Amanda Brackett, Christopher J. Still, K. Puettmann
{"title":"Residual canopy cover provides buffering of near-surface temperatures, but benefits are limited under extreme conditions","authors":"Amanda Brackett, Christopher J. Still, K. Puettmann","doi":"10.1139/cjfr-2023-0268","DOIUrl":"https://doi.org/10.1139/cjfr-2023-0268","url":null,"abstract":"Increasing summer temperatures and higher probabilities of extreme heat events have led to concerns about tree damage and mortality. However, insufficient attention has been given to conditions leading to heat-related regeneration failures in temperate forests. To address this managers need to understand how microclimate varies under a range of overstory conditions. We measured air temperatures at 2cm above-ground underneath a gradient of canopy cover on south-facing slopes in recently thinned Douglas-fir stands in western Oregon, USA. To expand the ecological relevance of these data to impacts on regeneration, we created the stress-degree hours (SDH) metric, representing the amount of time - and by how much – temperatures exceeded biologically relevant stress thresholds. Overall, for every 10% increase in canopy cover, maximum temperatures at 2cm were 1.3oC lower, the odds of temperatures exceeding stress thresholds for conifer regeneration declined by a multiplicative factor of 0.26, and the total of SDH decreased by 40%. These reductions are large enough to be worthy of attention when managing for tree regeneration. However, data collected during the Pacific Northwest Heat Dome in June 2021 indicate that with various climate change scenarios and heatwave occurrences, temperatures will be unfavorable for regeneration regardless of overstory cover.","PeriodicalId":9483,"journal":{"name":"Canadian Journal of Forest Research","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141001316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. Power, Stéphane Tremblay, Isabelle Auger, Emmanuel Duchateau
{"title":"Effects of commercial thinning on characteristics of naturally regenerated coniferous stands from Eastern North-America.","authors":"H. Power, Stéphane Tremblay, Isabelle Auger, Emmanuel Duchateau","doi":"10.1139/cjfr-2024-0009","DOIUrl":"https://doi.org/10.1139/cjfr-2024-0009","url":null,"abstract":"Commercial thinning is a silvicultural treatment that has been practiced for centuries in Europe. However, in Eastern Canada, its application to naturally regenerated stands is much more recent, and long-term monitoring of this treatment realized in an operational context is rare. We monitored 135 paired sample plots (thinned and control) over a 20-year period. The plots are in stands dominated by either black spruce (Picea mariana (Mill.) B.S.P.), jack pine (Pinus banksiana Lamb.) or balsam fir (Abies balsamea (L.) Mill.) and distributed throughout the boreal and temperate forests of Québec (Canada). Twenty years after treatment, thinning increased quadratic mean diameter (QMD) for balsam fir (1.7 cm) and jack pine (0.7 cm) while for black spruce the change in QMD varied according to the QMD before treatment. Periodic annual increment in gross merchantable volume of thinned and control plots was similar for balsam fir and jack pine but was less in thinned black spruce plots during the first 5 years. Thinning did not affect mortality, which remained low until 15 years after treatment. As commercial thinning should gain popularity over the next years, our study provides a benchmark of the expected effects when the treatment is performed in an operational context.","PeriodicalId":9483,"journal":{"name":"Canadian Journal of Forest Research","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141005441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Modeling stand- and tree-level growth of Chinese fir plantations","authors":"Hanyue Chen, Quang V. Cao, Yihang Jiang, Yuxin Hu, Jianguo Zhang, Xiongqing Zhang","doi":"10.1139/cjfr-2023-0195","DOIUrl":"https://doi.org/10.1139/cjfr-2023-0195","url":null,"abstract":"Growth and yield systems are essential tools for enhancing forest management decision-making. This study systematically evaluated three stand-level models and two data types for predicting stand survival and basal area of Chinese fir ( Cunning lanceolate (Lamb.) Hook.) plantations in southern China. The first model links survival and diameter through the self-thinning concept. The second model incorporates stand diameter, the previous year’s diameter, and stand survival, while the third model treats stand survival and diameter as mutually independent functions of only stand age. Model 2 was the best performer for short-term prediction (2–4 years), whereas Model 3 excelled in longer projection periods (6–10 years). Despite the independent predictions of stand survival and diameter in Model 3, it closely tracked observed self-thinning trajectories in long-term predictions. Tree-level model growth derived from Models 2 and 3 performed optimally for short-term and long-term tree-level predictions, respectively. While limited to four experimental sites, this research contributes theoretical groundwork to growth and yield modeling for Chinese fir plantations.","PeriodicalId":9483,"journal":{"name":"Canadian Journal of Forest Research","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141014718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Laurence Schimleck, Katherine A. McCulloh, Joseph Dahlen, D. Auty
{"title":"New perspectives on radial profiles of specific gravity in North American conifers","authors":"Laurence Schimleck, Katherine A. McCulloh, Joseph Dahlen, D. Auty","doi":"10.1139/cjfr-2023-0235","DOIUrl":"https://doi.org/10.1139/cjfr-2023-0235","url":null,"abstract":"North American conifers exhibit three radial specific gravity (SG) patterns (Type 1, 2 and 3) which balance hydraulic and mechanical requirements. Type 1 and 2 patterns (Pinaceae) have low SG and high microfibril angle (MFA) corewood ensuring compliance, whereas in outerwood high SG / low MFA provide stiffness and strength resisting bending. Hydraulically, corewood, especially in Type 2 species, is resistant to embolism, whereas outerwood has higher specific conductivity. Cupressaceae (Type 3) have hydraulically very efficient, low SG outerwood, facilitating rapid growth. Corewood is flexible, whereas outerwood is mechanically weak and compensated for by more conical stems and durable heartwood (which prevents Brazier buckling). Radially earlywood (EW) decreases, and latewood (LW) increases for all Types, whereas percent latewood (%LW) increases (Type 1), decreases then increases (Type 2) and decreases (Type 3). Ring SG increases when increasing LW SG and %LW are sufficient to counteract decreasing EW SG. Shade tolerance, crown recession, hormone gradients and environmental variation affect patterns. Auxin concentration decreases with increasing distance from juvenile foliage slowing cell division, concomitantly gibberellin concentration (lignification) and carbohydrates (cell wall thickening) increase, producing higher %LW. Across a species range regions receiving relatively high summer rainfall have trees with higher %LW (by ring).","PeriodicalId":9483,"journal":{"name":"Canadian Journal of Forest Research","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140659764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hanna McDonnell, C. Filipescu, Rod Stirling, Ignacio Barbeito
{"title":"Radial distribution of heartwood extractives in second-growth western redcedar","authors":"Hanna McDonnell, C. Filipescu, Rod Stirling, Ignacio Barbeito","doi":"10.1139/cjfr-2023-0095","DOIUrl":"https://doi.org/10.1139/cjfr-2023-0095","url":null,"abstract":"Western redcedar has high economic value and has been traditionally used for cultural purposes by Indigenous communities. Second-growth redcedar is potentially growing faster due to lower planting densities, fertilization and tree breeding. Little quantitative information is available about the impact of management practices on wood quality, particularly heartwood extractives. This study evaluated the effects of growth rate and site on heartwood extractives at two locations aged 70-90 years in British Columbia, Canada. A three-parameter sigmoid model was fit to the data using nonlinear mixed effects to analyze the relationship between heartwood extractives relative to cambial age, growth rate, and sampling site. The southern site had significantly higher cumulative extractive concentrations, while all extractive concentrations increased faster. This study shows that smaller trees will reach their peak concentrations earlier than larger trees. Results show that faster growth through active management of western redcedar may lead to increased and more uniformly distributed content of heartwood extractives.","PeriodicalId":9483,"journal":{"name":"Canadian Journal of Forest Research","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140674942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The Distribution of Tree Biomass Carbon within the Pacific Coastal Temperate Rainforest, a Disproportionally Carbon Dense Forest","authors":"Trevor A Carter, Brian Buma","doi":"10.1139/cjfr-2024-0015","DOIUrl":"https://doi.org/10.1139/cjfr-2024-0015","url":null,"abstract":"Spatially explicit global estimates of forest carbon storage are typically coarsely scaled. While useful, these estimates do not account for the variability and distribution of carbon at management scales. We asked how climate, topography, and disturbance regimes interact across and within geopolitical boundaries to influence tree biomass carbon, using the perhumid region of the Pacific Coastal Temperate Rainforest, an infrequently disturbed carbon dense landscape, as a test case. We leveraged permanent sample plots in southeast Alaska and coastal British Columbia and used multiple quantile regression forests and generalized linear models to estimate tree biomass carbon stocks and the effects of topography, climate, and disturbance regimes. We estimate tree biomass carbon stocks are either 211 (SD = 163) Mg C ha-1 or 218 (SD = 169) Mg C ha-1. Natural disturbance regimes had no correlation with tree biomass but logging decreased tree biomass carbon and the effect diminished with increasing time since logging. Despite accounting for 0.3% of global forest area, this forest stores between 0.63% - 1.07% of global aboveground forest carbon as aboveground live tree biomass. The disparate impact of logging and natural disturbance regimes on tree biomass carbon suggests a mismatch between current forest management and disturbance history.","PeriodicalId":9483,"journal":{"name":"Canadian Journal of Forest Research","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140683898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P. Schaberg, P. Murakami, Christopher F. Hansen, G. Hawley
{"title":"Assessing the influence of climate on the growth of green ash trees from five Plant Hardiness Zones growing in a range-wide provenance test near the species’ northern range limit","authors":"P. Schaberg, P. Murakami, Christopher F. Hansen, G. Hawley","doi":"10.1139/cjfr-2023-0194","DOIUrl":"https://doi.org/10.1139/cjfr-2023-0194","url":null,"abstract":"Green ash is threatened with extirpation from emerald ash borer (EAB) attack. Because green ash has an extensive range, its restoration could require both breeding for EAB resistance and possible adaptation to a variety of environmental gradients. We assessed the growth and climate sensitivity of green ash from five Plant Hardiness Zones (PHZs) growing in a range-wide provenance test in Vermont. Although there tended to be greater growth among trees from the warmest PHZ (7), differences were rarely statistically distinguishable. For trees from all PHZs, growth was positively correlated with precipitation in the current year and negatively correlated with precipitation the year before (a possible legacy effect). Growth was negatively associated with temperature the year of ring formation but positively associated with temperatures the year before. Growth was often positively correlated with winter snow but was negatively associated with spring or fall snow for the warmest PHZs. Climate correlations for PHZ 3 were unusual in that: 1) only positive correlations were detected, 2) no legacy effects were noted, and 3) despite being from the coldest region, no correlations with snow were found. Growth increased over time for the warmest PHZs during a period of simultaneous increases in temperature and precipitation.","PeriodicalId":9483,"journal":{"name":"Canadian Journal of Forest Research","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140696244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Representation of regeneration dynamics in growth and yield models: a review","authors":"Wynford Richard Dempster","doi":"10.1139/cjfr-2024-0016","DOIUrl":"https://doi.org/10.1139/cjfr-2024-0016","url":null,"abstract":"Models of forest regeneration dynamics have been less widely applied in forest management than those representing growth and mortality in later stages of stand development, in spite of the critical role of regeneration in maintaining forest ecosystems. This omission is demonstrated by a review of pertinent literature and examined in the context of reforestation in the province of Alberta. Regeneration assessments in Alberta are undertaken before the regeneration phase of stand development is complete. As a result, existing growth and yield models, used to predict whether regeneration performance will meet management objectives, do not adequately represent juvenile mortality, ingress of natural regeneration, stand density, and the responses of ingress and mortality to reforestation treatments. A long-term experiment monitoring regeneration of lodgepole pine stands following harvest has over the last 20 years attempted to address some of the resulting challenges. Opportunities and needs for regeneration modelling include extension to other boreal species and ecotypes, incorporation of climatic variables, and innovations in data collection and analytical techniques. Steps are recommended for expediting the required research.","PeriodicalId":9483,"journal":{"name":"Canadian Journal of Forest Research","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140732649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The Evolving Role of Wildfire in the Maritimes Region of Eastern Canada","authors":"Anthony Robert Taylor, David A. MacLean","doi":"10.1139/cjfr-2024-0032","DOIUrl":"https://doi.org/10.1139/cjfr-2024-0032","url":null,"abstract":"The Maritimes region of eastern Canada is not typically associated with wildfire, but the severe 2023 fire season has reminded ‘Maritimers’ that despite its cool, damp climate and diverse, mixed forests, the region is not immune to burning. In this perspectives article, we review the relationship of wildfire and the Maritimes by first providing a brief history on the role fire has played in shaping the forests of the Maritimes and our part in that relationship. We then describe the current state of wildfire management, including strategies and technologies used to prevent fire, and identify some key important challenges moving forward. Overall, our review shows that the people of this region have a long history with wildfire, but that since European colonization (1600s) the local fire regime has undergone significant shifts. While the introduction of forest protection legislation and technology during the early 20th century has greatly reduced the occurrence of fire and substantially lengthened the fire return interval, the growing, sprawling population of the Maritimes presents new challenges for managing fire in the wildland-urban interface. Combined with the threat of climate change, which is likely to increase the occurrence of wildfire, new urban planning and forest management strategies must be developed to address these emerging dangers.","PeriodicalId":9483,"journal":{"name":"Canadian Journal of Forest Research","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140748998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
O. Tahvonen, Antti-Jussi Suominen, Vesa-Pekka Parkatti, Pekka Malo
{"title":"Optimizing high-dimensional forestry for wood production and carbon sinks","authors":"O. Tahvonen, Antti-Jussi Suominen, Vesa-Pekka Parkatti, Pekka Malo","doi":"10.1139/cjfr-2023-0267","DOIUrl":"https://doi.org/10.1139/cjfr-2023-0267","url":null,"abstract":"Our model for optimizing stand-level wood production and carbon sinks includes individual-tree models for forest growth, an advanced model for soil carbon, detailed wood production economy, and an intertemporal objective for the value of wood production and carbon sinks/emissions. Carbon stocks include aboveground biomass and carbon in forest soil and in wood products. Optimization of the management regime, rotations and thinning timing, and type and intensity are carried out by reinforcement learning. Including the social price of carbon causes a regime switch from continuous cover forestry to clear-cuts, postponed lighter thinning, and a longer rotation, and, with a high carbon price, to solutions with pure clear-cuts or solutions utilizing stands as pure carbon stocks. Carbon price has profound effects on stand values, and the bare land value may well exceed the value before a clear-cut. The total average carbon stock is maximized with harvest and a long rotation instead of \"no harvesting\". Bioenergy, carbon capture, and storage (BECCS) always increases the value of wood production but not necessarily the value of carbon sinks. With BECCS, increasing carbon stocks in trees and forest soil remains optimal.","PeriodicalId":9483,"journal":{"name":"Canadian Journal of Forest Research","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140213341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}