Canadian Journal of Forest Research
0045-5067
1208-6037
Canada
Cơ quản chủ quản: Canadian Science Publishing , National Research Council of Canada
Lĩnh vực:
ForestryEcologyGlobal and Planetary Change
Phân tích ảnh hưởng
Thông tin về tạp chí
Published since 1971, this monthly journal features articles, reviews, notes and concept papers on a broad spectrum of forest sciences, including biometrics, conservation, disturbances, ecology, economics, entomology, genetics, hydrology, management, nutrient cycling, pathology, physiology, remote sensing, silviculture, social sciences, soils, stand dynamics, and wood science, all in relation to the understanding or management of ecosystem services. It also publishes special issues dedicated to a topic of current interest.
Các bài báo tiêu biểu
Genetic and phenotypic relationships between weevil (<i>Pissodes strobi</i>) resistance and height growth in spruce populations of British Columbia
Tập 27 Số 5 - Trang 732-739 - 1997
Stability of resistance to western gall rust and needle cast in lodgepole pine provenances Stability of 76 interior lodgepole pine (Pinus contorta ssp. latifolia Engelm.) provenances in resistance to western gall rust (Endocronartium harknessii (J.P. More) Y. Hiratsuka) and needle cast (Lophodermella concolor (Dearn.) Darker) was investigated from 19 and 23 sites in the British Columbia interior, respectively. Provenances, sites, and provenance by site interaction had significant effects on severity level of infection of both diseases. Susceptible provenances contributed mainly to the interaction. The resistant provenances to both diseases were very stable and essentially homeostatic across sites (regression coefficient approaching 0). Resistant provenances were concentrated in the jack pine (Pinus banksiana Lamb.) - lodgepole pine hybrid zone and adjacent areas, and provenances from the low-elevation interior wetbelt were also very resistant to needle cast. Geographic patterns of provenance variation revealed that the closer a lodgepole pine provenance is to the limit of jack pine distribution, the higher and more stable is its resistance to western gall rust and needle cast. The current multiple-site evaluation supports for the hypothesis that jack pine introgression influences pest defence in lodgepole pine and suggests genetic selection can be effective.
Tập 28 Số 3 - Trang 439-449 - 1998
Preliminary evaluation of genetic variation of weevil resistance in interior spruce in British Columbia White pine weevil (Pissodesstrobi (Peck)) damage in three interior spruce open-pollinated progeny tests in north central British Columbia was evaluated to examine the patterns of attack among families. While the overall incidence of damage was different across sites (i.e., Quesnel 9%, Red Rock 37%, and Aleza Lake 63%), correlations on a family-mean basis (percentage attacked per family) at Red Rock and Quesnel as well as Red Rock and Aleza Lake were significant (r = 0.63 and 0.71, respectively). Estimates of family heritability across sites for damage was high (hf = 0.77 ± 0.11), but individual heritability was only moderate (hi = 0.18 ± 0.03). More vigorous families, as determined by 10-year family mean height superiority prior to weevil attack, were damaged less frequently than those with average and poorer performance. Negative correlations of mean family height at 10 years of age with incidence of damage (on a family-mean basis) and mean family diameter with incidence of damage were significant (r = −0.51 and −0.44, respectively). These data suggest that there is a moderate genetic basis for resistance to weevil attack in interior spruce and that selection for height and diameter growth may improve resistance to weevil attack.
Tập 21 Số 2 - Trang 230-234 - 1991
Host plant traits associated with resistance of ponderosa pine to the sawfly, <i>Neodiprion</i><i>fulviceps</i> Phenotypic variation in defoliation of ponderosa pine, Pinusponderosa Laws., by the pine sawfly, Neodiprionfulviceps, is reported. Two field and one laboratory bioassays of paired phenotypically resistant and susceptible trees consistently indicated that sawfly egg, larval, and total survival were 5–14% lower on resistant trees. A suite of host-plant traits were assayed on resistant and susceptible trees including anatomical characteristics of the needles and concentration of terpene and nitrogen. Resistant trees had thicker outer cell layers, more fiber cells, higher toughness, and lower soluble nitrogen than susceptible trees. Resistant and susceptible trees were not distinguished by differences in terpenes. Generational survival of N. fulviceps was inversely related to foliage toughness and number of fiber cells.
Tập 23 Số 5 - Trang 839-845 - 1993
Genetically based differences in susceptibility of white spruce to the spruce bud moth The susceptibility of white spruce, Piceaglauca (Moench) Voss, leaders to damage by the spruce bud moth, Zeirapheracanadensis Mut. & Free., was assessed for 72 half-sib families at four half-sib family test sites and in one seedling seed orchard in New Brunswick. Trees of intermediate height (1.5–3.75 m) were the most damaged, and damage in one year was positively correlated to damage in the next. During 2 consecutive years, half-sib family explained only 1% of the variation in damage when all four test sites were analysed together. However, half-sib family explained between 2.9 and 7.9% of the variation in damage at individual sites. At the four test sites, mean growth reductions of trees in the two most susceptible families were estimated to be approximately 30% higher than those of trees in the two least susceptible families. When all 72 families were ranked with respect to height, trees in the most susceptible and least susceptible families were ranked very poorly and highly, respectively. This suggested that trees in more susceptible families were smaller because of damage by the spruce bud moth. However, this pattern was observed at all sites, including one where bud moth damage was negligible. Thus even in the absence of damage by the spruce bud moth, trees in these least susceptible families had a greater growth rate, in terms of height, than trees in the most susceptible families. This indicates that selection for plant traits reducing susceptibility to bud moth may be compatible with breeding programs attempting to improve height growth. Implications of these results for tree improvement programs are discussed.
Tập 21 Số 1 - Trang 42-47 - 1991
A multifunctional comparison of even-aged and uneven-aged forest management in a boreal region The choice between even- and uneven-aged forest management is a topical issue as the negative impacts of clear-felling are being increasingly criticized and the profitability of even-aged management has been questioned. This study compared these management systems in spruce and pine stands in terms of timber, carbon, and bilberry benefits, all of which can be predicted with reasonable accuracy and quantified in terms of money. Management was optimized by maximizing the total net present value (NPV) of the three benefits in a steady-state situation. The currently recommended type of even-aged management was also included in the comparisons. Uneven-aged management was the best in terms of the total NPV and with respect to bilberry benefits (NPV of bilberry harvesting). It was also better than even-aged management in terms of timber benefits when the discount rate was more than 1%. The ranking was less clear in terms of carbon sequestration and discounted carbon benefits.
Tập 41 Số 4 - Trang 851-862 - 2011
Using salvage logging and tolerance to risk to reduce the impact of forest fires on timber supply calculations It is acknowledged that natural forest fires cannot and even should not be eliminated from the North American boreal forest. Forest fires produce immediate losses of wood volume, disrupt the conversion of the actual forest age structure into a target structure, and prevent planned timber supply (PTS) levels from being achieved. In this paper, we explore the extent to which periodic shortfalls in available timber under various burn rates can be mitigated through salvage logging and the tolerance of forest managers to a given level of shortfall, both as a function of forest age class structure. Simulations are done using both a deterministic and a stochastic representation of burn rate over time. Results show that the frequency of shortfall events can be reduced by salvage logging and by the introduction of measures that generate a tolerance to shortfall and that this mitigation potential is influenced by initial forest age class structure and burn rate. Results also show that even a 100% rate of salvage logging cannot fully compensate for timber losses to fire and eliminate fire-induced timber shortfalls. Furthermore, interannual burn rate variability reduces the efficiency of both mitigation measures. As the PTS is never realized under fire risk, the real cost of opting for different PTS scenarios should be estimated not from the difference in PTS but rather from the more realistic difference in realized timber harvest.
Tập 45 Số 4 - Trang 480-486 - 2015
A refinement of models projecting future Canadian fire regimes using homogeneous fire regime zones Broad-scale fire regime modelling is frequently based on large ecological and (or) administrative units. However, these units may not capture spatial heterogeneity in fire regimes and may thus lead to spatially inaccurate estimates of future fire activity. In this study, we defined homogeneous fire regime (HFR) zones for Canada based on annual area burned (AAB) and fire occurrence (FireOcc), and we used them to model future (2011–2040, 2041–2070, and 2071–2100) fire activity using multivariate adaptive regression splines (MARS). We identified a total of 16 HFR zones explaining 47.7% of the heterogeneity in AAB and FireOcc for the 1959–1999 period. MARS models based on HFR zones projected a 3.7-fold increase in AAB and a 3.0-fold increase in FireOcc by 2100 when compared with 1961–1990, with great interzone heterogeneity. The greatest increases would occur in zones located in central and northwestern Canada. Much of the increase in AAB would result from a sharp increase in fire activity during July and August. Ecozone- and HFR-based models projected relatively similar nationwide FireOcc and AAB. However, very high spatial discrepancies were noted between zonations over extensive areas. The proposed HFR zonation should help providing more spatially accurate estimates of future ecological patterns largely driven by fire in the boreal forest such as biodiversity patterns, energy flows, and carbon storage than those obtained from large-scale multipurpose classification units.
Tập 44 Số 4 - Trang 365-376 - 2014
Vulnerability of timber supply to projected changes in fire regime in Canada’s managed forests The frequency of forest fires is predicted to increase in Canada, which may affect the availability of timber for industrial purposes. We therefore carried out an evaluation of the timber supply vulnerability to current and future fire risk through simplified calculations involving historical forest growth and harvest rates and current and projected forest burn rates. Calculations were performed at the level of forest management areas (FMAs) across the boreal and montane ecozones of Canada. For some FMAs, the vulnerability of timber supply to fire was estimated to be high to extreme by the middle of the century. For those FMAs, the increases in tree growth necessary to negate these risks were generally unrealistic. A modest simulated decrease in tree growth over time, however, was sufficient to raise the vulnerability of many other FMAs from low to moderate. Known biases in the analysis suggest that our assessment might underestimate the level of vulnerability in all FMAs. Other natural disturbances are not included in the analysis but their impact on timber supply may be additive to that of fire. Some adaptation measures to face these increasing risks are discussed.
Tập 45 Số 11 - Trang 1439-1447 - 2015
Résistance comparée de l'épinette blanche et du sapin baumier au renversement Information on eastern Canadian tree species vulnerability to windthrow is scarce. Some statements on relative species vulnerability have been made but they rely on empirical observations, which are often difficult to generalize. In this context, a study was conducted to compare the overturning resistance of balsam fir (Abies balsamea (L.) Mill.) and white spruce (Picea glauca (Moench) Voss) on a mesic site. To establish which tree characteristics would best explain the critical turning moment, simple linear regressions were calculated using tree dendrometric data. The best regressions were obtained with stem weight. With this variable, resistance to overturning did not differ between the two species. Only regressions involving total height showed a significantly greater resistance for white spruce. This difference can be explained by a difference between the species in heightdiameter relationships. For a similar height, spruce has a greater diameter, involving a higher stem weight and thus a greater resistance. Decay did not play a major role in our experiment as trees with external defects were excluded. Our results suggest that to minimize losses from windthrow, silvi cultural treatments on mesic sites should try to increase the proportion of trees of either species with the lowest height/diameter ratio.
Tập 32 Số 4 - Trang 642-652 - 2002