Pub Date : 2023-07-07DOI: 10.1080/02827581.2023.2231349
M. Naseri, Shaban Shataee Jouibary, H. Habashi
ABSTRACT In recent years, increasing tree diebacks and mortality in some forests, particularly in forest parks, created a need amongst forest managers to find effective methods to gather information about the rate of dieback and mortality and their reasons. High-quality air and space-born remote sensing data has established as an alternative to field surveys for certain inventory tasks. This study used high-quality UltraCam-Xp and UAV drone images from 2016 and 2021 to map tree dieback and mortality in Daland Forest Park, Golestan Province, Iran. High-quality ortho mosaics and Digital Surface Models (DSMs) were generated from UltraCam (2016) and UAV (2021) images. The images were then classified through object-based classification by Nearest Neighbor (NN), Support Vector Machine (SVM), and Bayes algorithms using various input data sets including spectral bands, Canopy Height Model (CHM), vegetation indices, and texture analysis features. Our results indicate that the Bayes algorithm is more precise in mapping tree dieback for the two time steps compared to other algorithms. The best tree dieback map on UltraCam images was obtained using the spectral bands with CHM, texture analysis features, and vegetation indices. This combination resulted in an overall accuracy of 91.20% and a Kappa coefficient of 0.88. It was also found that combining the UAV main bands with CHM and texture features did produce a high-accuracy map with an overall accuracy of 88.46% and a Kappa coefficient of 0.84. Change detection analysis of tree dieback showed that between 2016 and 2021, the number of healthy trees decreased, and the number of gaps and open areas increased in the study area. We conclude that UltraCam and UAV photographs can serve to identify and map tree dieback and dead trees with good accuracies and can hence support forest health monitoring.
{"title":"Analysis of forest tree dieback using UltraCam and UAV imagery","authors":"M. Naseri, Shaban Shataee Jouibary, H. Habashi","doi":"10.1080/02827581.2023.2231349","DOIUrl":"https://doi.org/10.1080/02827581.2023.2231349","url":null,"abstract":"ABSTRACT In recent years, increasing tree diebacks and mortality in some forests, particularly in forest parks, created a need amongst forest managers to find effective methods to gather information about the rate of dieback and mortality and their reasons. High-quality air and space-born remote sensing data has established as an alternative to field surveys for certain inventory tasks. This study used high-quality UltraCam-Xp and UAV drone images from 2016 and 2021 to map tree dieback and mortality in Daland Forest Park, Golestan Province, Iran. High-quality ortho mosaics and Digital Surface Models (DSMs) were generated from UltraCam (2016) and UAV (2021) images. The images were then classified through object-based classification by Nearest Neighbor (NN), Support Vector Machine (SVM), and Bayes algorithms using various input data sets including spectral bands, Canopy Height Model (CHM), vegetation indices, and texture analysis features. Our results indicate that the Bayes algorithm is more precise in mapping tree dieback for the two time steps compared to other algorithms. The best tree dieback map on UltraCam images was obtained using the spectral bands with CHM, texture analysis features, and vegetation indices. This combination resulted in an overall accuracy of 91.20% and a Kappa coefficient of 0.88. It was also found that combining the UAV main bands with CHM and texture features did produce a high-accuracy map with an overall accuracy of 88.46% and a Kappa coefficient of 0.84. Change detection analysis of tree dieback showed that between 2016 and 2021, the number of healthy trees decreased, and the number of gaps and open areas increased in the study area. We conclude that UltraCam and UAV photographs can serve to identify and map tree dieback and dead trees with good accuracies and can hence support forest health monitoring.","PeriodicalId":21352,"journal":{"name":"Scandinavian Journal of Forest Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46147090","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}
Pub Date : 2023-07-04DOI: 10.1080/02827581.2023.2227095
Nico Österberg, Vesa-Pekka Parkatti, O. Tahvonen
ABSTRACT We study the effect of forest stand growth models on the economically optimal management of boreal mixed-species forests. Our size-structured economic–ecological model includes the optimization of harvest timing, harvesting intensities, rotation periods, and the choice between rotation forestry and continuous cover forestry. We carry out a systemic comparison of economically optimal solutions obtained with three statistical–empirical stand growth models for both single- and mixed-species stands with up to four tree species. Given a 1% interest rate, the optimal choice between continuous cover and rotation forestry depends on the applied growth model. However, under a 3% interest rate, the optimal management regime is always continuous cover forestry. The optimal solution details are highly dependent on the growth models. With a 1% interest rate, it may become optimal to apply intensive close-to-clearcut harvesting that results in a dominant species change via natural regeneration. However, the level of natural regeneration varies strongly between the growth models. The economic superiority of a species mixture cannot be determined from overyielding differences. Mixed-species stands have higher maximum sustainable yields, bare land values, and average net revenues compared with monocultures.
{"title":"Comparing stand growth models in optimizing mixed-species forest management","authors":"Nico Österberg, Vesa-Pekka Parkatti, O. Tahvonen","doi":"10.1080/02827581.2023.2227095","DOIUrl":"https://doi.org/10.1080/02827581.2023.2227095","url":null,"abstract":"ABSTRACT We study the effect of forest stand growth models on the economically optimal management of boreal mixed-species forests. Our size-structured economic–ecological model includes the optimization of harvest timing, harvesting intensities, rotation periods, and the choice between rotation forestry and continuous cover forestry. We carry out a systemic comparison of economically optimal solutions obtained with three statistical–empirical stand growth models for both single- and mixed-species stands with up to four tree species. Given a 1% interest rate, the optimal choice between continuous cover and rotation forestry depends on the applied growth model. However, under a 3% interest rate, the optimal management regime is always continuous cover forestry. The optimal solution details are highly dependent on the growth models. With a 1% interest rate, it may become optimal to apply intensive close-to-clearcut harvesting that results in a dominant species change via natural regeneration. However, the level of natural regeneration varies strongly between the growth models. The economic superiority of a species mixture cannot be determined from overyielding differences. Mixed-species stands have higher maximum sustainable yields, bare land values, and average net revenues compared with monocultures.","PeriodicalId":21352,"journal":{"name":"Scandinavian Journal of Forest Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48493254","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}
Pub Date : 2023-07-03DOI: 10.1080/02827581.2023.2229732
M. Räty, A. Juutinen, K. Korhonen, K. Syrjänen, L. Kärkkäinen
ABSTRACT According to protection targets of EU Biodiversity Strategy 2030, 30% of EU’s land and sea area should be legally protected by 2030. While the actual targets and even terms are still to be defined, the strategy’s possible impacts can be simulated for policy support purposes. The strategy aims to increase protection by setting aside forests and extending closer-to-nature forest management practices. We simulated Finland’s forest resources with the European Forestry Dynamics Model (EFDM) considering the protection targets. According to our simulations, the total growing stock and net present value will be lower with the additional protection than by carrying on the business-as-usual management. The additional protection resulted in intensified harvesting in the remaining forest area available for wood supply with the current harvest level. This may weaken the positive ecological impacts of protection. Reducing the harvest level from the current level is not a likely alternative either, because the demand for biomass is predicted to increase in the future, while the supply is insufficient, and EU policies aim to avoid shifting the negative impacts of resource extraction outside the EU. The feasibility of the additional protection depends on the actual implementation and definitions.
{"title":"EU wood production vs. biodiversity goals – possible reconciliation in Finland?","authors":"M. Räty, A. Juutinen, K. Korhonen, K. Syrjänen, L. Kärkkäinen","doi":"10.1080/02827581.2023.2229732","DOIUrl":"https://doi.org/10.1080/02827581.2023.2229732","url":null,"abstract":"ABSTRACT According to protection targets of EU Biodiversity Strategy 2030, 30% of EU’s land and sea area should be legally protected by 2030. While the actual targets and even terms are still to be defined, the strategy’s possible impacts can be simulated for policy support purposes. The strategy aims to increase protection by setting aside forests and extending closer-to-nature forest management practices. We simulated Finland’s forest resources with the European Forestry Dynamics Model (EFDM) considering the protection targets. According to our simulations, the total growing stock and net present value will be lower with the additional protection than by carrying on the business-as-usual management. The additional protection resulted in intensified harvesting in the remaining forest area available for wood supply with the current harvest level. This may weaken the positive ecological impacts of protection. Reducing the harvest level from the current level is not a likely alternative either, because the demand for biomass is predicted to increase in the future, while the supply is insufficient, and EU policies aim to avoid shifting the negative impacts of resource extraction outside the EU. The feasibility of the additional protection depends on the actual implementation and definitions.","PeriodicalId":21352,"journal":{"name":"Scandinavian Journal of Forest Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45927273","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}
Pub Date : 2023-06-27DOI: 10.1080/02827581.2023.2221038
J. P. Skovsgaard, U. Johansson, J. Englund, Stefan Juravle
ABSTRACT This study quantified the effects of different establishment practices on survival, dieback and early growth of Juglans × intermedia NG23 and NG38 planted in a statistically designed field experiment on glacial till in southern Sweden. Establishment practices included the use or absence of nurse trees (Populus maximowiczii × trichocarpa var. OP42 planted one year before J. × intermedia), weed control (2 m2·tree−1) and fertilization (+25 g N·tree−1·year−1). NG23 transplants were smaller than NG38 at the time of planting. The overall survival rate was 97%. NG23 suffered marginally more mortality than NG38. Leader shoot dieback occurred in all treatment combinations but was most severe in the presence of nurse trees. NG23 suffered less dieback than NG38. Annual height growth of trees unaffected by dieback increased with increasing levels of precipitation during the growing season (194–407 mm) and with increasing soil quality in terms of nitrogen (94·10−3–607·10−3 g·g−1), base saturation (14–99%) or available soil water capacity (8.6–30.6 l·m−3). It was negatively influenced by poplar nurse trees and positively by fertilization. Weed control had no impact on height growth, possibly due to inefficient implementation. With nurse trees, NG23 had stronger growth than NG38. The opposite was true without nurse trees. It was hypothesized that less growth and more dieback resulted from competition for water.
{"title":"Walnut in Sweden: effects of nurse trees, weed control and fertilization on five-year survival and growth of planted Juglans × intermedia NG23 and NG38","authors":"J. P. Skovsgaard, U. Johansson, J. Englund, Stefan Juravle","doi":"10.1080/02827581.2023.2221038","DOIUrl":"https://doi.org/10.1080/02827581.2023.2221038","url":null,"abstract":"ABSTRACT This study quantified the effects of different establishment practices on survival, dieback and early growth of Juglans × intermedia NG23 and NG38 planted in a statistically designed field experiment on glacial till in southern Sweden. Establishment practices included the use or absence of nurse trees (Populus maximowiczii × trichocarpa var. OP42 planted one year before J. × intermedia), weed control (2 m2·tree−1) and fertilization (+25 g N·tree−1·year−1). NG23 transplants were smaller than NG38 at the time of planting. The overall survival rate was 97%. NG23 suffered marginally more mortality than NG38. Leader shoot dieback occurred in all treatment combinations but was most severe in the presence of nurse trees. NG23 suffered less dieback than NG38. Annual height growth of trees unaffected by dieback increased with increasing levels of precipitation during the growing season (194–407 mm) and with increasing soil quality in terms of nitrogen (94·10−3–607·10−3 g·g−1), base saturation (14–99%) or available soil water capacity (8.6–30.6 l·m−3). It was negatively influenced by poplar nurse trees and positively by fertilization. Weed control had no impact on height growth, possibly due to inefficient implementation. With nurse trees, NG23 had stronger growth than NG38. The opposite was true without nurse trees. It was hypothesized that less growth and more dieback resulted from competition for water.","PeriodicalId":21352,"journal":{"name":"Scandinavian Journal of Forest Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45746282","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}
Pub Date : 2023-06-27DOI: 10.1080/02827581.2023.2225870
Fernando Castedo‐Dorado, P. Rodríguez-Gonzálvez, E. González-Ferreiro, Guillermo Ramos-González, R. Álvarez-Esteban, Flor Álvarez-Taboada
ABSTRACT Populus spp. clones and hybrids are commonly cultivated for timber production worldwide due to their fast growth and adaptability. In Spain, growth models are currently available for the Populus × euramericana clones ‘I-214' and ‘MC'. However, the input variables required for these models are not typically available to potential users. For the most widely used P. × interamericana clones ('Beaupre', ‘Raspalje' and ‘Unal') there is currently no growth model available in Spain or elsewhere in Europe. The aim of the present study was to develop a whole-stand growth model for these five clones. Data were obtained from a network of 134 plots and 265 trees scanned by Terrestrial Laser Scanning. The structure of the growth model was mediated by plot data typically available from forest owners: plantation age, number of trees of each clone and arithmetic mean tree diameter (dm). The main component of the growth model is a dm projection function, enabling dm to be projected at any time. Sensitivity analysis of the prediction accuracy of this function revealed that the proposed model provides satisfactory predictions for time intervals of between 5 and 10 years. The growth model was implemented in a web-based plot growth simulator, facilitating its use.
{"title":"A user-driven, reduced whole-stand growth model for major hybrid poplar clones in Spain","authors":"Fernando Castedo‐Dorado, P. Rodríguez-Gonzálvez, E. González-Ferreiro, Guillermo Ramos-González, R. Álvarez-Esteban, Flor Álvarez-Taboada","doi":"10.1080/02827581.2023.2225870","DOIUrl":"https://doi.org/10.1080/02827581.2023.2225870","url":null,"abstract":"ABSTRACT Populus spp. clones and hybrids are commonly cultivated for timber production worldwide due to their fast growth and adaptability. In Spain, growth models are currently available for the Populus × euramericana clones ‘I-214' and ‘MC'. However, the input variables required for these models are not typically available to potential users. For the most widely used P. × interamericana clones ('Beaupre', ‘Raspalje' and ‘Unal') there is currently no growth model available in Spain or elsewhere in Europe. The aim of the present study was to develop a whole-stand growth model for these five clones. Data were obtained from a network of 134 plots and 265 trees scanned by Terrestrial Laser Scanning. The structure of the growth model was mediated by plot data typically available from forest owners: plantation age, number of trees of each clone and arithmetic mean tree diameter (dm). The main component of the growth model is a dm projection function, enabling dm to be projected at any time. Sensitivity analysis of the prediction accuracy of this function revealed that the proposed model provides satisfactory predictions for time intervals of between 5 and 10 years. The growth model was implemented in a web-based plot growth simulator, facilitating its use.","PeriodicalId":21352,"journal":{"name":"Scandinavian Journal of Forest Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48327204","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}
Pub Date : 2023-06-19DOI: 10.1080/02827581.2023.2225871
E. Olofsson, R. Jakobsson
ABSTRACT Private forest owners’ management decisions significantly impact the development of forest values in Sweden. This study explored the potential to develop environmental values on privately owned land in southern Sweden. Data were collected through interviews with 23 forest owners and analyzed with semantic content analysis. The interviewees owned estates of productive, predominantly coniferous forest ranging in size from 10–825 ha. They were aged 36–84, and 26% were female. Results showed that there is considerable potential to develop environmental values on private land since 1) Forest owners demonstrated multi-functional views of primarily social and emotional dimensions surrounding forest ownership, and the mindset of combining goals enables many different values to be developed, 2) Desired management showed numerous ideas that could bring a diversity of benefits, and 3) Practical management included various production-favoring measures, but even more for environmental, social, cultural, and emotional purposes that, largely unnoted, bring environmental conservation benefits. All forest owners perceived barriers to management and ownership, categorized primarily to structural or surrounding society factors. Financial incentives, policies encouraging forest owners’ initiatives, an adequate supply of resources and sound management advice are suggested measures to reduce barriers and facilitate the development of environmental values.
{"title":"The potential to develop environmental values on privately owned forest land in southern Sweden","authors":"E. Olofsson, R. Jakobsson","doi":"10.1080/02827581.2023.2225871","DOIUrl":"https://doi.org/10.1080/02827581.2023.2225871","url":null,"abstract":"ABSTRACT Private forest owners’ management decisions significantly impact the development of forest values in Sweden. This study explored the potential to develop environmental values on privately owned land in southern Sweden. Data were collected through interviews with 23 forest owners and analyzed with semantic content analysis. The interviewees owned estates of productive, predominantly coniferous forest ranging in size from 10–825 ha. They were aged 36–84, and 26% were female. Results showed that there is considerable potential to develop environmental values on private land since 1) Forest owners demonstrated multi-functional views of primarily social and emotional dimensions surrounding forest ownership, and the mindset of combining goals enables many different values to be developed, 2) Desired management showed numerous ideas that could bring a diversity of benefits, and 3) Practical management included various production-favoring measures, but even more for environmental, social, cultural, and emotional purposes that, largely unnoted, bring environmental conservation benefits. All forest owners perceived barriers to management and ownership, categorized primarily to structural or surrounding society factors. Financial incentives, policies encouraging forest owners’ initiatives, an adequate supply of resources and sound management advice are suggested measures to reduce barriers and facilitate the development of environmental values.","PeriodicalId":21352,"journal":{"name":"Scandinavian Journal of Forest Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44808262","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}
Pub Date : 2023-06-02DOI: 10.1080/02827581.2023.2219461
N. Erkan, Edanur Ayhan
ABSTRACT This study aimed to (1) investigate the long-term results of Cedrus libani + Pinus nigra mixed afforestation and (2) compare it with pure P. nigra afforestation in terms of wood production, economic return, and carbon (C) sequestration. The study was conducted in Elazığ-Sivrice, southeastern Turkey. Data were collected from six sample plots, and stem analysis for each species in the mixed stand was performed to reveal the growth and development of the basal-area-averaged trees. Statistical analyses showed that the pure P. nigra stands were superior to the mixed stands in terms of wood production (236 m3 ha−1 vs. 150 m3 ha−1), wood economic value ($19,551 ha−1 vs. $11,483 ha−1), and C sequestration (93 t ha−1 vs. 64 t C ha−1) at 54 years old. The lower values calculated for the mixed stand may have been due to the incompatible growth curves of the two species. These results imply that if the aim is to obtain wood products, pure P. nigra stands may be more advantageous than mixtures of C. libani and P. nigra for afforestation.
摘要:本研究旨在(1)研究杉木+黑松混合造林的长期效果，(2)与纯黑松造林在木材产量、经济效益和碳(C)固存方面进行比较。这项研究在土耳其东南部的Elazığ-Sivrice进行。利用6个样地的数据，对混交林各树种进行了茎干分析，揭示了基区平均树木的生长发育情况。统计分析表明，纯黑松林在木材产量(236 m3 ha - 1比150 m3 ha - 1)、木材经济价值(19,551 ha - 1美元比11,483 ha - 1美元)和54岁时碳固存(93 tha - 1比64 t C - ha - 1)方面优于混合林分。混交林的计算值较低可能是由于两种树种的生长曲线不相容。这些结果表明，如果目的是获得木材产品，纯黑桫椤林分可能比黑桫椤和黑桫椤混合林分更有利于造林。
{"title":"Growth rate and economic evaluation of mixed stands established with Cedrus libani and Pinus nigra","authors":"N. Erkan, Edanur Ayhan","doi":"10.1080/02827581.2023.2219461","DOIUrl":"https://doi.org/10.1080/02827581.2023.2219461","url":null,"abstract":"ABSTRACT This study aimed to (1) investigate the long-term results of Cedrus libani + Pinus nigra mixed afforestation and (2) compare it with pure P. nigra afforestation in terms of wood production, economic return, and carbon (C) sequestration. The study was conducted in Elazığ-Sivrice, southeastern Turkey. Data were collected from six sample plots, and stem analysis for each species in the mixed stand was performed to reveal the growth and development of the basal-area-averaged trees. Statistical analyses showed that the pure P. nigra stands were superior to the mixed stands in terms of wood production (236 m3 ha−1 vs. 150 m3 ha−1), wood economic value ($19,551 ha−1 vs. $11,483 ha−1), and C sequestration (93 t ha−1 vs. 64 t C ha−1) at 54 years old. The lower values calculated for the mixed stand may have been due to the incompatible growth curves of the two species. These results imply that if the aim is to obtain wood products, pure P. nigra stands may be more advantageous than mixtures of C. libani and P. nigra for afforestation.","PeriodicalId":21352,"journal":{"name":"Scandinavian Journal of Forest Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46886188","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}
Pub Date : 2023-05-19DOI: 10.1080/02827581.2023.2215545
Jiali Nie, Shuai Liu
ABSTRACT In forest resource inventory, tree height is often estimated by easily measurable diameter from height-diameter model. In this study, we tried to use random forest (RF), an important machine learning method, to model individual-tree height. Results showed that the optimized RF model had better fitting and prediction accuracy (R 2 = 0.8146 and RMSE = 2.2527 m). In terms of relative importance, diameter at breast height (DBH) was the most important factor, followed by neighborhood-related variables and other variables related to environmental conditions. Further, tree height was generally positively affected by DBH, mean diameter of neighbors, DBH dominance, number of neighbors, and mean annual precipitation, but negatively affected by elevation. The results indicated that the RF-based height model was statistically reliable and highly accurate, and it had strong interpretability with ecological significance. Our study will provide a new perspective for the application of machine learning algorithms to forest dynamic modeling.
{"title":"Incorporated neighborhood and environmental effects to model individual-tree height using random forest regression","authors":"Jiali Nie, Shuai Liu","doi":"10.1080/02827581.2023.2215545","DOIUrl":"https://doi.org/10.1080/02827581.2023.2215545","url":null,"abstract":"ABSTRACT In forest resource inventory, tree height is often estimated by easily measurable diameter from height-diameter model. In this study, we tried to use random forest (RF), an important machine learning method, to model individual-tree height. Results showed that the optimized RF model had better fitting and prediction accuracy (R 2 = 0.8146 and RMSE = 2.2527 m). In terms of relative importance, diameter at breast height (DBH) was the most important factor, followed by neighborhood-related variables and other variables related to environmental conditions. Further, tree height was generally positively affected by DBH, mean diameter of neighbors, DBH dominance, number of neighbors, and mean annual precipitation, but negatively affected by elevation. The results indicated that the RF-based height model was statistically reliable and highly accurate, and it had strong interpretability with ecological significance. Our study will provide a new perspective for the application of machine learning algorithms to forest dynamic modeling.","PeriodicalId":21352,"journal":{"name":"Scandinavian Journal of Forest Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42963362","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}
Pub Date : 2023-05-19DOI: 10.1080/02827581.2023.2216946
J. Siitonen, Hannes Pasanen, Matti Ylänne, L. Saaristo
ABSTRACT Many forestry practitioners need information on the amount of dead wood for various purposes, often at the level of individual stands. Our aim was to compare four simple dead-wood inventory methods of which systematic circular plot inventory is a well-known method, while relascope plot inventory (using the ordinary horizontal angle relascope also for downed trees), diameter class counting and total inventory are new methods. Seven surveyors tested the methods in four stands in southern Finland. All the methods produced rather accurate volume estimates. Mean percent error was the smallest (−5.7%) in total inventory and the largest (−12.4%) in diameter class counting. Precision differed significantly between the methods. Variation among individual measurements, expressed as percentage SD, was 15.9% in total inventory, 24.8% in diameter counting, 36.6% in relascope inventory and 43.0% in circular plot inventory. Diameter counting was by far the fastest method. Relascope inventory and circular plot inventory took about twice as much time, and total inventory over three times as much time as diameter counting. In conclusion, diameter class counting is a cost-effective dead-wood assessment method, if the purpose is to get an estimate of the total volume of dead wood within a forest stand with a reasonable precision.
{"title":"Comparison of four alternative survey methods in assessing dead wood at the stand level","authors":"J. Siitonen, Hannes Pasanen, Matti Ylänne, L. Saaristo","doi":"10.1080/02827581.2023.2216946","DOIUrl":"https://doi.org/10.1080/02827581.2023.2216946","url":null,"abstract":"ABSTRACT\u0000 Many forestry practitioners need information on the amount of dead wood for various purposes, often at the level of individual stands. Our aim was to compare four simple dead-wood inventory methods of which systematic circular plot inventory is a well-known method, while relascope plot inventory (using the ordinary horizontal angle relascope also for downed trees), diameter class counting and total inventory are new methods. Seven surveyors tested the methods in four stands in southern Finland. All the methods produced rather accurate volume estimates. Mean percent error was the smallest (−5.7%) in total inventory and the largest (−12.4%) in diameter class counting. Precision differed significantly between the methods. Variation among individual measurements, expressed as percentage SD, was 15.9% in total inventory, 24.8% in diameter counting, 36.6% in relascope inventory and 43.0% in circular plot inventory. Diameter counting was by far the fastest method. Relascope inventory and circular plot inventory took about twice as much time, and total inventory over three times as much time as diameter counting. In conclusion, diameter class counting is a cost-effective dead-wood assessment method, if the purpose is to get an estimate of the total volume of dead wood within a forest stand with a reasonable precision.","PeriodicalId":21352,"journal":{"name":"Scandinavian Journal of Forest Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48575128","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}
Pub Date : 2023-05-19DOI: 10.1080/02827581.2023.2211806
Lenka Marcineková (nee Navrátilová), P. Palátová, Jozef Výbošťok, V. Jarský, M. Riedl, Blanka Giertliova, R. Dudík, Jaroslav Šálka
ABSTRACT This study focuses on the issues of bioeconomy perception of students at forestry faculties in Slovakia and the Czech Republic. Bioeconomy is seen as a great window of opportunities, hence there is increased demand for bioeconomy education. This paper can help answer this demand and improve the curricula of universities providing bioeconomy-related education. The survey was conducted at the Technical University in Zvolen and the Czech University of Life Sciences Prague among 367 students. The results show that 70% of students have heard about bioeconomy, while this number is significantly higher amongst Slovak students. Considering bioeconomy awareness, we identified significant differences between different study programmes. The main information source about the bioeconomy issues turns out to be university courses followed by news. Czech students turned out to be less satisfied with bioeconomy involvement in curricula, and who also find it necessary to increase bioeconomy focus within their study curriculum. Our results show that targeted communication of bioeconomy is a key factor for general acceptance of bioeconomy and its further development among students and the general public. The results obtained can be used to increase the extent to which bioeconomy is being addressed in study programmes within the analysed universities.
{"title":"Students’ perception of bioeconomy as an important factor in communicating and further development of the bioeconomy in Slovakia and the Czech Republic","authors":"Lenka Marcineková (nee Navrátilová), P. Palátová, Jozef Výbošťok, V. Jarský, M. Riedl, Blanka Giertliova, R. Dudík, Jaroslav Šálka","doi":"10.1080/02827581.2023.2211806","DOIUrl":"https://doi.org/10.1080/02827581.2023.2211806","url":null,"abstract":"ABSTRACT This study focuses on the issues of bioeconomy perception of students at forestry faculties in Slovakia and the Czech Republic. Bioeconomy is seen as a great window of opportunities, hence there is increased demand for bioeconomy education. This paper can help answer this demand and improve the curricula of universities providing bioeconomy-related education. The survey was conducted at the Technical University in Zvolen and the Czech University of Life Sciences Prague among 367 students. The results show that 70% of students have heard about bioeconomy, while this number is significantly higher amongst Slovak students. Considering bioeconomy awareness, we identified significant differences between different study programmes. The main information source about the bioeconomy issues turns out to be university courses followed by news. Czech students turned out to be less satisfied with bioeconomy involvement in curricula, and who also find it necessary to increase bioeconomy focus within their study curriculum. Our results show that targeted communication of bioeconomy is a key factor for general acceptance of bioeconomy and its further development among students and the general public. The results obtained can be used to increase the extent to which bioeconomy is being addressed in study programmes within the analysed universities.","PeriodicalId":21352,"journal":{"name":"Scandinavian Journal of Forest Research","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49115179","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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