Showing papers in "Canadian Journal of Forest Research in 1981"
TL;DR: Above- and below-ground net primary production was estimated for 40-year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) stands growing on sites with apparently large differences in productiv...
Abstract: Above- and below-ground net primary production was estimated for 40-year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) stands growing on sites with apparently large differences in productiv...
523 citations
TL;DR: Biomass distribution and above- and below-ground net primary production were determined for 23- and 180-year-old Abiesamabilis (Dougl.) Forbes ecosystems growing at 1200-m elevation in the western Washington Cascade Range.
Abstract: Biomass distribution and above- and below-ground net primary production were determined for 23- and 180-year-old Abiesamabilis (Dougl.) Forbes ecosystems growing at 1200-m elevation in the western Washington Cascade Range. Total organic matter accumulations were 427.0 t•ha−1 in the young stand, and 1247.1 t•ha−1 in the mature stand. Aboveground tree and detritus biomass were 49.0 t•ha−1 and 130.2 t•ha−1, respectively, in the young stand compared with 445.5 t•ha−1 and 389.4 t•ha−1 in the mature stand. Net primary production (NPP) was 18.3 t•ha−1 in the young stand and 16.8 t•ha−1 in the mature stand. Belowground dry matter production was 65% of total net production in the young stand and 73% of total net production in the mature stand. Conifer fine root production was 35.9% of NPP in the young and 66.4% of NPP in the mature stand. This apparent shift in fine root production as a proportion of NPP may be related to detritus accumulation.
414 citations
TL;DR: In this article, the negative exponential and Wiebull distributions were used to estimate stand survivorship curves for forested sites in the Porcupine River drainage of interior Alaska, and the survivorship curve of P...
Abstract: The negative exponential and Wiebull distributions were used to estimate stand survivorship curves for forested sites in the Porcupine River drainage of interior Alaska. The survivorship curve of P...
178 citations
TL;DR: Seasonal changes in biomass and vertical distribution of fibrous, mycorrhizal, and total conifer fine roots were examined in 23- and 180-year-old Pacific silver fir ecosystems.
Abstract: Seasonal changes in biomass and vertical distribution of fibrous, mycorrhizal, and total conifer fine roots (≤ 2 mm) were examined in 23- and 180-year-old Pacific silver fir (Abiesamabilis (Dougl.) Forbes) ecosystems. In both stands, > 80% of fine roots was located in the upper 15 cm of the soil profile, in the forest floor (O1 and O2) and A horizon. During periods of active root growth in the young stand, significantly higher conifer root biomass occurred in the A horizon (370 to 690 g/m2) than the forest floor (200 to 350 g/m2). At all sampling times, a significantly higher biomass of conifer fine roots was located in the forest floor (550 to 1090 g/m2) than the A horizon (290 to 640 g/m2) in the old stand. In both stands, mycorrhizal roots comprised 10 to 15% of the total weight of conifer fine roots during peak root growth, 2 to 6% when roots were not growing, and 21 to 29% during the winter and early spring when roots were growing. Up to 69% of the biomass of fibrous and mycorrhizal roots was located...
125 citations
TL;DR: Thinning and heavy ferilization separately increased needle mass per tree after 7 years by 90% and, when combined, by 271%.
Abstract: The effect of two levels of thinning (zero and of basal area removed) and three levels of nitrogen fertilization (0,224, and 448 kg N/ha) on crown development of codominant, 24-year-old Douglas-fir...
117 citations
TL;DR: No other conifer tissue culture method has been reported to give such a large number of adventitious shoots of the same clone in a first generation, and induction of a smooth-surfaced, yellow–green, nodular meristematic tissue appears to be a requirement for the formation of large numbers of Adventitious shoots.
Abstract: The shoot-forming capacity of Pinusradiata D. Don juvenile explants under tissue culture conditions was examined. Three types of explant were used: whole embryos; cotyledons excised from whole embr...
109 citations
TL;DR: Evaluated black spruce ecosystems in interior Alaska found low soil temperature acted as a negative feedback control, suppressing soil biological activity, nutrient mineralization, and tree primary production to lower levels on the soil-permafrost-dominated site as compared with the permafrost free site.
Abstract: Selected indices of structure and function were used to evaluate the effect of differing soil thermal regimes on soil-permafrost-dominated (muskeg) and permafrost-free (north-slope) black spruce ecosystems in interior Alaska. The poorly drained, permafrost site displayed cooler soil temperatures and higher soil moisture content than were encountered on the well-drained north slope. Mineral soil nutrient pools generally were largest on the permafrost site. However, low soil temperature acted as a negative feedback control, suppressing soil biological activity, nutrient mineralization, and tree primary production to lower levels on the soil-permafrost-dominated site as compared with the permafrost-free site. Forty percent larger accumulation of tree biomass and 80% greater annual tree productivity occurred on the warmer site.
105 citations
TL;DR: A significant relationship was obtained between foliage nitrogen concentration and rate of photosynthesis, with an optimum rate at 1.74% foliar nitrogen and with no effect of nitrogen source.
Abstract: The effects of nitrogen fertilization on foliage nitrogen concentration, rates of photosynthesis, and stem diameter growth were studied for Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) trees, with a range of fertilizer applications from 0 to 896 kg N/ha. Ammonium nitrate (AN) and urea were compared as nitrogen sources. AN provided for a higher foliage nitrogen concentration and better growth the 1st year, but there was no source effect thereafter. A significant relationship was obtained between foliage nitrogen concentration and rate of photosynthesis, with an optimum rate at 1.74% foliar nitrogen and with no effect of nitrogen source. Stem diameter growth was increased at all fertilization rates, although no effect of the two lowest rates of fertilization (112 and 224 kg N/ha) was found on foliar nitrogen concentration.
96 citations
TL;DR: In this article, a simple model for Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) of different crown classes explains much of the observed differences in stem form development.
Abstract: The mechanical and physiological support of a tree's crown is the principal function of its bole. A simple model for Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) of different crown classes explains much of the observed differences in stem form development. Sapwood cross-sectional area at any height on the bole of the tree was found to be related linearly to the amount of foliage above that point; however, in large trees the sapwood area needed to supply transpiring foliage with water is insufficient to provide mechanical support. The combination of sapwood and heartwood was found to provide the stem form that would be expected to ensure uniform resistance to bending by the wind.
88 citations
TL;DR: Early chemical storage as related to growth changes that occur in cottonwood stems during dormancy induction was investigated, and leaf expansion and stem elongation had stopped by the 4th week under short days, and terminal buds had formed.
Abstract: Early chemical storage as related to growth changes that occur in cottonwood (Populusdeltoides Bartr. ex. Marsh) stems during dormancy induction was investigated. In this experiment, plant dormancy was induced by 8-h photoperiods (short days) and 20 °C: 14 °C temperature regimes. Tissue samples were taken at four stem positions for 8 weeks under short days. Leaf expansion and stem elongation had stopped by the 4th week under short days, and terminal buds had formed. Starch concentration in the lower stem began to increase during the 3rd week and continued throughout the dormancy induction period. By the 8th week starch concentration in the stem was about 24% residue dry weight (RDW). Total nonstructural carbohydrates (starch and soluble sugars) increased almost linearly after the 1st week to about 38% RDW. Free amino acids increased during the first 2 weeks to 1.6%, declined to 0.2% by 6 weeks, then remained constant. Triglyceride concentration remained level for the first 2 to 3 weeks, then increased fro...
80 citations
TL;DR: Individual isolates of Pisolithustinctorius (Pers.) Coker and Couch differed greatly, however, in growth response at various temperatures; these differences were unrelated to age of culture or reisolation.
Abstract: Twenty-one isolates of Pisolithustinctorius (Pers.) Coker and Couch of different ages and from different tree hosts and world locations were initially tested for ectomycorrhizal development on Pinustaeda L. seedlings in a growth room. Three oak isolates from the United States and seven pine isolates from the United States, Brazil, and Australia (1 – 17 years old) formed few or no ectomycorrhizae. Eleven remaining pine isolates (1 – 6 years old) collected in Taiwan, France, and nine locations in the United States formed abundant ectomycorrhizae.Reisolates were obtained from the above ectomycorrhizae formed by the original isolates. In pure culture on agar medium, most original isolates grew as fast or faster than the companion reisolates. Individual isolates differed greatly, however, in growth response at various temperatures; these differences were unrelated to age of culture or reisolation.In a nursery experiment, there were large differences among eight isolates and nine reisolates in degree of ectomyc...
TL;DR: In this paper, the aboveground biomass estimation equations were developed and compared for several components of Betulapapyrifera Marsh, trees using diameter at breast height (dbh) alone or dbh and height as independent variables.
Abstract: Aboveground biomass estimation equations were developed and compared for several components of Betulapapyrifera Marsh, trees using diameter at breast height (dbh) alone or dbh and height as independent variables. The data upon which the equations are based were collected by a number of different investigators working in Minnesota, Wisconsin, New Hampshire, and several sites in Maine and New Brunswick. Coefficients of determination ranged from 0.82 to 0.99, with higher values for bole than for crown components. The root mean-square deviation of the observations from the model was in the range 1 – 10 kg for any component. The largest trees in the data set (ca. 30 cm dbh) had total aboveground biomass of about 540 kg. In the absence of site-specific data, these equations provide acceptable estimates of biomass for B. papyrifera.
TL;DR: In small, dense and open-sided plantings of hybrid poplars, the edge effect extended through several rows, tree mortality increased and diameter at breast height (DHB), dry weight of individual trees, foliage weight, and leaf area index decreased from the border row to the center rows.
Abstract: In small, dense and open-sided plantings of hybrid poplars, the edge effect extended through several rows, tree mortality increased and diameter at breast height (DHB), dry weight of individual trees, foliage weight, and leaf area index decreased from the border row to the center rows. Edge trees next to unplanted border trees tend to spread outward, thus intercepting solar radiation from a larger area than the area delineated by lower stems. When an oscillating irrigation system is used, the inner rows may receive only a fraction of the water border trees receive. This may be partly responsible for the extent of "edge effect" in this and similar studies. These irregularities could create serious problems in interpreting the results from small plantings. Some ways of reducing edge effect in production studies are proposed.
TL;DR: Current annual nitrogen fixation estimates (using C2H2) of 130 kg•ha−1•year−1 for the red alder plot and 20 kg•ha... for the Sitka alder plots are obtained.
Abstract: Three comparisons examined acetylene reduction rate and nodule biomass of red alder (Alnusrubra Bong.) and Sitka alder (Alnussinuata (Regel) Rydb.) on Vancouver Island, British Columbia. The first ...
TL;DR: The rate of invasion and height growth of vegetation in logged-over areas were studied on four forest site types in the white spruce – alpine fir – Abieslasiocarpa (Hook.) Nutt forests north of Prince George, B.C.
Abstract: The rate of invasion and height growth of vegetation in logged-over areas were studied on four forest site types in the white spruce – alpine fir (Piceaglauca (Moench) Voss – Abieslasiocarpa (Hook....
TL;DR: Root biomass and production were calculated as being approximately 10% of the total biomass and of the annual production and the average rate of total production per unit leaf tissue was 5.7 g production/g leaf tissue for P. tremuloides and 3.7% for A. saccharum.
Abstract: Total biomass of an aspen – mixed hardwood – spodosol ecosystem in northern Wisconsin, U.S.A., was 197 t/ha and net primary production was 11.5 t/ha per year. Populustremuloides Michx. accounted fo...
TL;DR: Correlations of environmental variables with LI indicate that aspen longevity decreases with increasing mean annual temperature, and hypothesize that, under similar environmental conditions, variation in the timing of deterioration may be due to genotypic differences between clones.
Abstract: In order to test the hypothesis that the deterioration of trembling aspen (Populustremuloides Michx.) is related to variations in climate, soil properties, and genotype, 59 trembling aspen clones were sampled in Michigan, Wisconsin, Minnesota, and Ontario. A longevity index (LI) was calculated by taking the difference between predicted basal area from normal yield tables and measured basal area for each clone. Correlations of environmental variables with LI indicate that aspen longevity decreases with increasing mean annual temperature. Under similar temperature regimes, aspen growing on xeric sites and on sites low in exchangeable Ca are most susceptible to early breakup. Since there were negligible differences in soil properties between nine pairs of adjacent deteriorating and relatively well stocked clones, we hypothesize that, under similar environmental conditions, variation in the timing of deterioration may be due to genotypic differences between clones.
TL;DR: Direct evidence, based on segregation of allozymes in megagametophytes of heterozygous clones, is presented for nine loci in five systems (LAP, GPI, GOT, PGM, and AP), and recombination estimates suggest relatively strong linkage between LAP1-LAP2 and GPI2-GOT1; weaker linkage between H2O-H2O and LAP-GPI2 (based on one clone only).
Abstract: Megagametophyte tissue from seeds of 35 clones of Pinusstrobus L. were subjected to horizontal starch gel electrophoresis. The resulting gels were tested for activity of 10 enzyme systems. Isozymes...
TL;DR: Mortality for both spruce and fir was as high for mixed (hardwoods and budworm hosts) as for coniferous (predominantly spruce–fir stands) stands, and the protracted mortality of these two species following the end of the infestation.
Abstract: Spruce–fir stands in the Ottawa River watershed in Quebec were subjected to defoliation by spruce budworm, Choristoneurafumiferana (Clem.), between 1967 and 1975. Eighteen study plots were establis...
TL;DR: Survival was reasonably high for oaks as long as the top of the crown was receiving direct sunlight, but the expected 40-year survival rate of red oaks in such a position is only 20%, with an average growth rate of 1.0 mm in diameter per year.
Abstract: Mortality and growth rates of trees in various crown classes and size classes were analyzed from 40-year permanent plot records of slope and ravine forest dominated by chestnut oak (Quercusprinus L.) and northern red oak (Quercusrubra L.). Average 5-year mortality rates for suppressed trees ≥2.5 cm dbh of chestnut oak and red oak in the slope forest were 26 and 45%, respectively. None of the suppressed red oaks survived the 40-year period, compared with 14% of the chestnut oaks and 33% of the red maples (Acerrubrum L.). Mortality of oak trees in the intermediate crown class was less than half that of suppressed trees, but still much higher than that of maples and birches on the tracts. Survival was reasonably high for oaks as long as the top of the crown was receiving direct sunlight, but the expected 40-year survival rate of red oaks in such a position is only 20%, with an average growth rate of 1.0 mm in diameter per year. Curves and equations expressing average mortality and growth rates at various lev...
TL;DR: First-order branch characteristics that have a major influence on crown architecture were quantified for nine 4-year-old Populus clones grown at three spacings.
Abstract: First-order branch characteristics that have a major influence on crown architecture were quantified for nine 4-year-old Populus clones grown at three spacings (0.3 m × 0.3 m,0.6 m × 0.6 m, 1.2 m × 1.2 m) under short-rotation, intensive culture (SRIC) in northern Wisconsin, U.S.A. The branch characteristics included the number, length, and diameter of branches and the angles of origin and termination. Clone and spacing had statistically significant effects on all branch characteristics, but the clone–spacing interaction was not significant for any branch characteristic. As spacing increased, the number, sum of lengths, and angle of origin of branches increased, but the angle of termination decreased. Branch length and branch diameter were highly correlated within all clones. The correlation between the angles of origin and termination within a clone was low when pooled over all spacings and height growth increments. The two clones with the lowest angle of origin also had the lowest angle of termination, a...
TL;DR: Controlled-release fertilizers, applied to the root zone of 1-0 plug Douglas-fir seedlings at planting, stimulated shoot and root growth in the following two growing seasons and increased the number and in some cases the diameter of lateral roots in the root system.
Abstract: Controlled-release fertilizers, applied to the root zone of 1-0 plug Douglas-fir (Pseudotsugamenziesii Mirb. Franco) seedlings at planting, stimulated shoot and root growth in the following two growing seasons. Stem unit length was increased in the first growth flush after treatment, and a higher proportion of fertilized seedlings had a second growth flush that year. Fertilizing increased the number of needle primordia formed in the overwintered bud in the late summer and fall of the 1st year after treatment and increased the number of lateral buds formed the following spring, but did not affect the length of stem units elongated in the first growth flush of the 2nd year after treatment. Shoot–root ratio was not altered abnormally by fertilizing. Fertilizing increased the number and in some cases the diameter of lateral roots in the root system. Position of fertilizer placement did not alter root system symmetry in terms of the distribution of numbers of roots over 12 root zones.
TL;DR: Low addition levels of high enrichment isotope (>1% of the total nitrogen pool with 99.% excess 15N) were used to follow nitrogen movement through selected forest floor components of permafrost-...
Abstract: Low addition levels of high enrichment isotope (>1% of the total nitrogen pool with 99 at.% excess 15N) were used to follow nitrogen movement through selected forest floor components of permafrost-free and permafrost-dominated black spruce ecosystems in subarctic Alaska. The nitrogen pool examined in this study was the total nitrogen pool. 15N was retained most effectively by the feather moss layer (Pleuroziumschreberi (BSG.) Mitt. and Hylocomiumsplendens (Hedw.) BSG.) on both black spruce sites. Twenty-eight months after isotope application the feather moss layer still contained over 90% of the 15N that could be recovered. The limited movement of 15N between feather moss layers and underlying forest floor horizons appeared to be slightly affected by climatological events. Differences in 15N movement patterns between permafrost-free and permafrost-dominated black spruce sites are discussed in terms of precipitation, soil temperature, and biological controls.
TL;DR: The isoenzyme results indicate that western red cedar populations contain very little genetic polymorphism and management of the species will likely be more productive if concentrated on cultural practices rather than on intensive genetic improvement.
Abstract: Isoenzymes of newly germinated western red cedar seedlings (Thujaplicata Donn ex D. Don) from western Oregon and eastern and western Washington lacked variation in band patterns of nine enzymes. The isoenzyme results indicate that western red cedar populations contain very little genetic polymorphism. Management of the species will likely be more productive if concentrated on cultural practices rather than on intensive genetic improvement.
TL;DR: Seven coniferous species were grown in the Duke University phytotron under five ultraviolet-B (UV-B = 280–320 nm) radiation regimes for 11 weeks and were rated as slightly susceptible to UV-B radiation.
Abstract: Seven coniferous species were grown in the Duke University phytotron under five ultraviolet-B (UV-B = 280–320 nm) radiation regimes for 11 weeks The irradiation regimes were 765, 680, 637, 310, an
TL;DR: Biomass and nutrient accumulation by tree components for 66-year-old mature paper birch is presented and highest concentrations of most nutrients were in the foliage.
Abstract: Biomass and nutrient accumulation by tree components for 66-year-old mature paper birch is presented. Logarithmic regression equations are given relating aboveground tree component biomass and contents of N, P, K, Ca, and Mg to tree diameter at breast height (dbh). Branches, bole bark, and bole wood accounted for 90–97% of the total aboveground tree biomass. Highest concentrations of most nutrients were in the foliage. For the tree of mean basal area (dbh = 15 cm), the crown components of branches and foliage constituted only 16% of the biomass but accounted for 49, 57, 53, 37, and 44%, respectively, of the N, P, K, Ca, and Mg accumulated.
TL;DR: For example, this paper found that Pinustaeda L. exposed to a bidirectional mechanical perturbation for 6 months exhibited a reduced rate of stem elongation and a reduction in the length of both juvenile leaves and needles.
Abstract: Seedlings of five half-sibs (seedlings that share a commom maternal parent) of Pinustaeda L. exposed to a bidirectional mechanical perturbation for 6 months exhibited a reduced rate of stem elongation and a reduction in the length of both juvenile leaves and needles. Of the five half-sibs tested, two different anatomical mechanisms of radial enlargement could be identified. Two half-sibs exhibited increased radial growth in the xylem parallel to the direction of the perturbation and no change in the axis perpendicular to the perturbation. Two exhibited a reduction in growth perpendicular to the perturbation with no change in the axis parallel to the perturbation. One half-sib appears to be intermediate between the two other pairs of half-sibs.An overall increase in extractable compounds was observed in the organic solvent fraction of mechanically perturbed seedlings. The amount of lignin appeared to remain fairly constant, and there was no change in the amounts of holocellulose or water extractable compounds.
TL;DR: Inhibition and lack of inhibition of some species on certain litter components correlate with natural habitat preferences of these species and the nature of the litter in these habitats.
Abstract: Germination and growth of 12 native herbs, shrubs, and trees were followed in five litter components characteristic of successional stages of the northeastern Minnesota forest Various litter components stimulated or inhibited seed germination and seedling growth of some species Germination and growth were not always similarly affected, suggesting that different factors may be involved Inhibition and lack of inhibition of some species on certain litter components correlate with natural habitat preferences of these species and the nature of the litter in these habitats This information can be of use in improving results of seeding for site reclamation and reforestation
TL;DR: Forest floors, fallen branches and fallen tree boles were sampled in 13 balsam fir (Abiesbalsamea (L.) Mill.
Abstract: Forest floors, fallen branches and fallen tree boles were sampled in 13 balsam fir (Abiesbalsamea (L.) Mill.) stands in the subalpine zone (1220–1450 m) of the White Mountains in New Hampshire, U.S.A. These 13 stands were distributed in three sites of contrasting exposure, slope, and rockiness. Soil pits were excavated in three of the stands representing each of the three sites. The ash-free dry weights and major elemental contents of the forest floor and dead wood were compared along chronosequences following natural disturbances, between sites, and with other forest types. No significant trends in these components were found along chronosequence comparisons. For sites that are dissimilar in terms of physical position on the landscape and in the appearance of the trees, compensating biotic and abiotic factors apparently underlie the convergence in forest floor and soil characteristics, thereby eliminating site differences as well. The forest floor is massive; ash-free dry weight averages 92 200 kg•ha−1. ...
TL;DR: Controlled-release fertilizers applied to the root zone of 1-0 plug western hemlock at planting stimulated shoot and root growth in the following two growing seasons and the shoot–root ratio did not increase with an increase in seedling size, height, or total weight.
Abstract: Controlled-release fertilizers applied to the root zone of 1-0 plug western hemlock (Tsugaheterophylla Raf. Sarg.) at planting stimulated shoot and root growth in the following two growing seasons....