Pub Date : 2023-02-17DOI: 10.1080/02827581.2023.2177335
H. Szajsner, P. Bąbelewski, A. Koszelnik-Leszek, Magdalena Kuryś
ABSTRACT Scots pine is the main forest forming species in Poland. Despite the great importance of natural reconditioning of forest trees, a substantial source of reforestation is the nursery production of seedling material. Pre-sowing seed conditioning, consisting of chemical and physical treatments, is commonly used to improve seed quality as well as to advance uniform development and increase plant efficiency. The influence of semiconductor laser irradiation wavelength on Scots pine seeds (Pinus sylvestris L.) was tested in both laboratory and pot experiments. Irradiation rates used in trials were (D3) three-, (D6) six- and (D9) nine-fold of the basic rate of 2.5·10−1 J·cm−2 with a control (D0) of non-irradiated seeds. Irradiation accelerated emergence and increased seedling numbers. The germination energy and capacity of tested Scots pine genotypes were reduced under higher (D6) doses of laser irradiation. Stimulation of morphological traits and increase in chlorophyll contents was observed under the lowest (D3) irradiation rate, while an increase in polyphenol contents occurred under the highest, nine-fold rate of irradiation.
{"title":"Conditioning of Scots pine (Pinus sylvestris L.) sowing material","authors":"H. Szajsner, P. Bąbelewski, A. Koszelnik-Leszek, Magdalena Kuryś","doi":"10.1080/02827581.2023.2177335","DOIUrl":"https://doi.org/10.1080/02827581.2023.2177335","url":null,"abstract":"ABSTRACT Scots pine is the main forest forming species in Poland. Despite the great importance of natural reconditioning of forest trees, a substantial source of reforestation is the nursery production of seedling material. Pre-sowing seed conditioning, consisting of chemical and physical treatments, is commonly used to improve seed quality as well as to advance uniform development and increase plant efficiency. The influence of semiconductor laser irradiation wavelength on Scots pine seeds (Pinus sylvestris L.) was tested in both laboratory and pot experiments. Irradiation rates used in trials were (D3) three-, (D6) six- and (D9) nine-fold of the basic rate of 2.5·10−1 J·cm−2 with a control (D0) of non-irradiated seeds. Irradiation accelerated emergence and increased seedling numbers. The germination energy and capacity of tested Scots pine genotypes were reduced under higher (D6) doses of laser irradiation. Stimulation of morphological traits and increase in chlorophyll contents was observed under the lowest (D3) irradiation rate, while an increase in polyphenol contents occurred under the highest, nine-fold rate of irradiation.","PeriodicalId":21352,"journal":{"name":"Scandinavian Journal of Forest Research","volume":"38 1","pages":"1 - 8"},"PeriodicalIF":1.8,"publicationDate":"2023-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49624866","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 : 2023-02-17DOI: 10.1080/02827581.2023.2189296
R. Päivinen, G. Petrokofsky, W. Harvey, Leo Petrokofsky, P. Puttonen, J. Kangas, E. Mikkola, Leena Byholm, Liisa Käär
ABSTRACT Using bibliometric methods, this report analysed the volumes of global forest research and research collaboration between researchers, institutes and countries during the period 2010–2019. The keywords used in the bibliometric search resulted in a good match with the publication lists of three major Finnish forest research organisations. The final corpus of “forest” publications consisted of 355,000 articles, proceeding papers, reviews, books, book chapters and letters listed in the Web of Science database. During 2010–2019, the volume of Finnish publications in forest sciences have increased and the share of internationally collaborative papers has also grown. However, the international position of Finnish and Nordic forest research is slowly declining, owing to the modest growth in publishing, compared to fast-growing countries like China and Russia. When comparing Finnish and Swedish research organisations, those from Sweden were more internationally oriented. In both countries, the five top institutes produced more than three quarters of their country’s respective publications. Analyses based on bibliometric data used in this study reveal the status regarding publication output and trends. These analyses can provide objective evidence that is needed when developing research strategies and policies as well as allocating funding resources.
{"title":"State of forest research in 2010s – a bibliographic study with special reference to Finland, Sweden and Austria","authors":"R. Päivinen, G. Petrokofsky, W. Harvey, Leo Petrokofsky, P. Puttonen, J. Kangas, E. Mikkola, Leena Byholm, Liisa Käär","doi":"10.1080/02827581.2023.2189296","DOIUrl":"https://doi.org/10.1080/02827581.2023.2189296","url":null,"abstract":"ABSTRACT Using bibliometric methods, this report analysed the volumes of global forest research and research collaboration between researchers, institutes and countries during the period 2010–2019. The keywords used in the bibliometric search resulted in a good match with the publication lists of three major Finnish forest research organisations. The final corpus of “forest” publications consisted of 355,000 articles, proceeding papers, reviews, books, book chapters and letters listed in the Web of Science database. During 2010–2019, the volume of Finnish publications in forest sciences have increased and the share of internationally collaborative papers has also grown. However, the international position of Finnish and Nordic forest research is slowly declining, owing to the modest growth in publishing, compared to fast-growing countries like China and Russia. When comparing Finnish and Swedish research organisations, those from Sweden were more internationally oriented. In both countries, the five top institutes produced more than three quarters of their country’s respective publications. Analyses based on bibliometric data used in this study reveal the status regarding publication output and trends. These analyses can provide objective evidence that is needed when developing research strategies and policies as well as allocating funding resources.","PeriodicalId":21352,"journal":{"name":"Scandinavian Journal of Forest Research","volume":"38 1","pages":"23 - 38"},"PeriodicalIF":1.8,"publicationDate":"2023-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41882702","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 : 2023-02-17DOI: 10.1080/02827581.2023.2189297
M. Seki
ABSTRACT Stem taper models are helpful tools for predicting diameter of a tree at any height or volume of any stem section. In this study, traditional and artificial neural network (ANN) approaches were used to predict stem tapers of Scots pine individuals. The data used in this study correspond to destructively sampled trees in even-aged forest stands located in the three important locations where Scots pine grows naturally in northwestern Türkiye. In total, three regression type stem taper models from different categories and an ANN model were developed and evaluated both statistically and graphically. The best results were obtained by Kozak’s taper model accounting for the 99% of the total variance in stem diameter predictions.
{"title":"Predicting stem taper using artificial neural network and regression models for Scots pine (Pinus sylvestris L.) in northwestern Türkiye","authors":"M. Seki","doi":"10.1080/02827581.2023.2189297","DOIUrl":"https://doi.org/10.1080/02827581.2023.2189297","url":null,"abstract":"ABSTRACT Stem taper models are helpful tools for predicting diameter of a tree at any height or volume of any stem section. In this study, traditional and artificial neural network (ANN) approaches were used to predict stem tapers of Scots pine individuals. The data used in this study correspond to destructively sampled trees in even-aged forest stands located in the three important locations where Scots pine grows naturally in northwestern Türkiye. In total, three regression type stem taper models from different categories and an ANN model were developed and evaluated both statistically and graphically. The best results were obtained by Kozak’s taper model accounting for the 99% of the total variance in stem diameter predictions.","PeriodicalId":21352,"journal":{"name":"Scandinavian Journal of Forest Research","volume":"38 1","pages":"97 - 104"},"PeriodicalIF":1.8,"publicationDate":"2023-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43452640","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 : 2023-02-17DOI: 10.1080/02827581.2023.2191004
E. Ondrušková, S. Adamčík, M. Kobza, Zuzana Jánošíková, R. Ostrovský, K. Pastirčáková, M. Caboň, K. Adamčíková
ABSTRACT Lophodermium species are well known to be among the dominant endophytic fungi colonizing pine needles. The occurrence of two species with different life strategies on different Pinus trees across Slovakia was detected by PCR using species-specific primers. In general, the commensalistic species L. pinastri was more frequent than parasitic L. seditiosum. There were no significant differences observed between urban and natural environments, but natural environments have more frequent colonization by L. pinastri and less frequent were trees negatively tested to Lophodermium colonization. Among the most frequently sampled trees were non-native P. nigra and native P. sylvestris. A significant difference in Lophodermium incidence was detected between these two species in a natural environment, with increased frequency of L. pinastri on native Scots pine. In addition to one clade of L. pinastri, culture based species identification confirmed the presence of L. corconticum and an undescribed clade of L. seditiosum that is not sensitive to used PCR primers for the species detection.
{"title":"Checking the balance between pathogenic and mutualistic pine needle fungi of the genus Lophodermium in forested and urban areas of Slovakia","authors":"E. Ondrušková, S. Adamčík, M. Kobza, Zuzana Jánošíková, R. Ostrovský, K. Pastirčáková, M. Caboň, K. Adamčíková","doi":"10.1080/02827581.2023.2191004","DOIUrl":"https://doi.org/10.1080/02827581.2023.2191004","url":null,"abstract":"ABSTRACT Lophodermium species are well known to be among the dominant endophytic fungi colonizing pine needles. The occurrence of two species with different life strategies on different Pinus trees across Slovakia was detected by PCR using species-specific primers. In general, the commensalistic species L. pinastri was more frequent than parasitic L. seditiosum. There were no significant differences observed between urban and natural environments, but natural environments have more frequent colonization by L. pinastri and less frequent were trees negatively tested to Lophodermium colonization. Among the most frequently sampled trees were non-native P. nigra and native P. sylvestris. A significant difference in Lophodermium incidence was detected between these two species in a natural environment, with increased frequency of L. pinastri on native Scots pine. In addition to one clade of L. pinastri, culture based species identification confirmed the presence of L. corconticum and an undescribed clade of L. seditiosum that is not sensitive to used PCR primers for the species detection.","PeriodicalId":21352,"journal":{"name":"Scandinavian Journal of Forest Research","volume":"38 1","pages":"39 - 48"},"PeriodicalIF":1.8,"publicationDate":"2023-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45332256","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 : 2023-02-17DOI: 10.1080/02827581.2023.2184488
Ana de Lera Garrido, T. Gobakken, M. Hauglin, E. Næsset, O. Bollandsås
ABSTRACT The aim of this study was to analyze the accuracy of predictions of dominant height, mean height, basal area, and volume from the nationwide forest attribute map (SR16). The analysis took advantage of field observations from 33 different forest inventory projects across Norway used for validation. Forest attributes for more than 5000 plots were predicted using non-stratified and stratified models of SR16 and the predictions were compared against corresponding ground reference values. Finally, the effect of different factors that might have influenced the prediction errors were analyzed using partial least squared regression (PLSR) to determine under which conditions the SR16 is less apt. The overall results across all plots were adequate (RMSE of 10%, MD of 2% for dominant and mean height; RMSE of 28%, MD of 4% for basal area; RMSE of 31%, MD of 5% for volume). However, when the accuracy was assessed locally for each inventory project, large differences in accuracy were observed. The MD% values for some inventory projects were substantial (>30% for basal area and volume). The results showed that stratification did not necessarily improve the results and that factors related to the forest structure had the greatest impact on the PLSR analysis.
{"title":"Accuracy assessment of the nationwide forest attribute map of Norway constructed by using airborne laser scanning data and field data from the national forest inventory","authors":"Ana de Lera Garrido, T. Gobakken, M. Hauglin, E. Næsset, O. Bollandsås","doi":"10.1080/02827581.2023.2184488","DOIUrl":"https://doi.org/10.1080/02827581.2023.2184488","url":null,"abstract":"ABSTRACT The aim of this study was to analyze the accuracy of predictions of dominant height, mean height, basal area, and volume from the nationwide forest attribute map (SR16). The analysis took advantage of field observations from 33 different forest inventory projects across Norway used for validation. Forest attributes for more than 5000 plots were predicted using non-stratified and stratified models of SR16 and the predictions were compared against corresponding ground reference values. Finally, the effect of different factors that might have influenced the prediction errors were analyzed using partial least squared regression (PLSR) to determine under which conditions the SR16 is less apt. The overall results across all plots were adequate (RMSE of 10%, MD of 2% for dominant and mean height; RMSE of 28%, MD of 4% for basal area; RMSE of 31%, MD of 5% for volume). However, when the accuracy was assessed locally for each inventory project, large differences in accuracy were observed. The MD% values for some inventory projects were substantial (>30% for basal area and volume). The results showed that stratification did not necessarily improve the results and that factors related to the forest structure had the greatest impact on the PLSR analysis.","PeriodicalId":21352,"journal":{"name":"Scandinavian Journal of Forest Research","volume":"38 1","pages":"9 - 22"},"PeriodicalIF":1.8,"publicationDate":"2023-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46334547","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 : 2023-02-13DOI: 10.1080/02827581.2023.2177336
R. Spinelli, N. Magagnotti, Barnabas Kovacs, Patrik Heger, M. Mihelič
ABSTRACT The study compared the cut-to-length (CTL) and the whole-tree-harvesting (WTH) methods under two alternative log length specifications (2 m vs. 4 m) as deployed in the new medium-rotation poplar plantations. The goal of this study was to determine if any of the four combinations of harvesting method and log length incurred lower cost and/or better log yield than the others. The test was conducted in a 6-year-old plantation with a stocking between 30 and 60 bone-dry tons (BDT) per hectare. Each treatment was repeated 8 times – each repetition consisting of one sample plot with a 700 m2 surface area (115–130 trees). Researchers determined the mass obtained from each sample plot, as well as the time necessary to turn standing trees into logs and biomass piled at the landing. A calculator was developed for estimating harvesting costs as a function of variable machine rates. Under the conditions of the study, CTL harvesting into 4-m long logs was the most effective solution, because it offered a better log yield compared with WTH (60% vs. 50%) and incurred the same harvesting cost (∼ 33 € BDT−1). Shortening log length to 2 m determined a 25% increase of harvesting cost.
摘要:本研究比较了两种不同原木长度规格(2 m和4 m)下的切尺采伐(CTL)和整树采伐(WTH)方法在新中轮杨林中的应用。本研究的目的是确定采伐方法和原木长度的四种组合中是否有一种比其他组合成本更低和/或产量更高。试验在一个有6年树龄的人工林中进行，每公顷放养30至60干干吨(BDT)。每个处理重复8次，每次重复包括一个700 m2表面积的样地(115-130棵树)。研究人员确定了从每个样地获得的质量，以及将站立的树木变成原木和堆积在着陆处的生物质所需的时间。开发了一种计算器，用于估计作为可变机器率函数的收获成本。在本研究条件下，将CTL采伐成4米长的原木是最有效的解决方案，因为与WTH相比，它提供了更好的原木产量(60% vs 50%)，并且采伐成本相同(~ 33€BDT−1)。将原木长度缩短至2米决定了采伐成本增加25%。
{"title":"Productivity and cost assessment of two harvesting methods for medium-rotation poplar plantations","authors":"R. Spinelli, N. Magagnotti, Barnabas Kovacs, Patrik Heger, M. Mihelič","doi":"10.1080/02827581.2023.2177336","DOIUrl":"https://doi.org/10.1080/02827581.2023.2177336","url":null,"abstract":"ABSTRACT The study compared the cut-to-length (CTL) and the whole-tree-harvesting (WTH) methods under two alternative log length specifications (2 m vs. 4 m) as deployed in the new medium-rotation poplar plantations. The goal of this study was to determine if any of the four combinations of harvesting method and log length incurred lower cost and/or better log yield than the others. The test was conducted in a 6-year-old plantation with a stocking between 30 and 60 bone-dry tons (BDT) per hectare. Each treatment was repeated 8 times – each repetition consisting of one sample plot with a 700 m2 surface area (115–130 trees). Researchers determined the mass obtained from each sample plot, as well as the time necessary to turn standing trees into logs and biomass piled at the landing. A calculator was developed for estimating harvesting costs as a function of variable machine rates. Under the conditions of the study, CTL harvesting into 4-m long logs was the most effective solution, because it offered a better log yield compared with WTH (60% vs. 50%) and incurred the same harvesting cost (∼ 33 € BDT−1). Shortening log length to 2 m determined a 25% increase of harvesting cost.","PeriodicalId":21352,"journal":{"name":"Scandinavian Journal of Forest Research","volume":"38 1","pages":"79 - 86"},"PeriodicalIF":1.8,"publicationDate":"2023-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42544234","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 : 2023-01-27DOI: 10.1080/02827581.2023.2168045
R. Jonsson, M. Rönnqvist, P. Flisberg, Petrus Jönsson, O. Lindroos
ABSTRACT There is a need to decrease the costs of cut-to-length operations. The harwarder, a one-machine system with the potential to reduce the costs, has been compared to the two-machine system (TMS) at the stand and regional levels but not at the national level, which is important as basis for decision to implement. The objective was therefore to analyze its potential on a large scale in Swedish final fellings. It was evaluated using two modeling approaches in conjunction with data representing around 30% of Sweden’s yearly final fellings from five forestry organizations. The analyses revealed that total costs could be reduced by around 3% if up to 50% of the total volume was logged using harwarders rather than the TMS. This would require the introduction of up to 250 harwarders into machine fleets that currently use only the TMS. The two modeling approaches gave similar results. It was concluded that the harwarder may need to demonstrate greater potential to justify a full-scale implementation in Swedish forestry, but the machine could be improved through technological development, especially through automation.
{"title":"Country-wide analysis of the potential use of harwarders for final fellings in Sweden","authors":"R. Jonsson, M. Rönnqvist, P. Flisberg, Petrus Jönsson, O. Lindroos","doi":"10.1080/02827581.2023.2168045","DOIUrl":"https://doi.org/10.1080/02827581.2023.2168045","url":null,"abstract":"ABSTRACT There is a need to decrease the costs of cut-to-length operations. The harwarder, a one-machine system with the potential to reduce the costs, has been compared to the two-machine system (TMS) at the stand and regional levels but not at the national level, which is important as basis for decision to implement. The objective was therefore to analyze its potential on a large scale in Swedish final fellings. It was evaluated using two modeling approaches in conjunction with data representing around 30% of Sweden’s yearly final fellings from five forestry organizations. The analyses revealed that total costs could be reduced by around 3% if up to 50% of the total volume was logged using harwarders rather than the TMS. This would require the introduction of up to 250 harwarders into machine fleets that currently use only the TMS. The two modeling approaches gave similar results. It was concluded that the harwarder may need to demonstrate greater potential to justify a full-scale implementation in Swedish forestry, but the machine could be improved through technological development, especially through automation.","PeriodicalId":21352,"journal":{"name":"Scandinavian Journal of Forest Research","volume":"38 1","pages":"105 - 120"},"PeriodicalIF":1.8,"publicationDate":"2023-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44319717","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 : 2023-01-23DOI: 10.1080/02827581.2023.2168043
A. Roos, Elias Hurmekoski, L. Häyrinen, J. Jussila, K. Lähtinen, C. Mark-Herbert, E. Nagy, R. Toivonen, A. Toppinen
ABSTRACT People have different beliefs about the environmental impact of forest products. This quantitative web-survey study investigated public beliefs in Finland and Sweden about the environmental and climate impacts of using wood as a construction material for multi-story buildings. It was conducted with consumer panels reflecting the average populations of the two countries. The study analyzed factors affecting beliefs that multi-story Wood Buildings: (1) contribute to mitigating global warming, and (2) adversely impact biodiversity and the climate. It used consumer panel and multivariate statistics. Favorable climate-related beliefs were associated with Finnish nationality, male gender, age, children in household, university degree, and beliefs that climate change is induced by humans and causes weather disasters. Beliefs that wood buildings drive global warming and harm biodiversity were associated with non-rural residence, female gender, young age, children in household, low income, and beliefs that climate change causes weather disasters. No associations were recorded for current residence types. These findings highlight the importance of the wood construction industry to improve, document, and communicate to the public its impact on climate and biodiversity. They also indicate how market information can be formulated and targeted to communicate an accurate environmental image of wood construction.
{"title":"Beliefs on environmental impact of wood construction","authors":"A. Roos, Elias Hurmekoski, L. Häyrinen, J. Jussila, K. Lähtinen, C. Mark-Herbert, E. Nagy, R. Toivonen, A. Toppinen","doi":"10.1080/02827581.2023.2168043","DOIUrl":"https://doi.org/10.1080/02827581.2023.2168043","url":null,"abstract":"ABSTRACT People have different beliefs about the environmental impact of forest products. This quantitative web-survey study investigated public beliefs in Finland and Sweden about the environmental and climate impacts of using wood as a construction material for multi-story buildings. It was conducted with consumer panels reflecting the average populations of the two countries. The study analyzed factors affecting beliefs that multi-story Wood Buildings: (1) contribute to mitigating global warming, and (2) adversely impact biodiversity and the climate. It used consumer panel and multivariate statistics. Favorable climate-related beliefs were associated with Finnish nationality, male gender, age, children in household, university degree, and beliefs that climate change is induced by humans and causes weather disasters. Beliefs that wood buildings drive global warming and harm biodiversity were associated with non-rural residence, female gender, young age, children in household, low income, and beliefs that climate change causes weather disasters. No associations were recorded for current residence types. These findings highlight the importance of the wood construction industry to improve, document, and communicate to the public its impact on climate and biodiversity. They also indicate how market information can be formulated and targeted to communicate an accurate environmental image of wood construction.","PeriodicalId":21352,"journal":{"name":"Scandinavian Journal of Forest Research","volume":"38 1","pages":"49 - 57"},"PeriodicalIF":1.8,"publicationDate":"2023-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45696714","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 : 2023-01-23DOI: 10.1080/02827581.2023.2168044
Abbas Şahi̇n, Gafura Aylak Ozdemir, O. Oral, Batin Latif Aylak, Murat Ince, Emrah Ozdemir
ABSTRACT In this study, in order to estimate total tree height, three different model structures with different input variables were produced through the use of 872 tree data points obtained from different development stages and sites in coppice-originated pure sessile oak (Quercus petraea [Matt.] Liebl.) stands. These models were fitted with machine learning techniques such as artificial neural networks (ANNs), decision trees, support vector machines, and random forests. In addition, the model based on DBH was fitted and its parameters were calculated using the ordinary nonlinear least squares method and this model was selected as the best model in Model 1. In other model structures, ANN model was chosen as the best estimation method based on the relative ranking method in which the goodness of fit statistics of the estimation methods were evaluated together. The inclusion of stand variables in addition to the DBH measurement in the model increased the R 2 by about 36% and reduced the error rate by 55%.
{"title":"Estimation of tree height with machine learning techniques in coppice-originated pure sessile oak (Quercus petraea (Matt.) Liebl.) stands","authors":"Abbas Şahi̇n, Gafura Aylak Ozdemir, O. Oral, Batin Latif Aylak, Murat Ince, Emrah Ozdemir","doi":"10.1080/02827581.2023.2168044","DOIUrl":"https://doi.org/10.1080/02827581.2023.2168044","url":null,"abstract":"ABSTRACT In this study, in order to estimate total tree height, three different model structures with different input variables were produced through the use of 872 tree data points obtained from different development stages and sites in coppice-originated pure sessile oak (Quercus petraea [Matt.] Liebl.) stands. These models were fitted with machine learning techniques such as artificial neural networks (ANNs), decision trees, support vector machines, and random forests. In addition, the model based on DBH was fitted and its parameters were calculated using the ordinary nonlinear least squares method and this model was selected as the best model in Model 1. In other model structures, ANN model was chosen as the best estimation method based on the relative ranking method in which the goodness of fit statistics of the estimation methods were evaluated together. The inclusion of stand variables in addition to the DBH measurement in the model increased the R 2 by about 36% and reduced the error rate by 55%.","PeriodicalId":21352,"journal":{"name":"Scandinavian Journal of Forest Research","volume":"38 1","pages":"87 - 96"},"PeriodicalIF":1.8,"publicationDate":"2023-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49049919","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 : 2022-11-17DOI: 10.1080/02827581.2022.2155235
K. Aun, M. Kukumägi, M. Varik, M. Uri, M. Buht, J. Aosaar, A. Padari, A. Sepaste, K. Soosaar, H. Becker, V. Uri
ABSTRACT Clear-cutting is an extensively used silvicultural method in the Nordic and Baltic countries, which strongly influences the site’s carbon (C) budget. In the current study, C budgets for a young silver birch stand chronosequence (2–8-year-old) were compiled using the C budgeting method. High variability of annual NEP between stands of similar ages occurred, as the C accumulation ability of young stands was site specific. Heterotrophic respiration (Rh), the main C efflux from the ecosystem, varied between (3.7 and 6.3 t C ha−1 yr−1) across all stands. Modelling of the annual NEP dynamics across the chronosequence revealed the C compensation point at a stand age of 6 years. The estimated cumulative C loss for the period when NEP was negative was almost 5 t C ha−1 and the amount of lost C could have been recaptured already in a 10-year-old stand. The C sink capacity of the studied sites depended mostly on the production of herbaceous plants until the production of the new tree generation became the main driver of ecosystem’s net primary production. Hence, site’s C accumulation capacity largely depends on the density and quality of the new forest regeneration.
在北欧和波罗的海国家，采伐是一种广泛使用的造林方法，它强烈地影响了场地的碳(C)预算。本研究采用C预算法编制了幼龄白桦林分(2 ~ 8年)的C预算。相似林龄林分的年NEP具有较高的变异性，这是因为幼林的碳积累能力具有立地特异性。各林分的异养呼吸(Rh)，即生态系统的主要碳流出量，在(3.7 - 6.3 t C / ha - 1 yr - 1)之间变化。跨时间序列的年度NEP动态建模揭示了林龄为6年的C补偿点。在NEP为负的时期，估计的累积碳损失几乎为5 t cha - 1，损失的碳量可能已经在一个10年的林分中重新获得。研究样地的碳汇容量主要依赖于草本植物的生产，直到新一代乔木的生产成为生态系统净初级生产的主要驱动力。因此，立地的碳积累能力在很大程度上取决于新林更新的密度和质量。
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