Wildfires burned an estimated 2.2 million hectares in Alberta in 2023. We describe key attributes of the fires relative to historical fires and fire seasons and offer a perspective on potentially influential factors. Thirty-six large fires ≥ 10,000 ha generated 95% of annual area burned. Individually, these fires exhibited sizes, fire weather, and behaviour consistent with historical fires; there were simply far more of them in 2023. Thirteen fires reported in early May were ignited by lightning and reached final sizes ≥ 10,000 ha, revealing a previously unrecognized threat. Historically, large lightning-ignited fires reported before mid-May occur just once per decade on average. Collectively, 18 large fires reported in early May coincided with drier conditions compared with 18 large fires reported after mid-May. Early May fire weather was also warmer and drier than historical weather. The early May fire group was a temporally concentrated outbreak in west-central Alberta and coincided with extreme potential rate of fire spread. Large fires reported after mid-May were intermittent through to September, concentrated in northern regions and coincided with extreme potential for fuel consumption. Individually, these two spatiotemporal modes of fire season severity (outbreak, intermittent) produced annual burned areas on par with historical extremes. Together, the 2023 multi-modal pattern of fire season severity amplified area burned far above anything previously recorded. Potential contributing factors include climate warming, hemispheric teleconnections, phenology and exhaustion of suppression resources. Implications for future fire seasons, research and management are discussed
{"title":"Alberta’s 2023 wildfires: context, factors and futures","authors":"J. Beverly, Dave Schroeder","doi":"10.1139/cjfr-2024-0099","DOIUrl":"https://doi.org/10.1139/cjfr-2024-0099","url":null,"abstract":"Wildfires burned an estimated 2.2 million hectares in Alberta in 2023. We describe key attributes of the fires relative to historical fires and fire seasons and offer a perspective on potentially influential factors. Thirty-six large fires ≥ 10,000 ha generated 95% of annual area burned. Individually, these fires exhibited sizes, fire weather, and behaviour consistent with historical fires; there were simply far more of them in 2023. Thirteen fires reported in early May were ignited by lightning and reached final sizes ≥ 10,000 ha, revealing a previously unrecognized threat. Historically, large lightning-ignited fires reported before mid-May occur just once per decade on average. Collectively, 18 large fires reported in early May coincided with drier conditions compared with 18 large fires reported after mid-May. Early May fire weather was also warmer and drier than historical weather. The early May fire group was a temporally concentrated outbreak in west-central Alberta and coincided with extreme potential rate of fire spread. Large fires reported after mid-May were intermittent through to September, concentrated in northern regions and coincided with extreme potential for fuel consumption. Individually, these two spatiotemporal modes of fire season severity (outbreak, intermittent) produced annual burned areas on par with historical extremes. Together, the 2023 multi-modal pattern of fire season severity amplified area burned far above anything previously recorded. Potential contributing factors include climate warming, hemispheric teleconnections, phenology and exhaustion of suppression resources. Implications for future fire seasons, research and management are discussed","PeriodicalId":9483,"journal":{"name":"Canadian Journal of Forest Research","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141925711","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}
M. K. Parsapour, Y. Kooch, Seyed Mohsen Hosseini, Seyed Jalil Alavi
To assess the impact of forest plantations on soil microbial catabolic diversity, this study investigated the microbial response to the addition of various carbon-rich substrates in different ages of forest plantations and compared catabolic diversity between a nitrogen-fixing tree species (Alder, Alnus subcordata C. A. M.) and a non-nitrogen-fixing one (Oak, Quercus castaneifolia C. A. M.). The diversity indices (Simpson and Shannon diversity indicies) and Shannon evenness index demonstrated higher values in the oldest plantations than the youngest ones. In younger plantations (15 and 20 years old), oak stands exhibited higher microbial diversity compared to alder stands. However, at 25 years old, alder plantation displayed greater diversity than the oak plantation, as indicated by higher values for the Shannon diversity index (2.77), Simpson diversity index (0.93), and Shannon evenness index (0.89). Forest plantations with alder and oak species significantly enhanced catabolic evenness and diversity, thereby increasing the soil capacity to decompose organic matter and the resilience of the soil to disturbance. This this study highlights the influence of forest plantations on soil microbial catabolic diversity, demonstrating the potential of diverse tree species to promote soil health and resilience through enhanced functional complexity.
为了评估人工林对土壤微生物分解代谢多样性的影响，本研究调查了不同树龄人工林中微生物对添加各种富碳基质的反应，并比较了固氮树种（桤木，Alnus subcordata C. A. M.）和非固氮树种（橡树，Quercus castaneifolia C. A. M.）之间的分解代谢多样性。多样性指数（辛普森多样性指数和香农多样性指数）和香农均匀度指数显示，最老的人工林的数值高于最年轻的人工林。在较年轻的人工林（15 年和 20 年）中，橡树林的微生物多样性高于桤木林。然而，25 年树龄的赤杨林比橡树林显示出更高的多样性，这表现在香农多样性指数（2.77）、辛普森多样性指数（0.93）和香农均匀度指数（0.89）的数值更高。种植赤杨和栎树的人工林显著提高了分解均匀度和多样性，从而增强了土壤分解有机物的能力和土壤抗干扰能力。这项研究强调了植树造林对土壤微生物分解代谢多样性的影响，展示了多样化树种通过提高功能复杂性来促进土壤健康和恢复力的潜力。
{"title":"Assessing Soil Microbial Catabolic Diversity in Alder and Oak Plantations at Varying Developmental Stages","authors":"M. K. Parsapour, Y. Kooch, Seyed Mohsen Hosseini, Seyed Jalil Alavi","doi":"10.1139/cjfr-2023-0249","DOIUrl":"https://doi.org/10.1139/cjfr-2023-0249","url":null,"abstract":"To assess the impact of forest plantations on soil microbial catabolic diversity, this study investigated the microbial response to the addition of various carbon-rich substrates in different ages of forest plantations and compared catabolic diversity between a nitrogen-fixing tree species (Alder, Alnus subcordata C. A. M.) and a non-nitrogen-fixing one (Oak, Quercus castaneifolia C. A. M.). The diversity indices (Simpson and Shannon diversity indicies) and Shannon evenness index demonstrated higher values in the oldest plantations than the youngest ones. In younger plantations (15 and 20 years old), oak stands exhibited higher microbial diversity compared to alder stands. However, at 25 years old, alder plantation displayed greater diversity than the oak plantation, as indicated by higher values for the Shannon diversity index (2.77), Simpson diversity index (0.93), and Shannon evenness index (0.89). Forest plantations with alder and oak species significantly enhanced catabolic evenness and diversity, thereby increasing the soil capacity to decompose organic matter and the resilience of the soil to disturbance. This this study highlights the influence of forest plantations on soil microbial catabolic diversity, demonstrating the potential of diverse tree species to promote soil health and resilience through enhanced functional complexity.","PeriodicalId":9483,"journal":{"name":"Canadian Journal of Forest Research","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141824065","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}
J. van der Merwe, Gerard Lindner, Yolandi Ernst, Ilaria Germishuizen, Elane van Heerden, Hugo Zandberg, Gabigabi Sibiya, Ndamulelo Raboho, Lizette de Waal, Thabani Ndlovu, Leonard Mabaso, Niel Zondach, Nanette Christie, Charles D. Clarke, Shawn D. Mansfield
Plantation forests were introduced into South Africa to satisfy the regional demand for wood-based products, which are largely found in the Mpumalanga province. To better understand the impacts of climate on the dominant height growth of commercially important plantation species, enumeration data collected from 2012 to 2023 was scrutinised, representing 34740 plots in 2082 plantation compartments. Statistically significant multiple linear regression models were developed to predict dominant heights for Pinus elliottii, Pinus taeda, Pinus patula, and Pinus patula x Pinus tecunumanii hybrids using climate variables as independent factors. Mean annual maximum temperature was statistically significant when modelling dominant height for P. elliottii, while winter maximum temperature was significant for P . taeda, P. patula, and P. patula x P. tecunumanii. Rainfall was found to be significant for P. elliottii and P. taeda, while spring rainfall was found to be more important when modelling dominant height for P. patula. Interestingly, autumn rainfall was found to have a negative impact on dominant height growth of P. taeda and P. patula, while rainfall was not significant in P. patula x P. tecunumanii. The findings imply that the southern pines have water thresholds, while Mexican pines are more temperature limited than water limited.
人工林被引入南非，以满足该地区对木制产品的需求，这些产品主要分布在姆普马兰加省。为了更好地了解气候对具有重要商业价值的人工林树种优势高度生长的影响，我们仔细研究了从 2012 年到 2023 年收集的计数数据，这些数据代表了 2082 个人工林小区中的 34740 个地块。以气候变量为独立因素，建立了具有统计意义的多元线性回归模型，以预测埃利奥特松（Pinus elliottii）、泰达松（Pinus taeda）、斑叶松（Pinus patula）和斑叶松 x Tecunumanii 混交种的优势高度。在模拟 elliottii 的优势高度时，年平均最高气温在统计意义上是显著的，而冬季最高气温对泰达红松、斑叶松和斑叶松 x tecunumanii 的影响是显著的。降雨量对 P. elliottii 和 P. taeda 有显著影响，而在模拟 P. patula 的优势高度时，发现春季降雨量更为重要。有趣的是，秋季降雨量对 P. taeda 和 P. patula 的优势高度增长有负面影响，而降雨量对 P. patula x P. tecunumanii 的影响不大。研究结果表明，南方松树有水分阈值，而墨西哥松树受温度限制多于受水分限制。
{"title":"The impact of climate on the dominant height and climate thresholds for P. elliottii, P. taeda, P. patula, and P. patula x P. tecunumanii plantation forests","authors":"J. van der Merwe, Gerard Lindner, Yolandi Ernst, Ilaria Germishuizen, Elane van Heerden, Hugo Zandberg, Gabigabi Sibiya, Ndamulelo Raboho, Lizette de Waal, Thabani Ndlovu, Leonard Mabaso, Niel Zondach, Nanette Christie, Charles D. Clarke, Shawn D. Mansfield","doi":"10.1139/cjfr-2024-0005","DOIUrl":"https://doi.org/10.1139/cjfr-2024-0005","url":null,"abstract":"Plantation forests were introduced into South Africa to satisfy the regional demand for wood-based products, which are largely found in the Mpumalanga province. To better understand the impacts of climate on the dominant height growth of commercially important plantation species, enumeration data collected from 2012 to 2023 was scrutinised, representing 34740 plots in 2082 plantation compartments. Statistically significant multiple linear regression models were developed to predict dominant heights for Pinus elliottii, Pinus taeda, Pinus patula, and Pinus patula x Pinus tecunumanii hybrids using climate variables as independent factors. Mean annual maximum temperature was statistically significant when modelling dominant height for P. elliottii, while winter maximum temperature was significant for P . taeda, P. patula, and P. patula x P. tecunumanii. Rainfall was found to be significant for P. elliottii and P. taeda, while spring rainfall was found to be more important when modelling dominant height for P. patula. Interestingly, autumn rainfall was found to have a negative impact on dominant height growth of P. taeda and P. patula, while rainfall was not significant in P. patula x P. tecunumanii. The findings imply that the southern pines have water thresholds, while Mexican pines are more temperature limited than water limited.","PeriodicalId":9483,"journal":{"name":"Canadian Journal of Forest Research","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141640077","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}
Woongsoon Jang, B. Eskelson, K. Littke, E. Turnblom
Due to their high variability, the growth responses of western hemlock (Tsuga heterophylla (Raf.) Sarg.) stands to fertilization have been regarded as unresponsive or inconsistent. Tree-level fertilization response models for western hemlock were constructed to clarify the inconsistent stand-level responses, using extensive datasets from the United States and Canada. Tree growth in diameter and height, mortality, were assessed by fertilization, stand- and tree-level variables using generalized linear and non-linear mixed effects models. Western hemlock fertilization response was influenced not only by stand-level variables and application rates but also by tree social status and crown characteristics. Greater dominance and crown ratio in trees increased height growth responses but decreased diameter growth. The peak of fertilization effect on diameter growth was observed three years after application, while effect on height growth peaked at six years. Fertilization increased the overall mortality rate, but also ameliorated it for suppressed and steady-growing trees. These complicated fertilization responses of western hemlock may imply its tolerance and allocation strategy of resources at a given size and social status. The results highlight the importance of adopting a tree-level modelling approach to better understanding how western hemlock trees respond to fertilization, improving the accuracy of growth and yield prediction after fertilization.
{"title":"Individual Fertilization Response with Social Status and Crown Characteristics for Western Hemlock (Tsuga heterophylla)","authors":"Woongsoon Jang, B. Eskelson, K. Littke, E. Turnblom","doi":"10.1139/cjfr-2023-0258","DOIUrl":"https://doi.org/10.1139/cjfr-2023-0258","url":null,"abstract":"Due to their high variability, the growth responses of western hemlock (Tsuga heterophylla (Raf.) Sarg.) stands to fertilization have been regarded as unresponsive or inconsistent. Tree-level fertilization response models for western hemlock were constructed to clarify the inconsistent stand-level responses, using extensive datasets from the United States and Canada. Tree growth in diameter and height, mortality, were assessed by fertilization, stand- and tree-level variables using generalized linear and non-linear mixed effects models. Western hemlock fertilization response was influenced not only by stand-level variables and application rates but also by tree social status and crown characteristics. Greater dominance and crown ratio in trees increased height growth responses but decreased diameter growth. The peak of fertilization effect on diameter growth was observed three years after application, while effect on height growth peaked at six years. Fertilization increased the overall mortality rate, but also ameliorated it for suppressed and steady-growing trees. These complicated fertilization responses of western hemlock may imply its tolerance and allocation strategy of resources at a given size and social status. The results highlight the importance of adopting a tree-level modelling approach to better understanding how western hemlock trees respond to fertilization, improving the accuracy of growth and yield prediction after fertilization.","PeriodicalId":9483,"journal":{"name":"Canadian Journal of Forest Research","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141830919","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}
Noah Kussin-Bordo, S. Hinch, Y. Asadian, David C. Scott
To facilitate the movement and processing of timber in some regions of the Pacific Northwest, logs are tied together to form large rectangular rafts (often called “booms”) which are transported and stored in aquatic environments. In the lower Fraser River, British Columbia, some reaches have >50% of shoreline with adjacent log booms, yet our understanding of the effects of log booms on habitats and biota is very limited. We compared sites that have never had log booms to nearby ones with active boom storage occurring to examine differences in environmental characteristics. In contrast to reference sites, nearly all active sites had compacted sediments and little vegetation coverage, likely caused by logs “grounding” onto benthic environments due to tidally influenced water level changes. Total benthic invertebrate abundance was higher at reference sites which had relatively more Amphipoda and Trichoperta, but fewer Haplotaxida, compared to active sites whose compacted and more detrital-laden sediments should favour haplotaxids. Water quality variables generally did not differ between reference and active sites. Grounding of log booms and contact with the below substrate is in contradiction of best management practices and has clear effects on the physical habitat and biota of the area underneath booming sites.
{"title":"Effects of log booms on physical habitat, water quality, and benthic invertebrates in the lower Fraser River and estuary","authors":"Noah Kussin-Bordo, S. Hinch, Y. Asadian, David C. Scott","doi":"10.1139/cjfr-2023-0163","DOIUrl":"https://doi.org/10.1139/cjfr-2023-0163","url":null,"abstract":"To facilitate the movement and processing of timber in some regions of the Pacific Northwest, logs are tied together to form large rectangular rafts (often called “booms”) which are transported and stored in aquatic environments. In the lower Fraser River, British Columbia, some reaches have >50% of shoreline with adjacent log booms, yet our understanding of the effects of log booms on habitats and biota is very limited. We compared sites that have never had log booms to nearby ones with active boom storage occurring to examine differences in environmental characteristics. In contrast to reference sites, nearly all active sites had compacted sediments and little vegetation coverage, likely caused by logs “grounding” onto benthic environments due to tidally influenced water level changes. Total benthic invertebrate abundance was higher at reference sites which had relatively more Amphipoda and Trichoperta, but fewer Haplotaxida, compared to active sites whose compacted and more detrital-laden sediments should favour haplotaxids. Water quality variables generally did not differ between reference and active sites. Grounding of log booms and contact with the below substrate is in contradiction of best management practices and has clear effects on the physical habitat and biota of the area underneath booming sites.","PeriodicalId":9483,"journal":{"name":"Canadian Journal of Forest Research","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141642522","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}
Understanding past fire regimes requires reliable proxy data that record fire conditions and preserve them over time. The objective of this study was to determine if the oxygen isotope composition of charred bark samples (pyrogenic organic matter) could be used as proxy data to differentiate wildfires based on burn intensity. We collected charred and uncharred bark samples from three fire sites in northern Ontario, Canada that represented a gradient of fire intensity as depicted by Fire Weather Index (FWI) data. We hypothesized that the mean Δ18Obark-char (the difference between δ18O of uncharred bark and a charred sample) would be greater for fires with higher intensities. Analysis of variance of Δ18Obark-char indicated a significant effect of fire event (F=73.6, p<0.001), which explained 57.0 % of the variance. A prescribed surface fire treatment (mean FWI = 9.5) had significantly lower Δ18Obark-char than two natural crown fires (FWI = 21 and 27). These results demonstrate that Δ18Obark-char differentiated moderate from high intensity fires in a similar manner to the FWI data.
{"title":"Differences in the intensity of past forest fire events inferred from stable oxygen isotope analysis of charred bark.","authors":"Tegan McWhirter, Elizabeth Webb, Jeffery P Dech","doi":"10.1139/cjfr-2024-0025","DOIUrl":"https://doi.org/10.1139/cjfr-2024-0025","url":null,"abstract":"Understanding past fire regimes requires reliable proxy data that record fire conditions and preserve them over time. The objective of this study was to determine if the oxygen isotope composition of charred bark samples (pyrogenic organic matter) could be used as proxy data to differentiate wildfires based on burn intensity. We collected charred and uncharred bark samples from three fire sites in northern Ontario, Canada that represented a gradient of fire intensity as depicted by Fire Weather Index (FWI) data. We hypothesized that the mean Δ18Obark-char (the difference between δ18O of uncharred bark and a charred sample) would be greater for fires with higher intensities. Analysis of variance of Δ18Obark-char indicated a significant effect of fire event (F=73.6, p<0.001), which explained 57.0 % of the variance. A prescribed surface fire treatment (mean FWI = 9.5) had significantly lower Δ18Obark-char than two natural crown fires (FWI = 21 and 27). These results demonstrate that Δ18Obark-char differentiated moderate from high intensity fires in a similar manner to the FWI data.","PeriodicalId":9483,"journal":{"name":"Canadian Journal of Forest Research","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141649226","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}
Edward Philip Smith, N. Basiliko, Catherine Eimers, Kimber E. Munford, P. Hazlett, S. Watmough
The use of wood ash as a soil amendment remains restricted in many parts of Canada. To better understand belowground biogeochemical responses to wood ash, soil solution chemistry was measured over three years following the application of wood ash (0, 2.5, 5.0, 7.5 Mg·ha-1) at a hardwood stand in Ontario, after which soil microbial response was assessed using 16S rRNA gene and ITS sequencing. Metal concentrations in the locally sourced wood ash were below provincial regulatory limits. Significant increases in soil solution pH were observed within the forest floor in the first year of the trial, and significant increases in calcium and magnesium were also observed in later years of the trial. Concentrations of most metals in soil water either decreased or exhibited no significant change in response to wood ash. There was an increase in diversity and richness of soil prokaryotic groups in the FH horizon at the highest wood ash treatment that is most likely linked to the large increase in pH. This study indicates that wood ash has a strong ameliorative effect on soil and soil water chemistry without major changes to soil microbial communities and is a viable amendment to forest soils at dosages below 5 Mg·ha-1.
{"title":"Below ground chemical and microbial community responses of wood ash addition to a hardwood forest in central Ontario","authors":"Edward Philip Smith, N. Basiliko, Catherine Eimers, Kimber E. Munford, P. Hazlett, S. Watmough","doi":"10.1139/cjfr-2024-0075","DOIUrl":"https://doi.org/10.1139/cjfr-2024-0075","url":null,"abstract":"The use of wood ash as a soil amendment remains restricted in many parts of Canada. To better understand belowground biogeochemical responses to wood ash, soil solution chemistry was measured over three years following the application of wood ash (0, 2.5, 5.0, 7.5 Mg·ha-1) at a hardwood stand in Ontario, after which soil microbial response was assessed using 16S rRNA gene and ITS sequencing. Metal concentrations in the locally sourced wood ash were below provincial regulatory limits. Significant increases in soil solution pH were observed within the forest floor in the first year of the trial, and significant increases in calcium and magnesium were also observed in later years of the trial. Concentrations of most metals in soil water either decreased or exhibited no significant change in response to wood ash. There was an increase in diversity and richness of soil prokaryotic groups in the FH horizon at the highest wood ash treatment that is most likely linked to the large increase in pH. This study indicates that wood ash has a strong ameliorative effect on soil and soil water chemistry without major changes to soil microbial communities and is a viable amendment to forest soils at dosages below 5 Mg·ha-1.","PeriodicalId":9483,"journal":{"name":"Canadian Journal of Forest Research","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141656010","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}
Lichun Xiong, xue wu, baodong cheng, Fengting Wang
The purpose of this paper is to explore the effect of global value chain participation (GVCP) on the gains from trade and trade costs of the timber industry and reveal the underlying influence mechanism. The GVCP Index, Novy (2011) method, and WWZ Value Added Decomposition method have been used to measure the degree of global value chain participation, trade costs, and gains from trade of the timber industry, respectively. The results show that the export gains from trade of the timber industry featured inter-annual sustainability. Further, GVCP, has an insignificant impact, suggesting that the industry’s degree of GVCP is limited. While the current trade cost and policy barriers to forest product trade harm it. And the cost of export trade has a strong lag effect on gains from trade. The increase of current trade costs reduces the short-term benefits; but in the long run, the trade costs and benefits show a synchronous growth trend. To maintain and enhance its competitiveness, therefore, the industry will have to change the GVCP degree and mode of the timber industry, reduce short-term trade costs, and improve the quality and legitimacy certification level of timber products.
{"title":"Global value chain participation, trade cost and benefits of timber industry","authors":"Lichun Xiong, xue wu, baodong cheng, Fengting Wang","doi":"10.1139/cjfr-2024-0081","DOIUrl":"https://doi.org/10.1139/cjfr-2024-0081","url":null,"abstract":"The purpose of this paper is to explore the effect of global value chain participation (GVCP) on the gains from trade and trade costs of the timber industry and reveal the underlying influence mechanism. The GVCP Index, Novy (2011) method, and WWZ Value Added Decomposition method have been used to measure the degree of global value chain participation, trade costs, and gains from trade of the timber industry, respectively. The results show that the export gains from trade of the timber industry featured inter-annual sustainability. Further, GVCP, has an insignificant impact, suggesting that the industry’s degree of GVCP is limited. While the current trade cost and policy barriers to forest product trade harm it. And the cost of export trade has a strong lag effect on gains from trade. The increase of current trade costs reduces the short-term benefits; but in the long run, the trade costs and benefits show a synchronous growth trend. To maintain and enhance its competitiveness, therefore, the industry will have to change the GVCP degree and mode of the timber industry, reduce short-term trade costs, and improve the quality and legitimacy certification level of timber products.","PeriodicalId":9483,"journal":{"name":"Canadian Journal of Forest Research","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141668292","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}
Timothy L. White, Gregory W Adams, Anthony Robert Taylor, Rolland Gagnon, Josh Sherrill, Andrew McCartney
Maintaining forest diversity is an important value in long range management planning. This study was conducted in the ecologically diverse Acadian Forest Region in the Province of New Brunswick, Canada across 1.65 million hectares of publicly owned (Crown) and privately owned (Freehold) land. Tree species diversity using Hill numbers was evaluated across 21 forest type/age class combinations (Groups) using 1,691 sample plots to assess tree species richness (0D), typical species (1D) and abundant species (2D). Across the entire study area there were 0D = 31.0 total tree species observed, 1D = 11.5 typical species, and 2D = 7.0 abundant species. Among the 21 forest types/age class combinations, the Hill numbers ranged from 0D = 16.0-28.3, 1D = 5.6-11.5, and 2D = 3.5-8.4. A comparison of public and private land ownerships showed minor differences in tree species diversity at the landscape level. More intensively managed forest types (e.g., planted stands and naturally regenerated stands with silvicultural interventions) had similar levels of landscape-scale tree species diversity as comparable forest stands receiving no silvicultural interventions. This suggests that current management practices are maintaining tree species diversity across the landscape and highlights the importance of tailored management regimes for different forest types to support this diversity.
{"title":"Tree Species Diversity in Managed Acadian Forests of Eastern Canada","authors":"Timothy L. White, Gregory W Adams, Anthony Robert Taylor, Rolland Gagnon, Josh Sherrill, Andrew McCartney","doi":"10.1139/cjfr-2024-0110","DOIUrl":"https://doi.org/10.1139/cjfr-2024-0110","url":null,"abstract":"Maintaining forest diversity is an important value in long range management planning. This study was conducted in the ecologically diverse Acadian Forest Region in the Province of New Brunswick, Canada across 1.65 million hectares of publicly owned (Crown) and privately owned (Freehold) land. Tree species diversity using Hill numbers was evaluated across 21 forest type/age class combinations (Groups) using 1,691 sample plots to assess tree species richness (0D), typical species (1D) and abundant species (2D). Across the entire study area there were 0D = 31.0 total tree species observed, 1D = 11.5 typical species, and 2D = 7.0 abundant species. Among the 21 forest types/age class combinations, the Hill numbers ranged from 0D = 16.0-28.3, 1D = 5.6-11.5, and 2D = 3.5-8.4. A comparison of public and private land ownerships showed minor differences in tree species diversity at the landscape level. More intensively managed forest types (e.g., planted stands and naturally regenerated stands with silvicultural interventions) had similar levels of landscape-scale tree species diversity as comparable forest stands receiving no silvicultural interventions. This suggests that current management practices are maintaining tree species diversity across the landscape and highlights the importance of tailored management regimes for different forest types to support this diversity.","PeriodicalId":9483,"journal":{"name":"Canadian Journal of Forest Research","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141673182","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}
After canopy removing disturbance, recalcitrant understory shrubs can rapidly occupy the forest understory to the detriment of tree regeneration and growth. The expansion of recalcitrant species has been documented following stand replacing disturbances, such as fire and timber harvest. However, there is little information on how these species respond to much smaller canopy gaps created by the senescence and/or death of single or groups of canopy trees. In this study, we determined the response of Labrador tea (Rhododendron groenlandicum Oeder.), a recalcitrant ericaceous shrub, to canopy gaps in a late-successional boreal forest in northwestern Ontario, Canada. We evaluated functional traits related to the morphology and regeneration strategy of this plant to elucidate the mechanism of gap filling. We found that R. groenlandicum abundance and vigor were greater at the center of treefall gaps than in gap edges or the forest understory due to aggressive sprouting from buried clonal bud banks. Layering was higher in canopy gaps than in the understory. The composition of ground cover and rooting substrate was more influential on the adventitious rooting of the layered stems than increased light availability in gaps.We found a strong response of R. groenlandicum to small canopy openings, suggesting that the species can form recalcitrant understory layers even in the absence of stand replacing disturbance.
在树冠被移除的干扰之后，顽固的林下灌木会迅速占据林下空间，不利于树木的再生和生长。有记录表明，在火灾和木材采伐等林分替换干扰后，顽固物种会扩张。然而，对于这些物种如何应对因单株或成群冠层树衰老和/或死亡而造成的更小的冠层间隙，却鲜有资料。在这项研究中，我们确定了拉布拉多茶（Rhododendron groenlandicum Oeder.）我们评估了与这种植物的形态和再生策略有关的功能特征，以阐明间隙填充的机制。我们发现，由于从埋藏的克隆芽库积极萌发，树冠间隙中心的 R. groenlandicum 丰度和活力要高于间隙边缘或林下。树冠隙间的分层程度高于林下。地面植被和生根基质的组成对分层茎的不定根的影响比间隙中光照增加的影响更大。我们发现 R. groenlandicum 对小的树冠开口有强烈的反应，这表明即使在没有林分替换干扰的情况下，该物种也能形成顽强的林下层。
{"title":"Clonal response of a recalcitrant understory shrub, Labrador tea (Rhododendron groenlandicum Oeder.) to forest gaps","authors":"F.M Moola, Yu Zhao Ni, A.U Mallik","doi":"10.1139/cjfr-2024-0021","DOIUrl":"https://doi.org/10.1139/cjfr-2024-0021","url":null,"abstract":"After canopy removing disturbance, recalcitrant understory shrubs can rapidly occupy the forest understory to the detriment of tree regeneration and growth. The expansion of recalcitrant species has been documented following stand replacing disturbances, such as fire and timber harvest. However, there is little information on how these species respond to much smaller canopy gaps created by the senescence and/or death of single or groups of canopy trees. In this study, we determined the response of Labrador tea (Rhododendron groenlandicum Oeder.), a recalcitrant ericaceous shrub, to canopy gaps in a late-successional boreal forest in northwestern Ontario, Canada. We evaluated functional traits related to the morphology and regeneration strategy of this plant to elucidate the mechanism of gap filling. We found that R. groenlandicum abundance and vigor were greater at the center of treefall gaps than in gap edges or the forest understory due to aggressive sprouting from buried clonal bud banks. Layering was higher in canopy gaps than in the understory. The composition of ground cover and rooting substrate was more influential on the adventitious rooting of the layered stems than increased light availability in gaps.We found a strong response of R. groenlandicum to small canopy openings, suggesting that the species can form recalcitrant understory layers even in the absence of stand replacing disturbance.","PeriodicalId":9483,"journal":{"name":"Canadian Journal of Forest Research","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141678668","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}
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