Showing papers in "Canadian Journal of Forest Research in 1972"
TL;DR: In this paper, the basic assumptions of regression analysis are recalled with special reference to the use of a logarithmic transformation, and the limitations imposed on inference-making by failure to comply with these assumptions are discussed.
Abstract: The basic assumptions of regression analysis are recalled with special reference to the use of a logarithmic transformation. The limitations imposed on inference-making by failure to comply with th...
1,073 citations
TL;DR: In this paper, the quantities of N, P, K, Mg and Ca in the soil and above-ground portions of two spruce-pulpwood stands on sites of average fertility in northern and southern Quebec.
Abstract: Calculations are presented on the quantities of N, P, K, Mg and Ca in the soil and above-ground portions of two spruce-pulpwood stands on sites of average fertility in northern and southern Quebec. The magnitude of the depletions of these nutrients from the site, in full-tree and tree-length methods of logging, are compared with the available and total quantities of them in the soil. The ranges of values, from the literature, for the input of these nutrients in dust and precipitation, and the losses in leaching, are presented and discussed in relation to the logging losses.It is concluded that on both sites it is unlikely that full-tree logging will result in any reduction in growth, due to nutrient removal, during the second rotation of trees. However, nutrient depletion due to full-tree logging, particularly with respect to Ca, K and N, may require correction by means of fertilizers in forest ecosystems of marginal fertility. These are usually either dry sites with low reserves of organic matter and low...
156 citations
TL;DR: The occurrence of aggrading and degrading peat plateaus in the same area indicates that all developmental stages are permitted by the present climate.
Abstract: Twenty-six peat plateaus and eight palsas were examined near Flin Flon, Manitoba at the southern limit of discontinuous permafrost Peat plateaus in different developmental stages were identified on the basis of their morphology The permafrost is entirely within the peat in all peat plateaus within the study area, but extends into mineral subsoil under all palsas examined Doming in peat plateaus is largely explained by volume change due to change from unfrozen to frozen stage, and by buoyancy of the frozen mass floating on unfrozen peat The occurrence of aggrading and degrading peat plateaus in the same area indicates that all developmental stages are permitted by the present climate
99 citations
TL;DR: The amount consumed by fire was found to correlate well with the moisture content of the duff before fire, and with the Duff Moisture Code, a component of the Canadian Forest Weather Index.
Abstract: Data are presented on the consumption of duff by fire on six plots in a jack pine (Pinusbanksiana L.) stand and six plots in a red and white pine (P. resinosa Ait and P. strobus L.) stand. The amount consumed was found to correlate well with the moisture content of the duff before fire, and with the Duff Moisture Code, a component of the Canadian Forest Weather Index. A tentative theory to account for the amount of duff consumed is presented in terms of (a) downward heat transfer within the flaming front, and (b) the energy required to heat the duff to ignition temperature.
93 citations
TL;DR: Single tree plots in a 23-year-old stand of Douglas-fir were fertilized at a rate of 448 kg nitrogen per ha with NH4NO3 in April and irrigated in the summer of the same year and in the fo...
Abstract: Single tree plots in a 23-year-old stand of Douglas-fir were: (1) fertilized at a rate of 448 kg nitrogen (N) per ha with NH4NO3 in April; (2) irrigated in the summer of the same year and in the following year with 25 mm of water per week; (3) given the combined fertilizer and irrigation treatment, or (4) left untreated. Diameter growth at breast height (1.37 m) increased in the first year by 16, 15 and 59%, respectively, above that of the control. Similar effects were obtained at breast height in the second year and also at the one-half tree height position. Only earlywood production was affected significantly; this resulted from an increase in rate and length of time of earlywood production. Treatment effect on nitrogen, phosphorus (P) and potassium (K) concentration of leaves, leaf growth and water stress of soil and trees, was studied. Rate of photosynthesis was reduced similarly by water stress for fertilized and unfertilized trees; an increase in CO2 diffusion resistance appeared to cause the reduct...
65 citations
TL;DR: The degree of resistance to a pulsed electric current of wood in progressive stages of discoloration and decay in living trees was correlated primarily with the moisture and mineral contents of the wood.
Abstract: The degree of resistance to a pulsed electric current of wood in progressive stages of discoloration and decay in living trees was correlated primarily with the moisture and mineral contents of the wood. Below the fiber saturation point, the degree of resistance was correlated primarily with the amount of moisture while above the fiber saturation point resistance was correlated primarily with the concentration of mobile potassium and calcium ions. The apparatus used to produce the current and to measure the resistance to it was accurate in detecting and in indicating the stage of deterioration of discolored and decayed wood. The apparatus was tested and found to be reliable electrically within the range of resistances encountered in the trees studied.
58 citations
TL;DR: Many trees in stands of Douglas fir, western hemlock and western red cedar on Vancouver Island were joined by functional grafts, andTranslocation through grafts may partially explain the frequent stagnation and slow recovery of stands after thinning from above.
Abstract: Many trees in stands of Douglas fir, western hemlock and western red cedar on Vancouver Island were joined by functional grafts. In a partially cut stand, 45% of the stumps showed evidence of continued growth and half of these (23%) were still growing vigorously more than 22 years after logging. On experimentally detopped trees, growth extended several meters up the bole. Dominant trees usually supported the growth of the root system and lower boles of grafted suppressed trees.Translocation through grafts may partially explain the frequent stagnation and slow recovery of stands after thinning from above, and may be involved in the usually rapid increase of growth after thinning from below. It is probably a contributing factor in establishing dominance and determining mortality in overtopped trees. In species that graft freely, the use of silvicides in spacing and thinning treatments should be restricted to young stands before grafts are established.
50 citations
TL;DR: The resistance to a pulsed electric current decreased sharply as the tips of stainless steel electrodes entered discolored and decayed tissues in living deciduous trees as discussed by the authors, and the apparatus delivering th...
Abstract: The resistance to a pulsed electric current decreased sharply as the tips of stainless steel electrodes entered discolored and decayed tissues in living deciduous trees. The apparatus delivering th...
47 citations
TL;DR: Leaf surface area and leaf dry weight were highly correlated with leaf lamina length; the latter therefore provides an easily measured, non-destructive estimate of photosynthesizing leaf surface.
Abstract: The relationship between leaf production and wood production in two clones of Populus grown for 1 year under intensive culture was investigated. Wood weight at any one stem position was highly corr...
39 citations
TL;DR: In this article, the authors evaluated the performance of conventional and bole and branch harvesting systems on a mixed hardwood site in north central Wisconsin and found that minimum soil reserves of nitrogen, phosphorous, and magnesium are 5-15 times greater than the amounts removed by a harvest cut at the end of a 45-year rotation.
Abstract: Macronutrient removals by conventional and bole and branch harvesting systems were evaluated on a mixed hardwoods site in north central Wisconsin. Samples indicate that minimum soil reserves of nitrogen, phosphorous, and magnesium are 5–15 times greater than the amounts removed by a harvest cut at the end of a 45-year rotation. Currently available reserves of potassium and calcium are 1–3 times greater than harvest removals. Estimates indicate that natural inputs will supplement these reserves over such rotations, but may not balance drains over substantially shorter rotations. Nutrient cycling and possible replenishment of elements are discussed along with silvicultural implications.
39 citations
TL;DR: It is indicated that red and black spruces have hybridized extensively in central New Brunswick, and despite the ideal opportunities for contact and the fertility of the hybrids, parental species remain phenotypically pure in their respective characteristic habitats.
Abstract: The data obtained by rating 50 plots in red × black spruce populations throughout central New Brunswick with a hybrid index indicate that red and black spruces have hybridized extensively. In the New Brunswick Lowland, gentle slopes and flat uplands form a continuum between characteristic habitats, permitting extensive contact between the two species. Where a considerable zone of contact was present, hybrid populations were established. Selection pressure is apparently strong, for despite the ideal opportunities for contact and the fertility of the hybrids, parental species remain phenotypically pure in their respective characteristic habitats (as far as these could be defined). The composition of hybrid populations was related to the extent of resemblance of 'intermediate' sites to parental site preferences. Introgressed black spruce predominated in hybrid populations, possibly due to the overriding influence of disturbances such as fire, logging, and damage to red spruce types by spruce budworm.
TL;DR: Yield of black cottonwood (Populustrichocarpa Torr. and Gray) in 2-year rotations was affected in the first rotation by spacing and fertilization, while in the second rotation, yield was not significantly affected by spacing.
Abstract: Yield of black cottonwood (Populustrichocarpa Torr. and Gray) in 2-year rotations was affected in the first rotation by spacing and fertilization. Closest spacing (0.30 × 0.30 m) resulted in highest yield in the first rotation whereas in the second rotation, yield was not significantly affected by spacing. The average fresh weight yields were 13.4 tons/hectare/year in the first harvest and 20.9 tons/hectare/year in the second harvest. Initial fertilization with both N, and N, P, and K fertilizers improved growth in the first harvest but not in the second. During the first year, triazine herbicides controlled weeds but caused slight damage to the plants. Although there were no significant differences in yield between the herbicides, atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) reduced survival and first year height growth below that obtained with propazine (2-chloro-4, 6-bis[isopropylamino]-s-triazine) or simazine (2-chloro-4, 6-bis-ethylamino-s-triazine). Yield results and limited pulping ...
TL;DR: Repeated sampling of foliage from trees adjacent to highway 401 between May 1970 and May 1971 revealed that foliar concentrations of sodium and chloride declined from abnormally high values in May to 'normal' levels by August, and the rate of loss was proportional to the foliar concentration of these ions.
Abstract: Effects of deicing salt on eastern white pine (Pinusstrobus L.) were studied in the field and in the laboratory. Studies in controlled temperature chambers showed that solutions of deicing salt sprayed onto 4-year-old trees induced symptoms of foliar browning similar to those observed on trees growing near highways. Symptoms developed at 15 °C but not at 1.5 °C. The amount of injury that developed after 3 weeks at 15 °C appeared to be directly related to the concentration of sodium and chloride in the leaf tissue. Repeated sampling of foliage from trees adjacent to highway 401 between May 1970 and May 1971 revealed that foliar concentrations of sodium and chloride declined from abnormally high values (up to 1%) in May to 'normal' levels (0.02–0.1%) by August. The rate of loss was proportional to the foliar concentration of these ions. Growth of these trees, measured as bud weight, needle length, needle dry weight, needle bundles per leader, and leaf length, was suppressed on the side of trees exposed to t...
TL;DR: Tissue digestibility, essential oils, and levels of several chemical constituents were compared in foliage of Douglas-fir as mentioned in this paper, and the results suggest that these resistance characteristics, especially the chlorogenic acid content, might be used instead of conventional bioassays with captive deer, to screen Douglasfir breeding stock for resistance to deer browsing.
Abstract: Tissue digestibility, essential oils, and levels of several chemical constituents were compared in foliage of Douglas-fir. Genotypes with different susceptibilities to deer browsing were used, and foliage was collected during the dormant season. In general, clones resistant to deer browsing had lower dry-matter and cellulose digestibilities, essential oils with greater inhibitory action on rumen microbial activity, higher content of fats, total phenols, flavanols, and leucoanthocyanins, and lower levels of chlorogenic acid. Results suggest that these resistance characteristics, especially the chlorogenic acid content, might be used instead of conventional bioassays with captive deer, to screen Douglas-fir breeding stock for resistance to deer browsing.
TL;DR: Biomass of fine roots in a white spruce plantation in Maine was estimated at 696 ± 224 g/m2 or 3 kg per tree, compared favorably with published estimates of 2–3 kg per tree for other conifers in different parts of the world.
Abstract: Biomass of fine roots (≤3 mm diameter) in a white spruce (Piceaglauca (Moench) Voss) plantation in Maine was estimated at 696 ± 224 g/m2 or 3 kg per tree. Data consisted of 10 samples collected in midsummer from the top 45 cm of an imperfectly drained, silt loam, alluvial soil. Variation among individual samples was great, but appeared to be independent of distance to and size of closest tree. Results of this study compare favorably with published estimates of 2–3 kg per tree for other conifers in different parts of the world. The adequacy of this kind of study for understanding tree–soil relationships is discussed.
TL;DR: In this paper, the authors investigated the relationship between herbage production and crown cover in coniferous stands and found that there is a sufficiently close relationship between the two to make the technique useful in range surveys.
Abstract: Studies were undertaken to determine if approximations of herbage productivity could be made from estimates of tree-crown cover, also whether or not estimates from aerial photographs would be accurate enough for this purpose Results suggest that there is a sufficiently close relationship between herbage production and crown cover in coniferous stands to make the technique useful in range surveys Estimation of herbage yields from the ground is too slow to be useful in surveys where large acreages have to be covered in a very short time Similar results were obtained from ground estimates of crown canopy and those made from aerial photographs Estimates of herbage yields on a pasture made as a result of the survey were almost identical to those established from an earlier grazing trial
TL;DR: The above ground biomass, annual production, and leaf area index (LAI) were estimated for several years in aspen stands aged 6, 15, and 52 years old in 1968 as mentioned in this paper.
Abstract: Above-ground biomass, annual production, and leaf area index (LAI) were estimated for several years in aspen stands aged 6, 15, and 52 years old in 1968. Based on regressions of dry weight on stem diameter, biomass (stems and branches) estimates for 1968 were 21 500 kg ha−1 in the juvenile stand, 51 200 kg ha−1 in the intermediate stand, and 91 800 kg ha−1 in the mature stand. Net annual above-ground production (stems and branches) for these stands in 1968 was 6900, 7000, and 1340 kg ha−1 respectively. In 1969, foliage amounted to 2600, 2600, and 1500 kg ha−1, providing LAI of 2.4, 2.9, and 1.6 for the stands. Net assimilation rates were roughly 20, 17, and 9 g m−2 week−1.Aspen stands regenerated as suckers may attain maximum annual production within a few years, coincident with the development of maximum LAI.
TL;DR: No change of consequence occurred in tree form in the codominant and intermediate crown classes as a result of the volume response which was still evident, although greatly diminished, after 5 years after fertilization.
Abstract: Consideration is given to the distribution of growth increment at 6 points up the stem of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) 5 years after fertilization. The fully stocked stand, nea...
TL;DR: The study tests whether the lethal effect of overwintering Engelmann spruce seed in its O-horizon affects Douglas-fir, lodgepole pine and subalpine fir seeds and whether the O-Horizons of the three associated species have the same lethal effect on seeds.
Abstract: The study tests whether the lethal effect of overwintering Engelmann spruce seed in its O-horizon affects Douglas-fir, lodgepole pine and subalpine fir seeds and whether the O-horizons of the three...
TL;DR: Although considerable tree-to-tree variability did occur, it was not sufficient to obscure differences related to crown position and leaf age, except in the case of N, where no trends were demonstrable.
Abstract: Concentrations of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), and manganese (Mn) were examined in September, 1969, in leaves of different ages from different parts of the crowns of twelve 30- to 33-year-old Pinusbanksiana Lamb. growing in a natural stand on coarse glacio-fluvial soil in northern Ontario. Although considerable tree-to-tree variability did occur, it was not sufficient to obscure differences related to crown position and leaf age, except in the case of N, where no trends were demonstrable. Foliar P, K, and Mg concentrations were shown to decrease with increasing leaf age, whilst foliar Ca, Fe, and Mn concentrations were shown to increase. From top to bottom of the crown, foliar P, K, and Fe concentrations decreased, whilst Ca and Mn concentrations increased. For Mg, no trend relative to crown position was discernible. Coefficients of variation were calculated and compared as were numbers of sample trees needed for statistically reliable samples.
TL;DR: Detailed stem analysis data are presented for 6 trees which ranged in age from 44 to 68 years and grew on a range of soils which varied primarily in soil texture.
Abstract: Detailed stem analysis data are presented for 6 trees which ranged in age from 44 to 68 years and grew on a range of soils which varied primarily in soil texture. The use of measures of specific growth such as current annual height increment, Type 3 ring width sequences and specific volume increment is discussed in relation to supply of raw materials to the tree. The change in form of tree crown, as reflected by Type 1 ring width sequences is related to the other measures of specific growth. The use of selected parameters of tree growth in relation to tree development and its possible application in silviculture is discussed.
TL;DR: Dormancy in untreated Pinustaeda L. seeds is likely to be the result of mechanical constraint by the seedcoat, probably by restricting swelling of the megagametophyte and embryo.
Abstract: The rate and percent of dark germination were low in untreated Pinustaeda L. seeds. Both increased with seedcoat clipping or removal, but not to the level of stratified seeds. Coats did not reduce the rate of initial water inhibition but did limit total uptake prior to germination, probably by restricting swelling of the megagametophyte and embryo. Respiration followed the pattern of water absorption in decoated seeds. However, it was at a common low level in stratified, clipped, and unstratified seeds until germination began, and there seemed to be no causal relation between respiration and coat permeability. Dormancy is likely to be the result of mechanical constraint by the seedcoat.
TL;DR: Study of forage yield, standing stock of browse, and utilization of browse by moose, deer, and hares on commercially cut forest areas of five age classes in New Brunswick found three browsers shared a preference for some species but the total weights they ate were small compared to the amounts available.
Abstract: Studies of forage yield, standing stock of browse, and utilization of browse by moose (Alcesalcesamericana Clinton), deer (Odocoileusvirginianusborealis Miller), and hares (Lepusamericanusstruthopus Bangs) were made on commercially cut forest areas of five age classes in New Brunswick. The 6-year old cuts yielded most forage, while the 10–12-year old cuts had the greatest standing stock. Older cuts produced less forage and had smaller standing stock. Moose and white-tailed deer fed most heavily on the 2-year old cuts; hares on the 15–18-year old cuts, probably because more suitable shelter was available. The three browsers shared a preference for some species but the total weights they ate were small compared to the amounts available.
TL;DR: Thermophilic fungi colonized the inner regions of the wood chip pile where higher wood substance losses occurred, while thermotolerant fungi inhabited...
Abstract: A study into the distribution of thermophilic and thermotolerant fungi in a spruce-pine (Picea spp—Pinus spp) wood chip pile at Prince George, BC, was carried out Five treatments were examined: pine, spruce, spruce containing a core bag of fines, spruce containing a core bag of sterilized spruce chips and spruce containing a core bag of spruce chips inoculated with a Ptychogaster sp [probably Chrysosporiumpruinosum (Gilman and Abbott) Carmichael] Samples of wood chips buried at different locations in the chip pile were examined after 3, 6, and 12 month storage periods From 100 randomly selected chips from each sample, the fungi were isolated on 2% malt, 2% agar, and 05% malic acid medium Data on temperature during storage, pH of wood chips, moisture content, and weight loss at the time of sampling were calculated for the various sampling positionsThermophilic fungi colonized the inner regions of the wood chip pile where higher wood substance losses occurred, while thermotolerant fungi inhabited
TL;DR: Nitrate treatment enhanced cone production through a reduction in bud failure during the shoot elongation period, suggesting responses are not primarily due to factors other than form of nitrogen.
Abstract: Cone production increases of 2.5, 5.0 and 1.5 times that of control were obtained the year following treatment with 400 lb nitrate nitrogen per acre (1 lb/acre = 1.12 kg/ha), applied 6 weeks before vegetative bud break, at the start of bud break, and 10 days after the midpoint of the bud break period, respectively, on 20-year-old Douglas fir (Pseudotsugamenziesii (Mirb.) Franco.). Cone counts of 15, 26, 72, 142 and 155 were obtained from 0, 200, 400, 800 and 1600 lb nitrate nitrogen per acre, applied to 13-year-old trees during early bud break. Ammonium nitrogen, applied at the same rates and times, was ineffective for stimulation of cone production on either age of tree. There were no differences in rate of accumulation of total nitrogen in buds and foliage, shoot-growth responses, or total number of buds per shoot due to form of nitrogen. Nitrate treatment enhanced cone production through a reduction in bud failure during the shoot elongation period. These results suggest responses are not primarily due...
TL;DR: Numerical values of the equation coefficients varied with canopy level in the forest stand profile and with variations in vegetal structure within the forest community, and the lowest canopy in the vegetal profile, a fern canopy, had the most marked effect on rainfall redistribution.
Abstract: This paper presents mathematical equations describing the relationships between the amount of stemflow per canopy layer per storm and the amount of gross rain per storm for four different canopy layers in a multi-storied forest community. The curves representing the relationships were curvilinear; for three of the canopy layers stemflow per storm increased at an increasing rate as gross rain per storm increased, approaching a constant rate of increase. Numerical values of the equation coefficients varied with canopy level in the forest stand profile and with variations in vegetal structure within the forest community. The lowest canopy in the vegetal profile, a fern canopy, had the most marked effect on rainfall redistribution.
TL;DR: In this paper, Nitrogen (N), potassium (K), and calcium (Ca) in litter-fall, throughfall and stemflow were measured over a 24-week summer-autumn period in a 30-year-old Pinus banksiana Lamb, stand.
Abstract: Nitrogen (N), potassium (K) and calcium (Ca) in litter-fall, throughfall and stemflow were measured over a 24-week summer-autumn period in a 30-year-old Pinus banksiana Lamb, stand. Litter-fall from the forest canopy was the major contributor of N; whereas throughfall contributed the most K to the forest floor during the study period. Stemflow accounted for a very small proportion of the nutrients received by the forest floor. Additions of K and Ca from through fall were greater than those from litter-fall in July and August, a period of low organic additions to the forest floor. Tree litter-fall increased in the autumn. Nitrogen concentration of this litter-fall decreased from a high of 0.92% in early summer to a low of 0.21% in autumn; whereas Ca concentration increased from a July low of 0.16% to an autumn high of 0.57%.During September–November, overstory and understory vegetation contributed the greatest quantities of N; the overstory gave the most Ca, and the overstory, understory, and throughfall a...
TL;DR: Although average needle weights and their proportions of oven-dry weights can be estimated adequately for some studies of biomass and for simulation of forest fuels, sub-sampling for tree-to-tree differences should improve results obtained.
Abstract: Branches of young trees were sampled to determine length, width, thickness, and volume of 6-needle samples, both fresh and dry weights of 100-needle samples, and persistence of needles. Significant differences in needle size and weight were associated with position in crown, tree, year of formation, and species. Therefore special studies are required to document these differences and to determine, for example, influences of fertilizers on needles. Although average needle weights and their proportions of oven-dry weights can be estimated adequately for some studies of biomass and for simulation of forest fuels, sub-sampling for tree-to-tree differences should improve results obtained.
TL;DR: A factorial experiment was conducted in which Pinuscontorta var.
Abstract: A factorial experiment was conducted in which Pinuscontorta var. latifolia and Piceaglauca (Moench) Voss seedlings were grown for 6 weeks under controlled environmental conditions with deficient an...
TL;DR: The rocky heathlands of western Nova Scotia cover some 31,000 ha of coarse, bouldery ortstein podzol of granitic origin this article, and the shrubby vegetation, dominated by Gaylussaciabaccata, is closely correlated with topographic position and depth of soil over the impenetrable pan.
Abstract: The rocky heathlands of western Nova Scotia cover some 31 000 ha of coarse, bouldery ortstein podzol of granitic origin. The shrubby vegetation, dominated by Gaylussaciabaccata, is closely correlated with topographic position and depth of soil over the impenetrable pan.Pollen analysis suggests that the area has, for many centuries, been a very open woodland and that the present community is a reflection of soil poverty as well as of periodic burning.Because the site is so unproductive it is suggested that wilderness recreation is the best land use.