bluuebunny/crossref_metadata_2025 huggingface dataset:
Early growth of planted spruce
Authors: Burdett A. N. , Herring L. J. , Thompson C. F.
Published: January 2008

Observations were made on the growth of white spruce (Piceaglauca (Moench) Voss) and Engelmann spruce (P. engelmanni Parry), each planted at a single location in the interior of British Columbia. In both species bareroot stock (either 2 + 0 seedlings or 2 + 1 transplants) with a low root growth capacity made only limited height growth during the first two seasons after planting. In the first season, many short stem units were formed, whereas in the second season, stem units were much longer but many fewer. The length of needles formed after planting by the bareroot trees was, in the first season, only about half that of needles formed the previous year in the nursery. Needle length increased slightly in the 2nd year. Container-grown trees (1 + 0 seedlings from 336-mL containers), which had a high root growth capacity, made relatively good height growth in the first season when they formed long needles and stem units. Height growth by these seedlings was much less in the second season, however, as were needle length and stem unit number, but not stem unit length. Application of slow release N,P, and K fertilizer at planting improved shoot growth by bareroot trees more in the second season than the first. In contrast, the container-grown stock made a large shoot growth response to fertilization in both the first and the second seasons. The results are consistent with the hypothesis that, as root establishment proceeds, shoot growth tends to be limited by the supply, first of water, then of mineral nutrients. This implies that the early growth of planted spruce can be maximized by using stock with a high root growth capacity, or other adaptations to drought, and applying slow release fertilizer at planting. Observations on the white spruce revealed an acceleration in shoot growth by both stock types during the third season. This followed the establishment, by the end of the second season, of root systems several metres in diameter. A large difference in height: diameter ratio, observed at the time of planting, between the container-grown and bareroot white spruce disappeared entirely in the course of the first three growing seasons.
Estimating root disease losses in northern Rocky Mountain national forests
Authors: James R. L. , Stewart C. A. , Williams R. E.
Published: January 2008

Root disease losses were estimated on more than 3 million hectares of commercial forest land within seven national forests in the northern Rocky Mountains. Area estimates were made for root disease centers on all seven forests and scattered tree mortality on three forests. Tree mortality rate and associated volume loss were estimated for two forests. Approximately 31 600 ha (about 1% of the total commercial forest land) were occupied by large active disease centers discernable from large-scale aerial photographs on these forests. About 13% of the commercial forest land of three forests contained scattered root disease mortality of at least 3 trees/ha. About 35% of the annual tree mortality was associated with root diseases on two forests. Major root pathogens found were Armillariamellea and Phellinusweirii; bark beetles often infested root-diseased trees. Recommendations for improvement of survey techniques are discussed.
A simple model for predicting stand volume growth response to fertilizer application
Authors: Ballard T. M.
Published: January 2008

The equation R = KTACZQ is used to predict cumulative stand volume growth response (R) to fertilizer application, where K is a constant and the last five (dimensionless) multipliers represent functions of time, amount of fertilizer applied, stand composition, stocking, and site quality, respectively. Site-specific input data requirements are stand composition expressed as percent responding species, stocking expressed as a percentage of normal stocking, and site index. The model was calibrated for Douglas-fir response to nitrogen by using data from Washington and Oregon. A preliminary test of the model and its calibration compares predicted responses to estimates of actual response derived from some fertilizer trials on Vancouver Island. Soil drainage class and foliar analysis data may help in qualitatively inferring whether the model's site quality function leads to overestimation of response. Future development of the model may include development and calibration of a predictively better site quality function which quantitatively uses site water regime and stand nutrient data.
Seasonal cambial activity and xylem development in Pinuscontorta in relation to endogenous indol-3-yl-acetic and (S)-abscisic acid levels
Authors: Savidge Rodney A. , Wareing Philip F.
Published: January 2008

Seasonal cambial activity and xylem development were monitored anatomically at several main-stem positions in 20-year-old Pinuscontorta Dougl. Gas chromatography – mass spectrometry and electron-capture gas-chromatography quantifications of endogenous indol-3-yl-acetic acid (IAA) and (S)-abscisic acid (ABA), respectively, were made in these same tissues. In addition, IAA and ABA were measured in shoot apices, growing needles, and mature needles. Cambial reactivation occurred several weeks before budbreak at the base of the living crown, and it occurred only slightly before budbreak in younger cambia. Neither an acropetal nor a basipetal progression of reactivation were found. In contrast, early-wood development commenced in foliated stem locations well before commencing in nonfoliated regions. IAA and ABA levels in the cambial region increased, but little, immediately before cambial reactivation. IAA levels in extending apices, extending needle bases, and cambia reached maxima in midsummer. Cambial IAA levels remained high and ABA levels declined after both shoot and needle extension were complete. IAA levels in cambia were highest in the main stem near the crown base at all times; ABA levels varied little throughout the season. Following autumn inactivation of the cambium, IAA levels decreased and tracheids with narrow radial diameters differentiated at this time. ABA levels showed no significant increase as shoots, needles, and cambium ceased growing.
Factors affecting Canadian pulp and paper prices
Authors: Singh B. K. , Nautiyal J. C.
Published: January 2008

Price equations for the following product groupings of the Canadian pulp and paper industry were estimated using data from 1955 to 1981: (i) woodpulp; (ii) newsprint; (iii) "other paper and paperboard"; and (iv) "aggregate paper and paperboard," which includes (ii) and (iii). Price equations were formed on the assumption that firms markup average costs of production to set prices. These equations show the effects of factor costs, economies of scale, and technological progress on the prices of the products. They also help understand relevant aspects of production processes. Newsprint and "other paper and paperboard" production costs and prices are most responsive to the prices of material (woodpulp), labour, and energy, while woodpulp price responds more to the prices of pulpwood and energy. Substantial economies of scale are experienced by newsprint and woodpulp sectors. Such economies in the "other paper and board" sector are nonexistent. Technological progress has also contributed to reduction in the costs of production: 4.3% in woodpulp, 4.4% in "other paper and board," and 2.6% in newsprint per annum. Reduction in the cost of obtaining pulpwood to woodpulp sector is important in reducing the cost of paper and paperboard production. Substitution of existing capital with low energy and labour using capital is also required to lower the costs. Also, efforts to modernize the whole industry and the use of available economies of scale are indicated to keep the Canadian pulp and paper industry competitive in world markets.
Stomatal conductance, transpiration, and resistance to water uptake in a Pinussylvestris spacing experiment
Authors: Whitehead D. , Jarvis P. G. , Waring R. H.
Published: January 2008

Stomatal conductance was measured with porometers in two plots of Pinussylvestris L. with markedly different tree spacings (plot 1, 608 stems ha−1; plot 2, 3281 stems ha−1), and hourly rates of transpiration were calculated using the Penman–Monteith equation at intervals throughout one growing season. Stomatal conductance varied little in relation to height or age of foliage. There was a linear decrease in canopy conductance with increasing water vapour pressure deficit of the air. Transpiration rates on both plots increased during the summer (maximum 0.3 mm h−1); rates on plot 1 were always lower (ca. 0.7 times) than on plot 2. Needle water potentials were similar throughout the season and only slightly lower on plot 1 than on plot 2. The mean hydraulic resistance of the trees on plot 1 was 2.4 times that on plot 2. The results support a hypothesis that considers the changes in transpiration rate, conducting cross-sectional area, canopy leaf area, water potential, and hydraulic resistance following thinning as a set of homeostatic relationships.
The effect of four new Frankia isolates on growth and nitrogenase activity in clones of Alnusrubra and Alnussinuata
Authors: Carpenter Carolyn V. , Robertson Linda R. , Gordon John C. , Perry David A.
Published: January 2008

Two clones of red alder (Alnusrubra Bong) and two clones of Sitka alder (Alnussinuata (Regel) Rydb) were inoculated with four new Frankia isolates. The endophytes included a red and a Sitka alder isolate from Vancouver Island, British Columbia, and a red and a Sitka alder isolate from Mount Hood National Forest, Oregon. All inoculated ramets were well nodulated and had an active nitrogenase system as measured by the acetylene reduction assay. For the inoculated red alder clones, host genotype had a significant effect on stem height and root weight. None of the growth parameters was affected by endophyte strain or by clone–endophyte interaction. For Sitka alder clones, host genotype affected all growth variables. While endophyte strain had no effect on plant growth, clone–endophyte interaction occurred with stem height and leaf weight. Conversely, acetylene reduction values were not affected by clone or clone–endophyte interaction in either species. In red alder, acetylene reduction values were significantly affected by endophyte strain showing both inter- and intra-species variations. In Sitka alder, endophyte strain did not affect acetylene reduction values. The results indicate that both host genotype and endophyte may affect the efficiency of host–endophyte symbioses.
Stability of forestry and stability of regions: contradictory goals? The Swedish case
Authors: Lönnstedt Lars
Published: January 2008

This article concentrates on discussing forestry and the forest industry (the "forest sector") as the main rural employers when there is an institutional requirement for sustainable yield. Problems arise when total wood removals are on the same level as annual forest growth. Possibilities to increase employment in the forest sector are limited through the requirement for a sustainable yield. At the same time, a continuing increase in productivity within the forest sector will cause a gradual reduction of the labor force.
Distribution of the radiative index of dryness and forest site quality in a mountainous watershed
Authors: Tajchman S. J.
Published: January 2008

The radiative aridity index, β (i.e., the ratio of yearly sums of net radiation to those of the latent heat of precipitation), and forest biomass were obtained for 245 terrain segments [Formula: see text] in an Appalachian watershed. A hypothesis was tested that β can be used as a site quality indicator in complex terrain. Regression analysis yielded the following relationship between the average forest biomass of the watershed (Mo = 15.94 kg m−2), the biomass (Mi), the radiative aridity index (βi), and the azimuth (Ai) of terrain segments: Mi/M0 = 2βi[l−Ai/2π + (Ai/2π)4] ± 0.27. The value of the expression in the bracket reaches its maximum for Ai = 0 (north facing slopes), and a minimum for Ai = 227° (southwest facing slopes). A possible interpretation of the obtained relationship is that p represents long term (e.g., daily and seasonal) effects of water and energy exchanges of terrain segments on growth, and the expression in the bracket represents the aspect-related effects of daily fluctuations of microclimate of terrain segments on growth.
Interception de la pluie dans la sapinière à bouleau blanc, Forêt Montmorency
Authors: Plamondon André P. , Prévost Marcel , Naud Rénald C.
Published: January 2008

Rainfall interception from four balsam fir stands and in a clearcut site, was examined in lake Laflamme watershed area, Montmorency Forest, 80 km north of Québec City. The four balsam fir stands were 25 to 65 years old and were defoliated from 20 to 70% by spruce budworm (Choristoneurafumiferana (Clem.)); the clearcut site was covered by logging debris and vegetation less than 1 m high. Rainfall interception in the balsam fir stands varied from 15.1 to 38.6%; it tended to decrease with increasing defoliation and to increase with increasing cover. During the summer of 1982, interception in the clearcut and the average for the lake Laflamme forested watershed were 32.3 and 35.0%, respectively. Stemflow (0.3 to 3.8%) was negligible in those stands. Net precipitation and interception can be calculated from gross rainfall and the relations established in this study.
Impact of tephra deposition on growth in conifers: the year of the eruption
Authors: Hinckley Thomas M. , Imoto Hiromi , Lee Katharine , Lacker Susan , Morikawa Yasushi , Vogt Kristiina A. , Grier Charles C. , Keyes Michael R. , Teskey Robert O. , Seymour Virginia
Published: January 2008

Seven sites ranging from 15 to 135 km from Mount St. Helens were selected to study the impact of air-fall tephra on the growth of Abiesamabilis (Dougl.) Forbes, A. procera Rehd., Pseudotsugamenziesii (Mirb.) Franco, Tsugaheterophylla (Raf.) Sarg., and T. mertensiana (Bong.) Carr. As tephra depth increased, there was a corresponding increase in visible foliar damage and associated decreases in diameter and height growth. Reduction in diameter growth was greater than reduction in height growth. The reduction in diameter growth approached 50% in both trees and saplings of A. amabilis. Growth reduction in true firs was greater than in associated species. This difference was related to their greater capacity for interception and retention of air-fall tephra. Damage to trees, and resulting growth reductions, were due to tephra coverage of both the foliage and the soil. Coverage of the foliage resulted in foliar damage, foliage abscission and reduction of total tree foliar area, and increased fine root mortality. Tephra coverage of the soil had the potential to restrict oxygen diffusion into the soil. However, soil oxygen concentrations less than 10% were measured only once over a 2-year period.
Electrophoretic identification of clones in trembling aspen
Authors: Cheliak W. M. , Pitel J. A.
Published: January 2008

Electrophoretic techniques which can be used to aid the identification of clones are described. An example using members (putative ramets) from 10 morphologically distinct putative clones of trembling aspen is presented. In this example, it is demonstrated that phenotypically uniform groups of trees (putative clones) can actually be composed of several electrophoretically distinct genotypes.
Survival and regeneration of American elm callus cultures after being frozen in liquid nitrogen
Authors: Ulrich Jane M. , Mickler Robert A. , Finkle Bernard J. , Karnosky David F.
Published: January 2008

Ulmusamericana L. callus cultures were established from hypocotyls of aseptically germinated seeds and from three 18-month-old cell lines. Callus was treated with an aqueous cryoprotective mixture of polyethylene glycol, glucose, and dimethylsulfoxide (10, 8, and 10% w/v, respectively), frozen at 1 °C/min to −30 °C, and then immersed in liquid nitrogen. The callus was thawed rapidly, the cryoprotectant was washed out, and the callus was placed on Kao semisolid medium. Plantlets were regenerated from actively growing callus cultures by transfer to modified woody plant medium. Results suggest that preservation of germplasm for future tree improvement may be possible via liquid nitrogen storage of woody dicot callus.
The effects of atmospheric deposition on potassium, calcium, and magnesium cycling in two deciduous forests
Authors: Johnson D. W. , Richter D. D. , Lovett G. M. , Lindberg S. E.
Published: January 2008

Sulfate was the dominant anion in throughfall and soil solutions from a chestnut oak (Quercuspinus L.) and a yellow poplar (Liriodendrontulipifera L.) forest in eastern Tennessee. Assuming much of this [Formula: see text] was of anthropogenic origin, cation-leaching rates from foliage and in soils of these forests would have to have been accelerated by acid deposition by two- to three-fold. This acclerated leaching could, in turn, cause changes in the rates of K+, Ca2+, or Mg2+ cycling according to any of a number of possible scenarios explored in this paper. Subsoils beneath the chestnut oak stand adsorbed [Formula: see text] from atmospheric deposition, which reduced [Formula: see text]-mediated cation leaching to some extent. In contrast, subsoils from the yellow poplar stand showed a current net output of [Formula: see text] (perhaps desorbing sulfate adsorbed during previous periods of higher input) and much higher rates of cation leaching. The yellow poplar site showed net annual exports of Ca2+, Mg2+, K+, and Na+, but the chestnut oak site showed a net accumulation of Ca2+ and lower net annual exports of Mg2+ and K+ than the yellow poplar site. Both sites had inexplicably large net exports of Na+.
Predicting fine root production and turnover by monitoring root starch and soil temperature
Authors: Marshall J. D. , Waring R. H.
Published: January 2008

To determine how the longevity of fine roots (those without secondary thickening) is controlled, shoots of Douglas-fir (Pseudotsugamenziesii Mirb. (Franco)) seedlings were exposed to light or maintained in darkness while roots were maintained at 10, 20, or 30 °C. Fine root maintenance respiration rates, estimated from rates of starch and sugar depletion in the seedlings maintained in darkness, ranged from 0.83 to 3.25 mg starch g dry weight−1 day−1. At 20 and 30 °C, starch deposition was curtailed and previously deposited starch was used to maintain the older roots, whether current photosynthate was entering the root system or not. On the other hand, at 10 °C starch was deposited in the roots whenever the root systems grew. Based on these results, we suggest that starch deposition in a fine root occurs only when the root is being formed and the root carbon balance is positive. Starch is subsequently respired to meet maintenance requirements exclusively. A simple means of estimating root biomass production and turnover based on root starch and soil temperature is described and compared with field estimates.
Chemosystematic studies in the genus Pinus. V. Variation in the leaf oil terpene composition of young and old lodgepole pine trees from different moisture regimes near Prince George, British Columbia
Authors: Rudloff E. Von , Lapp Martin S. , McMinn R. G.
Published: January 2008

The leaf oil terpene composition of lodgepole pine stands from contrasting moisture regimes (400–1200 mm precipitation) within upland and bog sites in the Prince George area of central British Columbia was investigated. In addition to the terpene patterns recorded previously, a new one with relatively high percentages (5–28%) of the terpinene group was found. This pattern was encountered mainly in old trees with very low yields (less than 0.1%) of volatile oil, especially in trees from shaded stands. The absence of resin canals in the leaves of such trees may be the reason for the low yields, but the reason for the link with relatively high terpinene group percentages is obscure. Young trees growing in the vicinity of such stands had mainly the normal patterns. No differences between upland and bog sites or dry and wet sites were found in young trees. Hence, old trees from bogs or wet sites east of Prince George provided progeny with the normal terpene patterns, even though many of the old trees have the new terpene pattern. Samples from two 12- to 13-year-old provenance trials originating from west and east of Prince George had terpene patterns similar to those of the young trees from the natural stands.
Stand structure and growth form of the birch transition community in an industrially damaged ecosystem, Sudbury, Ontario
Authors: James G. I. , Courtin G. M.
Published: January 2008

The anthropogenic birch transition community has developed in the vicinity of Sudbury, Ont., as a result of base-metal mining and smelting, logging, and forest fires over the past century. This study investigates the floristic composition and structure of an exposed ridge site and a protected woodland site in this community, a coppice woodland dominated by Betulapapyrifera Marsh. and Acerrubrum L. For convenience in the field, vegetation was classified into growth forms I to V on the basis of morphological development and stem diameter to separate multiple-stemmed stools from single-stemmed individuals and seedlings from saplings of seedling size but older than 1 year. The ridge was dominated by small stools (growth form II) of B. papyrifera, whereas both large stools (growth form I) and small stools of B. papyrifera and A. rubrum characterized the woodland. No A. rubrum and only a few B. papyrifera seedlings became established at the ridge. Seedlings that survive develop into growth form II while still less than 1 m high. At the woodland, regeneration also was low, but A. rubrum seedlings were more frequent than those of B. papyrifera. Lack of seedlings, the persistence of coppicing, and periodic crown dieback maintain this coppice woodland in its present form so that little change with time is expected.
Vertical variation of sapwood thickness in Pinusbanksiana Lamb. and Larixlaricina (Du Roi) K. Koch
Authors: Yang K. C. , Hazenberg G. , Bradfield G. E. , Maze J. R.
Published: January 2008

Variation of sapwood thickness, in terms of a linear measurement (sapwood width) and a growth ring count (sapwood ring), in relation to age, height, aspect, and radial growth rate was studied in jack pine (Pinusbanksiana Lamb.) and tamarack (Larixlaricina (Du Roi) K. Koch). In general, jack pine has more sapwood rings and a greater sapwood width than tamarack. In jack pine, the number of sapwood rings steadily declined with increasing height, but in tamarack, the number of sapwood rings at first increased and then declined with increasing height. Sapwood width tended to show a species-specific constant thickness along the trunk, but both species exhibited a slight increase at the base and at the crown. The number of sapwood rings shows strong correlation with age, height, and sapwood radial growth rate, but not with sapwood width. In both species, the south aspect of the tree has wider sapwood and fewer sapwood rings than the north aspect. There is no statistical relationship between sapwood width and the number of sapwood rings.
Variabilité de la densité du bois et de la production des provenances d'épinette blanche, 20 ans après plantation
Authors: Beaulieu J. , Corriveau A.
Published: January 2008

The variability of wood specific gravity and yield of 23 white spruce provenances from the Great Lakes – St. Lawrence forest region was studied 20 years after planting at Harrington Forest Farm, Québec. The results indicate no relationship between wood specific gravity of provenances and their respective growth performance. The southwestern section of this region showed a small decrease in wood specific gravity, but it was compensated for by a strong increase in volume growth, resulting in an important gain in dry weight productivity. The variability of white spruce wood specific gravity was split into three sources: 11% was attributed to provenance differences, 8% to provenance and repetition interaction, and the remainder to differences among trees of the same provenance and to experimental error. In a breeding program, a first selection should be made at the provenance level on the basis of volume productivity and a second selection on the basis of wood specific gravity values within the selected provenances, to maximize the overall genetic and economic gain.
Chemical and pedogenetic effects of simulated acid precipitation on two eastern Canadian forest soils. I. Nonmetals
Authors: Hern J. A. , Rutherford G. K. , vanLoon G. W.
Published: January 2008

An experiment involving the addition of simulated acid rain to two Canadian Shield orthic humo-ferric podzolic forest soils was carried out in the field and in the laboratory. Soils were subjected to treatments of pH 5.7, 3.5, and 2.0 water containing added nitric and sulphuric acids in a 1:2 molar ratio. Pore-water concentrations of H+, [Formula: see text], [Formula: see text], [Formula: see text], and Cl− were monitored at depths of 15–60 cm for up to 2 years. Some of the laboratory columns were dismantled after 1 year and total soil N, S, soil pH, and S adsorption characteristics were measured. Half the columns were sterilized in an attempt to assess the relative importance of microbial processes. Considerable H+ buffering by the soils was indicated, with soil pH unchanged even under the most acidic treatment. Nitrate but not ammonium production was suppressed under highly acid treatment conditions in the laboratory, while in the field only small concentrations of both nitrogen species were detected in pore water. No change in total soil N was detected. Sulphur retention was assessed, with major amounts retained by the soil just below the Ae horizon where iron and aluminum oxides along with organic matter accumulate. Sterile column data indicates microbial processes are also of considerable importance in the immobilization of S inputs.
Chemical and pedogenetic effects of simulated acid precipitation on two eastern Canadian forest soils. II. Metals
Authors: Rutherford G. K. , VanLoon G. W. , Mortensen S. F. , Hern J. A.
Published: January 2008

A study to determine the effects of simulated acid rain on two Canadian Shield podzolic soils was performed on field plots and reconstructed profiles. Soils were irrigated with deionized water and HNO3 and H2SO4 (1:2 molar ratio) solutions at pH 3.5 and 2.0. Pore–water concentrations of Na, K, Mg, Ca, Fe, Mn, and Al were measured at 15–60 cm over 2 years. Half the reconstructed profiles were dismantled after 1 year. Total organic C, exchange cations Ca, Mg, K, and Na, and titratable acidity were measured and three different extraction procedures were used to determine soil free iron and aluminum oxides. Al mobilization high in the profiles, with extreme values up to 40 mg/L at pH 2.0, was followed by redeposition lower in the profile. Up to threefold enhancement of Ca and Al leaching was observed under the most acidic conditions, particularly in the field. Evidence in the present study suggests that anion affinity of the mineral soil reduces the leaching of base cations. A significant decrease in free iron oxides just below the Ae horizon was observed in one of the soils.
A nonparametric technique for taper function estimation
Authors: M'Hirit O. , Postaire J. G.
Published: January 2008

The most common method for determining tree profile models is by fitting an analytical function to a set of sample trees. In situations where the forester has relatively little a priori knowledge about the nature of profiles, choosing the analytical form of the parametric model is a critical problem without a satisfactory solution. An alternative is to use a nonparametric approach in which the model of the profile is explicitly specified by a tabulation of diameters at discrete heights. In this paper, it is shown how the model can be determined from the sample trees by means of a classical nonparametric probability density function estimation technique. Field tests and a measure of goodness of fit are used to express how well the models match the actual stem profiles. Using the Moroccan cedar (Cedrusatlantica Manetti) tree as an example, it is shown how the new nonparametric model can be compared with any classical parametric model. The results achieved demonstrate the advantages in using a nonparametric representation of stem profiles, which, moreover, is well suited to computer calculation constraints.
Effective use of ethylene-releasing agents to prevent spread of eastern dwarf mistletoe on black spruce
Authors: Livingston William H. , Blanchette Robert A. , Brenner Mark L. , Zuzek Kathryn J.
Published: January 2008

Ethylene-releasing agents (ethephon, ethanedial dioxime, etacelasil, 2-chloroethyl-methylbis(phenylmethoxy)-silane, and 1-aminocyclopropane-1-carboxylic acid) applied to dwarf mistletoe (Arceuthobiumpusillum Pk.) infections on black spruce (Piceamariana (Mill.) B.S.P.) in four separate tests (August 1982, 1983, and 1984 and May 1983) promoted premature abscission of mistletoe shoots. Concentrations of the chemicals ranged from 12 to 5000 μg/g. Surfactants (Ortho X-77 and PGFI-100) were evaluated for increasing the effectiveness of the ethylene-releasing agents. The treatment combination that consistently resulted in 74–100% abscission of dwarf mistletoe shoots was August applications of 2500 μg/g ethephon plus either surfactant. Treatments did not significantly affect growth of black spruce or subsequent growth of dwarf mistletoe shoots. Abscission of dwarf mistletoe shoots prevents spread of the disease in black spruce for 2 years and for at least 4 years in some western conifers.
Effects of root rot on the growth of balsam fir
Authors: Whitney Roy D. , MacDonald G. Blake
Published: January 2008

Growth increments were compared on balsam fir (Abiesbalsamea (L.) Mill.) trees with varying amounts of decay on the stump (15 cm above ground) that originated from the roots. In 1612 trees, from 20 to 156 years of age on 139 plots across northern Ontario, the average height and radial increments over the last 3 years were 13.5 and 10.9% smaller, respectively, in trees with ground-level decay compared with trees having no decay at this level. Stand basal area was more useful than tree age as a stratification variable for revealing the effect of root rot on growth. Growth reductions were the smallest in trees with intermediate surrounding basal areas and in trees on drier or heavier textured soils.
Observations on fungi associated with spruce budworm infested balsam fir needles
Authors: Miller J. David , Strongman D. , Whitney N. J.
Published: January 2008

Fungi (ca. 2000 isolates) were isolated from balsam fir needles infested by the spruce budworm (Choristoneurafumiferana Clem.) as well as from uninfested needles. Most of the isolates were well-known colonizers of the conifer needle phylloplane. However, approximately 6% of the isolates obtained from the infested needles were unusual needle phylloplane fungi and some of these were toxigenic and (or) pathogenic. Some isolates (23) associated with the needles, frass, and larvae were cultured; solvent extracts of the freeze-dried material of some of these were cytotoxic to HeLa 229 cells. The isolates showing cytotoxicity were grown and the resulting hyphae were incorporated (1%, w/w) into a spruce budworm diet. Hyphae from several isolates in these diets resulted in slower growth rate and mortality. The results of this study show that the presence of the spruce budworm altered the phylloplane mycoflora and the data suggest that there are toxic effects to spruce budworm that consume phylloplane fungi.
Comparison of isozyme variation among natural stands and plantations: jack pine and black spruce
Authors: Knowles Peggy
Published: January 2008

Isozymes from needles of jack pine (Pinusbanksiana) and black spruce (Piceamariana) were analysed to test differences among young stands, mature stands, plantations from seed-zone seed collections, a plus-tree clonal seed orchard, and a progeny plantation from the seed orchard. Analyses based on approximately 100 trees per population resolved seven polymorphic loci for jack pine and five for black spruce. For intraspecies comparisons, allelic heterogeneity tests indicated no differences between young stands and plantations from seed-zone seed collections. The black spruce clonal seed orchard and mature natural stands were genetically homogeneous. Allelic heterogeneity test and discriminant analysis indicated that the progeny plantation from the clonal seed orchard differed from other black spruce samples. It is proposed that nonrandom mating conditions in the clonal seed orchard altered allele frequencies of the resultant progeny plantation.
On a social discount rate for forestry
Authors: Harou P. A.
Published: January 2008

After a review of the literature on the discount rate in economics and forestry, a methodology is proposed to arrive at an appropriate social discount rate to appraise public forestry investments. In the proposed approach, the opportunity cost of capital is considered in the establishment of a shadow price of investment. The social discount rate, which should weight the project net social benefits through time, is an unknown of the net present worth equation set equal to zero.
Effects of sowing depth on emergence and growth of Douglas-fir, western hemlock, and noble fir seedlings
Authors: Minore Don
Published: January 2008

The effects of sowing depth of seeds of several western forest tree species were studied in greenhouse experiments. Emergence and seedling weight of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco), western hemlock (Tsugaheterophylla (Raf.) Sarg.), and noble fir (Abiesprocera Rehd.) were reduced by sowing seeds in soil at depths greater than 1 cm. Deep sowing in a peat–vermiculite mixture also reduced the emergence of Douglas-fir and western hemlock, but increased the hypocotyl diameters and weights of Douglas-fir seedlings.
A multifactor ecological classification of the northern hardwood and conifer ecosystems of Sylvania Recreation Area, Upper Peninsula, Michigan
Authors: Spies Thomas A. , Barnes Burton V.
Published: January 2008

An ecological method of multifactor ecosystem classification was applied in the Sylvania Recreation Area, an 8500-ha tract of old-growth northern hardwood – conifer forests in upper Michigan. The uplands and wetlands were subjectively classified into 25 ecosystems by a method combining reconnaissance, plot sampling, data analysis, and ecosystem mapping. Each ecosystem was a characteristic combination of physiography, ecological species groups (ground vegetation), and soil. Discriminant analysis was used to evaluate the distinctness of the upland ecosystems and to compare the discriminating abilities of different ecosystem components (physiography, ground vegetation, and soil). The classification was corroborated in the multivariate analyses. The lowest estimated error rate (9.4%) in discriminant analysis was obtained by a model based on a combination of physiographic and soil characteristics and ecological species groups. The estimated error rates based on the species groups alone and physiography and soil alone were 42.2 and 25.0%, respectively. The discriminant analyses indicate that neither vegetation alone nor physiography and soil alone could be used with high reliability in classifying and mapping ecosystems. An additional discriminant analysis of the three ecosystem components indicated that the ecosystems could be distinguished by field characteristics without information from soil laboratory analyses. This analysis also demonstrated the particular value of the vegetation component as a readily observed, acceptable substitute for soil laboratory data in identifying and mapping ecosystem units.
Desiccation and water potentials in the roots, leaves, and shoots of bare-root red pine and white spruce
Authors: Sucoff Edward , Buschena Cindy , Tamte Perry
Published: January 2008

Bare-root seedlings of red pine (Pinusresinosa Ait.) and white spruce (Piceaglauca (Moench) Voss) were dried in various controlled situations before measurement of water potential (ψ) and moisture contents. For each situation, root ψ was directly proportional to and highly correlated with shoot ψ. The regression lines did not vary with environment for fully exposed seedlings within a seedling lot. Regressions did differ between seedling lots and between seedlings that had roots only, shoots only, or both roots and shoots exposed. Since the differences between root and shoot ψ were sometimes large and roots are more likely to be damaged by a given level of desiccation during handling, we suggest that root ψ may be the preferred predictor of postplanting seedling behavior.
Inheritance and linkage relationships of some isozymes of black spruce in New Brunswick
Authors: Boyle T. J. B. , Morgenstern E. K.
Published: January 2008

Thirteen polymorphic loci from eleven enzyme systems in black spruce (Piceamariana (Mill.) B.S.P.) were studied by gel electrophoresis using embryos and haploid megagametophyte tissue. Two loci (Mdh-1 and Sdh) showed deviations from the expected 1:1 segregation ratio of megagametophytes from heterozygous maternal plants that were significant at the 1 % level and a third (Aat) at the 5% level. Of the 78 possible pairwise comparisons for the linkage analysis, 58 could be tested for jointly independent segregation. Linkage could be detected between three pairs of loci: Aat–Pgi, Gdh–Idh, and Fum–Pgm.
Effects of direct contact of Pinusresinosa seeds and young seedlings with N-dimethylamino succinamic acid, (2-chloroethyl)trimethylammonium chloride, or maleic hydrazide
Authors: Kozlowski T. T.
Published: January 2008

Critical concentrations of two growth retardants, N-dimethylamino succinamic acid (Alar) and (2-chloroethyl)trimethylammonium chloride (CCC), and one growth inhibitor, maleic hydrazide, applied continuously to Pinusresinosa seedlings in the cotyledon stage greatly suppressed seedling growth and development and killed many seedlings. Both Alar and CCC arrested the elongation of stems, roots, cotyledons, and primary needles, inhibited the expansion of mesophyll cells, and decreased the amount of intercellular space in the cotyledons and cortex. Growth was inhibited by lower concentrations of CCC than of Alar. Maleic hydrazide reduced the growth of shoots, roots, cotyledons, and primary needles, with growth inhibited by much lower concentrations than those of Alar or CCC. Cell expansion was stimulated by maleic hydrazide at concentrations below 2500 ppm and inhibited by concentrations at or above 2500 ppm. Maleic hydrazide at 100 ppm caused chlorosis and induced wall thickening of ground tissue cells in the hypocotyl and cotyledons. The greater reduction of root growth than of shoot growth as well as the inhibition of the growth of primary needles by nonlethal concentrations of Alar, CCC, or maleic hydrazide will increase the mortality risk of Pinusresinosa seedlings in the cotyledon stage of development.
Bioassay of forest floor phosphorus supply for plant growth
Authors: Cleve K. Van , Harrison A. F.
Published: January 2008

not available
The influence of litter and humus accumulations and canopy openness on Piceasitchensis (Bong.) Carr. and Tsugaheterophylla (Raf.) Sarg. seedlings growing on logs
Authors: Harmon Mark E.
Published: January 2008

The influence of litter and humus accumulations on the surface of logs and canopy openness upon growth and survival of Piceasitchensis (Bong.) Carr. and Tsugaheterophylla (Raf.) Sarg. seedlings was tested experimentally at Cascade Head Experimental Forest, near Otis, Oregon. This was done by adding litter and humus to the surface of freshly fallen logs. Survival rates of both species increased asymptotically as litter accumulations on logs increased. Mean maximum survival was 58% for Picea and 34% for Tsuga. Picea seedling survival peaked when tree canopy cover ranged from 70 to 80% with lower survival at either higher or lower values. Tsuga survival was highest under closed canopies. Seedling growth increased as litter–humus accumulation and canopy openness increased.
Testing for stand dynamics effects on red spruce growth trends
Authors: Deusen Paul C. Van
Published: January 2008

Increment-core data for old-growth red spruce (Picearubens Sarg.) were collected for dendrochonological purposes and compared with second-growth data obtained from USDA Forest Service inventory plots in Maine, New Hampshire, Vermont, and New York. The research objective was to test the hypothesis suggested by J. W. Hornbeck and R. B. Smith (1985, Can. J. For. Res. 15: 1199–1201) that red spruce show reduced growth in the Northeastern United States due to stand dynamics resulting from past logging and insect activity. A graphical approach and a modeling approach based on the Kalman filter were employed. The results indicate that the growth reduction is greater in second-growth stands and that the second-growth stands are converging to an old-growth condition. This supports the stand dynamics hypothesis for second-growth stands.
Decomposition, litter fall, and forest floor nutrient dynamics in relation to fire in eastern Ontario jack pine ecosystems
Authors: Weber M. G.
Published: January 2008

Decomposition, litter fall, and nutrient and organic matter turnover rates were determined in five eastern Ontario jack pine (Pinusbanksiana Lamb.) stands having various burning histories, including wildfire. The stands included a 65-year-old age-class (stand No. 1), two stands within this age-class that were treated with nonlethal understorey fires in 1962 and 1963 (stand Nos. 2 and 3, respectively), a 21-year-old age-class (stand No. 4), and an 8-year-old age-class (stand No. 5) created by experimental burning plots within the 21-year-old age-class. Overstorey and understorey litter decomposition was assessed separately using the litterbag (1-mm mesh size) technique over a 2-year period. Overstorey litter weight loss did not vary among stands and understorey litter lost significantly more weight (P < 0.05) in the older age-classes (stands 1,2, and 3) compared with the younger stands (stands 4 and 5). Litterbag nutrient dynamics between overstorey and understorey were significantly different (P < 0.05) for P, K, and Cain all stands. Magnesium and N dynamics were the same in both litter types on all treatments, as was Fe, except in the 65-year-old stand where significantly more Fe was accumulated in understorey litter (P < 0.04) at the end of the litterbag exposure period. Three-year averages of annual litter fall ranged from 119 kg•ha−1•year−1 in the 8-year-old age-class to 4182 kg•ha−1•year−1 in the older stands. Nutrient inputs through litter fall reflect the developmental stage occupied by the younger stands along a continuum leading to equilibrium conditions of the 65-year-old age-class. Forest floor nutrient and organic matter residence times (or annual fractional turnover) were longest (least amount cycled) in the 8-year-old stand (57.6 years for organic matter), indicating harsh environmental controls over nutrient dynamics. Recovery for the 21-year-old age-class to turnover rates approaching equilibrium conditions (10-year residence time for organic matter) was rapid, demonstrating ecosystem stability in its interaction with fire. Detrimental effects on ecosystem processes can be expected if a stand-replacing fire recurs during early stages of jack pine ecosystem development.
Modelling and decomposition for planning long-term forest harvesting in an integrated industry structure
Authors: Gunn Eldon A. , Rai Ajith K.
Published: January 2008

Economists' models for optimal forest rotation have typically focused on the unit area landholder since the early work of Faustmann. This focus on the growth process has ignored the existence of an industry with an ongoing need to keep mills working at some significant fraction of capacity. In this paper we discuss a model framework that will enable the calculation of regeneration harvest policies in a long term context of wood supply to an integrated industry. The paper briefly reviews the literature on economic approaches to forest rotation and then goes on to examine the mathematical programming approaches, particularly the Model I and Model II forms discussed by Johnson and Scheurmann. Only the work of Barros and Weintraub attempts to model both growth and harvest together with an integrated industry structure. Their work, however, uses the Model I formulation, which severely restricts the alternative regeneration harvest policies. We examine a new model based on a Model II type of modelling of the forest growth and harvesting. Like Barros and Weintraub, we use a simple integrated industry structure. The resulting mathematical programming model is large but possesses considerable special structure. We outline a simple approach to decomposition to permit the rapid solution of this model and report on some preliminary computational experience.
Climate, site conditions, and tree growth in subtropical northwestern Argentina
Authors: Villalba Ricardo , Boninsegna Jose A. , Ripalta Alberto
Published: January 2008

Tree-ring widths were used to measure the relationship between climate and tree growth in the subtropical montane forest of northwestern Argentina. The comparisons between weather records and tree-ring series were made in terms of percentage of agreement, correlation, and response functions. In each of the six sites sampled, climatic variables affecting JuglansaustralisGriseb., Cedrelaangustifolia Sesse Moc, and Cedrelalilloi C. DC. were determinated. Species growing in ecologically comparable sites showed similar variations in ring widths which reflected the influences of climate. On the other hand, on sites that were ecologically different, tree growth was not synchronous, even for the same species. This study shows that dendroclimatological studies in the subtropics and growth of deciduous trees can be reliable climatological indicators.
The diffusion and toxicity of the fumigant chloropicrin injected in sugar maple and white birch tree
Authors: Goodell Barry , Hosli Johannes P. , Kropp Bradley
Published: January 2008

Twenty sugar maple (Acersaccharum Marsh.) and 20 white birch trees (Betulapapyrifera Marsh.), all containing columns of decayed or discolored wood, were bored and injected with one of three dosages of chloropicrin or were left untreated. One year after treatment, four trees of each species were felled and dissected. The wood was then analyzed for fumigant concentration and assayed for the presence of fungi. All remaining trees were inspected yearly for adverse response to treatment. Three years after treatment, dieback and leaf discoloration were apparent in birch trees treated with moderate to high dosages of chloropicrin. No adverse response to treatment was apparent in any maple tree or in birch trees treated with low dosages of chloropicrin. In the dissected trees, chloropicrin vapors were generally detected in the interior of the trees at sites 0.5 m above and 0.5 m below the treatment site. In the higher dosage birch trees, chloropicrin was detected more frequently and in higher concentrations from outer sapwood. Control of the causal decay fungi in the trees was not ascertained in this study; however, in the birch trees, growth of opportunistic decay fungi was inhibited in sections from treated but not untreated trees.