Pub Date : 2022-01-02DOI: 10.2989/20702620.2021.2017762
K. T. Barbosa, A. Acosta, M. Lazarotto, R. Beltrame, Claudia Fernanda Lemons e Silva, C. Fior
Australian red cedar (Toona ciliata M. Roem.) is a forest species planted in Brazil especially for lumber production. This study aimed to evaluate technological properties of the wood after selective first thinning of a plantation 5 years after planting. The technological properties evaluated were: (i) physical – apparent specific mass at 12% moisture content and shrinkage; (ii) mechanical – modulus of elasticity (E), modulus of rupture (σ), and brittleness; (iii) weathering; (iv) surface macrostructure – colour and roughness; (v) chemical – soluble and insoluble lignins, and holocellulose and ash contents; and vi) thermal – thermogravimetric analysis and calorific value. Apparent specific mass was 380 g m−3; the calculated shrinkage anisotropy of 1.04 and swelling anisotropy of 1.14 fit the classification ‘excellent quality’; the elasticity modulus was calculated as 4 700 MPa, and strength to flexion was 45 MPa. The mechanical properties other than brittleness were not compromised with weathering exposure. However, the accelerated weathering testing as a simulation of natural weathering showed modified colour of the wood and reduction of the mechanical properties. The calorific value of the wood (4 634.03 Kcal g−1) was similar to that reported for other fast-growing woods at even more advanced planting ages. Thermal stability of the wood was comparable to other fast-growing species used for energy purposes, owing especially to high holocellulose content.
澳大利亚红雪松(Toona ciliata M. Roem.)是一种种植在巴西的森林树种，特别用于木材生产。本研究旨在评价种植5年后选择性第一次间伐后木材的技术性能。技术性能评估如下:(i)物理- 12%含水率下的表观比质量和收缩率;(ii)力学——弹性模量(E)、断裂模量(σ)和脆性;(3)风化;(iv)表面宏观结构——颜色和粗糙度;(v)化学可溶性和不可溶性木质素，以及纤维素和灰分含量;热-热重分析和热值。表观比质量为380 g m−3;计算得到的收缩各向异性为1.04，膨胀各向异性为1.14，符合“优良”等级;弹性模量为4700 MPa，抗弯强度为45 MPa。除脆性外，其力学性能不受风化暴露的影响。然而，模拟自然风化的加速老化试验表明，木材的颜色发生了变化，机械性能下降。该木材的热值为4 634.03 Kcal g−1，与其他速生木材在更早种植年龄时的热值相似。木材的热稳定性可与用于能源目的的其他速生树种相媲美，特别是由于高纤维素含量。
{"title":"Technological characterisation of wood from Australian red cedar after first thinning of a plantation at five years","authors":"K. T. Barbosa, A. Acosta, M. Lazarotto, R. Beltrame, Claudia Fernanda Lemons e Silva, C. Fior","doi":"10.2989/20702620.2021.2017762","DOIUrl":"https://doi.org/10.2989/20702620.2021.2017762","url":null,"abstract":"Australian red cedar (Toona ciliata M. Roem.) is a forest species planted in Brazil especially for lumber production. This study aimed to evaluate technological properties of the wood after selective first thinning of a plantation 5 years after planting. The technological properties evaluated were: (i) physical – apparent specific mass at 12% moisture content and shrinkage; (ii) mechanical – modulus of elasticity (E), modulus of rupture (σ), and brittleness; (iii) weathering; (iv) surface macrostructure – colour and roughness; (v) chemical – soluble and insoluble lignins, and holocellulose and ash contents; and vi) thermal – thermogravimetric analysis and calorific value. Apparent specific mass was 380 g m−3; the calculated shrinkage anisotropy of 1.04 and swelling anisotropy of 1.14 fit the classification ‘excellent quality’; the elasticity modulus was calculated as 4 700 MPa, and strength to flexion was 45 MPa. The mechanical properties other than brittleness were not compromised with weathering exposure. However, the accelerated weathering testing as a simulation of natural weathering showed modified colour of the wood and reduction of the mechanical properties. The calorific value of the wood (4 634.03 Kcal g−1) was similar to that reported for other fast-growing woods at even more advanced planting ages. Thermal stability of the wood was comparable to other fast-growing species used for energy purposes, owing especially to high holocellulose content.","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75324320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-02DOI: 10.2989/20702620.2021.2011468
Thaynara Reis, Simone Silva, Ivaldo Tavares Junior, R. Leite, M. Taquetti, Kemely Atanazio, L. Fardin, J. Cruz, H. Leite
Growth and yield estimates are extremely important for forest stand management. The application of simple models is often useful, as it allows the use of plots with few or a single measurement. The objective of this study was to evaluate methods for modelling eucalypt stand volume under different conditions of climate and soil. We fitted the Gompertz, Logistic and Exponential models, stratifying by project and for the entire data set, to model the dominant height and volume based on the usual validation statistics and residue analyses. To model growth and yield, five alternatives were evaluated: the Gompertz, Logistic and Exponential models, exponential-modified with the inclusion of the variable site index (SI) and the Clutter model. The best model was selected based on the validation statistics and the histogram of the relative error (RE). We conclude that the stratification by project presented greater accuracy of forecast. The best model to estimate yield was the exponential model modified with the inclusion of the variable SI. The technical age of cutting ranged from 36 months, in areas of higher productivity, to 84 months, in areas with low productivity.
{"title":"Assessing alternatives for growth and yield modelling in eucalypt stands","authors":"Thaynara Reis, Simone Silva, Ivaldo Tavares Junior, R. Leite, M. Taquetti, Kemely Atanazio, L. Fardin, J. Cruz, H. Leite","doi":"10.2989/20702620.2021.2011468","DOIUrl":"https://doi.org/10.2989/20702620.2021.2011468","url":null,"abstract":"Growth and yield estimates are extremely important for forest stand management. The application of simple models is often useful, as it allows the use of plots with few or a single measurement. The objective of this study was to evaluate methods for modelling eucalypt stand volume under different conditions of climate and soil. We fitted the Gompertz, Logistic and Exponential models, stratifying by project and for the entire data set, to model the dominant height and volume based on the usual validation statistics and residue analyses. To model growth and yield, five alternatives were evaluated: the Gompertz, Logistic and Exponential models, exponential-modified with the inclusion of the variable site index (SI) and the Clutter model. The best model was selected based on the validation statistics and the histogram of the relative error (RE). We conclude that the stratification by project presented greater accuracy of forecast. The best model to estimate yield was the exponential model modified with the inclusion of the variable SI. The technical age of cutting ranged from 36 months, in areas of higher productivity, to 84 months, in areas with low productivity.","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90292649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-02DOI: 10.2989/20702620.2021.2019563
Imani A. Kikoti, C. Mligo, H. Ndangalasi
Anthropogenic modification of montane forests to other land uses has significant effects on native vegetation and the ecological functions of plant communities, such as in the forests of Mount Kilimanjaro. This study was carried out in Kilimanjaro National Park at the former Engushai forest village, where local people were relocated for conservation in 2006. Forty 20 × 50 m plots were established in areas with different historical land use (former settlement, former cultivation, transition and natural forest). We recorded 132 plant species, representing 114 genera and 58 families. The highest tree species richness was recorded in the forest zone (11 ± 1 per plot), followed by in the transition zone (7 ± 1), former cultivation zone (4 ± 1) and former settlement zone (4 ± 0.4). The natural forest was more diverse in terms of tree species than other sites (H’ = 1.83 ± 0.09, evenness of 0.48 ± 0.02). Analysis of variance showed significant variation in tree species richness, diversity index and evenness among previously disturbed sites and natural forests. The vegetation is at an early stage of succession in anthropogenically impacted areas. However, the domination of Vernonia lasiopus and Bothriocline longipes in the formerly degraded areas was crucial for restoring the microclimate and soil fertility vital for forest development. There is adequate potential for and patterns of natural regeneration of indigenous trees in the anthropogenically impacted areas. The current passive management by Kilimanjaro National Park facilitates forest recovery, indicating the high resilience of these montane forests. It is recommended to monitor the future recovery and succession of the lower montane forest.
{"title":"Assessment of plant species composition and natural regeneration in abandoned settlements in the lower montane forest of Kilimanjaro National Park, Tanzania","authors":"Imani A. Kikoti, C. Mligo, H. Ndangalasi","doi":"10.2989/20702620.2021.2019563","DOIUrl":"https://doi.org/10.2989/20702620.2021.2019563","url":null,"abstract":"Anthropogenic modification of montane forests to other land uses has significant effects on native vegetation and the ecological functions of plant communities, such as in the forests of Mount Kilimanjaro. This study was carried out in Kilimanjaro National Park at the former Engushai forest village, where local people were relocated for conservation in 2006. Forty 20 × 50 m plots were established in areas with different historical land use (former settlement, former cultivation, transition and natural forest). We recorded 132 plant species, representing 114 genera and 58 families. The highest tree species richness was recorded in the forest zone (11 ± 1 per plot), followed by in the transition zone (7 ± 1), former cultivation zone (4 ± 1) and former settlement zone (4 ± 0.4). The natural forest was more diverse in terms of tree species than other sites (H’ = 1.83 ± 0.09, evenness of 0.48 ± 0.02). Analysis of variance showed significant variation in tree species richness, diversity index and evenness among previously disturbed sites and natural forests. The vegetation is at an early stage of succession in anthropogenically impacted areas. However, the domination of Vernonia lasiopus and Bothriocline longipes in the formerly degraded areas was crucial for restoring the microclimate and soil fertility vital for forest development. There is adequate potential for and patterns of natural regeneration of indigenous trees in the anthropogenically impacted areas. The current passive management by Kilimanjaro National Park facilitates forest recovery, indicating the high resilience of these montane forests. It is recommended to monitor the future recovery and succession of the lower montane forest.","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81412801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-02DOI: 10.2989/20702620.2021.1976604
T. S. Batista, L. P. Teodoro, G. B. D. Azevedo, G. T. D. O. S. Azevedo, Nerison Luis Poersch, Marcus Vinicius Vieira Borges, P. Teodoro
Wood volume is the variable that best represents the yield of planted forests, and several regression models are used in its estimation. Artificial neural networks (ANNs) are recognised for their accuracy and generalisation capacity associated with the quality and quantity of data in training and validation. Box–Müller transformation generates random variables from the original data and provides a consistent dataset. Given the above, the hypothesis of this research is that the expansion of data by the Box–Müller theorem provides more accurate estimates for predicting wood volume in eucalyptus species. The objectives were to (i) to evaluate the efficiency of the Box–Müller method for expanding the dataset of eucalyptus sample tree cubing, (ii) use different ANN topologies to predict the wood volume of different Eucalyptus species, and (iii) compare the estimates with those obtained by using the Schumacher and Hall model. The experimental design used randomised blocks with four replicates, composed of the following treatments: Corymbia citriodora and different Eucalyptus species. Sample trees were cubed at ages 2 years and 4.5 years. The estimated volume was obtained using the Schumacher and Hall non-linear regression model for each species and compared with the ANNs through Pearson’s correlation, and root mean square error at the steps training, validation, and utilisation. Two ANN architectures were tested, multilayer perceptron (MLP) and radial basis function (RBF). Dataset expansion of cut-down sample trees for cubing is efficient and can be used for ANNs training when there are cubing restrictions of sample size. The topology with seven neurons in the first hidden layer and 12 in the second with expanded data of RBF showed better performance for predicting wood volume. When evaluating all species, the accuracy of the estimates provided by ANNs was higher than that obtained with non-linear regression.
木材体积是最能代表人工林产量的变量，在估算中使用了几种回归模型。人工神经网络(ann)因其准确性和泛化能力而得到认可，这与训练和验证中数据的质量和数量有关。box - m ller变换从原始数据生成随机变量，并提供一致的数据集。综上所述，本研究的假设是，通过box - m ller定理对数据进行扩展，可以为预测桉树树种的木材体积提供更准确的估计。目的是(i)评估box - m ller方法扩展桉树样本立方体数据集的效率，(ii)使用不同的人工神经网络拓扑来预测不同桉树物种的木材体积，以及(iii)将估计结果与使用Schumacher和Hall模型获得的估计结果进行比较。试验设计采用随机区组，每组4个重复，分别采用枸杞和不同桉树品种处理。样本树分别在2岁和4.5岁时被立方体化。使用Schumacher和Hall非线性回归模型获得每个物种的估计体积，并通过Pearson相关和训练、验证和利用步骤的均方根误差与人工神经网络进行比较。测试了两种神经网络结构:多层感知器(MLP)和径向基函数(RBF)。对砍断样本树进行数据扩展进行立方化是一种有效的方法，可以在样本量有立方化限制的情况下用于人工神经网络的训练。第一隐层7个神经元，第二隐层12个神经元，扩展RBF数据的拓扑结构对木材体积的预测效果更好。在评估所有物种时，人工神经网络提供的估计精度高于非线性回归的估计精度。
{"title":"Artificial neural networks and non-linear regression for quantifying the wood volume in Eucalyptus species","authors":"T. S. Batista, L. P. Teodoro, G. B. D. Azevedo, G. T. D. O. S. Azevedo, Nerison Luis Poersch, Marcus Vinicius Vieira Borges, P. Teodoro","doi":"10.2989/20702620.2021.1976604","DOIUrl":"https://doi.org/10.2989/20702620.2021.1976604","url":null,"abstract":"Wood volume is the variable that best represents the yield of planted forests, and several regression models are used in its estimation. Artificial neural networks (ANNs) are recognised for their accuracy and generalisation capacity associated with the quality and quantity of data in training and validation. Box–Müller transformation generates random variables from the original data and provides a consistent dataset. Given the above, the hypothesis of this research is that the expansion of data by the Box–Müller theorem provides more accurate estimates for predicting wood volume in eucalyptus species. The objectives were to (i) to evaluate the efficiency of the Box–Müller method for expanding the dataset of eucalyptus sample tree cubing, (ii) use different ANN topologies to predict the wood volume of different Eucalyptus species, and (iii) compare the estimates with those obtained by using the Schumacher and Hall model. The experimental design used randomised blocks with four replicates, composed of the following treatments: Corymbia citriodora and different Eucalyptus species. Sample trees were cubed at ages 2 years and 4.5 years. The estimated volume was obtained using the Schumacher and Hall non-linear regression model for each species and compared with the ANNs through Pearson’s correlation, and root mean square error at the steps training, validation, and utilisation. Two ANN architectures were tested, multilayer perceptron (MLP) and radial basis function (RBF). Dataset expansion of cut-down sample trees for cubing is efficient and can be used for ANNs training when there are cubing restrictions of sample size. The topology with seven neurons in the first hidden layer and 12 in the second with expanded data of RBF showed better performance for predicting wood volume. When evaluating all species, the accuracy of the estimates provided by ANNs was higher than that obtained with non-linear regression.","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80647382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-02DOI: 10.2989/20702620.2022.2045879
N. Ndlovu, K. Little, B. Baillie, C. Rolando
Pesticides are important for the management of pests and diseases that have a negative impact on the sustainability of the forestry industry. Nevertheless, there is a trend to reduce pesticide use owing to the potential detrimental impacts they pose to terrestrial and aquatic environments and human health. This study aimed to determine the extent of South African forestry-related research that has been conducted on the environmental behaviour, fate and risks associated with pesticides used operationally within South African forest plantations. A second aim was to determine the potential risks posed by pesticides used within the South African forestry industry to terrestrial and aquatic environments. This was achieved through an extensive review of field studies and/or studies that consider field-relevant exposures of pesticides used within South African plantations. It was determined that although pesticide environmental fate studies have been conducted within plantations abroad and within South African agriculture, no studies have been conducted within the South African forestry industry to understand the actual impact of the currently used pesticides to the environment. Since pesticide environmental fate is complex and dependent on a variety of local conditions and use patterns, conclusions obtained from the studies reviewed here can only be used in part to effectively guide South African forestry-relevant pesticide-related legislation and decisions of certification bodies. Consequently, field studies that determine the environmental fate of pesticides under South African plantation silvicultural regimes and environmental conditions are necessary.
{"title":"An evaluation of the environmental behaviour, fate and risk of key pesticides used in South African forest plantations","authors":"N. Ndlovu, K. Little, B. Baillie, C. Rolando","doi":"10.2989/20702620.2022.2045879","DOIUrl":"https://doi.org/10.2989/20702620.2022.2045879","url":null,"abstract":"Pesticides are important for the management of pests and diseases that have a negative impact on the sustainability of the forestry industry. Nevertheless, there is a trend to reduce pesticide use owing to the potential detrimental impacts they pose to terrestrial and aquatic environments and human health. This study aimed to determine the extent of South African forestry-related research that has been conducted on the environmental behaviour, fate and risks associated with pesticides used operationally within South African forest plantations. A second aim was to determine the potential risks posed by pesticides used within the South African forestry industry to terrestrial and aquatic environments. This was achieved through an extensive review of field studies and/or studies that consider field-relevant exposures of pesticides used within South African plantations. It was determined that although pesticide environmental fate studies have been conducted within plantations abroad and within South African agriculture, no studies have been conducted within the South African forestry industry to understand the actual impact of the currently used pesticides to the environment. Since pesticide environmental fate is complex and dependent on a variety of local conditions and use patterns, conclusions obtained from the studies reviewed here can only be used in part to effectively guide South African forestry-relevant pesticide-related legislation and decisions of certification bodies. Consequently, field studies that determine the environmental fate of pesticides under South African plantation silvicultural regimes and environmental conditions are necessary.","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82526111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-02DOI: 10.2989/20702620.2021.2005454
Myriam Solís, M. Wingfield, Izette Greyling, N. Q. Pham
Eucalypt plantations in South Africa make up an important part of the local forestry industry. Recently, one-year-old nursery plants of a Eucalyptus grandis × Eucalyptus urophylla variety displayed symptoms of leaf and shoot anthracnose disease. Samples were collected from these plants and isolations were made from the disease symptoms. Isolates were identified based on their morphological characteristics and DNA sequence data for eight gene regions. Phylogenetic analyses led to the isolates being identified as Colletotrichum theobromicola and the reduction of Colletotrichum pseudotheobromicola to synonymy with the former species. Pathogenicity trials with isolates of C. theobromicola were conducted on clones of E. grandis and hybrids of E. grandis × E. urophylla and E. grandis × Eucalyptus camaldulensis. Resulting symptoms were similar to those found on naturally infected plants and the fungus was re-isolated from the infections. Colletotrichum theobromicola is known to cause anthracnose on various plants including eucalypts in Brazil, but this is the first record of the pathogen in South Africa.
{"title":"A serious shoot and leaf disease caused by Colletotrichum theobromicola discovered on eucalypts in South Africa","authors":"Myriam Solís, M. Wingfield, Izette Greyling, N. Q. Pham","doi":"10.2989/20702620.2021.2005454","DOIUrl":"https://doi.org/10.2989/20702620.2021.2005454","url":null,"abstract":"Eucalypt plantations in South Africa make up an important part of the local forestry industry. Recently, one-year-old nursery plants of a Eucalyptus grandis × Eucalyptus urophylla variety displayed symptoms of leaf and shoot anthracnose disease. Samples were collected from these plants and isolations were made from the disease symptoms. Isolates were identified based on their morphological characteristics and DNA sequence data for eight gene regions. Phylogenetic analyses led to the isolates being identified as Colletotrichum theobromicola and the reduction of Colletotrichum pseudotheobromicola to synonymy with the former species. Pathogenicity trials with isolates of C. theobromicola were conducted on clones of E. grandis and hybrids of E. grandis × E. urophylla and E. grandis × Eucalyptus camaldulensis. Resulting symptoms were similar to those found on naturally infected plants and the fungus was re-isolated from the infections. Colletotrichum theobromicola is known to cause anthracnose on various plants including eucalypts in Brazil, but this is the first record of the pathogen in South Africa.","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82837044","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-02DOI: 10.2989/20702620.2021.1994343
Qiangqiang Cheng, Dejia Ji, Xiaoyan Guo, Honglang Huang, Lu Zhang
Toona ciliata var. pubescens (family Meliaceae) is an endangered species of mahogany endemic to China. It is now under Class II protection, and stem cuttings are an important means for its clonal propagation. However, the metabolic changes that occur in the cuttings during adventitious root formation and how these are influenced by indole-3-butyric acid (IBA) are still unclear. This study investigated the influence of cutting positions (top, middle and base) on the rooting ability and the associated metabolic changes during adventitious root formation. We compared treatment with 800 mg l−1 IBA with controls. The results showed that the rooting percentage, taproots per cutting, and longest root length differed significantly depending on the cutting position. Base cuttings had the best rooting ability and exhibited the highest average rooting percentage, the longest roots, and most taproots per cutting. The contents of soluble sugar, starch, non-structural carbohydrates (NSCs) and soluble proteins, and the peroxidase (POD) activity, were significantly higher in base cuttings than in middle and top cuttings; however, polyphenol oxidase (PPO) activity did not differ significantly among the positions. Metabolic changes occurred during the cutting process. The levels of POD and PPO activities increased significantly until 20 days after planting, suggesting that this period is key for the induction of adventitious rooting in this species. In the rooting process, IBA promoted an increase in the contents of soluble sugar, starch, NSCs and soluble proteins in the stem cuttings and it also increased the activities of POD and PPO. Bark-water extract from the stem cuttings inhibited the germination of Chinese cabbage seeds in a concentration-dependent manner, irrespective of the cutting position.
{"title":"Endogenous metabolic content of the cutting positions and ndole-3-butyric acid influence rooting of Toona ciliata var. pubescens stem cuttings","authors":"Qiangqiang Cheng, Dejia Ji, Xiaoyan Guo, Honglang Huang, Lu Zhang","doi":"10.2989/20702620.2021.1994343","DOIUrl":"https://doi.org/10.2989/20702620.2021.1994343","url":null,"abstract":"Toona ciliata var. pubescens (family Meliaceae) is an endangered species of mahogany endemic to China. It is now under Class II protection, and stem cuttings are an important means for its clonal propagation. However, the metabolic changes that occur in the cuttings during adventitious root formation and how these are influenced by indole-3-butyric acid (IBA) are still unclear. This study investigated the influence of cutting positions (top, middle and base) on the rooting ability and the associated metabolic changes during adventitious root formation. We compared treatment with 800 mg l−1 IBA with controls. The results showed that the rooting percentage, taproots per cutting, and longest root length differed significantly depending on the cutting position. Base cuttings had the best rooting ability and exhibited the highest average rooting percentage, the longest roots, and most taproots per cutting. The contents of soluble sugar, starch, non-structural carbohydrates (NSCs) and soluble proteins, and the peroxidase (POD) activity, were significantly higher in base cuttings than in middle and top cuttings; however, polyphenol oxidase (PPO) activity did not differ significantly among the positions. Metabolic changes occurred during the cutting process. The levels of POD and PPO activities increased significantly until 20 days after planting, suggesting that this period is key for the induction of adventitious rooting in this species. In the rooting process, IBA promoted an increase in the contents of soluble sugar, starch, NSCs and soluble proteins in the stem cuttings and it also increased the activities of POD and PPO. Bark-water extract from the stem cuttings inhibited the germination of Chinese cabbage seeds in a concentration-dependent manner, irrespective of the cutting position.","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79161900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-02DOI: 10.2989/20702620.2021.1997067
Luiza Marina Esteves de Carvalho, A. Melo, G. Umbelino, J. Mund, Jhonathan Gomes dos Santos, J. Rosette, Daniel Silveira, E. Gorgens
The charcoal stock in a forestry business is controlled based on the theoretical capacity of the masonry ovens (input) and shipped trucks (output). During the year, the company must monitor the stock for accountability reports and internal governance. This paper proposes a more efficient and precise survey method that overcomes the challenges of the common monitoring system in Brazil. In this study, a monitoring method based on digital stereoscopy from UAV images was implemented and evaluated. The results were compared with those of the traditional topographic survey based on RTK equipment. A multi-engine UAV, with an integrated global navigation satellite system (GNSS) and real-time kinematic positioning (RTK) equipment was used to fly over and survey a masonry oven complex containing eight charcoal heaps. Two stereoscopic processing methods were applied: (1) very low quality and (2) high quality to image alignment, reconstruction of a dense cloud, facet count and a three-dimensional mesh creation. Low-quality products showed geometric deformities when compared to high quality, but resulted in estimations similar to the topographic survey. Results indicated that the volume estimation of the charcoal heaps using UAV derived orthomosaics can replace the conventional method of GNSS RTK surveys with considerable gains in stockpile volume accuracy, inventory frequency and labour safety. The high quality processing method registered improvements in geometric precision and accuracy.
{"title":"Charcoal heaps volume estimation based on unmanned aerial vehicles","authors":"Luiza Marina Esteves de Carvalho, A. Melo, G. Umbelino, J. Mund, Jhonathan Gomes dos Santos, J. Rosette, Daniel Silveira, E. Gorgens","doi":"10.2989/20702620.2021.1997067","DOIUrl":"https://doi.org/10.2989/20702620.2021.1997067","url":null,"abstract":"The charcoal stock in a forestry business is controlled based on the theoretical capacity of the masonry ovens (input) and shipped trucks (output). During the year, the company must monitor the stock for accountability reports and internal governance. This paper proposes a more efficient and precise survey method that overcomes the challenges of the common monitoring system in Brazil. In this study, a monitoring method based on digital stereoscopy from UAV images was implemented and evaluated. The results were compared with those of the traditional topographic survey based on RTK equipment. A multi-engine UAV, with an integrated global navigation satellite system (GNSS) and real-time kinematic positioning (RTK) equipment was used to fly over and survey a masonry oven complex containing eight charcoal heaps. Two stereoscopic processing methods were applied: (1) very low quality and (2) high quality to image alignment, reconstruction of a dense cloud, facet count and a three-dimensional mesh creation. Low-quality products showed geometric deformities when compared to high quality, but resulted in estimations similar to the topographic survey. Results indicated that the volume estimation of the charcoal heaps using UAV derived orthomosaics can replace the conventional method of GNSS RTK surveys with considerable gains in stockpile volume accuracy, inventory frequency and labour safety. The high quality processing method registered improvements in geometric precision and accuracy.","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86188780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-02DOI: 10.2989/20702620.2021.1994345
Ivaldo da Silva Tavares Júnior, Jianne Rafaela Mazzini de Souza, L. S. D. S. Lopes, L. Fardin, G. G. Casas, Ricardo Rodrigues de Oliveira Neto, R. Leite, H. Leite
The quantification of a stand’s wood stock is one of the most important procedures for Tectona spp. (teak) management. An optimal method for estimating tree volume must accommodate the variation of the data collected in the inventory. This study evaluated alternative methods to estimate the volume on stems of teak trees. We cut and measured the outside bark, inside bark, and heartwood diameters at heights of 0.1, 0.5, 1.5 m and every meter thereafter until the minimum outside bark diameter reached 3 cm, using 180 trees of ages 3 to 12 years. We tested two approaches (A1 and A2) to estimate stem volumes of the outside bark, inside bark, and heartwood (v ob, v ib and v hw, respectively): modelling the tree volume in A1, and the taper model in A2, with the techniques of regression, artificial neural network (ANN) and support vector regression (SVR). In addition, we obtained the percentages of heartwood, sapwood and bark in the stem. The accuracies of the estimates were evaluated using bias, correlation and root-mean-square error (RMSE). Validation was made for the outside bark, inside bark and heartwood volumes, and the outside bark, inside bark and heartwood diameters, from the taper models. In A1, the ANN technique more accurately predicted v ob and v ib, with RMSE% values of 18.88% and 18.54%, respectively; for v hw, the regression technique was more accurate, with RMSE% equal to 26.87%. In A2, the regression technique obtained the highest precision in the prediction of v ob, v ib and v hw, with RMSE% values of 13.99%, 13.31% and 26.50%, respectively. Approach A2 showed more accurate results compared with A1 for predicting the multiple volumes of teak trees with the three tested techniques.
{"title":"Machine learning and regression models to predict multiple tree stem volumes for teak","authors":"Ivaldo da Silva Tavares Júnior, Jianne Rafaela Mazzini de Souza, L. S. D. S. Lopes, L. Fardin, G. G. Casas, Ricardo Rodrigues de Oliveira Neto, R. Leite, H. Leite","doi":"10.2989/20702620.2021.1994345","DOIUrl":"https://doi.org/10.2989/20702620.2021.1994345","url":null,"abstract":"The quantification of a stand’s wood stock is one of the most important procedures for Tectona spp. (teak) management. An optimal method for estimating tree volume must accommodate the variation of the data collected in the inventory. This study evaluated alternative methods to estimate the volume on stems of teak trees. We cut and measured the outside bark, inside bark, and heartwood diameters at heights of 0.1, 0.5, 1.5 m and every meter thereafter until the minimum outside bark diameter reached 3 cm, using 180 trees of ages 3 to 12 years. We tested two approaches (A1 and A2) to estimate stem volumes of the outside bark, inside bark, and heartwood (v ob, v ib and v hw, respectively): modelling the tree volume in A1, and the taper model in A2, with the techniques of regression, artificial neural network (ANN) and support vector regression (SVR). In addition, we obtained the percentages of heartwood, sapwood and bark in the stem. The accuracies of the estimates were evaluated using bias, correlation and root-mean-square error (RMSE). Validation was made for the outside bark, inside bark and heartwood volumes, and the outside bark, inside bark and heartwood diameters, from the taper models. In A1, the ANN technique more accurately predicted v ob and v ib, with RMSE% values of 18.88% and 18.54%, respectively; for v hw, the regression technique was more accurate, with RMSE% equal to 26.87%. In A2, the regression technique obtained the highest precision in the prediction of v ob, v ib and v hw, with RMSE% values of 13.99%, 13.31% and 26.50%, respectively. Approach A2 showed more accurate results compared with A1 for predicting the multiple volumes of teak trees with the three tested techniques.","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87220399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-02DOI: 10.2989/20702620.2021.1936687
Irineu Barros Nunes, Eduardo da Silva Lopes, Millana Bürger Pagnussat, J. Arce
Extraction is the most costly and complicated stage of timber harvest operations. The forwarder’s productive capacity in timber harvesting, from planted forests, is influenced by several operational variables, especially by extraction distance and tree volume. Prior knowledge about the effect of these variables on the operation is required for efficient planning. The goal of this research was to model and simulate a forwarder productivity curve for timber extraction in scenarios with different tree average volumes (TAV) and average extraction distances (AED). The research was carried out in a forestry company in the state of Mato Grosso do Sul, Brazil, in clonal eucalyptus stands with TAV varying from 0.186 to 0.310 m3 tree−1 and AED from 0 to 280 m. We performed a time and motion study of the forwarder, following the operation with a DJI-Phantom 4 Advanced drone. Productivity simulations were carried out in different operational scenarios. The models were evaluated using the adjusted determination coefficients (R 2 adj.), standard error of absolute estimate and F-value. Results have shown that as the TAV increased, productivity also increased 14% while the AED presented a relationship inversely proportional to productivity. The highest productivity of the machine occurred in the forest condition with a TAV of 0.31 to 0.36 m3 tree−1 and in the shortest extraction distances. The best-adjusted model explained 46.3% of the machine’s productivity variation. We concluded that TAV and AED variables had a significant impact on the forwarder’s productivity and that it is important to obtain the machine’s productivity curves for efficient forest operations planning.
{"title":"Productivity curve models in eucalypt timber forwarding","authors":"Irineu Barros Nunes, Eduardo da Silva Lopes, Millana Bürger Pagnussat, J. Arce","doi":"10.2989/20702620.2021.1936687","DOIUrl":"https://doi.org/10.2989/20702620.2021.1936687","url":null,"abstract":"Extraction is the most costly and complicated stage of timber harvest operations. The forwarder’s productive capacity in timber harvesting, from planted forests, is influenced by several operational variables, especially by extraction distance and tree volume. Prior knowledge about the effect of these variables on the operation is required for efficient planning. The goal of this research was to model and simulate a forwarder productivity curve for timber extraction in scenarios with different tree average volumes (TAV) and average extraction distances (AED). The research was carried out in a forestry company in the state of Mato Grosso do Sul, Brazil, in clonal eucalyptus stands with TAV varying from 0.186 to 0.310 m3 tree−1 and AED from 0 to 280 m. We performed a time and motion study of the forwarder, following the operation with a DJI-Phantom 4 Advanced drone. Productivity simulations were carried out in different operational scenarios. The models were evaluated using the adjusted determination coefficients (R 2 adj.), standard error of absolute estimate and F-value. Results have shown that as the TAV increased, productivity also increased 14% while the AED presented a relationship inversely proportional to productivity. The highest productivity of the machine occurred in the forest condition with a TAV of 0.31 to 0.36 m3 tree−1 and in the shortest extraction distances. The best-adjusted model explained 46.3% of the machine’s productivity variation. We concluded that TAV and AED variables had a significant impact on the forwarder’s productivity and that it is important to obtain the machine’s productivity curves for efficient forest operations planning.","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86516653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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