Showing papers in "Canadian Journal of Forest Research in 1989"
TL;DR: In this paper, a methodology was proposed for developing a disturbance chronology in forests of complex age structure by identifying the probable date of canopy accession for each sample tree, based on an evaluation of radial growth pattern and early growth rates of existing canopy trees.
Abstract: Analysis of the frequency of past moderate and high-intensity disturbances has been hindered in forests of complex age structure by methodological problems. A methodology is proposed for developing a disturbance chronology in such stands by identifying the probable date of canopy accession for each sample tree. Canopy accession dates are based on an evaluation of radial growth pattern and early growth rates of existing canopy trees. Canopy disturbance intensity is defined as the percentage of sample trees with canopy accession events in each decade. Rotation periods for disturbances of various intensities are calculated from the chronology. The method was evaluated using 893 increment cores from 70 plots in northern hardwood stands of western Upper Michigan. The estimated average disturbance rate for all plots and decades was 5.7–6.9% of land area per decade, with an implied average canopy tree residence time of 145–175 years. These estimates are similar to those obtained by on-site estimates of canopy tr...
447 citations
TL;DR: The most obvious form of floralturbation is the uprooting of trees, which is a natural proc... as mentioned in this paper, which is an important pedologic process in forested areas.
Abstract: Floralturbation, the mixing of soil by the action of plants, is an important pedologic process in forested areas. The uprooting of trees, the most obvious form of floralturbation, is a natural proc...
228 citations
TL;DR: In this article, carbon content and indices of microbial biomass and activity were determined in different soil horizons of two nitrogen-fertilized pine forests in Sweden and the Kroksbo site was fertilized in...
Abstract: Carbon content and indices of microbial biomass and activity were determined in 1985 in different soil horizons of two nitrogen-fertilized pine forests in Sweden. The Kroksbo site was fertilized in...
222 citations
TL;DR: A dendroecological study was carried out on 196 sites distributed throughout the whole natural range of silver fir (Abiesalba Miller) in the Vosges mountains of northeastern France and revealed a great increase in mean vigour from 1830 to 1930–1940 and a slight decrease from 1930-1940 to the present.
Abstract: A dendroecological study was carried out on 196 sites distributed throughout the whole natural range of silver fir (Abiesalba Miller) in the Vosges mountains of northeastern France. At each site, s...
201 citations
TL;DR: Compared with the uncut mature forest, forest floor contents of N and K were lower in the WTH area 3 years after harvest; Ca and Mg were higher in the CH area, probably owing to inputs in logging slash; and mineral soil Ca and pH wereHigher in the harvested areas than in the unc cut area.
Abstract: Soil and water chemistry and soil-respiration activity were studied in a mature, mixed conifer and hardwood forest and in adjacent whole-tree harvest (WTH) and conventional harvest (CH) areas domin...
191 citations
TL;DR: The distribution of tree biomass and the allocation of production was measured in four stands of lodgepole pine (Pinuscontorta var. latifolia Engelm.), two growing on sites with xeric soil moisture regimes and two on Sites with mesic soil moisture regime.
Abstract: The distribution of tree biomass and the allocation of production was measured in four stands of lodgepole pine (Pinuscontorta var. latifolia Engelm.), two growing on sites with xeric soil moisture...
156 citations
TL;DR: The role of insects in the decomposition of and nutrient release from Douglas-fir logs was studied in the Cedar River Watershed near Seattle, Washington to determine decomposition rates by mass loss and total frass production.
Abstract: The role of insects in the decomposition of and nutrient release from Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) logs was studied in the Cedar River Watershed near Seattle, Washington. In April 1976, two large-diameter (average diameter at breast height, 41.7 cm) and two small-diameter (average diameter at breast height 26.3 cm) trees were felled. Three pairs of 91 cm length sections were cut from each tree. Half the sections were covered with window screening to prevent insect entry. The number of Douglas-fir beetle (Dendroctonuspseudotsugae Hpk.) attacks on each section, as well as the frass production, were monitored. After 10 years, decomposition rates were determined by mass loss. Douglas-fir beetles attacked large-diameter (23 attacks/m2) and small-diameter (27 attacks/m2) log sections at similar rates. Total frass production was also similar (33.6 g•m−2 for large logs and 32.6 g•m−2 for small logs). Large-diameter unscreened log sections tended to decompose faster (k = 0.050 per year) than s...
153 citations
TL;DR: This paper presents a meta-model of private forest landowner behavior that helps clarify the motivations of landowners for seeking nonmonetary as well as monetary returns from their forest investments.
Abstract: Recent models of nonindustrial private forest landowner behavior have suggested that landowners seek nonmonetary as well as monetary returns from their forest investments. In this paper, landowners are modeled as maximizing utility, which is a function of income and nonpecuniary benefits. We explore the implications of this model for both harvesting and reforestation decisions, present empirical evidence that supports the model, and discuss some policy implications of the model.
143 citations
TL;DR: One Mexican population was genetically distinct from the rest of the species, which suggests the possibility of additional Pseudotsuga species in Mexico and transition zones between the varieties were found to be narrower and more abrupt than has been suggested previously.
Abstract: Seeds from 104 geographical locations throughout the range of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) were analyzed at 20 enzyme loci to determine patterns of genetic variation and to make phylogenetic inferences. On average, the populations were polymorphic at 37% of the loci (range 5.0–65.0). Mean expected heterozygosity was 0.137 (range 0.021–0.239). Of the total genie diversity (HT = 0.182) observed, 24% was due to differentiation among populations. One Mexican population was genetically distinct from the rest of the species, which suggests the possibility of additional Pseudotsuga species in Mexico. The rest of the populations clustered into two groups corresponding to the recognized coastal and interior varieties. In addition, the interior variety separated into northern and southern subgroups near 44° latitude. Transition zones between the varieties were found to be narrower and more abrupt than has been suggested previously. Populations within the coastal variety and the northern interio...
142 citations
TL;DR: In this article, potential net nitrogen (N) mineralization, potential net nitrification, and overstory (boles and branches) biomass were measured in nine forest ecosystems commonly found within the well-drained upl...
Abstract: Potential net nitrogen (N) mineralization, potential net nitrification, and overstory (boles and branches) biomass were measured in nine forest ecosystems commonly found within the well-drained upl...
130 citations
TL;DR: In this article, a series of 12 experimental fires were conducted in a mature jack pine (Pinusbanksiana Lamb.) stand (1899 origin) in north central Ontario between 1973 and 1983.
Abstract: Between 1973 and 1983 a series of 12 experimental fires, each 0.4 ha in size, was conducted in a mature jack pine (Pinusbanksiana Lamb.) stand (1899 origin) in north central Ontario. The fires were carried out under a broad range of burning conditions to gather quantitative fire behavior data for forest fire management purposes. Fire weather severity, as expressed through the component codes and indices of the Canadian Forest Fire Weather Index System, was strongly correlated with fire behavior and impact characteristics (i.e., rate of spread, depth of burn, fuel consumption, and frontal fire intensity). Guidelines for the quantitative prediction of the fire behavior in major Canadian forest fuel types are currently being developed, primarily on the basis of this type of experimental fire data combined with information gathered on selected wildfires.
TL;DR: Tree mortality caused by spruce budworm (Choristoneurafumiferana (Clem.)) defoliation was assessed annually from 1976 to 1985 in 20 mature balsam fir stands on Cape Breto...
Abstract: Tree mortality caused by spruce budworm (Choristoneurafumiferana (Clem.)) defoliation was assessed annually from 1976 to 1985 in 20 mature balsam fir (Abiesbalsamea (L.) Mill.) stands on Cape Breto...
TL;DR: Changes in the availability of soil cations, as recorded in tree rings, may provide an ecosystem-level method of evaluating the historical response of forest soils to atmospheric deposition.
Abstract: Concentration ratios of aluminum to calcium, magnesium, and other divalent cations in increment cores obtained from red spruce and eastern hemlock trees growing in the Great Smoky Mountains National Park in Tennessee and North Carolina have increased in an unprecedented manner during the last 15–40 years. These trends, which also occur in other trees growing in eastern North America and Germany may reflect the mobilization of exchangeable aluminum by and deposition. The soil chemistry and plant physiology bases for this hypothesis are presented. Many of the spruce and hemlock cores from the Great Smoky Mountains also showed an inverse relationship between radial growth and aluminium:alcium ratios in the wood. Changes in the availability of soil cations, as recorded in tree rings, may provide an ecosystem-level method of evaluating the historical response of forest soils to atmospheric deposition.
TL;DR: The saturated sapwood permeability (k) of jack pine (Pinusbanksiana Lamb.) from stands of different ages and site qualities was measured using a constant water flow apparatus.
Abstract: The saturated sapwood permeability (k) of jack pine (Pinusbanksiana Lamb.) from stands of different ages and site qualities was measured using a constant water flow apparatus. Saturated sapwood per...
TL;DR: In a Rocky Mountain aspen forest, decomposition of leaf litter of trembling aspen, a relatively slow-decomposing, nutrient-poor species, and green alder, a nutrient-rich, faster-Decomposing species, as well as a mixture of the two, for 2 years is followed.
Abstract: Decomposition of a slow-decaying litter type is expected to be faster in the presence of a nutrient-rich, fast-decaying litter type, but this effect has never been conclusively demonstrated for deciduous leaves. In a Rocky Mountain aspen forest, we followed decomposition of leaf litter of trembling aspen (Populustremuloides), a relatively slow-decomposing, nutrient-poor species, and green alder (Alnuscrispa), a nutrient-rich, faster-decomposing species, as well as a mixture of the two, for 2 years. Mass losses over the first winter were greatest for aspen alone, probably as a result of loss of solubles, but the mass loss rate overall was lowest for aspen (k = −0.191/year) and greatest for alder (k = −0.251/year). Mass loss rate for mixed litter (k = −0.245/year) was much closer to the rate for alder than for aspen, demonstrating a marked acceleration of mass loss rates in the mixed-litter bags. At these rates, 95% mass loss would be achieved by aspen, alder, and mixed litter in 14.5, 11.5, and 11.6 years,...
TL;DR: In this article, the 187-year presettlement fire history record in the Boundary Waters Canoe Area, Minnesota, was analyzed using reconstructed "fire-year" maps, and the distribution of forest-fire intervals has been characterized by fitting statistical distributions, such as that of Weibull.
Abstract: The distribution of forest-fire intervals has been characterized by fitting statistical distributions, such as that of Weibull. The parameters of fitted distributions can then be used to compare fire regimes. Fire-interval distributions for the 187-year presettlement fire history record in the Boundary Waters Canoe Area, Minnesota, were analyzed using reconstructed "fire-year" maps. Distributions were determined for sampling units at five spatial scales, from about 25 000 to 400 000 ha. Fire-interval distributions varied from positively to negatively skewed, but for most units the Weibull distribution fit significantly. The distributions varied spatially, and cluster analysis suggested that three fire regions, each containing a relatively homogeneous fire regime, could be identified. The sources of this spatial variation are unknown. There was less variation between scales within a fire region than between fire regions. This contrasts with a previous finding, using the same fire-history data, that scale s...
TL;DR: In this article, soil chemical properties were studied after a wildfire in stands of white spruce (Piceaglauca (Moench) Voss), black spruce, paper birch (Betulapapyrifera Marsh), and quaking aspen (Populustremuloides Michx).
Abstract: Soil chemical properties were studied after a wildfire in stands of white spruce (Piceaglauca (Moench) Voss), black spruce (Piceamariana (Mill.) B.S.P.), paper birch (Betulapapyrifera Marsh.), and quaking aspen (Populustremuloides Michx.). Samples of the forest floor and surface 5 cm of mineral soil were collected from burned sites and unburned controls and analyzed soon after the fire. With the exception of soil pH, effects of the fire on soil chemistry differed among the four forest types. Generally, amounts of exchangeable K, Ca, and Mg did not appreciably increase in the forest floor and surface mineral soil except in heavily burned areas in white spruce and black spruce. Fire reduced amounts of N by about 50% in white spruce, aspen, and birch forest floors. In black spruce, quantities of N were slightly higher in heavily burned locations. Forest floor C:N ratios were substantially lower in heavily burned locations in white spruce and black spruce than in unburned controls. Burning did not have a mark...
TL;DR: In the rain shadow of the Andes in northern Patagonia, the evergreen beech Nothofagusdombeyi occurs in mixed stands with the xeric trees Austrocedruschilensis and (or) Noth ofagusantarctica.
Abstract: In the rain shadow of the Andes in northern Patagonia, the evergreen beech Nothofagusdombeyi occurs in mixed stands with the xeric trees Austrocedruschilensis and (or) Nothofagusantarctica. In two ...
TL;DR: Stand development of a subalpine forest in the Colorado Front Range following a ca.
Abstract: Stand development of a subalpine forest in the Colorado Front Range following a ca. 15-ha blowdown was examined by analyzing tree population age structures and radial growth patterns. The stand studied was initiated by a fire at the start of the 18th century and was dominated by a dense population of lodgepole pine (Pinuscontorta Dougl. var. latifolia Engelm.) at the time of blowdown in 1973. Before the blowdown, the subcanopy was characterized by abundant subalpine fir (Abieslasiocarpa (Hook.) Nutt.) and scarce Engelmann spruce (Piceaengelmannii (Parry) Engelm.). Comparison with an adjacent control stand, affected only slightly by the blowdown, indicates that new seedling establishment following the blowdown was slight. Instead, the response was dominated by the release of the subcanopy fir and spruce, resulting in acceleration of the successional replacement of lodgepole pine by these shade-tolerant species. Given the >300 years required for an old-growth fir and spruce stand to develop following catast...
TL;DR: In this article, the authors quantified fire behavior, fuel consumption, and forest-floor responses to understory fires prescribed to cover a wide range and variable combination of fuel loadings, fuel moisture levels, and weather conditions in Sierra Nevada mixed conifer forests.
Abstract: We quantified fire behavior, fuel consumption, and forest-floor responses to understory fires prescribed to cover a wide range and variable combination of fuel loadings, fuel moisture levels, and weather conditions in Sierra Nevada mixed conifer forests. At each of three locations, five burns were conducted under each of four different prescriptions (n = 60). Fuel loads ranged from 75–102 Mg/ha on an open site of low productivity to 125–177 Mg/ha on more productive sites. Total fuel consumption ranged from 15% in early spring burns to 92% in early fall burns. Organic horizons (litter and duff) composed 62–84% of the total fuel load. Consumption of the organic horizons ranged from 11 to 94%. Lower duff (Oa horizon) moisture content was 135% in the former and 15% in the latter. Consumption of the organic horizon was significantly correlated with lower duff moisture content (r2 = 0.51). More than 72% of all fuel was consumed after the flaming front had passed over an area. Postburn mineral soil exposure was ...
TL;DR: Experiments indicate that α-pinene autoxidizes under normal temperature and atmospheric conditions to form significant quantities of trans-verbenol, an aggregation pheromone for many species of bark beetles.
Abstract: The monoterpene α-pinene, a major component of the terpene composition of Pinus spp., has been reported to act as a host-produced kairomone for a variety of bark beetle species, including the mount...
TL;DR: The induction of the enzyme nitrate reductase in needles may be a prerequisite for the assimilation of foliar-absorbed nitrogen oxide pollutants by red spruce (Picearubens Sarg.) trees as discussed by the authors.
Abstract: The induction of the enzyme nitrate reductase in needles may be a prerequisite for the assimilation of foliar-absorbed nitrogen oxide pollutants by red spruce (Picearubens Sarg.) trees. To test for induction of nitrate reductase, 1-year-old red spruce seedlings were exposed to NO2, HNO3 vapor, or acid mist containing nitrate, and the activity of nitrate reductase in needles was measured. One day after exposure to NO2 (75 nL•L−1) began, nitrate reductase activity was three times greater than that of unexposed control plants. One day after exposure ended, the nitrate reductase activity returned to the control level. Older red spruce seedlings that had been excavated from a spruce–fir stand exhibited a similar pattern of response, but the level of nitrate reductase activity was much lower than that of the 1-year-old seedlings. Nitric acid vapor (75 nL•L−1) also induced nitrate reductase in red spruce needles, and the pattern of response was similar to that with NO2, except that the nitrate reductase activity...
TL;DR: In this article, three indices of nitrogen availability were compared in the field over a 1-year period in an old-growth and a young-growth mixed-conifer forest.
Abstract: Three indices of nitrogen (N) availability were compared in the field over a 1-year period in an old-growth and a young-growth mixed-conifer forest. The indices utilized were ion exchange resin (IER) bags, buried bags, and a core-IER method employing intact soil cores enclosed in tubes capped at both ends by IER bags. The results from all three methods indicated that in the surface mineral soil, N availability was higher in the young-growth stand than in the old-growth stand. However, seasonal patterns of N availability were generally not well correlated among the methods (correlation coefficients ranged from 0.32 to 0.62). For a given amount of net N mineralized in buried bags, more N accumulated on IER bags placed in the young-growth stand than in those placed in the old-growth stand. This was the result of greater net nitrification in the young-growth stand coupled with the greater mobility of relative to in soil. Ten-month estimates of net N mineralization measured by the core-IER and buried-bag metho...
TL;DR: The investigation of the structure of growth equations shows that most of them describe the growth decline by a negative exponential function, but the equation based on this assumption is the best available model of diameter growth.
Abstract: The investigation of the structure of growth equations shows that most of them describe the growth decline by a negative exponential function. This decline can also be described by a power function...
TL;DR: In this article, the cold tolerance of treated seedlings generally increased with increasing nitrogen uptake, with the exception of the highest N treatment, and there was no evidence of a N'×'P interaction.
Abstract: Red spruce (Picearubens Sarg.) seedlings were treated with one of four concentrations of NH4NO3 (0, 300, 1500, and 3000 kg N•ha−1•year−1) applied to the soil, with and without triple superphosphate, during early, mid-, or late summer. Laboratory freezing assessments indicated that cold tolerance of treated seedlings generally increased with increasing nitrogen (N) uptake, with the exception of the highest N treatment. Seedlings receiving 1500 kg N•ha−1•year−1 were most cold tolerant on most sample dates. In general, these seedlings were hardier than those receiving 300 kg N•ha−1•year−1, which were hardier than unfertilized control seedlings. Seedlings receiving supplemental N also acclimated to cold more rapidly in autumn and deacclimated more slowly in spring than unfertilized controls. Supplemental phosphorus (P) had no influence on cold tolerance, and there was no evidence of a N × P interaction. Significant differences in cold tolerance associated with time of N application (early, mid-, and late summ...
TL;DR: In this paper, the authors investigated the origin of the phosphorus deficiency previously observed in declining sugar maple (Acersaccharum Marsh.) in several sites of the Quebec Appalachians, soils originating from 10 maple stands with foliar P concentrations ranging from 0.85 to 2.36 mg • g−1 were subjected to the following analyses: the chemical composition and P pools of L and F horizons, as well as pH, total nitrogen (N), exchangeable cations, total organic and inorganic P, P reserves fractionated according to their availability, and
Abstract: To investigate the origin of the phosphorus (P) deficiency previously observed in declining sugar maple (Acersaccharum Marsh.) in several sites of the Quebec Appalachians, soils originating from 10 maple stands with foliar P concentrations ranging from 0.85 to 2.36 mg • g−1 were subjected to the following analyses: the chemical composition and P pools of L and F horizons, as well as pH, total nitrogen (N), exchangeable cations, total organic and inorganic P, P reserves fractionated according to their availability, and extractable iron (Fe) and aluminum (Al) of Ah (or H) and B horizons. The number of root tips per unit volume of soil was measured at 0–15 cm depth. Foliar P concentrations were positively correlated with P concentrations and P pools of L and F horizons, with the contents of readily available P fractions of the Ah or H horizon, and with the number of root tips to 15 cm depth. In contrast, foliar P concentrations and the available P fractions of the Ah or H horizon were negatively correlated w...
TL;DR: This paper presents a meta-modelling scheme that automates the very labor-intensive and therefore time-heavy and therefore expensive and expensive process of manually selecting units for harvest in multiple-use forests.
Abstract: Multiple-use management of forests often requires imposition of spatial constraints on the selection of units for harvest. To satisfy such constraints, harvest units must be treated as integral units. A biased sampling search technique is used to find integer solutions to operationally sized problems. Solutions found for the sample problems are within 8% of the upper bound of the corresponding linear programming solution and less than 4% below the upper bound on the true optimum as defined by a confidence interval estimator.
TL;DR: Periodic functions of Julian calendar dates were used to incorporate seasonal variation into logistic regression models designed to predict daily people-caused forest fire occurrence in the Northern Region of the province of Ontario.
Abstract: Periodic functions of Julian calendar dates were used to incorporate seasonal variation into logistic regression models designed to predict daily people-caused forest fire occurrence in the Northern Region of the province of Ontario. Three years of independent test data were used to evaluate predictions produced by the models.
TL;DR: Pre- and post-harvest regeneration levels were compared for Abiesbalsamea (L.) Mill and Betulapapyrifera Marsh forests in an area of the southern clay belt of northwestern Quebec.
Abstract: Pre- and post-harvest regeneration levels were compared for Abiesbalsamea (L.) Mill. –Betulapapyrifera Marsh. –Picea spp. forests in an area of the southern clay belt of northwestern Quebec. Results revealed abundant advance softwood regeneration (mean = 65 000 stems/ha), almost entirely of Abies prior to harvest. The survey following mechanical and manual whole-tree harvesting suggested a 92% reduction of softwood regeneration and a shift from softwood to a mixed or hardwood-shrub dominated regeneration. Ninety percent of softwood seedlings collected after harvest were pre-established. Destruction of advance regeneration was generally greater on fine-textured soils. Hierarchic cluster analysis of ecological types based on softwood, hardwood, and shrub tree regeneration data as variables, revealed nine groups that could serve as a basis for operational silvicultural decision making. In general, Salix spp. and Alnusrugosa (Du Roi) Spreng. are the major competitors on poorly drained sites; Betula sp., Acers...
TL;DR: Anatomical characters of the early and late-wood of individuals of a ring-porous oak (bur oak, Quercusmacrocarpa Michx) growing in southeastern Nebraska display sensitivity to yearly variations in precipitation.
Abstract: Anatomical characters of the early- and late-wood of individuals of a ring-porous oak (bur oak, Quercusmacrocarpa Michx) growing in southeastern Nebraska display sensitivity to yearly variations in precipitation Characteristics of the latewood increment (latewood vessel diameter and density) are closely related to ring width, with vessel diameter varying directly and vessel density varying inversely with ring width Various analyses indicate that ring width appears to be a less direct climatic indicator than latewood vessel diameter in these trees A regression equation incorporating latewood vessel diameter is used successfully to reconstruct precipitation over a 9-month period (October–June)