Quantification of regional soil carbon changes in boreal forests in China is difficult for high spatial heterogeneity, especially considering soil CH4 fluxes in permafrost regions. This study attempted to quantify the variation of soil CO2 emission and its relationship with other soil properties along a permafrost hillslope in Larix gmelinii Kuzen. forest. Using a closed-chamber method, the soil CO2 emission was measured at four slope positions in the Greater Xing’an Range of China in two growing seasons. The results showed that soil CO2 changes have high spatial variability in Larix gmelinii forest along the slope, and average soil CO2 emission at the upper part of the slope was 64% higher than at the bottom. Soil CO2 fluxes showed high positive correlation with soil temperature at 10 cm depth and fungi numbers and negative correlation with soil CH4 change. This study showed the complexity of CO2 emission and could provide data support for forest carbon measurement caused by hillslope in the boreal forest of China. Study Implications: The forest area of Larix gmelinii Kuzen. in the Greater Xing’an Range accounts for 13.2% of the total forest area China. Therefore, the accurate calculation of carbon sequestration of Larix gmelinii forest is significant to the forest carbon measurement of China. However, due to the topographical complexity of the Greater Xing’an Range, the measurement of soil carbon has always been a problem. This study explored the soil carbon dioxide emissions at different slope positions along a hillslope and provided some methods and data support to solve measurement problems caused by hillslope in boreal forest in China.
{"title":"Soil Carbon Dioxide Emission along a Permafrost Hillslope in Larix gmelinii Forest in China","authors":"Yuyang Luo, Shangyuan Li, Ying-Rui Ma, Fanxu Meng, Bolin Wang, Xu Wang, Shusen Wang","doi":"10.1093/forsci/fxad001","DOIUrl":"https://doi.org/10.1093/forsci/fxad001","url":null,"abstract":"\u0000 Quantification of regional soil carbon changes in boreal forests in China is difficult for high spatial heterogeneity, especially considering soil CH4 fluxes in permafrost regions. This study attempted to quantify the variation of soil CO2 emission and its relationship with other soil properties along a permafrost hillslope in Larix gmelinii Kuzen. forest. Using a closed-chamber method, the soil CO2 emission was measured at four slope positions in the Greater Xing’an Range of China in two growing seasons. The results showed that soil CO2 changes have high spatial variability in Larix gmelinii forest along the slope, and average soil CO2 emission at the upper part of the slope was 64% higher than at the bottom. Soil CO2 fluxes showed high positive correlation with soil temperature at 10 cm depth and fungi numbers and negative correlation with soil CH4 change. This study showed the complexity of CO2 emission and could provide data support for forest carbon measurement caused by hillslope in the boreal forest of China.\u0000 Study Implications: The forest area of Larix gmelinii Kuzen. in the Greater Xing’an Range accounts for 13.2% of the total forest area China. Therefore, the accurate calculation of carbon sequestration of Larix gmelinii forest is significant to the forest carbon measurement of China. However, due to the topographical complexity of the Greater Xing’an Range, the measurement of soil carbon has always been a problem. This study explored the soil carbon dioxide emissions at different slope positions along a hillslope and provided some methods and data support to solve measurement problems caused by hillslope in boreal forest in China.","PeriodicalId":12749,"journal":{"name":"Forest Science","volume":"157 3","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72448929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mohammad Nasir Shalizi, Trevor D. Walker, Austin J. Heine, K. Payn, F. Isik, B. Bullock, S. McKeand
To facilitate the utility of genetic improvement in loblolly pine, individual-tree volume (productivity) scores estimated from single-tree plot or row-plot progeny test designs were compared with stand-level volume per unit area from block plots. A large number of families representing a wide range of progeny test scores for volume were established in growth and yield trials to generalize the results to families created by the breeding program. Individual-tree volume scores from progeny tests strongly corresponded with stand-level volume from block plots, especially after accounting for site quality and the risk of fusiform rust disease. A ten-point increase in the volume score from progeny test data was estimated to increase stand-level volume by 3.9 m3 ha-1 at age 6 years. A prediction model is presented that includes a new statistic, rust risk index, which is the expected rust incidence for a family at a new site when the hazard of rust for a checklot can be estimated from historical data. The study results through age 6 years corroborate the Performance Rating System as effective in guiding family deployment decisions. The models presented are based on pre-crown closure data at 6 years and will be updated with older measurements as the study matures. Study Implications: The Performance Rating System (PRS™) has been a successful tool for presenting genetic merit of improved loblolly pine families for landowners and forest managers in a more coherent and standardized manner. This system can be easily applied in other forest tree improvement programs, because it makes genetic improvement user-friendly for silviculturists and forest managers. Landowners can use this system to make decisions for selecting improved families suited to their specific forest management objectives. Seed orchard and nursery managers also depend on the PRS to choose the families to produce and as a third-party verification to market their genetic merit to customers. This study demonstrates that higher stand-level volume per unit area can be achieved when forest managers plant fast growing families with low fusiform rust disease risk on productive sites. The combined effect of genetic improvement for productivity and fusiform rust disease resistance is significant on stand-level volume per unit area.
{"title":"Performance Based on Measurements from Individual-Tree Progeny Tests Strongly Predicts Early Stand Yield in Loblolly Pine","authors":"Mohammad Nasir Shalizi, Trevor D. Walker, Austin J. Heine, K. Payn, F. Isik, B. Bullock, S. McKeand","doi":"10.1093/forsci/fxad002","DOIUrl":"https://doi.org/10.1093/forsci/fxad002","url":null,"abstract":"\u0000 To facilitate the utility of genetic improvement in loblolly pine, individual-tree volume (productivity) scores estimated from single-tree plot or row-plot progeny test designs were compared with stand-level volume per unit area from block plots. A large number of families representing a wide range of progeny test scores for volume were established in growth and yield trials to generalize the results to families created by the breeding program. Individual-tree volume scores from progeny tests strongly corresponded with stand-level volume from block plots, especially after accounting for site quality and the risk of fusiform rust disease. A ten-point increase in the volume score from progeny test data was estimated to increase stand-level volume by 3.9 m3 ha-1 at age 6 years. A prediction model is presented that includes a new statistic, rust risk index, which is the expected rust incidence for a family at a new site when the hazard of rust for a checklot can be estimated from historical data. The study results through age 6 years corroborate the Performance Rating System as effective in guiding family deployment decisions. The models presented are based on pre-crown closure data at 6 years and will be updated with older measurements as the study matures.\u0000 Study Implications: The Performance Rating System (PRS™) has been a successful tool for presenting genetic merit of improved loblolly pine families for landowners and forest managers in a more coherent and standardized manner. This system can be easily applied in other forest tree improvement programs, because it makes genetic improvement user-friendly for silviculturists and forest managers. Landowners can use this system to make decisions for selecting improved families suited to their specific forest management objectives. Seed orchard and nursery managers also depend on the PRS to choose the families to produce and as a third-party verification to market their genetic merit to customers. This study demonstrates that higher stand-level volume per unit area can be achieved when forest managers plant fast growing families with low fusiform rust disease risk on productive sites. The combined effect of genetic improvement for productivity and fusiform rust disease resistance is significant on stand-level volume per unit area.","PeriodicalId":12749,"journal":{"name":"Forest Science","volume":"65 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76789354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The adoption of nature-based solutions, such as forests, is playing an increasingly important role in risk analysis and related decision-making. However, decision-makers struggle to put a value on the services provided by these solutions, as there is no reference market, and are thus faced with several challenges, which relate to the choice of the best forest management program or the interventions needed to make a forest resistant and resilient to the expected negative impacts of ongoing climate change. In this article, we started with an exploratory analysis to identify the key factors in the choice of an economic method to build predictive models to support the choice in an evaluation of the forest protection service against natural hazards. The exploratory analysis showed that non-demand-based methods have a good degree of replicability and reliability and are cheaper, whereas stated preference methods can estimate the intangible component. Concerning predictive models, almost all methods showed a high level of correct classification (95%), apart from the avoided damages method (90%) and, more generally, there is no method that is valid for all operational contexts but rather the choice changes depend on the demands made by the stakeholders and their availability in economic, human, and technological terms. In conclusion, it should be remembered that the methodological framework chosen should not be seen as a substitute for the human ability to analyze complex situations but rather as an aid to this process. Study Implications: The adoption of decision support systems and methodological frameworks and guidelines can help decision-makers to make the most effective and efficient choices, in terms of time needed, resources used, and intervention costs. The combination of this decision support system with other tools, such as frameworks and guidelines, provides a flexible support system aimed at improving the design and implementation of future ecosystem service assessments and management as well as related decision-making.
{"title":"The Decision Trees Method to Support the Choice of Economic Evaluation Procedure: The Case of Protection Forests","authors":"S. Bruzzese, Simone Blanc, Filippo Brun","doi":"10.1093/forsci/fxac062","DOIUrl":"https://doi.org/10.1093/forsci/fxac062","url":null,"abstract":"\u0000 The adoption of nature-based solutions, such as forests, is playing an increasingly important role in risk analysis and related decision-making. However, decision-makers struggle to put a value on the services provided by these solutions, as there is no reference market, and are thus faced with several challenges, which relate to the choice of the best forest management program or the interventions needed to make a forest resistant and resilient to the expected negative impacts of ongoing climate change. In this article, we started with an exploratory analysis to identify the key factors in the choice of an economic method to build predictive models to support the choice in an evaluation of the forest protection service against natural hazards. The exploratory analysis showed that non-demand-based methods have a good degree of replicability and reliability and are cheaper, whereas stated preference methods can estimate the intangible component. Concerning predictive models, almost all methods showed a high level of correct classification (95%), apart from the avoided damages method (90%) and, more generally, there is no method that is valid for all operational contexts but rather the choice changes depend on the demands made by the stakeholders and their availability in economic, human, and technological terms. In conclusion, it should be remembered that the methodological framework chosen should not be seen as a substitute for the human ability to analyze complex situations but rather as an aid to this process.\u0000 Study Implications: The adoption of decision support systems and methodological frameworks and guidelines can help decision-makers to make the most effective and efficient choices, in terms of time needed, resources used, and intervention costs. The combination of this decision support system with other tools, such as frameworks and guidelines, provides a flexible support system aimed at improving the design and implementation of future ecosystem service assessments and management as well as related decision-making.","PeriodicalId":12749,"journal":{"name":"Forest Science","volume":"89 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86056771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ana Carolina Tavora, Micheline Carvalho-Silva, E. J. Amaral, Mônica A. Cupertino‐Eisenlohr, E. V. Nogueira, C. B. Munhoz
The understories of tropical forests comprise complex communities and can be divided into permanent understory, where the generally shade-tolerant plant growth forms are less developed in height, and transient understory, where young tree individuals are only temporarily present. Despite a high contribution to species richness in tropical forests, the understory is poorly studied. Here, we examined the species composition, richness, structure, diversity, and the relative contribution of growth forms in permanent and transient understories of gallery forests in the Brazilian Cerrado. A total of 211 species distributed into sixty-seven families and 153 genera were sampled. The most species-rich family was Rubiaceae, and Miconia was the genus with the highest species richness. The species Hildaea pallens had the highest importance in the forests. The best-represented growth forms were tree seedlings, followed by shrubs and lianas. The transient component of the understory in gallery forests was the most diverse. However, in terms of species relative cover, both transient and permanent understory species contributed equally to the understory structure, mainly due to the high cover of Poaceae species. Our study is the first to examine composition, structure, diversity, and growth forms in the permanent and transient understories of gallery forests. Study Implications: Our study is innovative in describing the plant community attributes of gallery forest understories in the Brazilian Cerrado. The understories of tropical forests comprise complex communities and can be divided into permanent and transient understory. The transient component of the understory in gallery forests was the most diverse, represented by seedlings and young tree specimens. However, in terms of species relative cover, both transient and permanent understory species contributed equally to the understory structure. Here, we provide evidence that may be useful to initiatives seeking to conduct ecological restoration and conservation of gallery forests in the Cerrado.
{"title":"Revealing the Permanent and Transient Plant Understory in Gallery Forests in the Cerrado of Central Brazil","authors":"Ana Carolina Tavora, Micheline Carvalho-Silva, E. J. Amaral, Mônica A. Cupertino‐Eisenlohr, E. V. Nogueira, C. B. Munhoz","doi":"10.1093/forsci/fxac063","DOIUrl":"https://doi.org/10.1093/forsci/fxac063","url":null,"abstract":"\u0000 The understories of tropical forests comprise complex communities and can be divided into permanent understory, where the generally shade-tolerant plant growth forms are less developed in height, and transient understory, where young tree individuals are only temporarily present. Despite a high contribution to species richness in tropical forests, the understory is poorly studied. Here, we examined the species composition, richness, structure, diversity, and the relative contribution of growth forms in permanent and transient understories of gallery forests in the Brazilian Cerrado. A total of 211 species distributed into sixty-seven families and 153 genera were sampled. The most species-rich family was Rubiaceae, and Miconia was the genus with the highest species richness. The species Hildaea pallens had the highest importance in the forests. The best-represented growth forms were tree seedlings, followed by shrubs and lianas. The transient component of the understory in gallery forests was the most diverse. However, in terms of species relative cover, both transient and permanent understory species contributed equally to the understory structure, mainly due to the high cover of Poaceae species. Our study is the first to examine composition, structure, diversity, and growth forms in the permanent and transient understories of gallery forests.\u0000 Study Implications: Our study is innovative in describing the plant community attributes of gallery forest understories in the Brazilian Cerrado. The understories of tropical forests comprise complex communities and can be divided into permanent and transient understory. The transient component of the understory in gallery forests was the most diverse, represented by seedlings and young tree specimens. However, in terms of species relative cover, both transient and permanent understory species contributed equally to the understory structure. Here, we provide evidence that may be useful to initiatives seeking to conduct ecological restoration and conservation of gallery forests in the Cerrado.","PeriodicalId":12749,"journal":{"name":"Forest Science","volume":"2 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90951476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Timberland returns have three main drivers: biological growth, timber price, and land value. Among three of these drivers, timber price is the most volatile. Therefore, modeling and predicting timber prices has been of great concern for timberland investors and other stakeholders. In this study, the spatial dependency and spillover effect of sawtimber prices were investigated across 11 southern states with three different spatial panel models. The findings revealed a strong positive spatial dependency in sawtimber prices across these states, and the observed spillover effect for significant independent variables was over 35% of the total effect. Similarly, pulpwood prices not only have positive impact on the sawtimber prices of a given state but also on its contiguous states. In addition, the impact of COVID-19 pandemic on sawtimber prices was positive and significant. These results would facilitate the valuation of timberland investments as well as predict future timber prices. Study Implications: The sawtimber prices of one state positively affect the future sawtimber prices of neighboring states in addition to its own. Similarly, a shock in a given state also affects the sawtimber prices of its neighbors. Given the volatile nature of timber prices, gaining a better understanding of spatial integration of timber markets improves prediction of sawtimber price fluctuations and trends that ultimately help timberland investors to make effective decisions.
{"title":"Spatial Spillover Effects of Pine Sawtimber Stumpage Prices in the US South","authors":"Sabhyata Lamichhane, B. Mei, J. Siry","doi":"10.1093/forsci/fxac061","DOIUrl":"https://doi.org/10.1093/forsci/fxac061","url":null,"abstract":"\u0000 Timberland returns have three main drivers: biological growth, timber price, and land value. Among three of these drivers, timber price is the most volatile. Therefore, modeling and predicting timber prices has been of great concern for timberland investors and other stakeholders. In this study, the spatial dependency and spillover effect of sawtimber prices were investigated across 11 southern states with three different spatial panel models. The findings revealed a strong positive spatial dependency in sawtimber prices across these states, and the observed spillover effect for significant independent variables was over 35% of the total effect. Similarly, pulpwood prices not only have positive impact on the sawtimber prices of a given state but also on its contiguous states. In addition, the impact of COVID-19 pandemic on sawtimber prices was positive and significant. These results would facilitate the valuation of timberland investments as well as predict future timber prices.\u0000 Study Implications: The sawtimber prices of one state positively affect the future sawtimber prices of neighboring states in addition to its own. Similarly, a shock in a given state also affects the sawtimber prices of its neighbors. Given the volatile nature of timber prices, gaining a better understanding of spatial integration of timber markets improves prediction of sawtimber price fluctuations and trends that ultimately help timberland investors to make effective decisions.","PeriodicalId":12749,"journal":{"name":"Forest Science","volume":"9 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84773075","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study applies a static single-region computable general equilibrium model to provide a snapshot of the economy-wide impacts of anticipated increase in wood products demand in Kentucky. Two counterfactual scenarios of supply increase in the forest sector are simulated. Results show an increase in welfare of high-income households, whereas welfare of low-income households declines marginally due to increase in producer supply prices. Thus, complementary policies to improve welfare of low-income households are imperative as the forest sector expands. Overall, Kentucky’s economy is positively affected through increase in gross regional product. Findings provide valuable policy-relevant information for a sustainable Kentucky forest sector. Study Implications: This study provides insights into economic contributions and impacts associated with increase in demand for Kentucky sector products. Results suggest that expansion in the forest sector has an overall positive impact on the state’s economy. Findings reveal that increase in demand for forest products stimulates overall economic growth. Households experience income gains, but household income is affected disproportionately, with low-income households receiving the least income gains. Further, household income gains may not be enough to offset resultant producer price increases, especially those for low-income households. Findings from this study are useful from a policy perspective for evaluating the economic role of the forest sector in Kentucky’s economy, and they provide valuable information on why forestlands in Kentucky need to be sustainably managed to ensure a continuous supply of timber resources for the state’s forest sector.
{"title":"Modeling Potential Economy-Wide Impacts of Increased Demand for Forest Products in Kentucky","authors":"Domena A. Agyeman, T. Ochuodho","doi":"10.1093/forsci/fxac057","DOIUrl":"https://doi.org/10.1093/forsci/fxac057","url":null,"abstract":"\u0000 This study applies a static single-region computable general equilibrium model to provide a snapshot of the economy-wide impacts of anticipated increase in wood products demand in Kentucky. Two counterfactual scenarios of supply increase in the forest sector are simulated. Results show an increase in welfare of high-income households, whereas welfare of low-income households declines marginally due to increase in producer supply prices. Thus, complementary policies to improve welfare of low-income households are imperative as the forest sector expands. Overall, Kentucky’s economy is positively affected through increase in gross regional product. Findings provide valuable policy-relevant information for a sustainable Kentucky forest sector.\u0000 Study Implications: This study provides insights into economic contributions and impacts associated with increase in demand for Kentucky sector products. Results suggest that expansion in the forest sector has an overall positive impact on the state’s economy. Findings reveal that increase in demand for forest products stimulates overall economic growth. Households experience income gains, but household income is affected disproportionately, with low-income households receiving the least income gains. Further, household income gains may not be enough to offset resultant producer price increases, especially those for low-income households. Findings from this study are useful from a policy perspective for evaluating the economic role of the forest sector in Kentucky’s economy, and they provide valuable information on why forestlands in Kentucky need to be sustainably managed to ensure a continuous supply of timber resources for the state’s forest sector.","PeriodicalId":12749,"journal":{"name":"Forest Science","volume":"585 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84771702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Steenberg, J. Laganière, Nathan W. Ayer, P. Duinker
Forest bioenergy production can represent a renewable energy supply while benefiting the forest sector. However, greenhouse gas (GHG) reductions are often not immediate. The point of carbon parity where bioenergy starts delivering GHG benefits may be years to decades in the future. This study examined the life-cycle emissions associated with bioenergy production at combined heat-and-power (CHP) projects in Nova Scotia, Canada. We examined the effects and sensitivities of different feedstock mixes of chips from harvested roundwood and mill residues, the implementation of intensive and extensive silviculture strategies, and different market/supply-chain assumptions around additionality and product substitution. We found contrasting GHG outcomes for bioenergy, depending largely on additionality assumptions and biomass type. When primary biomass (roundwood) was used as the feedstock type, carbon parity was achieved within four to nine years when pulp and paper products were substituted, whereas carbon parity was achieved in 86–100 years or longer when biomass harvests were additional. Net GHG benefits were achieved in 10 years with the use of secondary biomass (mill residues) as the bioenergy feedstock, although they were delayed when at lower energy conversion efficiencies. Adoption of more intensive silvicultural practices (plantations) reduced the time to carbon parity because of increased yields, although uncertainties in long-term soil carbon storage exist. Study Implications: Our analysis shows that the use of forest biomass in local CHP facilities can deliver GHG benefits in the short term but there is substantial variability. Carbon parity times were the longest with the use of additional primary biomass feedstocks (i.e., roundwood) but were substantially reduced when biomass harvests substituted harvests for pulp and paper products and when secondary biomass (i.e., mill residues) was used. This study highlights the nuance of different forest management dimensions (e.g., silviculture) while also presenting novel findings on the importance of assumptions around biomass harvesting being additional to current practices or a substitution for declines in traditional forest products.
{"title":"Life-Cycle Greenhouse Gas Emissions from Forest Bioenergy Production at Combined Heat and Power Projects in Nova Scotia, Canada","authors":"J. Steenberg, J. Laganière, Nathan W. Ayer, P. Duinker","doi":"10.1093/forsci/fxac060","DOIUrl":"https://doi.org/10.1093/forsci/fxac060","url":null,"abstract":"\u0000 Forest bioenergy production can represent a renewable energy supply while benefiting the forest sector. However, greenhouse gas (GHG) reductions are often not immediate. The point of carbon parity where bioenergy starts delivering GHG benefits may be years to decades in the future. This study examined the life-cycle emissions associated with bioenergy production at combined heat-and-power (CHP) projects in Nova Scotia, Canada. We examined the effects and sensitivities of different feedstock mixes of chips from harvested roundwood and mill residues, the implementation of intensive and extensive silviculture strategies, and different market/supply-chain assumptions around additionality and product substitution. We found contrasting GHG outcomes for bioenergy, depending largely on additionality assumptions and biomass type. When primary biomass (roundwood) was used as the feedstock type, carbon parity was achieved within four to nine years when pulp and paper products were substituted, whereas carbon parity was achieved in 86–100 years or longer when biomass harvests were additional. Net GHG benefits were achieved in 10 years with the use of secondary biomass (mill residues) as the bioenergy feedstock, although they were delayed when at lower energy conversion efficiencies. Adoption of more intensive silvicultural practices (plantations) reduced the time to carbon parity because of increased yields, although uncertainties in long-term soil carbon storage exist.\u0000 Study Implications: Our analysis shows that the use of forest biomass in local CHP facilities can deliver GHG benefits in the short term but there is substantial variability. Carbon parity times were the longest with the use of additional primary biomass feedstocks (i.e., roundwood) but were substantially reduced when biomass harvests substituted harvests for pulp and paper products and when secondary biomass (i.e., mill residues) was used. This study highlights the nuance of different forest management dimensions (e.g., silviculture) while also presenting novel findings on the importance of assumptions around biomass harvesting being additional to current practices or a substitution for declines in traditional forest products.","PeriodicalId":12749,"journal":{"name":"Forest Science","volume":"61 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81062616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Sundararaj, Purushotham Swetha, S. Mondal, Mustypally Kantha Reddy, R. Raja Rishi, Narayanaswamy Mamatha
Indian sandalwood (Santalum album L.) is a semi-parasitic tree, well known for its valuable sandalwood oil extracted from heartwood and roots. Extensive loss of heartwood as a result of its decay is observed in living trees and this has inspired the current study, to investigate the health of sandalwood in Marayur sandalwood forest reserves. Located in Kerala, India, the majority of the trees in Marayur are facing high mortality with the loss of heartwood. The current study evaluated the health status and heartwood-rot disease severity of each tree, which revealed that only 16.67 % of the total trees were healthy and 1.5 % of them were dead. Statistical analysis revealed increasing girth class of trees has a significant positive association with increased disease severity at a 0.05 level of significance. Laboratory analysis confirmed the presence of the major wood-rotters Allophoma tropica, Xylaria berteroi, Diaporthe sp., Fomes sp., Ganoderma appalanatum, and Trametes sp., and that they are collectively responsible for the heart rot. A durability assessment revealed sandalwood is highly resistant (durability class I) to white-rot fungi (viz., Trametes hirsutus and T. [Coriolus] versicolor) and moderately resistant (durability class II) to brown-rot fungi (Oligoporous placenta and Fomitopsis meliae). Study implications: This study highlights the health status and heart-rot disease severity of sandalwood trees in Marayur Forest Reserves. Of the total trees surveyed, about 1.5% mortality was observed and only 17% of the trees were devoid of any heart-rot symptoms. Allophoma tropica, Ganoderma applanatum, Xylaria berteroi isolate SR52, Diaporthe sp., Fomes sp., G. appalanatum, and Trametes sp. are typical species collectively responsible for the heart rot and this was found to be the case in our study. These findings will sensitize forest managers to the loss of valuable sandalwood and death of the trees due to the heart rot, thereby enabling them to take appropriate preventive measures. Also, the natural durability of sandalwood against brown- and white-rot fungi is reported for the first time, indicating that sandalwood falls in the resistance class I (highly resistant) against white-rot fungi (Trametes hirsutus and T. (Coriolus) versicolor) and resistance class II (resistant) against brown-rot fungi (Oligoporous placenta and Fomitopsis meliae).
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There has been increasing interest among foresters and landowners in modifying existing even-aged forest structures to multi-aged or uneven-aged structures. Maintaining a continuous forest structure often provides a wider array of forest values over the long term. The conversion process is challenging in regions of the Northeast United States characterized by forests composed of dense diseased beech thickets and low-vigor deformed overstory trees. Abundance of noncommercial beech may result in negative cash flows during the conversion process to achieve a desired balanced uneven-aged structure. The Forest Vegetation Simulator was used to model growth and yield. Given the possibility of negative cash flows, a least-cost dynamic program with a penalty function was used to determine least-cost time paths for two management scenarios, one characterized by the successful removal of beech and the other simulating the continued presence of beech. Incorporating a penalty function allowed creating a continuum of least-cost paths from a zero penalty with the greatest weight given to net revenue goals to the largest penalty with the greatest weight given to ecological goals. Sensitivity analyses revealed least-cost paths were more stable given changes in prices and wages when greater emphasis was placed on the ecological goals associated with the target structure. Study Implications: There has been increasing interest in modifying existing even-aged forest structures to multi-aged or uneven-aged structures. However, in cases where the initial forest is dominated by undesirable growing stocks and might not provide sufficient revenue to cover management costs, a least-cost optimization would be more a suitable approach. The proposed method creates a continuum of least-cost paths from a zero penalty with the greatest weight given to net revenue goals to the largest penalty with the greatest weight given to ecological goals. This also allows identifying the opportunity cost of choosing one least-cost management regime over another. Finally, the landowner’s choice of the least-cost path most consistent with their management goals is the revealed optimal solution to maximize their welfare.
{"title":"A Least-Cost Dynamic Optimization Approach for Obtaining a Desired Balanced Uneven-Aged Structure","authors":"Basanta Lamsal, J. Wagner, R. Germain","doi":"10.1093/forsci/fxac042","DOIUrl":"https://doi.org/10.1093/forsci/fxac042","url":null,"abstract":"\u0000 There has been increasing interest among foresters and landowners in modifying existing even-aged forest structures to multi-aged or uneven-aged structures. Maintaining a continuous forest structure often provides a wider array of forest values over the long term. The conversion process is challenging in regions of the Northeast United States characterized by forests composed of dense diseased beech thickets and low-vigor deformed overstory trees. Abundance of noncommercial beech may result in negative cash flows during the conversion process to achieve a desired balanced uneven-aged structure. The Forest Vegetation Simulator was used to model growth and yield. Given the possibility of negative cash flows, a least-cost dynamic program with a penalty function was used to determine least-cost time paths for two management scenarios, one characterized by the successful removal of beech and the other simulating the continued presence of beech. Incorporating a penalty function allowed creating a continuum of least-cost paths from a zero penalty with the greatest weight given to net revenue goals to the largest penalty with the greatest weight given to ecological goals. Sensitivity analyses revealed least-cost paths were more stable given changes in prices and wages when greater emphasis was placed on the ecological goals associated with the target structure.\u0000 Study Implications: There has been increasing interest in modifying existing even-aged forest structures to multi-aged or uneven-aged structures. However, in cases where the initial forest is dominated by undesirable growing stocks and might not provide sufficient revenue to cover management costs, a least-cost optimization would be more a suitable approach. The proposed method creates a continuum of least-cost paths from a zero penalty with the greatest weight given to net revenue goals to the largest penalty with the greatest weight given to ecological goals. This also allows identifying the opportunity cost of choosing one least-cost management regime over another. Finally, the landowner’s choice of the least-cost path most consistent with their management goals is the revealed optimal solution to maximize their welfare.","PeriodicalId":12749,"journal":{"name":"Forest Science","volume":"1 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2022-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88393993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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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