terpene types.
The Range of Tamarack (Larixlaricina (Du Roi) K. Koch) in Northern Yukon Territory
Authors: Zoltai S. C.
Published: July 2007

Tamarack (Larixlaricina (Du Roi) K. Koch) is a common constituent of the sub-Arctic forest some 175 km (108 miles) beyond the previously known range, extending across the continental divide in northern Yukon. It occurs on imperfectly to poorly drained mineral soils, often near the timber line, and on wet organic soils.
Sugar-maple Borer Injury in Four Hardwood Stands in New Hampshire
Authors: Shigo Alex L. , Leak William B. , Filip Stanley M.
Published: July 2007

Forty-three percent of 348 sugar-maple trees, Acersaccharum Marsh., in 60 plots, in four hardwood stands were injured by the sugar-maple borer, Glycobiusspeciosus (Say). The percentage of injured trees was greater in uneven-aged stands than in even-aged stands. The microorganisms isolated from discolored and decayed wood associated with borer injuries were the same as those isolated from discolored and decayed wood associated with wounds on sugar maple.
Kraft Pulping of Trembling Aspen Tops and Branches
Authors: Hunt K. , Keays J. L.
Published: July 2007

Ontario trembling aspen (Populustremuloides Michx.) unmerchantable tops and branches, with and without bark, gave unbleached kraft pulps with greater permanganate numbers and screen rejects than pulps from corresponding boles when cooked by the same schedule. Oven-dried pulp strengths of components, with and without bark, after beating in a P.F.I, mill, were less than those of the oven-dried pulp from an internal standard. Tops and branches with bark yielded pulps with substantially lower strength values than pulps from the tops and branches without bark, and also took longer to beat to 300 ml C.S.F. It is suggested that aspen tops and small-diameter boles without bark could be pulped with wood from mature boles in limited amounts (5–10%) to give a satisfactorily homogeneous pulp. However, inclusion of branches with mature boles, both without bark, would give a more heterogeneous pulp mixture. Any mixtures of tops, small boles and/or branches with bark, and mature boles without bark would give a highly heterogeneous pulp.
Comparison of Electrical Resistance and Impedance Measurements in Wood in Progressive Stages of Discoloration and Decay
Authors: Tattar Terry A. , Saufley George C.
Published: July 2007

Direct current resistance and alternating current impedance were used to detect and quantify wood in progressive stages of discoloration and decay in living trees. Results were comparable to those obtained with pulsed current under similar conditions.
Effect of vegetative competition on regeneration of white spruce
Authors: Eis S.
Published: July 2007

The rate of invasion and height growth of vegetation in logged-over areas were studied on four forest site types in the white spruce – alpine fir (Piceaglauca (Moench) Voss – Abieslasiocarpa (Hook.) Nutt.) forests north of Prince George, B.C. On Cornus–Moss, Aralia–Dryopteris, and Devil's Club site types, which generally had full stocking, vegetation that grew under the canopy of trees was replaced after logging by aggressive pioneer species. Annuals were the first to invade the logged-over area, followed by biennials and perennials. The invasion of shrubs was the slowest. After logging, 6 or 7 years elapsed before vegetation became a serious hindrance to regeneration and, by that time, white spruce seedlings planted immediately after logging were tall enough to withstand competition. On the Alluvium site type, where stocking is usually open and shrubs and grasses that thrive in the logged-over areas are present, spruce seedlings were overtopped during the first growing season and eliminated as the density of shrubs increased.
Biomass and production of an aspen – mixed hardwood – spodosol ecosystem in northern Wisconsin
Authors: Pastor John , Bockheim J. G.
Published: July 2007

Total biomass of an aspen – mixed hardwood – spodosol ecosystem in northern Wisconsin, U.S.A., was 197 t/ha and net primary production was 11.5 t/ha per year. Populustremuloides Michx. accounted for 60% of the total biomass and 56% of the annual production and Acersaccharum Marsh, accounted for 25% of the biomass and 28% of the annual production. For all species combined, bole wood was 63% of the total biomass and bole bark was 12%. Bole wood was 33% and bole bark was 7% of the total production. Although crowns accounted for only 15% of the total biomass, they were responsible for 49% of net annual production. Using allometric equations from the literature, root biomass and production were calculated as being approximately 10% of the total biomass and of the annual production. The average rate of total production per unit leaf tissue was 5.7 g production/g leaf tissue for P. tremuloides and 3.7 g/g for A. saccharum.
A dynamic model of growth in defoliated fir stands
Authors: Baskerville G. , Kleinschmidt S.
Published: July 2007

Constructing a dynamic model of growth in fir stands (age 30–70 years), based on gross physiological structure of the stand, made possible reasonable qualitative and quantitative forecasts of growth loss due to defoliation by insects in a wide variety of situations. Analysis of the model, in comparison with the natural world, indicates that the key to understanding growth loss in fir stands subjected to defoliation by spruce budworm lies in more explicit knowledge of the mechanisms of new foliage production.
Comparison of the chemical properties of forest floors, decaying wood, and fine roots in three ecosystems on Vancouver Island
Authors: Quesnel H. J. , Lavkulich L M.
Published: July 2007

Elemental concentrations were measured and compared for LF horizons, H horizons, decaying wood, and fine (< 2 mm) roots of three ecosystems on northern Vancouver Island. The principal tree species of these ecosystems were western hemlock (Tsugaheterophylla (Raf.) Sarg.), amabilis fir (Abiesamabilis (Dougl.) Forbes), and western red cedar (Thujaplicata Donn.). The H horizons had greater Mg and Na values than the LF horizons, while the opposite result was found for K and loss on ignition (LOI). The decaying wood represents a significant accumulation of nutrient-deficient biomass that could immobilize N. The decomposing fine roots will temporarily immobilize N while possibly increasing the concentration of elements such as Fe, Al, and Mn. These materials should be separated from forest floor samples in order to represent more accurately the nutrient status of forest floor horizons.
Factors affecting spread of Cronartiumcomptoniae on the sweetfern host
Authors: Smeltzer Dale L. K. , French D. W.
Published: July 2007

Infection of sweetfern plants (Comptoniaperegrina (L.) Coult.) by Cronartiumcomptoniae Arth. was observed at a maximum of 30 m from the aeciospore source on two field plots in northeastern Minnesota, U.S.A. Amount of infection per spores trapped decreased significantly as dispersal distance increased from the source of inoculum. Infection of sweetfern was limited most by the decrease in spore viability, but lack of rain may have limited infection at least twice during the summer. Inoculations of sweetfern with aeciospores and uredospores in a growth chamber resulted in infection at 0–28 °C, a wider temperature range than for spore germination on agar. Infection occurred after 1 h in a humid chamber and was inhibited by light, especially high intensities. Free water and spores on the undersurface of the sweetfern leaf were required for infection.
Fertilisation azotée en forêt de pin gris (Pinusbanksiana). I. Cheminement des engrais dans le sol
Authors: Camiré C. , Bernier B.
Published: July 2007

Six nitrogen fertilizers (urea, sulfur-coated urea, urea-formaldehyde, ammonium nitrate, ammonium sulfate, and ammonium nitrate) were individually applied, either in fall or in spring, at a rate of 224 kg N/ha and compared for nitrogen retention in the different horizons of a podzol under jack pine. Despite its susceptibility to nitrogen losses through ammonia volatilization, urea was by far, among readily available nitrogen fertilizers, the one whose nitrogen is best retained in soil surface horizons. Retention varied with weather conditions that prevailed immediately after fertilizer application. With the other fertilizers used, nitrogen retention followed this order: ammonium sulfate > ammonium nitrate > calcium nitrate. After four seasons, about 50% of the nitrogen applied as sulfur-coated urea and urea-formaldehyde was still found in its original form. Ammonium sulfate is next to urea among the recommended nitrogen sources for similar jack pine sites, considering that fertilizers with nitrate are prone to leaching and the sulfur-coated urea and urea-formaldehyde used presented problems of nitrogen availability.
Genetics of isozyme variants and linkage relationships among allozyme loci in 35 eastern white pine clones
Authors: Eckert R. T. , Joly R. J. , Neale D. B.
Published: July 2007

Megagametophyte tissue from seeds of 35 clones of Pinusstrobus L. were subjected to horizontal starch gel electrophoresis. The resulting gels were tested for activity of 10 enzyme systems. Isozymes observed were under control of at least 17 loci. Direct evidence, based on segregation of allozymes in megagametophytes of heterozygous clones, is presented for nine loci in five systems (LAP, GPI, GOT, PGM, and AP). Three polymorphic loci were detected for LAP. No genetic variation was detected for IDH, ADH, GLY-3-PD, GDH, or 6 PDG.Five pairs of linked loci were detected by chi-square analyses of joint segregation. Twenty-five of 36 possible two-locus combinations among 18 clones were evaluated. Recombination estimates suggest relatively strong linkage between LAP1-LAP2 and GPI2-GOT1; weaker linkage between LAP2-GPI2 (based on one clone only); and weak linkage between LAP2-AP1 and GOT3-AP1.
Provenance variation in seed weight, cotyledon number, and growth rate of western hemlock seedlings
Authors: Kuser John E. , Ching Kim K.
Published: July 2007

A range-wide sample of western hemlock (Tsugaheterophylla (Raf.) Sarg.) seedlings from 21 provenances showed significant variation in seed weight, frequency of seedlings with four cotyledons, and growth rates of seedlings under continuous growth in controlled environments. Growth responses were strongly influenced by air and soil temperatures and seed source. Variation among provenances and between families within provenances was highly significant, with family variation averaging up to one-half of the provenance variation for most responses. Seedlings from southern latitudes, medium elevations, or coastal provenances generally grew faster than those originating in northern latitudes, high elevations, or the Rocky Mountains; but these trends had marked exceptions. A strong north–south cline was found in the variation among coastal provenances. Rocky Mountain hemlock populations seemed to differ from coastal hemlock populations in growth rate, shoot: root ratio, and frequency of seedlings with four cotyledons.
Predicting seed germination and seedling establishment in containers
Authors: Pepper W. D. , Barnett J. P.
Published: July 2007

General equations for predicting number of blank cells, number of excess seedlings to be thinned, and number of plantable seedlings after thinning were developed for containerized seedling operations. The binomial model which is employed in the prediction equations was tested with germination and survival data from Pinustaeda L. It was concluded that the binomial model satisfactorily represents the germination and survival process in containers for Pinustaeda L. provided the containers do not differ significantly from those used in this study. The effect of thinning Pinuspalustris Mill, seedlings in containers was studied. It was concluded that thinning had a negligible effect on the remaining seedlings and that prediction equations needed no adjustment for thinning mortality.
Intraseasonal growth and nutrient composition of jack pine needles following fertilization
Authors: Morrow L. D. , Timmer V. R.
Published: July 2007

Seasonal responses in dry weight, nutrient concentration, and nutrient content of current and year-old needles of plantation jack pine (Pinusbanksiana Lamb.) were examined after treatment with factorial combinations of N, P, and K applied at 0 and 100 kg/ha, respectively. Nitrogen fertilization not only increased dry matter production and N composition of new needles, but also increased uptake of P, K, Ca, and Mg by prolonging the active growing season. Net translocation of N from old to new foliage occurred only in N-deficient trees at the peak of the growing season. Application of P and (or) K failed to increase growth and nutrient uptake of needles, except for P additions which induced luxury consumption of phosphorous. Diagnosis of foliar nutrient status indicated P and K as sufficient and N as deficient for growth in this stand.
Effect of cutting diameter and stem or branch position on establishment of a difficult-to-root clone of a Populusalba hybrid
Authors: Hansen Edward A. , Tolsted David N.
Published: July 2007

A total of 357 hardwood cuttings 20 cm long were collected from 22 one- and two-year-old trees (established from rooted cuttings) of a difficult-to-root Populusalba × P. grandidentata clone. The cuttings, planted in book planters, were grown in a greenhouse for 3 months; survivors were then transplanted into the field. Survival and growth were recorded periodically. After 2 months in the greenhouse, height growth was significantly related to diameter, but there was no further diameter effect on height growth after that. Branches, 1- and 2-year-old stem wood provided cuttings with comparable survival percentages for any given diameter class. Survival increased with increasing cutting diameter of both stem and branches and was highest for cuttings from the lower positions of the stem and branches. Position was slightly more efficient than diameter as a selection criterion of stem cuttings, since cuttings from the lower stem positions generally had high survival even if diameters were relatively small. However, for branch cuttings, selection based on diameter alone adequately segregated those with the best survival. Of several proposed alternative cutting selection criteria, two were judged to be best. They were to select (1) all cuttings with diameter > 9 mm and (2) a combination of all branch cuttings with diameter > 9 mm plus the four basal stem cuttings regardless of diameter. When these selection criteria were used survival increased from 29% to just over 50%.
The effect of Frankia isolates from Comptoniaperegrina and Alnuscrispa on the growth of Alnusglutinosa, A. cordata, and A. incana clones
Authors: Dawson Jeffrey O. , Sun Soon-Hwa
Published: July 2007

Three Alnus clones, one each of A. glutinosa (L.) Gaertn., A. cordata (Lois.) Desg., and A. incana (L.) Ait., were inoculated with Frankia isolates from root nodules of Comptoniaperegrina (L.) Coult. and A. crispa var. mollis Fern. Both Frankia isolate and Alnus clone contributed significantly to postinoculation height and diameter growth of plants in nitrogen-free culture, while interaction between isolate and clone was not statistically significant (α = 0.05). All combinations of host plants and isolates yielded nodules that were effective in fixing nitrogen as evidenced by the ability of nodules to reduce acetylene to ethylene. Alnus plants inoculated with the Comptonia isolate grew in height at a rate 1.9 times that of Alnus plants inoculated with the A. crispa isolate, while more than doubling the stem diameter growth increment of plants inoculated with the A. crispa isolate. The A. glutinosa clone grew at least four times as rapidly in height and at least twice as rapidly in diameter as the other two Alnus clones after inoculation with Frankia isolates. Results indicate that potential exists for the improvement of growth rates of Alnus and other Frankia-nodulated plants by selection of both Frankia isolates and host plant genotypes for specific environments.
Shoot morphology and shoot growth potential in 1-year-old Scots pine seedlings
Authors: Thompson S.
Published: July 2007

When seedlings of a single seed source of Scots pine (Pinussylvestris L.) were raised for 26 weeks in a naturally lit, heated greenhouse, two types of shoot morphology were observed. Type 1 was that normally found in 1-year-old seedlings. Type 2 had a shoot morphology similar to that of seedlings raised outdoors for two growing seasons. When compared with type 1 plants, type 2 plants had an earlier start to shoot elongation, set their buds earlier, and stopped shoot elongation sooner. After one growing season, type 2 plants were shorter, had fewer stem units for shoot elongation in the second season, but carried a greater foliage biomass than 1-year-old type plants. After two seasons they remained shorter. Thus, plant rearing practices which result in the production of seedlings with this type of shoot morphology arc undesirable.The relationship between early "budsct," shoot morphology, and plant height suggests that the proportion of seedlings with a 2-year-old shoot morphology after one growing season in a heated greenhouse may be used as an early test for height growth potential in seed origins and possibly in progenies of north temperate pine species.
Generalized biomass estimation equations for Betulapapyrifera Marsh.
Authors: Schmitt Mark D. C. , Grigal D. F.
Published: July 2007

Aboveground biomass estimation equations were developed and compared for several components of Betulapapyrifera Marsh, trees using diameter at breast height (dbh) alone or dbh and height as independent variables. The data upon which the equations are based were collected by a number of different investigators working in Minnesota, Wisconsin, New Hampshire, and several sites in Maine and New Brunswick. Coefficients of determination ranged from 0.82 to 0.99, with higher values for bole than for crown components. The root mean-square deviation of the observations from the model was in the range 1 – 10 kg for any component. The largest trees in the data set (ca. 30 cm dbh) had total aboveground biomass of about 540 kg. In the absence of site-specific data, these equations provide acceptable estimates of biomass for B. papyrifera.
Effects of sand pine scion on monoterpene composition of slash pine rootstocks
Authors: Kossuth Susan V. , Barnard E. L. , Squillace A. E. , Kratka S.
Published: July 2007

Xylem oleoresin was analyzed from slash–slash, sand–slash, and sand–sand pine scion–rootstock graft combinations varying in age from ca. 8 to 15 years in a northwest Florida seed orchard. The predominant components, α-pinene, β-pinene, and β-phellandrene averaged 48.8, 23.5, and 21.4% of the monoterpene composition in slash–slash trees compared with 21.6, 71.4, and 2.2% in sand–sand trees. When sand pine was grafted onto slash pine, the percent composition of β-pinene in the slash pine was significantly increased from 23 to 50% while rootstock content of β-phellandrene was significantly reduced from 19 to 2%, and α-pinene was not significantly altered.