bluuebunny/crossref_metadata_2025 huggingface dataset:
Changes in phosphorus nutrition of sugar maple along a topographic gradient in the Quebec Appalachians
Authors: Paré D. , Bernier B.
Published: February 2008

In a typical sugar maple (Acersaccharum Marsh.) stand in the Quebec Appalachians, foliar phosphorus concentrations increased from the bottom to the top of the hill, while the humus form varied from a mull to a mor along the same slope sequence. Although limited, these observations within one stand presumably subjected to the same anthropogenic stresses, including acid loading, are consistent with those obtained on a regional scale by comparing the phosphorus nutrition of sugar maple stands growing on soils with contrasting humus forms. They support the observation that under the conditions prevailing in the Quebec Appalachians, phosphorus nutrition is affected mainly in stands growing on soils with a moderately acid mull humus. As foliar phosphorus may vary with variations in the humus form over short distances, corrective measures require planning for limited, well-defined areas.
A form-class tree-grading algorithm
Authors: Liu C. J.
Published: February 2008

The mathematical relationship dbh–dith was formulated, according to the definition of Girard form class. By incorporating this formula, the USDA Forest Service hardwood tree grades for factory lumber, and a previously devised general tree-grading algorithm, a form-class tree-grading algorithm was developed. This algorithm, designed primarily for tree grading in field conditions, facilitates the grading of hardwood trees with 12-, 14-, or 16-ft sections located at various positions in the butt log, and serves as a basis for computer programming.
The calculation of average yarding distance to a centralized landing, given a polygonal mesh approximation of the setting surface
Authors: Greulich Francis E.
Published: February 2008

A new formula for average yarding distance is presented. This formula permits the development of an algorithm suitable for calculating average yarding distance under very general conditions when cable yarding to centralized landings. The minimal assumptions are that the surface of the setting is adequately approximated by a polygonal mesh and that a straight line segment provides an adequate description of the path followed by each turn from its setting location to the landing. Examination of the results obtained from a specific example offers tentative validation of the formula and the algorithm. The algorithm-calculated parameters are shown to closely match the corresponding statistics obtained by way of an independent simulation model. Both the theoretical basis and the computational efficiency of turn location parameter estimation in general logging engineering practice should be enhanced by this new formula and computational algorithm.
Characteristic discolorations of coniferous foliage related to spruce decline in Europe and North America
Authors: Liedeker Heiko , Klein Richard M.
Published: February 2008

Characteristic spotting of foliage on Norway spruce in Europe, used as an indicator for Waldsterben, was also found and described on foliage of Piceaabies (L.) Karst., P. rubens Sarg., P. glauca (Moench) Voss, P. mariana (Mill.) B.S.P., Abiesbalsamea (L.) Mill., Pinusstrobus L., P. banksiana Lamb., P. resinosa Ait., P. sylvestris L., and Tsugacanadensis (L.) Carr. in northeastern North America. Yellow spotting is restricted to the upper, sun-exposed surface of the needles. These chlorotic spots generally start along ridges of the needles and merge into larger necrotic areas in later stages. It was observed that the number of spots per needle and the number of needles per internode exhibiting such spots are increasing with foliage age. The symptom was prominent on overstory and understory trees in high-elevation spruce–fir forests in Germany and northeastern North America. It was also found in all low-elevation stands sampled.
Growth and survival of black spruce in the range-wide provenance study
Authors: Morgenstern E. K. , Mullin T. J.
Published: February 2008

Field experiments of the range-wide black spruce (Piceamariana (Mill.) B.S.P.) provenance study were established between 1973 and 1977 through the cooperation of several organizations in the United States and Canada from the Atlantic Coast to Alberta. This study evaluates performance at 11 or 15 years from seed in 29 locations divided into 8 regional clusters of 2 to 10 experiments each. Analytical methods include correlations of height and survival with geographic and climatic variables, analyses of variance, and polynomial regressions followed by contour plotting. Best height was obtained in the Great Lakes States and in other temperate regions, and best survival in Newfoundland and some temperate regions with long growing seasons. Correlations between height and survival were positive and significant only in 10 locations, 8 of which were located in temperate regions. In many locations in boreal regions, correlations with latitude or climatic variables at the place of seed origin and height have opposite signs of correlations with survival, indicating difficulties when simultaneously selecting for good height and high survival in cold climates. Contour plots from the regressions demonstrate a similar trend by showing good pattern overlap of height and survival primarily in mild coastal (Newfoundland) or temperate continental climates (southern Quebec and Ontario, Great Lakes States). There is evidence that provenance differences are still developing and changes in rank are taking place, and therefore additional assessments are required in the future.
Foliar responses to fertilization identify nutrient limitation in loblolly pine
Authors: Valentine David W. , Allen H. Lee
Published: February 2008

Postfertilization patterns of fascicle weight and foliar nutrient concentration can diagnose nutrient limitation and stem growth response of coniferous species that have one annual needle flush. We tested this approach on loblolly pine (Pinustaeda L.), a species with several annual growth flushes, by using only foliage from the first annual growth flush following fertilization. We analyzed the responses of foliage weight and nutrient concentrations to a 4 × 3 factorial application of nitrogen (0–336 kg/ha) and phosphorus (0–56 kg/ha), and used the results to predict growth limitation. Nitrogen fertilization increased fascicle weight and foliar nitrogen concentration in eight of the nine study sites, implying nitrogen limitation. Phosphorus fertilization increased fascicle weight and foliar phosphorus concentration in three sites, implying phosphorus limitation. Two- and 4-year diameter growth response data generally supported these predictions. Diameter growth responded to nitrogen or nitrogen plus phosphorus in all predicted sites, but the technique failed to identify phosphorus limitation in one site and nitrogen plus phosphorus limitation in another. Growth response predictions based on initial foliar nutrient concentrations or foliar responses to fertilization were equally accurate. The greater expense of using the foliar response method may not be justified in operational assessments of forest nutrition.
Whole-plant 14C-photosynthate allocation in Pinustaeda: seasonal patterns at ambient and elevated ozone levels
Authors: Adams M. B. , Edwards N. T. , Taylor Jr. G. E. , Skaggs B. L.
Published: February 2008

The seasonal patterns of carbon gain and allocation were examined in Pinustaeda L. seedlings grown under field conditions. To investigate how ozone stress may influence whole-plant carbon budgets over the growing season, the seedlings were grown in either ambient air or air enriched with ozone at twice-ambient levels. On five sampling dates during the 1987 growing season, seedlings were labeled with 14CO2, and whole-plant carbon budgets were constructed. Rate of assimilation of CO2 varied by a factor of 2 during the growing season, with a late spring maximum during the first growth flush. Respiratory losses were highest in the spring and then declined sharply during the summer when photosynthate allocation to the foliage increased rapidly. A second major shift in the carbon budget occurred in the autumn when allocation to the fine roots increased at the expense of the foliage. The proportion of photosynthate allocated to coarse roots and stems varied only slightly over the growing season. Allocation to any plant component was highest when growth of that component was at a maximum. No statistically significant effects of elevated ozone on either carbon gain or photosynthate allocation were detected at any specific time during the growing season. However, seedlings grown at twice-ambient ozone levels consistently exhibited the following trends: (i) lower rates of CO2 assimilation, (ii) greater allocation of photosynthate to respiration, and (iii) corresponding reduction in photosynthate allocation to fine roots. An individual-fascicle 14C-labeling technique was found to reflect the seasonal patterns of carbon import and export by foliage and thus may serve as an acceptable surrogate for whole-tree tagging. The pronounced seasonality of the carbon budgets in P. taeda in conjunction with a pattern of ozone effects on carbon assimilation and photosynthate allocation suggests that whole-plant carbon budgets are sensitive and biologically meaningful indicators of seedlings' responses to anthropogenic changes in atmospheric chemistry.
Development of comandra blister rust on lodgepole pine
Authors: Geils Brian W. , Jacobi William R.
Published: February 2008

The comandra blister rust parasite (Cronartiumcomandrae Pk.) causes a serious canker disease of lodgepole pine (Pinuscontorta Dougl. ex Loud. ssp. latifolia (Engelm.) Critch.) in the central Rocky Mountains. The expansion, longevity, and distribution of comandra blister rust cankers were studied by annual monitoring, reconstructing canker histories, and random sampling. In saplings, infections occur throughout the lower 80% of the crown; and branch cankers expand toward the bole at 2.5 cm•year−1, regardless of temperature, age, position, tree size, vigor, or susceptibility to infection. The proportion of branch cankers that develop into stem cankers decreases logistically both with distance from infection site to bole and with time since infection. Fewer than 50% of branch cankers that are farther than 20 cm from the bole or more than 8 years old are expected to establish stem cankers. The proportion of branch cankers that become stem cankers decreases with distance more rapidly for comandra blister rust than for other stem rusts. The mean height of stem cankers increases with total tree height, but cankers are uncommon at the top of the crown and low on the trunk of larger trees. The number of years for a canker to girdle its host equals the diameter of the stem at the center of the canker measured in centimetres. Because girdling cankers develop infrequently, slowly, and predictably, potential losses from comandra blister rust can be reduced by timely and appropriate removal of damaged trees.
A comparison of methods for determining proximate carbon fractions of forest litter
Authors: Ryan Michael G. , Melillo Jerry M. , Ricca Andrea
Published: February 2008

Ten forest litters with decomposition state varying from 16.6 to 100% weight remaining were partitioned into sub-samples; each subsample was analyzed for proximate carbon fractions using one of two chemical analysis procedures (forage fiber and forest products analyses). Proximate carbon fractions from the simpler forage fiber techniques accurately estimated extractives, cellulose, lignin, and acid-hydrolyzed carbohydrates (R2 > 0.83) determined by the more complex forest products analyses. Decomposition state accounted for most of the residual variance and significantly improved predictive equations for lignin and extractives. The relationship between proximate carbon fractions from the different techniques also varied somewhat among wood, hardwood leaves, and conifer leaves; however, variations were minor relative to the overall trend. Equations developed can be used to extend data availability for developing and validating decomposition models.
Influence of land classification systems on timber harvest scheduling models
Authors: Jamnick M. S. , Davis L. S. , Gilless J. K.
Published: February 2008

Differences between linear program based timber harvest schedules that use decision variables based on stand types (homogeneous but generally noncontiguous areas) and management units (generally heterogeneous but contiguous areas) were investigated. It was proposed that (i) optimal harvest schedules identified using stand type decision variables should have larger present net value objective function values than those identified using models with management unit decision variables, (ii) optimal present net value objective function values in management unit models should decline as management unit size is increased, and (iii) as the number of management choices increases, differences between stand type and management unit optimal present net values should decrease. The propositions were tested using 48 linear programming timber harvest scheduling models constructed for the University of California's Blodgett Forest Experiment Station. These models, which form 12 model groups, differ in the numbers and type of prescriptions considered for existing or regenerated stands, and harvest flow or ending inventory policies. The results generally supported the propositions and indicate that the number of management choices considered in the timber harvest scheduling model is probably a more important factor influencing the optimal harvest schedules than is land classification.
The effect of spacing on Sitka spruce weevil damage to Sitka spruce
Authors: Alfaro Rene I. , Omule S. A. Y.
Published: February 2008

Tree diameter, height, form, and number of stem defects were recorded in 26-year-old plantations of Sitka spruce, Piceasitchensis (Bong.) Carr., established at three initial spacings (2.74 × 2.74, 3.66 × 3.66, and 4.57 × 4.57 m). These plantations were heavily attacked by the Sitka spruce weevil, Pissodesstrobi Peck, from an early age. Denser plantations sustained a lower intensity of attack than the more open plantations. Although the three spacings had similar average number of stem defects per tree, trees in the close spacing had a significantly higher frequency of trees of good form relative to the more open plantations. It was concluded that trees planted at close spacing had lower levels of weevil damage. As a management regime, it is recommended that Sitka spruce plantations be started at close spacing (2.74 × 2.74 m) and precommercially thinned at age 25. By this age trees will average about 19 cm in dbh and 12 m in height, thus ensuring a first log of good quality.
Croissance et enracinement de deux provenances d'Épinette noire en fonction de la densité apparente du sol et de ses propriétés hydriques
Authors: Prévost Marcel , Bolghari Hassan A.
Published: February 2008

As part of a study to determine the parameters for effective scarification and promotion of black spruce natural regeneration, an invitro experiment was conducted to assess growth and rooting ability in sandy soils of four bulk densities (0.85, 1.05, 1.25, and 1.45 g cm−3). The experiment included seeds from two origins, one representative of a well-drained upland site and the other, of a poorly drained lowland site. Results show that black spruce successfully established itself in all bulk densities under study. Shoot growth was best in bulk density 1.25 g cm−3 with the seeds of upland origin. It was also good for seeds of both origins in the 0.85 and 1.05 g cm−3 soils. However, seedlings established in the soil compacted to 1.45 g cm−3 showed reduced growth. Bulk densities of 0.85 and 1.05 g cm−3 favored deep root penetration, whereas densities of 1.25 and 1.45 g cm−3 restricted rooting. As a whole, upland seedlings developed better rooting than lowland seedlings, indicating that the selected sites of origin could represent two distinct ecotypes. As to allocation between shoots and roots, an interaction was found between bulk density and seed origin.
A dynamic program for cross-dating tree rings
Authors: Deusen Paul C. Van
Published: February 2008

An algorithm for cross-dating tree rings based on dynamic programming is presented. The algorithm considers all possible combinations of missing and double rings while minimizing a squared error loss function in relation to a reference chronology. There is a provision for the user to increase the penalty associated with inserting missing or double rings. Therefore, the algorithm is not totally objective and depends on informed user interaction and repeated application to perform successfully. The end result is a list of years where the algorithm suggests that missing or double rings have occurred.
Size-specific mortality, growth, and structure of a Great Smoky Mountains red spruce population
Authors: Busing Richard T. , Wu Xinyuan
Published: February 2008

Old-growth population dynamics of Picearubens Sarg. were studied in a montane spruce–fir forest in North Carolina and Tennessee. Size-class structure fit a semilogarithmic rotated sigmoid curve typical of a stable population. Although the population contained trees of all ages, a large proportion of the population was less than 100 years old; few trees were greater than 350 years old. Mortality rates were estimated from a 2-decade census and from population structure data. For trees above breast height, annual mortality was approximately 1% of the population. Small trees (<30 cm dbh) and large trees (>60 cm dbh) had mortality rates exceeding 0.7% per year. Intermediate-sized trees tended to have low mortality rates (<0.5% per year) and high radial growth rates. Growth in the 10-year interval preceding death tended to be slow for standing dead trees. Standing death of canopy trees was more prevalent than death by windfall. These findings emphasized the influence of stand dynamics on spruce growth and mortality.
Douglas-fir forest soils colonized by ectomycorrhizal mats. I. Seasonal variation in nitrogen chemistry and nitrogen cycle transformation rates
Authors: Griffiths Robert P. , Caldwell Bruce A. , Cromack Jr. Kermit , Morita Richard Y.
Published: February 2008

Monthly samples of ectomycorrhizal mat soils from a maturing Douglas-fir forest and adjacent nonmat soils were collected and analyzed for respiration, acetylene reduction activity, denitrification rates, extractable ammonium, nitrogen mineralization, microbial biomass, temperature, pH, percent moisture, total phosphate, nitrogen, and carbon. Seasonal patterns suggested complex interactions among the host tree, ectomycorrhizal fungus, and the mat microbial community as influenced by seasonal changes in moisture, temperature, and light availability. The most dramatic changes in rates were found during moisture-temperature transition periods in the spring and fall. Respiration within the mat community was highest during the period when tree growth is normally the greatest (in the spring and fall). In addition, there was a major respiration peak observed in the winter that we hypothesize was caused by the utilization of labile carbon by microheterotrophs. Differences were also observed between mat and nonmat soils in respiration rates, microbial biomass carbon, acetylene reduction activity, and levels of mineralizable nitrogen, which were all generally higher in the mat soils, and pH and denitrification rates, which were generally lower in nonmat soils. There is also evidence that suggests that nitrogen is very tightly coupled within the mat communities.
Twentieth-century climate change, fire suppression, and forest production and decomposition in northwestern Minnesota
Authors: Clark James S.
Published: February 2008

Long-term fire, climate, and vegetation data were used together with simulation models to estimate the effects of 20th century climate change and fire suppression on fire regime and organic-matter accumulation in mixed-conifer stands of Itasca State Park, northwestern Minnesota. Spatial and temporal patterns of fire occurrence and forest composition over the last 150 years determined by stratigraphic charcoal, fire-scar, tree-ring, and pollen analyses in separate studies provide evidence for vegetation and fire relationships. Water balances constructed from temperature and precipitation data collected since 1840 were used to model fire probability and intensity of burn before fire suppression which began in 1910. Existing patterns of biomass accumulation in forest-floor, herb, shrub, and tree components were compared with fire history and topographic variability to provide a spatial perspective on fire effects. Simulation models used these relationships to estimate (i) how accumulation of organic matter had changed through the past under the different fire regimes that prevailed on different topographic aspects, (ii) the changes brought about by fire suppression in 1910, and (iii) the fire regimes and their effects that would have prevailed since fire suppression with the warm–dry climate of the 20th century. Humus, litter, shrubs, and herb cover were less abundant and more variable spatially and temporally before fire suppression. Spatial variability in forest-floor organic matter, which resulted from different fire frequencies in different vegetation and topographic settings before fire suppression, was largely gone by 1920 as a result of fire suppression. Had fire suppression not been instituted in 1910, fire frequency would have increased by 20–40% in the 20th century because of warmer and drier conditions. Forest-floor oganic matter would have been largely depleted by frequent and severe fires exposing mineral soils, particularly during the drought years of the 1930s. Herb biomass would have increased, shrubs would have been more variable, and tree seedling establishment would have been substantially altered. Time required for buildup of fuels limits the extent to which increased moisture deficits increase fire frequency.
A comparison of water relations, visual symptoms, and changes in stem girth for evaluating impact of Phytophthoracinnamomi dieback on Eucalyptusmarginata
Authors: Crombie D. Stuart , Tippett J. T.
Published: February 2008

Water relations, stem girth, and crown vigour were measured in jarrah (Eucalyptusmarginata Donn ex Sm.) trees in adjoining areas of healthy and dieback-affected forest. The soil-borne fungus Phytophthoracinnamomi Rands was recovered from soils in the dieback areas, but not from neighbouring healthy forest. Trees on dieback sites were found to be more water stressed (with lower dawn water potentials and daytime stomatal conductances) than healthy trees on nearby areas free of P. cinnamomi. Severe water stress usually preceded crown deaths by several weeks to months. Dawn water potential and midday stomatal conductance were the most useful nondestructive indicators of dieback severity in declining trees. Subjective assessment of crown form was slightly less reliable than water relations as a separator of dieback and healthy trees. Changes in trunk girth were the least sensitive indicators of dieback severity. Midday stomatal conductance is recommended as a useful tool for monitoring short-term changes in vigour of dieback-affected trees.
Variations in carbon 14 content in tree rings during the last 30 years: application to wood dating
Authors: Auclair Daniel , Evin Jacques , Pages Loïc
Published: February 2008

Robiniapseudoacacia stem annual growth rings from 1958 to 1987 were analyzed for 14C content. The radioactivity of annual rings was found to be strongly correlated with 14C concentration in the atmosphere, which showed a very sharp rise until 1963 due to nuclear weapon tests followed by a regular decrease from then on. Taking into account seasonal variations in both atmospheric 14C concentration and CO2 assimilation slightly improved the relation between 14C in wood and the atmosphere. A predictive curve that gives the year of wood formation as a function of radioactivity with a 5% confidence interval is shown. These results can be used to analyze wood for which traditional analysis is impossible, for example, trees with false rings or missing rings, or wood from stumps or roots.
Effect of fertilization on seedling growth, ectomycorrhizal symbiosis, and nutrient uptake in Larixlaricina
Authors: Chakravarty P. , Chatarpaul L.
Published: February 2008

Container-grown Larixlaricina (Du Roi) K. Koch seedlings were inoculated with the ectomycorrhizal fungus Laccarialaccata (Scop, ex Fr.) Berk and Br. and grown under two levels of slow-release fertilizer (Osmocote) or two levels of soluble fertilizer (N–P–K). Nonmycorrhizal seedlings grew better under high fertility regimes, whereas no significant differences were observed between low and high fertility levels for the mycorrhizal seedlings. Mycorrhizal seedlings had significantly greater root length, total biomass, and a lower shoot:root ratio under all fertility treatments. Ectomycorrhizal development was excellent regardless of fertilizer treatment. Nitrogen, P, K, Ca, and Mg concentrations were significantly higher in the mycorrhizal seedlings than in the nonmycorrhizal seedlings under all fertility regimes.
Lodgepole pine regeneration in an old, self-perpetuating forest in south central Oregon
Authors: Stuart John D. , Agee James K. , Gara Robert I.
Published: February 2008

not available
Stand history: an alternative explanation of red spruce radial growth reduction
Authors: Reams Gregory A. , Huso Manuela M.P.
Published: February 2008

We classified red spruce (Picearubens Sarg.) sites from northern Maine by radial growth release history. Two major releases were apparent for a majority of the sites. The first was a reduction and subsequent increase in radial increment in 1920. The second was an increase in radial increment from 1935 to 1955. Red spruce radial growth reduction in the 1960s is apparent only for sites released from 1935 to 1955 (approximately 54% of the sites in this study). These sites are now approaching the radial growth rates of the unreleased stands. Birch dieback is suggested as a probable contributor to the 1935–1955 red spruce growth increase and subsequent 1960s growth reduction.
DNA amplification from vegetative and sexual tissues of trees using polymerase chain reaction
Authors: Bousquet Jean , Simon Luc , Lalonde Maurice
Published: February 2008

A simple protocol for the extraction of total DNA from minute amounts of tissues and subsequent amplification of specific sequences by polymerase chain reaction is presented. The method is applicable to a wide variety of vegetative tissues such as leaves, single needles and rootlets, cell suspensions, and also single sexual embryos and megagametophytes derived from a variety of gymnosperms and perennial angiosperms. Amplification of DNA is shown using pairs of primers specific to genes that encode the small ribosomal subunit.
Genetic variation and productivity of Populustrichocarpa and its hybrids.: IV. Performance in short-rotation coppice
Authors: Heilman Paul E. , Stettler R. F.
Published: February 2008

Resprouting after harvest and rapid growth of sprouts are often considered essential for success of close-spaced, short-rotation cultural systems. This study examined resprouting, subsequent growth, and dry weight production following the initial 4-year harvest of a "common garden" trial of 50 clones of Populustrichocarpa Torr. & Gray. The clones were selected from 10 populations (sources) from major river drainages from western British Columbia, Washington, and Oregon. Additionally, three P. trichocarpa × P. deltoides (Bartr.) hybrids, a 'Robusta' clone, and a previously selected P. trichocarpa clone from Cottage Grove, Oregon, were included in the experiment. Mean yield of P. trichocarpa clones was 11.3 Mg•ha−1•year−1 (CV among clones = 61%) in the coppice rotation vs. 12.6 Mg•ha−1•year−1 (CV among clones = 40%) in the initial rotation; a difference that may, at least in part, be due to the use of less fertilizer in the coppice rotation. Nevertheless, a number of clones including the hybrids had higher yields in the coppice than in the initial rotation. Yield of clones in the coppice rotation was only moderately correlated with yield in the initial harvest (r2 = 0.48), but the same two clones, hybrids 11-11 and 11-05, were the top-producing clones in both rotations. Cumulative mortality of P. trichocarpa at the end of the experiment, including failed cuttings, averaged 36%, but was highly variable (range = 7–66% among clones). Yield in both harvests differed significantly among sources of P. trichocarpa. As with other components of productivity reported earlier, performance in coppice varied significantly among the 50 P. trichocarpa clones, and more so than in the first rotation. Populustrichocarpa clones identified as superior in coppicing in this experiment represent potential parents for new hybrids intended for short-rotation systems involving coppicing.
Estimating salal leaf area index and leaf biomass from diffuse light attenuation
Authors: Smith N. J. , Clark D. R.
Published: February 2008

Salal (Gaultheriashallon Pursh) leaf area index and leaf biomass were estimated from 37 quadrat samples in 13 stands dominated by Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) on eastern Vancouver Island, British Columbia. Leaf area index and biomass were predicted from a Beer's Law light attenuation model using diffuse photosynthetically active radiation (400–700 nm wavelength). The extinction coefficients, determined using reduced major axis maximum likelihood, were 0.8055 m2/m2 for leaf area index and 0.0069 g/m2 for leaf biomass. Salal leaf area index and biomass were then predicted for any convenient height in the understory canopy using a cumulative Weibull model based on dominant salal height per quadrat. The models are of use for objectively assessing the amount of Columbian black-tailed deer (Odocoileushemionuscolumbianus Richardson) winter browse and to quantify competitive leaf area.
Some effects of different forest herbicides on upland Salix spp.
Authors: Pollack John C. , LePage Philip , Thienen Frank Van
Published: February 2008

A variety of vegetation management treatments were tested in an upland willow community in the Sub-Boreal Spruce Zone. Two years after treatment, broadcast applications of 2,4-D ester and liquid hexazinone did not greatly damage Salix spp. saplings. Manual cutting resulted in vigorous resprouting. Spotgun liquid hexazinone, broadcast granular hexazinone, and broadcast glyphosate treatments had more pronounced effects.
Growth, wood density, and ethylene production in response to mechanical perturbation in Pinustaeda
Authors: Telewski Frank W.
Published: February 2008

Ethylene, emitted by the first internode of intact stems of 3-year-old Pinustaeda L. (loblolly pine), was trapped before and after mechanical perturbation. The analysis was conducted as a 2 × 2 design on eight different half-sib families grown (i) without exposure to shaking (control) or (ii) with preconditioning to mechanical perturbation for a 2-year period. Ethylene production was determined per gram fresh weight of stem tissue and per square centimetre of cambial tissue. Ethylene produced over a 14-h period varied from 0.15 to 0.55 nmol/g fresh weight among families in the control group prior to mechanical perturbation. Mechanical perturbation increased ethylene emission from all stems of control and preconditioned trees from all families. Ethylene production per gram fresh weight correlated positively with juvenile wood density (p < 0.005, r2 = 0.76) and negatively with stem diameter (p < 0.032, r2 = 0.56) in the control trees. Ethylene production per square centimetre of vascular cambium correlated negatively with wood density (p < 0.05, r2 = 0.50) and positively with stem diameter (p < 0.02, r2 = 0.62) in preconditioned trees.
Integrated control of Fusarium damping-off in red pine seedlings with the ectomycorrhizal fungus Paxillusinvolutus and fungicides
Authors: Chakravarty P. , Peterson R. L. , Ellis B. E.
Published: February 2008

Damping-off caused by Fusariumoxysporum Schlecht. in red pine (Pinusresinosa Ait.) was significantly reduced when seedlings were treated with either of two fungicides (benomyl or oxine benzoate) concomitantly with the ectomycorrhizal fungus Paxillusinvolutus (Batsch.) Fr. compared with inoculation with P. involutus alone. Both fungicides at concentrations of 10 ppm and above significantly reduced spore germination and germ-tube length of F. oxysporuminvitro. On the other hand, invitro growth of P. involutus mycelium was not affected by the fungicides at concentrations up to 1000 ppm. The growth of P. involutus was, however, significantly reduced by the two fungicides at 5000 and 10 000 ppm. Inoculation of red pine seedlings with P. involutus was effective under growth chamber and greenhouse conditions in reducing the incidence of damping-off induced by F. oxysporum. When benomyl and oxine benzoate were applied in combination with P. involutus, seedling mortality was not observed. Oxine benzoate was phytotoxic and inhibited mycorrhiza formation by P. involutus at the recommended dose. Benomyl, on the other hand, had no inhibitory effect on seedling growth and stimulated ectomycorrhiza formation either by a naturally occurring mycorrhizal fungus or P. involutus in the greenhouse. The concept of incorporating integrated biological and chemical treatment for controlling Fusarium damping-off of red pine seedlings is suggested.
Modern pollen rain within and adjacent to two giant sequoia (Sequoiadendrongiganteum) groves, Yosemite and Sequoia national parks, California
Authors: Anderson R. Scott
Published: February 2008

Analysis of modern pollen (from polsters) and plant percentage coverage (from relevés) within and near two giant sequoia (Sequoiadendrongiganteum) groves provide data on the relationship between plant abundance and pollen dispersion. Most Sequoiadendron pollen is deposited within or near the groves, substantiating previously established theoretical models on pollen dispersion. Within the groves, Sequoiadendron is only slightly overrepresented by its pollen (R value average, 1.6). At the Tuolumne Grove, Sequoiadendron pollen averages 1.5% at stations within 450 m of the grove boundary. Pollen percentage is slightly higher (8%) for similar stations at Lost Grove. This contrasts with the more widely dispersed pollen of Pinus and Quercus, and the less widely dispersed Chrysolepis and Cornus. Patterns of pollen dispersal away from the groves are consistent with the prevailing wind direction and diurnal air mass movements. For Sequoiadendron, the relatively poor dispersal has implications for future paleoecologic studies interpreting the sedimentary pollen record from meadow sediment cores; and for understanding the exchange of genetic information between these trees that grow in stands somewhat isolated from each other.
Influence of leaf surface wax and leaf area to water content ratio on cuticular transpiration in western conifers, U.S.A.
Authors: Hadley Julian L. , Smith William K.
Published: February 2008

High cuticular water loss, desiccation, and leaf mortality during winter in conifers at alpine timberline represent especially dramatic examples of the ecophysiological importance of cuticular transpiration. However, little research has been conducted on the winter water relations of forest trees, even though recent evidence suggests a potentially high leaf mortality due, at least in part, to winter desiccation. Two factors that could have important influences on cuticular transpiration, leaf surface wax and the ratio of leaf area (A) to saturated water content (Mw), were compared for six conifer species common to the central Rocky Mountains, United States. Leaves were collected from forest trees at the end of winter (May) to compare the amount of leaf surface wax, cuticular conductance to water vapor (gc), and leaf water content. Decreases in relative leaf water content were much more linearly related to transpiration per unit saturated water content than either gc or A/Mw, separately. Only A/Mw appeared correlated with the rate of cuticular transpiration. Also, linear increases in gc occurred with increasing leaf water content. Estimated desiccation resistance during winter corresponded closely to the degree of drought tolerance characterized previously for each species based only on summer growth conditions. Thus, winter desiccation resistance may be an important, yet under-emphasized, ecological factor influencing conifer distribution patterns.
A dendroecological analysis of eastern larch (Larixlaricina) in subarctic Quebec
Authors: Arquillière Sylvie , Filion Louise , Gajewski K. , Cloutier Conrad
Published: February 2008

Two new dendrochronological series of eastern larch (Larixlaricina (Du Roi) K. Koch) from subarctic Quebec extend from 1710 to 1987 (Whapmagoostui–Kuujjuarapik, eastern Hudson Bay) and from 1596 to 1978 (Rivière aux Feuilles, western Ungava). In both regions, the tree-ring series show similar long-term variations. Generally, conditions were more favorable for growth at the end of the 19th century and during the 20th century than before. A comparison of several larch and white spruce (Piceaglauca (Moench) Voss) tree-ring series from northern Quebec indicates significant shared variance between regions and species. Larch chronologies show two important depressions during the 20th century, between 1905–1908 and 1940–1946, which are more obvious in the two series from the southern forest–tundra than in the series from Ungava. These may be caused by outbreaks of the larch sawfly, Pristiphoraerichsonii (Htg.).
Effect of soil changes caused by red alder (Alnusrubra) on biomass and nutrient status of Douglas-fir (Pseudotsugamenziesii) seedlings
Authors: Brozek Stanislaw
Published: February 2008

The effect of soil changes caused by red alder (Alnusrubra Bong.) on the biomass and nutrition of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedlings was determined by comparing two adjacent plots of seedlings planted on former Douglas-fir and red alder sites. The seedlings grown on the former red alder site showed a 65% biomass increase in current twigs, 41% increase in older twigs, and 45% increase in stems. Foliage and roots were not significantly affected. The seedlings also developed shallower but wider root systems than those on the site formerly occupied by Douglas-fir. The seedlings on the red alder site showed an increase in N and decrease in P, Ca, and Mg concentrations. There were also higher N/P and N/K ratios and lower availability of soil P. Accelerated depletion of extractable P in soil was observed. Nutritional differences and biomass changes in seedlings can be attributed in part to the N and organic matter accumulated in the soil by the former red alder forest.
Bootstrap confidence intervals for red spruce ring-width chronologies and an assessment of age-related bias in recent growth trends
Authors: Cook Edward R.
Published: February 2008

Bootstrap confidence intervals are developed for mean ring-width chronologies of red spruce (Picearubens Sarg.). These confidence intervals are robust, easy to compute, and useful for determining the "significance of recent trends in radial growth that may be related to forest decline. By comparing the mean chronologies of different age-classes of red spruce trees in two different collections, it is shown that a serious age-related bias may result if the series are blindly averaged without considering the differences in growth rate related to tree age and stand dynamics. However, even when age differences are taken into account, there is evidence for a common increase in radial growth rate of red spruce in the 1950s followed by rapid and sustained decrease after 1960. The cause of this widespread growth increase and decrease has not yet been established, and some current hypotheses are discussed.
Organic matter and mineral distribution in an old-growth Acersaccharum forest near the northern limit of its range
Authors: Morrison I. K.
Published: February 2008

Two sites, both supporting old-growth Acersaccharum Marsh, dominated forest on rugged topography in central northern Ontario, were compared in terms of organic matter and N, P, K, Ca, Mg, S, Fe, Mn, Zn, and Cu content in the tree- and field-layer phytomass, the forest floor, and the mineral soil. One site was on a shallow, low-base, Precambrian-derived till, and the other was on a till of somewhat higher base status. Gross and net growth of the overstory tree layer were also determined. Total phytomass values for the two stands at the beginning of the study period were 245 000 and 210 000 kg•ha−1, respectively. Gross growth was largely offset by mortality in both stands, producing a rough equilibrium with regard to net increment. Growth before mortality was on the order of 2.4–2.5 m3•ha−1•year−1 in terms of gross total wood volume or 3700–3900 kg•ha−1•year−1 in terms of phytomass, and it was slightly greater in percent terms on the higher base site. In addition to that in the phytomass, organic matter in the forest floor and mineral soil to a depth of 1 m also contributed to the total organic matter content of 638 000–642 000 kg•ha−1 (equivalent to 34 8000–353 000 kg•ha−1 of C) on both sites and was distributed as follows: 29–34% in phytomass, 5% in the forest floor, and 61–66% in mineral soil. The order of abundance of elements in the phytomass was similar on both sites: Ca > N > K > Mg > S > Mn > P > Fe > Zn > Cu, with accumulation in the phytomass in rough proportion to occurrence in the soil. A more base-rich parent material would appear to be the origin of 1452 kg•ha−1 of Ca estimated to be in the phytomass and forest floor on the higher base soil, compared with 1250 kg•ha−1 in the phytomass and forest floor on the lower base soil.
Isolation and characterization of alcohol dehydrogenase cDNAs from Pinusradiata
Authors: Kinlaw C. S. , Harry D. E. , Sederoff R. R.
Published: February 2008

Three alcohol dehydrogenase (ADH) cDNAs were isolated from Pinusradiata. Two of the cDNAs appear to correspond to alleles of one ADH locus, and the third cDNA appears to correspond to a second ADH locus. Nucleotide and amino acid sequences of the coding region of ADH genes from the following species were compared: Pinusradiata, Zeamays, Hordeumvulgare, Triticumaestivum, Oryza sativa, Pisumsativum, and Arabidopsisthaliana. A phylogenetic tree was constructed of coding sequences of pine and angiosperm ADH genes. This tree shows three plant ADH clusters: monocot, dicot, and pine. The distance between pine and the two angiosperms is only slightly greater than the distance between either angiosperm, supporting the fossil evidence that suggests that monocots and dicots diverged from each other shortly after angiosperms diverged from gymnosperms. The structure of pine ADH genes was investigated by Southern blot analysis. The restriction fragment pattern of ADH genes from pines is more complex than the pattern from angiosperm genes, suggesting that pine ADH genes are either larger or more numerous than their angiosperm counterparts.
A comparison of FORMAN and linear programming approaches to timber harvest scheduling
Authors: Jamnick Mark S.
Published: February 2008

Harvest schedules are developed and compared for two hypothetical 129 900-ha forests using the FORMAN wood supply model and linear programming. The purpose is to determine how the harvest schedules and models differ and under what conditions one model would be preferred over the other. The results clearly demonstrate that compared with FORMAN, linear programming is able to find solutions with higher harvest volumes in every case considered. Additionally, fundamental differences between the model capabilities were discovered. The FORMAN model is preferred in situations where the harvest scheduling problem is relatively simple and conforms to the activities included in the model. Linear programming is preferred when the analyst is concerned with the economics of wood supply and controlling a variety of activities and outputs.
Genetic control of rooting ability of stem cuttings from loblolly pine
Authors: Foster G. S.
Published: February 2008

Stem cuttings from 546 loblolly pine (Pinustaeda L.) seedlings were set for rooting during each of three separate trials over time. The seedlings arose from 54 full-sib families derived from four factorial mating designs. Phenotypic variation in rooting percentage was partitioned into genetic variance, environmental variance, and genotype × environment interaction variance. Virtually all genetic variance was due to additive gene effects, with little evidence for dominance gene effects and with no epistasis present. Genetic control of rooting percentage was weak with narrow-sense and broad-sense heritabilities of 0.15 and 0.13, respectively. Selection based on either family means or clone means represented a better strategy than mass selection, as evidenced by narrow-sense and broad-sense heritabilities of 0.46 and 0.40, respectively. Predicted genetic gain in rooting percentage was estimated using two population improvement alternatives. Selection of the best 10% of the clones would increase overall rooting percentage to 53.6% in the current generation, an increase of 11.3%; whereas selection of the best individual within the best 24 of the 54 families and intermating the select trees would increase rooting percentage of the next generation to 54.1 %, an increase of 11.8%.
The effect of nitrogen and copper on characteristics of wood tissue in Pinusradiata
Authors: Downes Geoffrey M. , Turvey Nigel D.
Published: February 2008

Seedling form, biomass production, and wood characteristics were examined in Pinusradiata D. Don seedlings grown in a glasshouse under the influence of high or low nitrogen concentrations and with or without copper treatments. Environments with low amounts of copper resulted in severe stem deformation associated with low foliar copper concentrations and low lignification of wood. High-nitrogen treatments resulted in an increase in foliar biomass production and stem deformation and a reduction in root biomass but did not increase stem height. Stem lignin concentrations were positively correlated with foliar copper concentrations. Low lignification of wood was found to be responsible for an inability to recover from deformation rather than an increased susceptibility to deformation. Similarly, the high-nitrogen treatment was associated more with impairing seedling recovery than with increasing susceptibility to deformation. Reductions in the net microfibril angle in the wood cell wall were positively correlated with stem lean but were not associated with any treatment effects.
Effect of shelterwood removal methods on established regeneration in an Alaska white spruce stand
Authors: Youngblood Andrew P.
Published: February 2008

Seedling damage during overstory removal was compared among different yarding methods; almost three times more mortality was associated with rubber-tired ground skidding than with skyline cable yarding. Seedlings ranging in height from 0.4 to 1.0 m generally received less damage or had lower mortality rates from cable yarding than did shorter or taller seedlings. Snowpack disturbance and percentage of seedling mortality were positively correlated. Results suggested that with attention to seedling height growth and yarding method, the shelterwood regeneration system is a viable option for white spruce (Piceaglauca (Moench) Voss) stand regeneration in interior Alaska.