Canadian Journal of Forest Research
ISSN / EISSN : 0045-5067 / 1208-6037
Published by: Canadian Science Publishing (10.1139)
Total articles ≅ 11,148
Latest articles in this journal
Canadian Journal of Forest Research; https://doi.org/10.1139/cjfr-2021-0140
Tracheid length and width patterns from pith to bark at a height of 0.6 m in uneven-aged Norway spruce (Picea abies L. (H.) Karst) trees were addressed. The identification of the main factors and a comparison with even-aged stands were also pursued. 96 trees were sampled from experimental stands in Southern Finland. The material encompassed the variation in tracheid properties from early years to silvicultural maturity, i.e. from corewood to outerwood up to a cambial age of 111 years. Data from 39 Norway spruce trees from even-aged stands we utilized for comparison. Models fitted to the data indicated that annual ring widths did not influence mean tracheid dimensions but the latewood proportion showed a significant influence on tracheid dimensions. Tracheids in uneven-aged stands were slightly wider and longer at the base of the stem with a similar tree diameter, cambial age, and annual ring number.
Canadian Journal of Forest Research; https://doi.org/10.1139/cjfr-2020-0351
Argan tree (Argania spinosa skeels) is one of the most affected species by desertification and global warming. To advance knowledge on how this tree can withstand drought stress, Arbuscular mycorrhizal fungi (AMF) inoculation with a native complex, mainly formed of Glomus genus, was studied on a set of growth and physiological parameters. Under controlled conditions, inoculated and non- inoculated Argan seedlings were grown for three months under three water regimes (25%, 50%, 75% relatively to the field capacity of used soil substrate). Results showed that the Argan tree had different growth abilities to develop and withstand the various applied water limitations. The AMF complex stimulates growth and mineral nutrition of Argan seedlings under the different imposed levels of water deficiency). The Relative water content (RWC) in leaves, the hydric potential and the stomatal conductance in Argan leaves had shown a general improvement in inoculated seedlings compared to non-inoculated ones. Soluble sugar and proline contents significantly increased in non-inoculated compared with inoculated seedlings under water-limiting conditions (25%). This was similar to oxidative enzyme (Catalase, peoxydase, superoxide dismutase) whose activity increased significantly in drought stressed seedlings.
Canadian Journal of Forest Research pp 1-1; https://doi.org/10.1139/cjfr-2021-0249
Canadian Journal of Forest Research; https://doi.org/10.1139/cjfr-2021-0148
Biological invasion is a growing problem, and species of the genus Pinus are known to be a problem in the forests southern Brazil, including Conservation Units (CUs). Here, we studied the ecology of Pinus taeda invasion at Rio Canoas State Park (PAERC) based on forest inventory, soil seed bank analysis and seed rain assessment in three distinct successional stages inside the park denoted as “Pinus invasion”, “Old Growth Vegetation” and “Initial Vegetation”. Forest inventory of 33 (20x20m) plots, found Pinus in 2 of the 3 evaluated environments. Seed rain was collected bimonthly using 33 (1x1m) seed traps for a period of one year. The major seed distribution periods were in April and June, confirming data found in the literature. The seed bank was analyzed in February (summer) and June (winter) of 2018. Samples were kept in a greenhouse for a period of 120 days each. Summer evaluation showed no emergence of Pinus taeda seedlings, but the winter evaluation (June) did show the emergence of seedlings. Results showed that the soil seed bank is not persistent. Accordingly, the Pinus invasion reported at PAERC requires a restoration program, as well as one that controls reinfestation.
Canadian Journal of Forest Research; https://doi.org/10.1139/cjfr-2020-0312
Climate smart forestry (CSF) is considered as a promising approach for climate change adaptation and mitigation strategies as highlighted in several European policy documents. This paper describes a prospective approach to introducing an incentive-based scheme to facilitate the implementation of CSF through a case study in Iceland. It is argued that the payments for ecosystem services (PES) scheme allows for effective CSF management and long-term sustainability if introduced in compliance with local, cultural and social values. In a case study of an Icelandic afforestation programme, we conducted an institutional analysis of the PES scheme and assessed its effect on forest ecosystem services provision on long-term sustainability. We provide preliminary findings on the application of CSF in the 30-year-old Icelandic afforestation programme scheme. The perspectives of forest and policy experts, as well as local farmers participating in the scheme, were crucial for assessing the effectiveness of PES scheme performance in Iceland.
Canadian Journal of Forest Research; https://doi.org/10.1139/cjfr-2021-0088
Dipteryx alata Vogel (Fabaceae) is a fruit tree species native to the Cerrado with ecological and economic potential. However, water deficit can be a limiting factor to the initial growth of this species, requiring knowledge on technologies that can alleviate this stressful effect. We hypothesized that inoculation with arbuscular mycorrhizae fungi contributes to stress mitigation during and after water deficit. D. alata seedlings were subjected to two water regimes (control: seedlings irrigated daily; and water deficit: irrigation suspension); associated with inoculation with arbuscular mycorrhizal fungi (AMF): AM- = without inoculation; AM+ = inoculation with Rhizophagus clarum; and three evaluation periods: T0 - time zero; F0 - zero photosynthesis (seven days of water restriction); REC - recovery (100 days). Water deficit impaired water relations, decreasing the quality of D. alata seedlings. AM+ seedlings showed higher relative water content (RWC), leaf area ratio, chlorophyll index, and Rubisco carboxylation capacity (A/Ci), which helped in photosynthetic metabolism. Inoculation with R. clarum alleviated the impact of stress on water use efficiency, water potential, RWC, and A/Ci in REC. Inoculation with AMF is a promising management technique in the production of D. alata seedlings for increasing seedling quality and resilience to water deficit.
Canadian Journal of Forest Research; https://doi.org/10.1139/cjfr-2021-0174
After decades of multiyear defoliation episodes in southern New England, Lymantria dispar dispar (previously gypsy moth) populations diminished with the appearance of the L. dispar fungus in 1989. Multiyear defoliations did not occur again until 2015-2018. To assess the impact of the return of multiyear defoliations, we examined 3095 oaks on 29 permanent study areas in Connecticut and Rhode Island that were established at least eleven years before the latest outbreaks. Pre-defoliation stand level oak mortality averaged 2% (three-year basis). Post-defoliation mortality did not differ between managed and unmanaged stands, but was much higher in severely defoliated stands (36%) than in stands with moderate (7%) or low-no defoliation (1%). Pre-defoliation mortality of individual trees differed among species, was lower for larger diameter trees and on unmanaged than managed stands. Post-defoliation mortality on plots with no to moderate defoliation was similar to pre-defoliation mortality levels. Following multiyear defoliations, white oak mortality was higher than for northern red and black oak. There was weak evidence that mortality was elevated on stands with higher basal area following severe defoliation. Natural resource managers should not assume that oaks that survived earlier multiyear defoliations episodes will survive future multiyear outbreaks, possibly because trees are older.
Canadian Journal of Forest Research; https://doi.org/10.1139/cjfr-2021-0184
Tree height (H) is one of the most important tree variables and is widely used in growth and yield models, and its measurement is often time-consuming and costly. Hence, height-diameter (H-D) models have become a great alternative, providing easy-to-use and accurate tools for H prediction. In this study, H-D models were developed for Larix olgensis in Northeast China. The Chapman-Richards function with three predictors (diameter at breast height, dominant tree height, and relative size of individual trees) performed best. Nonlinear mixed effects (NLME) models and nonlinear quantile regressions (NQR9, 9 quantiles; NQR5, 5 quantiles; and NQR3, 3 quantiles) were further used and improved the generalized H-D model, successfully providing accurate H predictions. In addition, the H predictions were calibrated using several measurements from subsamples, which were obtained from different sampling designs and sizes. The results indicated that the predictive accuracy was higher when calibrated by using any number of height measurements for the NLME model and more than 3 height measurements for the NQR3, NQR5 and NQR9 models. The best sampling strategy for the NLME and NQR models involved sampling the medium-sized trees. Overall, the newly developed H-D models can provide highly accurate height predictions for L. olgensis.
Canadian Journal of Forest Research pp 1-13; https://doi.org/10.1139/cjfr-2020-0215
Allometric models embedding independent variables such as diameter at breast height (d) and total height (h) are useful tools to predict the biomass of individual trees. Models for tropical forests are often constructed based on datasets composed of species with different morphological features and architectural models. It is reasonable to expect, however, that species-specific models may reduce uncertainties in biomass predictions, especially for palms, tree ferns, and trees with peculiar morphological features, such as stilt roots and hollow trunks. In this sense, three species with wide geographical distribution in the Brazilian Atlantic Forest were sampled, namely Euterpe edulis Mart., Cyathea delgadii Sternb., and Cecropia glaziovii Snethl., with the aim to (i) quantify their aboveground biomass (AGB), (ii) evaluate the AGB distribution in different plant compartments, (iii) fit species-specific models for predicting AGB at the individual level, and (iv) assess the performance of specific and generic models available in the literature to predict the AGB of individuals of these species. The compartment stem represented, on average, ∼74% of the total AGB of E. edulis individuals; in turn, the caudex compartment of C. delgadii represented, on average, ∼87% of the total AGB, while the trunk compartment of C. glaziovii represented, on average, ∼74%. Among the fitted models, the power model [Formula: see text] showed the best performance for E. edulis and C. delgadii. In turn, the asymptotic logistic model [Formula: see text], where dc is the diameter above the upper stilt root, presented the best performance for C. glaziovii. The variable h appeared as the most important predictor of AGB of E. edulis and C. delgadii; in contrast, the stem and caudex mean basic specific gravities were not suitable predictors. The fitted species-specific models outperformed the specific and generic models selected from the literature. They may, therefore, contribute to the reduction of uncertainties in AGB estimates. In addition, the results support evidence that specific models may be necessary for species with different growth forms and (or) peculiar morphological features, especially those with great abundance and wide geographic distribution.
Canadian Journal of Forest Research; https://doi.org/10.1139/cjfr-2021-0169
Invasive plant species can alter litter decomposition rates through changes in litter quality, environment conditions and decomposer organisms (microflora and soil fauna) but limited research has examined the direct impact on soil fauna. We assessed the abundance and relative contribution of soil meso- and macrofauna to litter decomposition in invaded forest by Ligustrum lucidum and non-invaded forest in a subtropical mountain forest of northwest Argentina using litterbags (0.01, 2 and 6 mm mesh size). Additionally, we analyzed litter quality and soil properties of both forest types. Soil fauna abundance was lower in invaded than in non- invaded forest. The contribution of soil macrofauna to litter decomposition was important in both forest types, but soil mesofauna contribution was only significant in non-invaded forest. Litter decomposition was significantly faster in invaded than in non-invaded forest, consistent with its highest quality. Invaded forest had significantly lower litter accumulation, lower soil moisture and greater soil pH than non-invaded forest. Our results showed that, although soil fauna was less abundant and played a less pronounced role in litter decomposition in invaded forest; these changes did not translate into a reduced litter decomposition rate due to the higher quality of litter produced in the invaded forest.