bluuebunny/crossref_metadata_2025 huggingface dataset:
Beech bark disease: patterns of spread and development of the initiating agent Cryptococcusfagisuga
Authors: Houston D. R. , Parker E. J. , Lonsdale D.
Published: April 2011

Beech bark disease occurs when beech trees, predisposed by infestation of the beech scale Cryptococcusfagisuga (Lindinger) (C. fagi (Baer.)), are infected by species of the fungal genus Nectria. Infestation patterns of C. fagisuga on individual trees and in forest stands were studied. Fagussylvatica L. was infested artificially with C. fagisuga. After 3 years, secondary colonization on individual trees was generally restricted to within 1 m from points of introduction. Cryptococcusfagisuga was associated positively with the bark lichen Lecanoraconizaeoides Nye ex Cromb. and negatively with the bark fungus Ascodichaenarugosa Butin. In a young plantation, patterns of scale infestation were related to distance from a large old relic tree and to wind-direction records for the insect's dispersal period. In another plantation the infestation patterns were associated with site topography. In North America, the pattern of continuous spread of C. fagisuga (and of associated disease development) since its introduction in 1890 strongly supports the sequential nature of the causal agent complex proposed by Ehrlich and suggests that susceptibility of F. grandifolia Ehrh. to infestation is so high, at least in the first encounter, that environmental factors which might influence this susceptibility are unimportant in the disease complex.
Delay of floral and leaf development by overtree irrigation in black walnut
Authors: Beineke Walter F. , Hunley Jimmy L.
Published: April 2011

Overtree irrigation in black walnut (Juglansnigra L.) delayed leaf foliation by 6 days and delayed pollen maturation and pistillate receptivity by 5 days. Duration of the delay was theoretically long enough to avoid frost damage if a late frost had occurred but was insufficient to prevent pollen contamination.
Susceptibility of balsam fir to spruce budworm defoliation as affected by thinning
Authors: Crook Gregory W. , Vézina Paul E. , Hardy Yvan
Published: April 2011

Spruce budworm, Choristoneurafumiferana (Clemens), defoliation of balsam fir, Abiesbalsamea (L.) Mill., was studied in thinned stands of the Lower St. Lawrence region of Quebec. The object of the study was to quantify defoliation levels in treated and control plots in order to determine what effect, if any, thinning had on the susceptibility of balsam fir.Three main forest types were studied: (a) coniferous, (b) mixed, and (c) hardwood with a fir understory. The coniferous forest type was subdivided into three types: (1) pure balsam fir; (2) balsam fir – white spruce, Piceaglauca (Moench) Voss; (3) balsam fir – hardwoods. Defoliation levels were estimated using two current techniques: the Dorais–Hardy (1976) and the Fettes (1950) methods.Susceptibility of balsam fir to spruce budworm defoliation was not affected after thinning in coniferous and hardwood forest types; however, susceptibility was increased in mixed stands when part of the hardwood cover was removed. In any situation, defoliation of fir was found to be more intense with an increase of the basal area of the coniferous species (balsam fir, red spruce, Picearubens Sarg., and white spruce) while an increase of the basal area of hardwoods resulted in lower defoliation levels; likewise, a higher number of stems per hectare brought higher defoliation levels of fir. Defoliation was also found to vary with stand composition; susceptibility of fir in the three main cover types decreased in the following order: (a) coniferous, (b) mixed, (c) hardwood. Stand age was not a factor influencing the susceptibility of balsam fir for the two age classes studied (30 and 50 years).
Interception of aerially applied ammonium nitrate by hardwood and softwood trees
Authors: Mahendrappa M. K.
Published: April 2011

The quantities of ammonium and nitrate nitrogen (N) in stemflow and throughfall samples collected from hardwood and softwood stands were determined before and after aerial application of ammonium nitrate. Distribution of fertilizer reaching the ground during the aerial fertilization of the area was determined daily during the operation.Before fertilization, the concentrations of nitrate and ammonium N in stemflow and through-fall samples from both hardwood and softwood stands were negligible. Although more fertilizer prills per unit area were recovered in the hardwood than in the softwood stands, N levels in the stemflow and throughfall samples collected were higher in the softwood than in the hardwood stands. It was, therefore, concluded that the softwood trees intercepted larger quantities of aerially applied ammonium nitrate than did the hardwood trees.
Nitrogen fertilization stimulates germination of dormant pin cherry seed
Authors: Auchmoody L. R.
Published: April 2011

Nitrogen fertilizers triggered germination of dormant Prunuspensylvanica L. seed naturally buried in the forest floor of 60-year-old Allegheny hardwood stands. Neither triple superphosphate nor muriate of potash applied with urea increased germination over that which occurred with urea alone. Rates as low as 56 kg/ha N from urea and calcium nitrate and 112 kg/ha N from ammonium sulfate stimulated germination. Nitrate was apparently responsible for breaking dormancy.
Goal programming for reconciling economic, even-flow, and regulation objectives in forest harvest scheduling
Authors: Kao Chiang , Brodie J. Douglas
Published: April 2011

To resolve the traditional quantifiable but incommensurate objectives of perfect regulation, maximization of present net worth, and even-flow harvest, goal programming (GP) was applied to a sample forest, providing optimal solutions for each goal and a compromise solution that jointly considered all three as weighted goals. Goal programming overcame problems of infeasible specification and satisfied alternate criteria in cases with multiple optima. The GP approach provided a means of considering each of the three goals and minimizing the appropriately weighted deviations.
Hormonal enhancement of cone production in Douglas-fir grafts and seedlings
Authors: Puritch George S. , McMullan Eleanor E. , Meagher Michael D. , Simmons Clarence S.
Published: April 2011

not available
An anatomy of stumpage value
Authors: Nautiyal J. C.
Published: April 2011

This paper goes into details of the components of the stumpage value of forests in the context of a single-seller, single-buyer market. It concludes that for practicing efficient management of forests on long term licences covering crown lands, the stumpage charge must be seen by the licensee as a fixed cost.
A new method for screening herbicides for use in pine nurseries
Authors: South David B. , Sung Shi-Jean Susana
Published: April 2011

A rapid bioassay developed for testing photosynthesis-inhibiting herbicides was adapted for use with pine cotyledon tissue. Several herbicides having different modes of action were tested using loblolly pine (Pinustaeda L.) cotyledons. In addition to being a promising bioassay method for determining pine tolerance of photosynthesis inhibitors, differences in pine species' tolerance to hexazinone could be detected. This method could be useful as a preliminary test for screening herbicides for use in pine nurseries.
Comparison of sample rules for estimating jack pine density, basal area, and percentage with sweetfern rust cankers
Authors: Gross Henry L. , Ek Alan R. , Patton Robert F.
Published: April 2011

Sample rules that rate a cluster of trees at each sample point were investigated for performance in estimating the percentage of jack pine (Pinusbanksiana Lamb.) affected by cankers caused by sweetfern rust (Cronartiumcomptoniae Arth.). Performance for estimating the density and basal area of jack pine and cankered jack pine was also considered. Rule performance was rated with respect to efficiency in terms of the number of clusters or trees required for an adequate sample, bias, cluster size relative to optimal cluster size, and estimate precision.The types of rules included were fixed-area strip and circular plots, point samples, strips that include a constant number of trees, and rules based on point to tree distances. All rules appeared to provide unbiased estimates of the percentage of jack pine trees or basal area affected by sweetfern rust cankers. A cluster size of 18 was found to be optimal for such estimates with a confidence level of 80% and acceptable error size of E = ± 0.05. Optimal cluster size for other error factors and an efficient cluster size range were also identified. Only point sample and fixed-area rules appeared to be unbiased for density and basal area estimates. The best rule for all variables of interest was fixed-area strips with size adjusted to include an average of 18 jack pines per sample point.
Duff weight and depth in a high elevation Pinusconforta Dougl. forest
Authors: Woodard P. M. , Martin R. E.
Published: April 2011

not available
Photosynthate allocation in Pinustaeda. II. Seasonal aspects of photosynthate allocation to different biochemical fractions in shoots
Authors: Chung Hsu-Ho , Barnes Robert L.
Published: April 2011

Research was conducted to study (1) seasonal changes in tissue composition and (2) dynamic allocation of photosynthate to different biochemical fractions in growing shoots of the current and previous years of 15-year-old loblolly pine (Pinustaeda L.). As the growing season progressed, the shoots increased rapidly in total biomass; however, old needles formed in the previous year lost dry weight. The most striking biochemical change was a rapid decrease in starch content of old needles early in the growing season. Soluble sugars and organic acids in old needles also decreased slightly. Contents of biochemical constituents generally increased in current axes and needles as the organs grew and increased in weight, although there were decreases in organic acid contents of current axes early in the growing season. Formation of nonlabile major constituents (cellulose, hemicelluloses, lignin, and protein) in current-year shoots proceeded at different rates. These rates were interpreted in terms of aspects of shoot growth and development. Seasonal allocation of photosynthates into biochemical constituent fractions in current year growth flushes was calculated. Results suggested that photosynthates were allocated to constituents of different functional categories (metabolism, storage, structure, and protection) at different times of the growing season in such a way that structural growth was of first priority. Thus, allocation of photosynthates to structural growth early in the season enables branches to compete for favorable growing conditions.
Photosynthate allocation in Pinustaeda. III. Photosynthate economy: its production, consumption and balance in shoots during the growing season
Authors: Chung Hsu-Ho , Barnes Robert L.
Published: April 2011

Using data on CO2 exchange, growth, and biochemical composition, an approach was developed to calculate the seasonal production, consumption, and surplus of photosynthate in shoots of loblolly pine (Pinustaeda L.). The amounts of CO2 released and of glucose substrate required in biosynthesis of shoot biomass over the growing season were also calculated. Individual growth flushes of different age-classes, as well as of an entire 1-year-old branch unit, ofPinustaeda were used as bases for calculations.Substrate requirements and CO2 production were relatively constant throughout the growing season. Within the whole 1-year-old branch unit, 63% of the photosynthate production was supplied by the two growth flushes of the previous year. Growth of the current year's shoot represented the major consumption of photosynthate, and this made up 66% of the total photosynthate consumed in the branch unit. Surplus of photosynthate, which would be available for translocation from the branch, was about 38% of the total photosynthate produced. Most of the photosynthate surplus was derived from the growth flushes of the previous year. Source and sink relationships, with regard to photosynthate partitioning in the 1-year-old branch unit over the growing season, were clarified and described.
Alternative models for estimating woody plant biomass
Authors: Crow T. R. , Laidly P. R.
Published: April 2011

A number of untransformed regression models were compared to the log-log form of the allometric function for estimating biomass. Models were evaluated using two tree species, Betulapapyrifera Marsh, and Pinusresinosa Ait., and one tall shrub, Ilexverticillata (L.) Gray, with total aboveground biomass as the dependent variable. Using goodness of fit as the criterion, both weighted linear and weighted nonlinear models proved to be acceptable alternatives to the transformed allometric equation. Weighted models retain the advantage of the log-log form, i.e., compatibility with the homogeneity of variance assumption, but avoid the transformational bias.
Enzyme variation in natural populations of Sitka spruce (Piceasitchensis). 1. Genetic variation patterns among trees from 10 IUFRO provenances
Authors: Yeh Francis C. , El-Kassaby Yousry A.
Published: April 2011

Genetic variation at 24 enzyme loci was studied for 10 IUFRO populations of Sitka spruce (Piceasitchensis (Bong.) Carr.). The average proportion of polymorphic loci per population was 0.51 ± 0.02 and the average proportion of heterozygous loci per individual was 0.15 ± 0.03. The following generalizations were advanced: (1) the amount of genetic polymorphism varied considerably from locus to locus; (2) many populations were similar in the amount and pattern of genetic variation for most loci; (3) but some loci had large differences among populations.Eight percent of the gene diversity was attributed to interpopulation differentiation; 92% of the total gene diversity resided within populations. Pairwise comparisons of genetic distances averaged 0.014, a value which reflected very little differentiation between geographic sources.
Contribution of feeding by European pine sawfly larvae to litter production and element flux in Scots pine plantations
Authors: Fogal W. H. , Slansky Jr. F.
Published: April 2011

The contribution of larvae of the European pine sawfly, Neodiprionsertifer (Geoff.), to litter fall and element input was determined in two contiguous 25-year-old plantations of Scots pine (Pinussylvestris L.) near Glencairn, Ont., in 1972. Tree spacings were 1.2 × 1.2 and 1.8 × 1.8 m. Tree diameters, numbers of needle-bearing branches per tree, and the number of larval colonies per tree were greater in the less dense plantation. On the other hand, there was no difference between plantations with respect to tree height, number of needles per branch, number of larvae per colony, or percent defoliation. For the denser and less dense plantations, frass was the largest insect-derived component of litter fall at 804 and 1255 kg ha−1, respectively; needles constituted the major tree component of litter fall at 1107 and 929 kg ha−1, respectively, and the total combined contribution of tree and insect material to litter fall was 2395 and 2744 kg ha−1, respectively. Average element input (kilograms per hectare) to the soil via frass for the two plantations was greatest for nitrogen (6.9), followed by potassium (5.0), calcium (4.1), phosphorus (0.8), and magnesium (0.6).
Clonal variation of wood specific gravity, moisture content, and stem bark percentage in 1-year-old shoots of 20 fast-growing Salix clones
Authors: Sennerby-Forsse Lisbeth
Published: April 2011

Specific gravity, moisture content of the wood, and stem bark percentages in 1-year-old shoots of 20 Salix (L.) clones originating from natural and artificial stands in Sweden were measured for 3 years. Clones were classified into three groups with high, medium, and low specific gravity. Ranking stability for specific gravity was high. Moisture content and bark percentage fluctuated considerably from one year to another but showed a slight increase from the high to the medium and low specific gravity groups.
Some relationships between Uredinopsismirabilis, Paradiplosistumifex, and Dasineurabalsamicola in the needles of Abiesbalsamea
Authors: Bergdahl D. R. , Mazzola M.
Published: April 2011

Of the approximately 2300 needles of Abiesbalsamea L. (Mill.) examined each year, 7 and 12% were infected with Uredinopsismirabilis (Peck) Magnus and 23 and 24% were infested with Paradiplosistumifex Gagne during 1982 and 1983, respectively. Of the needles infested with P. tumifex, about 11% were infected with U. mirabilis in both years and, in 1983, 21% were infested with Dasineurabalsamicola (Lintner). All needles infected with U. mirabilis died, including those which also had either P. tumifex or P. tumifex and D. balsamicola.
The effect of cupric carbonate on root morphology of containerized mycorrhizal pine seedlings
Authors: Ruehle John L.
Published: April 2011

Loblolly (Pinustaeda L.), longleaf (Pinuspalustris Mill.), shortleaf (Pinusechinata Mill.), and eastern white (Pinusstrobus L.) pine seedlings inoculated with Pisolithustinctorius (Pers.) Coker & Couch (Pt) were raised in a greenhouse in containers painted with latex paint containing 50 g/L cupric carbonate (CuCO3). To determine the effects of CuCO3 on root development and morphology, seedlings were sampled in the middle and at the end of the test. The treatment was effective in preventing most first-order laterals of all species from growing down the container wall, yet it had no significant effect on seedling height, root-collar diameter, or top and root fresh weight. Cupric carbonate had little effect on ectomycorrhizal formation on loblolly and shortleaf seedlings, but significantly increased it on longleaf seedlings and decreased it on eastern white seedlings. Using CuCO3 to alter root morphology of containerized southern pine seedlings inoculated with Pt has the potential for developing stock that will grow long laterals near the soil surface for anchorage and increase the rate of spread of Pt ectomycorrhizae from the plug to new roots after planting.
Species interactions in seedling populations of Populustremuloides and Populusbalsamifera: effects of density and species ratios
Authors: Morris D. M. , Farmer Jr. R. E.
Published: April 2011

A deWit replacement series was combined with a Nelder's design to study the interaction of trembling aspen (Populustremuloides Michx.) and balsam poplar (Populusbalsamifera L.) seedlings growing at seven relatively high densities for 9 weeks after germination. Aspen dominated in all mixes and at all densities.
Measurement considerations and trends in biomass heat storage of a mixed forest
Authors: Saxton W.L. , McCaughey J.H.
Published: April 2011

Biomass heat storage is examined for a mixed forest in the summer of 1985 at the Petawawa National Forestry Institute, Chalk River, Ontario. The importance of including this term in the hourly energy balance is noted. Although biomass storage is small at night and around midday, it is a substantial contributor to the total canopy storage at times when net radiation is small. The measurement techniques involved in producing accurate estimates of biomass storage are also examined. Biomass estimates are best derived using individual species equations and summing the mass of every tree. Simplified methods using equations derived for all species and grouping trees into manageable diameter groups also produces reasonable results. Biomass temperature change is characterized by its lag in time of response in comparison to that of the air; using air temperature as a surrogate for biomass temperature is not recommended.
Multivariate analysis of allozyme variation patterns in coastal Douglas-fir from southwest Oregon
Authors: Merkle S. A. , Adams W. T. , Campbell R. K.
Published: April 2011

Isozyme data collected from megagametophytes of coastal Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco var. menziesii) parent trees, representing 22 southwest Oregon breeding zones, were analyzed by multivariate techniques to describe the distribution of genotypic variation among and within breeding zones and to relate genotypic and environmental variation. Data entered were mean haploid genotype scores obtained by averaging two haploid genotype scores from each parent tree. Haploid genotype scores were created from 27-locus haploid genotypes of two megagametophytes collected from each of 1230 parent trees. Although principal components analysis did not indicate the presence of linkage disequilibria among loci, canonical discriminant analysis suggested that much more genotypic variation may be accounted for by breeding-zone differences than was evident from single-locus techniques. The first two canonical variables, which accounted for ~25% of the genotypic variation, appeared to separate breeding zones on the basis of geographic and elevational differences among zones. Regressing canonical variable scores against location variables failed to provide a model attributing > 10% of genotypic variation to latitude, elevation, or distance from the ocean. Although canonical correlation analysis of mean haploid genotype scores with the same location variables produced two significant canonical variables accounting for 39% of the variation, little of the variation accounted for by the canonical variables was related to location variables. Although these results may be due to the small geographic scale of the study, the region covered is characterized by extreme environmental heterogeneity, to which variability in seedling quantitative traits has been strongly correlated in a companion common garden study. In sum, multivariate techniques were not markedly better than single-locus techniques in providing evidence that allozyme variation is adaptive in the coastal Douglas-fir breeding zones studied. Consequently, multivariate techniques cannot be expected to improve the use of allozymes for certifying seed or for designating breeding zones in this region.
Wood quality and the input and output choices of sawmilling producers for the British Columbia coast and the United States Pacific Northwest, west side
Authors: Constantino Luis F. , Haley David
Published: April 2011

A transcendental logarithmic restricted profit function is used to represent the structure of the sawmilling industry. Lumber and pulp chips are treated as separate outputs and a measure of wood quality is developed and incorporated in the model in a novel way. Data for the British Columbia coast and the United States Pacific Northwest, west side (1957–1982) are used to estimate the model. Wood quality is shown to be an important variable in lumber industry modelling. The hypothesis of zero technical progress is rejected for both regions. The output mix is shown to be very responsive to changes in wood quality and relative prices.
Winter browsing preferences of snowshoe hares for coniferous seedlings and its implication in large-scale reforestation programs
Authors: Bergeron Jean-Marie , Tardif Josée
Published: April 2011

Seedlings of five conifer species were offered to snowshoe hares (Lepusamericanus) at 20 feeding stations throughout winter. Extensive damage was recorded on the stems of two species, Norway spruce (Piceaabies) and jack pine (Pinusdivaricata), while various levels of branch debarking was noted on three others (Pinusresinosa, Pinusstrobus, and Piceaglauca). Because Norway spruce and jack pine are widely distributed in reforestation programs in Quebec and both represent highly preferred winter food for snowshoe hares, high losses might be expected in areas also supporting high densities of hares.
A procedure for constructing timber management strategies under uncertainty
Authors: Marshall P. L.
Published: April 2011

A methodology for constructing timber management strategies is described which recognizes potential deviations from expected response and various degrees of risk aversion. The technique employs a mathematical programming structure to identify an efficient management strategy expected to satisfy a particular harvesting profile. Aversion to the risk associated with the uncertainty of treatment response is reflected by a penalty component in the objective function. A simple example employing linear programming is presented and discussed to illustrate potential applications.
Wind direction and fir wave motion
Authors: Boyce Richard L.
Published: April 2011

The direction of travel for each of 11 fir waves in the White Mountains of New Hampshire was determined from their positions on aerial photographs taken in 1978, 1966, and 1943–1944. The direction toward which trees within each wave were flagged was determined in the field and used to infer the direction of prevailing winds. Flagging and fir wave directions are found to be closely related. Most wave velocities fall within the range 1–3 m year−1, as found in earlier studies. Wave direction generally parallels the fall line, but in cases where the flagging direction crosses the fall line, the wave follows the flagging direction. The flagging observed in fir waves appears to be caused by rime ice damage. It indicates that a narrow range of mean annual wind velocities are present where waves occur. The close relationship between flagging and fir wave directions suggests that wind and rime ice buildup are important factors in advancing the dieback zone of fir waves.
A graphical depiction of multivariate similarity among sample plots
Authors: Smith N. J. , Iles K.
Published: April 2011

A system for graphically comparing multivariate similarity between a large number of sample plots is presented. Two-dimensional nonmetric (rank order) multidimensional scaling is used to generate maps. These maps display either stand variables (site index, basal area, normality (used as a measure of stocking), change in normality, age and stems per hectare), or three site variables (aspect, elevation, and latitude). The distance between any two points (representing a plot) on these maps is the measure of similarity. Regression equations are used to predict additional map locations.
Precipitation and throughfall chemistry for a montane hardwood forest ecosystem: potential contributions from cloud water
Authors: Sigmon J. T. , Gilliam F. S. , Partin M. E.
Published: April 2011

This study analyzed the chemical composition of cloud water, bulk precipitation, and throughfall in a hardwood forest at the top of a watershed in the Virginia Blue Ridge Mountains to further investigate canopy–atmosphere interactions. The composition of both cloud water and bulk precipitation was dominated by H+, NH4+, SO42−, and NO3−. On average, cloud water was four times more acidic than bulk precipitation (251 vs. 63 μequiv./L in 1986 and 158 vs. 40 µequiv./L in 1987, respectively) and had higher NH4+/Ca2+ ratios (22.2 vs. 0.7 in 1986 and 9.4 vs. 1.2 in 1987, respectively), indicating possibly below-cloud scavenging of primary aerosols by rain, dry deposition of Ca2+, and (or) differential dissolution of NH3 gas in cloud water and rainwater. Acidity in throughfall was less than that in bulk precipitation (H+ of 40 vs. 63 μequiv./L in 1986 and 25 vs. 40 μequiv./L in 1987, respectively). Potassium and Ca2+ were leached from the canopy, whereas NH4+ and NO3− were retained by the canopy. Cloud water was a major source for the retained NH4+ and NO3−. Deposition of cloud water during the warm season was estimated from precipitation-throughfall volume relationships to be approximately 5.21 cm in 1986, an increase of about 23% over precipitation inputs, and approximately 5.42 cm in 1987, an increase of about 8% over precipitation. The resulting inputs of major ions from cloud water may, however, equal or exceed that of precipitation at the ridgetop site and may contribute significantly to canopy fertilization and acidification. Further study is needed to determine the spatial extent down the watershed and the ultimate effects of this enhanced deposition to high elevation forests.
Mating success in a coastal Douglas-fir seed orchard as affected by distance and floral phenology
Authors: Erickson V. J. , Adams W. T.
Published: April 2011

The effect of distance and stage of phenological development on cross-pollination in a Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seed orchard was investigated by estimating the proportion of viable embryos resulting from fertilization by designated male trees. The pollen source was identified by unique allozyme genetic markers that occurred in two clones in the orchard. In 38 mother trees, the proportion of embryos fertilized by the male marker ranged from 0 to 71.4%. Very little pollen was dispersed beyond 30 m. Within 30 m, mating success was only weakly associated with distance. Multiple regression analyses determined that phenological factors strongly influenced mating patterns; nearly one-third of the variation was dependent on a phenological variable (LMmf), which measured the combined effects of floral overlap and relative pollen fecundity of potential male parents. The interaction between LMmf and distance was highly significant, indicating that the floral status of mating pairs had a strong influence on the effect of distance. Our results suggest that a lack of complete floral synchrony between near neighbors may reduce preferential mating and thus help to promote cross-fertilization within Douglas-fir seed orchards.
Pathogenicity and attraction to host extracts of Canadian pinewood nematodes: studies with Scots pine, western larch, and black spruce seedlings
Authors: Futai Kazuyoshi , Sutherland Jack R.
Published: April 2011

Two isolates of the pinewood nematode, Bursaphelenchusxylophilus (Steiner and Buhrer), from Canada (an r form from Ontario and an m form from Quebec) and one from Japan (an r form) were inoculated into Scots pine, Pinussylvestris L., western larch, Larixoccidentalis Nutt., and black spruce, Piceamariana (Mill.) B.S.P. to determine the pathogenicity of this nematode and to observe changes in its numbers as well as the effect it had on seedling water and tannin content. Attractiveness of water, ethyl ether, and ethyl acetate stem extracts of these conifers to the pinewood nematode was also determined. The r form of the pinewood nematode was pathogenic on all three conifers: the Japanese isolate killed more Scots pine and the Ontario isolate, more black spruce. The Quebec isolate was as pathogenic as the other two isolates to western larch, weakly pathogenic to black spruce, and nonpathogenic to Scots pine. In general, there was a positive relationship between nematode population buildup and seedling mortality. No clear relationship was found between the water content of seedling stems and changes in nematode populations. Tannin content of stems increased following inoculation with pinewood nematode, but whereas correlation values between tannin content and nematode numbers were positive and significant, they were small. Although all three isolates were attracted to all host extracts, regardless of solvent used, ethyl acetate extracts were generally more attractive. The Japanese and Ontario isolates, which originated from pines, showed no particular affinity for Scots pine extracts; however, the Ontario isolate, which was especially attracted to black spruce extracts, was also most pathogenic to black spruce.
Accuracy of equations describing diameter growth
Authors: Zeide Boris
Published: April 2011

The investigation of the structure of growth equations shows that most of them describe the growth decline by a negative exponential function. This decline can also be described by a power function. It was found that the equation based on this assumption is the best available model of diameter growth. Some applications of this equation are discussed.
Invitro shoot formation among 17-year-old Douglas-fir provenances
Authors: Dunstan David I. , Bethune Terry , Kikcio Susan , Lapp Martin S.
Published: April 2011

A study of the invitro shoot production capabilities of 19 phenotypically ranked trees showed that trees grown from seed from transition zone provenances of British Columbia were more likely to succeed in producing shoots invitro than trees from interior wet or interior dry zone provenances. Examples of trees that succeeded in producing shoots did exist, however, for each ecological zone studied. Leaf-oil terpenes from each tree source were analysed to determine whether they could be employed as predictable markers of the subsequent response of excised buds invitro. The results from this study indicate that it was the ecological zone of origin that had the greatest influence on invitro culturability. It was found, however, that neither the amount of any single leaf-oil terpene nor any discrete combinations of highly positively correlated terpenes could be correlated to invitro culturability.
Juvenile wood specific gravity of loblolly pine tissue culture plantlets and seedlings
Authors: Frampton Jr. L. J. , Jett J. B.
Published: April 2011

Juvenile-wood specific gravity of loblolly pine (Pinustaeda L.) tissue culture plantlets and seedlings were compared. Wood samples collected from several (6 to 13) families at three sites, each at a different age (2, 3, and 6 years), showed a significant difference between the overall plantlet and seedling mean specific gravity only in the youngest material (0.387 versus 0.356, respectively). Another collection of wood samples from three different sites at age 5 years showed that the within-site variation in specific gravity for a single clone was 29% that of the open-pollinated family from which it was derived. When tissue culture techniques become practical, operational clonal plantations of loblolly pine should offer substantial improvement in the uniformity of wood produced relative to the heterogeneous seedling-origin plantations currently being established.
Seasonal growth patterns of Nyssasylvatica var biflora, Nyssaaquatica, and Taxodiumdistichum s affected by hydrologic regime
Authors: Keeland B.D. , Sharitz R.R.
Published: April 2011

Hydrologic regime is a major influence on the growth of wetland plants. We examined seasonal growth patterns of three wetland tree species, Nyssasylvatica var. biflora (Walter) Sargent, Nyssaaquatica L., and Taxodiumdistichum (L.) Rich., to determine responses to variations in hydrologie regime. Five study sites were chosen in two river-floodplain swamps to represent a gradient of hydrologie regimes, and the weekly changes in diameter of over 600 mature trees at these sites were measured with dendrometer bands throughout two growing seasons. Total growth, time of growth cessation, and length of the growth phase of canopy trees of all three species differed significantly among hydrologie regimes. Nyssasylvatica var. biflora and N. aquatica achieved greatest growth under deep periodic flooding. Maximum growth of T. distichum occurred with shallow permanent flooding. Subcanopy trees differed less among hydrologic regimes than canopy trees. These results suggest that modifications of natural hydrologie regimes can cause short-term changes in tree growth and have long-term effects on the dynamics of forested wetlands.
An ecologically based model for site index conversion among species
Authors: Wang G. Geoff
Published: April 2011

When suitable site trees are lacking in a stand, indirect methods are often used to predict site index. One such indirect method is to convert the site index of one species (the present one) into the site index of another species (the missing one) through a site index conversion equation. To develop a site index conversion equation, it is required that site index estimates must be obtained from those stands with both species present. Because of interspecific interactions, this requirement intrinsically violates assumptions behind the site index concept. To solve this problem, an ecologically based model was proposed in this study. Based on data obtained from the Sub-boreal Spruce zone of British Columbia, pure or single species dominated stands of lodgepole pine (Pinus contorta Dougl. ex Loud.) and white spruce (Picea glauca (Moench) Voss) were matched within each of the three studied subzones by using the concept of ecologically equivalent sites. The method of reduced major axis (RMA) was used to develop site index conversion equations between the two species. The resulting equation was then compared with the soil-site studies and the site index comparison study on the same two species conducted in the same region. By applying the ecologically based model, site index conversion equations can be developed for any possible pair of species existing in a study area, thus making site index conversion among species operationally feasible based on forest inventory data.
Observations of the micrometeorology of two forests in eastern Canada. 1. Interannual variations in summer radiation and energy balance
Authors: Lafleur Peter M , McCaughey J Harry , Bartlett Paul A , Strachan Ian B
Published: April 2011

Measurements of radiation and energy balances were made over two forests, 12.8 km apart, in eastern Ontario during three summers, 1989-1991. The two sites were AECL, a primarily deciduous forest with fine sandy soils, and PNFI, a mixed forest over a thin sandy-loam soil. The objective of the study was to investigate spatial heterogeneity in energy fluxes in a mixed forest landscape by examining interannual variations in radiation and energy balance components between the sites. The two sites showed small differences in albedo and net radiation. Total heat storage was not different between the two sites, yet there were some differences in the relative magnitudes of the storage components. The largest between-site differences were in energy partitioning between the convective fluxes of sensible heat, QH, and latent heat, QE. The QH was usually larger at PNFI and QE was usually larger at AECL. Thus, Bowen ratios were almost always smaller at AECL. The magnitude of these differences was controlled by soil moisture stress, with moisture stress frequently observed at PNFI but not at AECL. The implications of these results for regional-scale surface-vegetation-atmosphere climate modelling are discussed.
Response of red alder (Alnus rubra) seedlings to a woolly alder sawfly (Eriocampa ovata) outbreak
Authors: Markham John H , Chanway C P
Published: April 2011

We monitored the effect of an outbreak of Eriocampa ovata L.on experimental Alnus rubra Bong. seedlings during the year of the outbreak (1993) and the following growing season. Seedlings planted on low-elevation sites had significantly more of their leaves damaged (>50% per tree) than plants on high-elevation sites (<25% per tree), with significant differences between low-elevation sites during the year of the outbreak. There was a positive relationship between the amount of herbivore damage and plant relative growth rate early in the growing season and a negative relationship by August. This suggests that the sawflies attacked the largest and fastest growing plants, reducing their growth by midsummer. Plants with the highest degree of herbivore damage were the largest by the end of the growing season with no effects on plant growth the following year. Leaves from plants that had previously been defoliated were less palatable to E. ovata in 1994, but plants with a high degree of herbivore damage in 1994 were likely plants that had a high degree of damage in 1993.
Diversity, production, and nutrient dynamics of fungal sporocarps on logs in an old-growth temperate rain forest, Olympic National Park, Washington
Authors: Edmonds Robert L , Lebo David S
Published: April 2011

Fungal sporocarps were sampled on 47 logs in six 0.1-ha plots in an old-growth Sitka spruce (Picea sitchensis (Bong.) Carr.) - western hemlock (Tsuga heterophylla (Raf.) Sarg.) forest in the Hoh River Valley, Olympic National Park, Washington, from October 1993 to May 1994. Log biomass averaged 205 Mg/ha and the surface area of plots occupied by logs was 9.8%. Most fungal fruiting occurred on decay class 3 logs, the most common type on a scale from 1 (least decayed) to 5 (most decayed). Eighty-two taxa of fleshy fungi (63 saprophytic, 18 mycorrhizal, and one pathogenic) and six taxa of large annual or perennial fungi occurred on logs. Most fungi were basidiomycetes. Highest fleshy sporocarp production occurred in fall (456 g/ha) rather than spring (40 g/ha). Ischnoderma resinosum had the highest annual production (88 g/ha). Concentrations of N, P, K, Ca, Mg, Mn, Na, Fe, Zn, Al, B, and Cu in fruiting bodies were determined. Lower N concentrations occurred in perennial fungi (0.45%) than mycorrhizal (4.33%) and fleshy saprophytic species (3.30%). Only a small fraction of the nutrient capital in the logs was exported to the forest floor in fungal sporophores.
Genetic parameters for spiral grain in two 18-year-old progeny trials with Sitka spruce in Denmark
Authors: Hansen Jon Kehlet , Roulund Hans
Published: April 2011

The spiral grain at ring 10 at 1.3 m was investigated in two trials with 64 open-pollinated families of age 18 years from plus-trees of Sitka spruce (Piceasitchensis (Bong.) Carr.) selected from 16 populations. Significant differences were found between the families on both sites, and the individual narrow-sense heritability of the spiral grain was 0.63 and 0.78, assuming half-sib families. The mean spiral grain was 3.8 and 4.1° to the left in the two trials and the individual standard deviations 1.86 and 1.62°. No signs of genotype environment interaction was found. Genetic correlations with diameter growth, stem form, and pilodyn were not apparent in the trials. Reductions of the mean spiral grain by 0.51° in the juvenile wood seems possible even with simultaneous gains for stem straightness and diameter growth, either from selections among plus-trees grafted in a clonal seed orchard or from the progenies in the trials.
Ecosystem management or infeasible guidelines? Implications of adjacency restrictions for wildlife habitat and timber production
Authors: Murray Alan T
Published: April 2011

The concept of ecosystem management has recently been investigated by Carter et al. (1997. Can. J. For. Res. 27: 1302-1310) from a harvest scheduling perspective incorporating adjacency, exclusion periods, and flow restrictions. This is a likely contribution to the debates questioning the usefulness and capabilities of these constraints in forest management models. This research note discusses an error in the mathematical model formulation presented in Carter et al. (1997). Such an error may impact the findings presented and perhaps alter conclusions. This is an increasingly important issue, given the ease of planning problem formulation and application using current optimization software packages.
Methods based on k-nearest neighbor regression in the prediction of basal area diameter distribution
Authors: Maltamo Matti , Kangas Annika
Published: April 2011

In the Finnish compartmentwise inventory systems, growing stock is described with means and sums of tree characteristics, such as mean height and basal area, by tree species. In the calculations, growing stock is described in a treewise manner using a diameter distribution predicted from stand variables. The treewise description is needed for several reasons, e.g., for predicting log volumes or stand growth and for analyzing the forest structure. In this study, methods for predicting the basal area diameter distribution based on the k-nearest neighbor (k-nn) regression are compared with methods based on parametric distributions. In the k-nn method, the predicted values for interesting variables are obtained as weighted averages of the values of neighboring observations. Using k-nn based methods, the basal area diameter distribution of a stand is predicted with a weighted average of the distributions of k-nearest neighbors. The methods tested in this study include weighted averages of (i)Weibull distributions of k-nearest neighbors, (ii)distributions of k-nearest neighbors smoothed with the kernel method, and (iii)empirical distributions of the k-nearest neighbors. These methods are compared for the accuracy of stand volume estimation, stand structure description, and stand growth prediction. Methods based on the k-nn regression proved to give a more accurate description of the stand than the parametric methods.
Landscape ecosystem diversity of river floodplains in northwestern Lower Michigan, U.S.A.
Authors: Baker Matthew E , Barnes Burton V
Published: April 2011

We present a classification and comparison of river floodplains using an ecological, multifactor approach integrating physiography, hydrology, soil, and vegetation within a relatively homogenous macroclimate. Aerial photographs and field reconnaissance were used to locate 22 river valley transects along nine major rivers in the Manistee National Forest, northwestern Lower Michigan. Distinct ecosystems along each transect were sampled extensively. Twenty-three floodplain ecosystem types were identified and classified primarily on the basis of physiographic systems and fluvial landforms within a regional context. Physiographic systems are broad-scale, surficial landforms characterized by distinctive form, parent material, soil, hydrologic regimes, and vegetation. We examined landscape ecosystem differences between different physiographic systems, within a physiographic system, and on a single fluvial landform. Different physiographic systems have different kinds and patterns of floodplain ecosystems in successive valley segments along a river. Within a physiographic system, the physiographic position of different fluvial landforms and ecosystem types within a single fluvial landform leads to marked ecosystem diversity laterally away from the river. The results indicate that physiography is an important determinant of floodplain ecosystem diversity and that an ecological, multifactor approach is useful in distinguishing floodplain ecosystems at multiple scales within a regional context.
Age-age correlations for tracheid length and wood density in Pinus sylvestris
Authors: Hannrup Björn , Ekberg Inger
Published: April 2011

The existence of strong genetic correlations between traits at an early age and at an adult age should shorten the generation turnover of tree breeding populations and render forest tree breeding more effective. Genetic age-age correlations for tracheid length and wood density were estimated in Scots pine (Pinus sylvestris L.) and the efficiency of early selection for these traits was evaluated. Increment cores of 10-mm diameter were collected from trees of 106 full-sib families in a progeny trial located in southeastern Sweden and consisting of controlled matings between 30 parent trees. The additive genetic age-age correlations were consistently close to unity for all traits and ages studied. The additive genetic variance differed significantly from zero for all traits. The dominance variance was zero for tracheid length and small and insignificant for wood density. The heritabilities varied between 0.3 and 0.5. The genetic gain per year for both tracheid length and wood density was largest if selection was carried out at tree age 11, the lowest age studied, indicating that early tests for these traits will be efficient.
Performance of initial attack airtanker systems with interacting bases and variable initial attack ranges
Authors: Islam Kazi MS , Martell David L
Published: April 2011

Each day, forest fire managers must deploy airtankers at initial attack bases to minimize initial attack response times. They must decide how many airtankers to deploy at each base and the initial attack range of each airtanker. We develop a daily airtanker simulation model and use it to investigate how airtanker system performance varies as a function of initial attack range, fire arrival rates, and time of day. Our results indicate that the optimal initial attack range decreases as the daily fire load increases. Fire managers can use this information to design airtanker dispatch policies that will minimize initial attack response times.