Southern Forests: a Journal of Forest Science最新文献_第7页

Technological characterisation of wood from Australian red cedar after first thinning of a plantation at five years 澳大利亚红杉木第一次疏林后5年的技术特征

Southern Forests: a Journal of Forest Science Pub Date : 2022-01-02 DOI: 10.2989/20702620.2021.2017762

K. T. Barbosa, A. Acosta, M. Lazarotto, R. Beltrame, Claudia Fernanda Lemons e Silva, C. Fior

{"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":"23 1","pages":"52 - 59"},"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}

引用次数: 0

Assessing alternatives for growth and yield modelling in eucalypt stands 评估桉树林分生长和产量模型的备选方案

Southern Forests: a Journal of Forest Science Pub Date : 2022-01-02 DOI: 10.2989/20702620.2021.2011468

Thaynara Reis, Simone Silva, Ivaldo Tavares Junior, R. Leite, M. Taquetti, Kemely Atanazio, L. Fardin, J. Cruz, H. Leite

{"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":"52 1","pages":"34 - 43"},"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}

引用次数: 3

Assessment of plant species composition and natural regeneration in abandoned settlements in the lower montane forest of Kilimanjaro National Park, Tanzania 坦桑尼亚乞力马扎罗山国家公园下山林废弃居民点植物物种组成及自然更新评估

Southern Forests: a Journal of Forest Science Pub Date : 2022-01-02 DOI: 10.2989/20702620.2021.2019563

Imani A. Kikoti, C. Mligo, H. Ndangalasi

{"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":"43 1","pages":"60 - 69"},"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}

引用次数: 1

Artificial neural networks and non-linear regression for quantifying the wood volume in Eucalyptus species 人工神经网络与非线性回归在桉树材积量化中的应用

Southern Forests: a Journal of Forest Science Pub Date : 2022-01-02 DOI: 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

{"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":"248 1","pages":"1 - 7"},"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}

引用次数: 0

An evaluation of the environmental behaviour, fate and risk of key pesticides used in South African forest plantations 对南非森林种植园中使用的主要农药的环境行为、命运和风险的评估

Southern Forests: a Journal of Forest Science Pub Date : 2022-01-02 DOI: 10.2989/20702620.2022.2045879

N. Ndlovu, K. Little, B. Baillie, C. Rolando

{"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":"6 1","pages":"83 - 92"},"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}

引用次数: 2

A serious shoot and leaf disease caused by Colletotrichum theobromicola discovered on eucalypts in South Africa 在南非桉树上发现一种由可可炭疽菌引起的严重茎叶病害

Southern Forests: a Journal of Forest Science Pub Date : 2022-01-02 DOI: 10.2989/20702620.2021.2005454

Myriam Solís, M. Wingfield, Izette Greyling, N. Q. Pham

{"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":"287 1","pages":"8 - 20"},"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}

引用次数: 2

Endogenous metabolic content of the cutting positions and ndole-3-butyric acid influence rooting of Toona ciliata var. pubescens stem cuttings 插枝位置和吲哚-3-丁酸的内源代谢含量影响香椿茎插枝的生根

Southern Forests: a Journal of Forest Science Pub Date : 2021-10-02 DOI: 10.2989/20702620.2021.1994343

Qiangqiang Cheng, Dejia Ji, Xiaoyan Guo, Honglang Huang, Lu Zhang

{"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":"5 1","pages":"284 - 293"},"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}

引用次数: 0

Charcoal heaps volume estimation based on unmanned aerial vehicles 基于无人机的木炭堆体积估计

Southern Forests: a Journal of Forest Science Pub Date : 2021-10-02 DOI: 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

{"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":"38 1","pages":"303 - 309"},"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}

引用次数: 0

Machine learning and regression models to predict multiple tree stem volumes for teak 用机器学习和回归模型预测柚木的多棵树干体积

Southern Forests: a Journal of Forest Science Pub Date : 2021-10-02 DOI: 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

{"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":"36 1","pages":"294 - 302"},"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}

引用次数: 2

Productivity curve models in eucalypt timber forwarding 桉树木材运输的生产力曲线模型

Southern Forests: a Journal of Forest Science Pub Date : 2021-10-02 DOI: 10.2989/20702620.2021.1936687

Irineu Barros Nunes, Eduardo da Silva Lopes, Millana Bürger Pagnussat, J. Arce

{"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":"86 1","pages":"231 - 239"},"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}

引用次数: 1