Pub Date : 2023-10-02DOI: 10.2989/20702620.2023.2257663
A. Starke, C. Geldenhuys, Tim G. O’Connor, Colin S. Everson
Tree species providing non-timber forest products (NTFPs) have the potential to enhance the socio-economic value of forestry plantation systems and mitigate biodiversity loss associated with production landscapes in Southern Africa. This can be accomplished by integrating NTFP agroforestry systems with forestry plantation systems but raises questions around which species and products are suited to the different environments that exist within large plantation systems or plantation landscapes. These questions can be answered by assessing the NTFP and agroforestry system (AFS) value of native species that form part of secondary vegetation within forestry plantations by shedding light on the disturbance regimes and environmental conditions that NTFP species prefer. This study assessed the NTFP value of secondary vegetation growing within abandoned clear-felled and abandoned unharvested forestry compartments. It addressed differences between the NTFP value of secondary vegetation and natural forest while providing options for how native species could be integrated into a forestry plantation system using agroforestry. We found that secondary vegetation growing in abandoned compartments provided roughly two-thirds of the NTFP uses provided by natural forest. The state of the compartment at the time of abandonment influenced which NTFPs were available. Secondary woodland developing in clear-felled compartments contained NTFPs which were associated with fire-adapted woodland species (e.g. fruit and oils from Marula trees). Naturalising forest in unfelled plantation compartments contained a composition of NTFPs associated with the provision of wood products. Our results show that native vegetation growing as secondary vegetation in forestry plantation systems has the potential to guide the development of native species agro-forestry systems and, in general, can contribute to a more formalised approach for integrating NTFP supply in forestry plantation systems.
{"title":"Secondary vegetation provides a reservoir of non-timber forest products and agroforestry service options for forestry plantation systems, Maputaland, South Africa","authors":"A. Starke, C. Geldenhuys, Tim G. O’Connor, Colin S. Everson","doi":"10.2989/20702620.2023.2257663","DOIUrl":"https://doi.org/10.2989/20702620.2023.2257663","url":null,"abstract":"Tree species providing non-timber forest products (NTFPs) have the potential to enhance the socio-economic value of forestry plantation systems and mitigate biodiversity loss associated with production landscapes in Southern Africa. This can be accomplished by integrating NTFP agroforestry systems with forestry plantation systems but raises questions around which species and products are suited to the different environments that exist within large plantation systems or plantation landscapes. These questions can be answered by assessing the NTFP and agroforestry system (AFS) value of native species that form part of secondary vegetation within forestry plantations by shedding light on the disturbance regimes and environmental conditions that NTFP species prefer. This study assessed the NTFP value of secondary vegetation growing within abandoned clear-felled and abandoned unharvested forestry compartments. It addressed differences between the NTFP value of secondary vegetation and natural forest while providing options for how native species could be integrated into a forestry plantation system using agroforestry. We found that secondary vegetation growing in abandoned compartments provided roughly two-thirds of the NTFP uses provided by natural forest. The state of the compartment at the time of abandonment influenced which NTFPs were available. Secondary woodland developing in clear-felled compartments contained NTFPs which were associated with fire-adapted woodland species (e.g. fruit and oils from Marula trees). Naturalising forest in unfelled plantation compartments contained a composition of NTFPs associated with the provision of wood products. Our results show that native vegetation growing as secondary vegetation in forestry plantation systems has the potential to guide the development of native species agro-forestry systems and, in general, can contribute to a more formalised approach for integrating NTFP supply in forestry plantation systems.","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139324914","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 : 2023-09-08DOI: 10.2989/20702620.2023.2218560
Ashik Rubaiyat, Nicholas Rollings, Stephen D. Galvin, R. Mitloehner, Sohag Miah, Hans Juergen Boehmer
{"title":"Tree diversity, vegetation structure and management of mangrove systems on Viti Levu, Fiji Islands","authors":"Ashik Rubaiyat, Nicholas Rollings, Stephen D. Galvin, R. Mitloehner, Sohag Miah, Hans Juergen Boehmer","doi":"10.2989/20702620.2023.2218560","DOIUrl":"https://doi.org/10.2989/20702620.2023.2218560","url":null,"abstract":"","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75979900","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 : 2023-08-08DOI: 10.2989/20702620.2023.2220893
S. Augustina, T. Darmawan, Sudarmanto, Narto Narto, A. Bahanawan, D. S. Adi, D. Triwibowo, Y. Amin, I. A. Sofianto, P. S. Sejati, W. Dwianto, Witjaksono, R. Widyorini, P. Gérardin, S. D. Marbun
{"title":"Effects of succinic acid impregnation on physical properties of sapwood and heartwood from plantation-grown short-rotation teak","authors":"S. Augustina, T. Darmawan, Sudarmanto, Narto Narto, A. Bahanawan, D. S. Adi, D. Triwibowo, Y. Amin, I. A. Sofianto, P. S. Sejati, W. Dwianto, Witjaksono, R. Widyorini, P. Gérardin, S. D. Marbun","doi":"10.2989/20702620.2023.2220893","DOIUrl":"https://doi.org/10.2989/20702620.2023.2220893","url":null,"abstract":"","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72751916","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 : 2023-04-03DOI: 10.2989/20702620.2023.2198092
Joy Aduralere Ogunsuyi, J. Owoyemi, O. Makinde
Modelling of wood drying is important for predicting the performance and efficiency of solar dryers and to optimise the drying process during each season of the year. The attainable moisture content (MC) of Alstonia boonei wood was studied when dried in a laboratory-scale solar kiln. Meteorological data (temperature, relative humidity, wind speed/direction and solar radiation) were observed over a period of 31 days. For the purpose of this study, three of the variables: temperature, relative humidity and solar radiation—were used for mathematical modelling of the drying process. The average attainable MC observed over a 31-day drying period was divided into a 70:30 dataset, representing calibrating and validating sets. Several regression models were formulated using the calibrating set. The optimal model was selected based on higher values of R 2 and R, and lower standard error, after which validation was done using the remaining dataset (validating set) by performing tests of bias and percentage bias and a student’s t-test. To meet the required criteria for a suitable model, values of the validating parameters must be low and have p-values that denote significance. The log polynomial model MC = −16 + 3.99 ln(SR2) + 1.49 ln(T2) + 5.80 ln(H2) was judged best for computing the attainable MC of A. boonei wood using a solar dryer across the whole year in the study area (Ondo State, Nigeria). The computational results showed fair agreement between the predicted and measured MC, which established the validity of the model and its suitability for application when drying low-density wood in the range of 340–370 kg/m3.
{"title":"Predictive modelling to determine the attainable moisture content of Alstonia boonei wood using a solar kiln dryer","authors":"Joy Aduralere Ogunsuyi, J. Owoyemi, O. Makinde","doi":"10.2989/20702620.2023.2198092","DOIUrl":"https://doi.org/10.2989/20702620.2023.2198092","url":null,"abstract":"Modelling of wood drying is important for predicting the performance and efficiency of solar dryers and to optimise the drying process during each season of the year. The attainable moisture content (MC) of Alstonia boonei wood was studied when dried in a laboratory-scale solar kiln. Meteorological data (temperature, relative humidity, wind speed/direction and solar radiation) were observed over a period of 31 days. For the purpose of this study, three of the variables: temperature, relative humidity and solar radiation—were used for mathematical modelling of the drying process. The average attainable MC observed over a 31-day drying period was divided into a 70:30 dataset, representing calibrating and validating sets. Several regression models were formulated using the calibrating set. The optimal model was selected based on higher values of R 2 and R, and lower standard error, after which validation was done using the remaining dataset (validating set) by performing tests of bias and percentage bias and a student’s t-test. To meet the required criteria for a suitable model, values of the validating parameters must be low and have p-values that denote significance. The log polynomial model MC = −16 + 3.99 ln(SR2) + 1.49 ln(T2) + 5.80 ln(H2) was judged best for computing the attainable MC of A. boonei wood using a solar dryer across the whole year in the study area (Ondo State, Nigeria). The computational results showed fair agreement between the predicted and measured MC, which established the validity of the model and its suitability for application when drying low-density wood in the range of 340–370 kg/m3.","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91539268","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 : 2023-04-03DOI: 10.2989/20702620.2023.2218561
W. Brink, G. van den Berg, A. Nel, B. du Toit
Hybridising Eucalyptus grandis with Eucalyptus nitens produces progeny intended to combine the favourable traits of both parents. E. grandis exhibits good growth, stem form, wood properties and rooting ability for vegetative propagation. E. nitens displays superior cold tolerance, including superior frost and snow tolerance, and high wood density. Eucalypt hybrids developed specifically for improved cold tolerance tend to produce fewer viable hybrid progeny and are more recalcitrant rooters than their sub-tropical counterparts. To overcome these challenges, a novel testing strategy was developed and used to identify promising varieties for commercial deployment. As a result, a large population of E. grandis × E. nitens hybrids was developed through controlled pollinations, propagated via mini-cuttings and established in a total of 21 field trials, across the KwaZulu-Natal and Mpumalanga provinces of South Africa, to investigate growth and adaptability. Data of three growth traits, namely diameter at breast height (DBH), total tree height and volume were analysed to determine the genetic parameters of these traits. Combined-site broad sense heritability for DBH, height and volume were 0.39, 0.46 and 0.35 respectively, indicating a moderate level of genetic control. This, in conjunction with large genetic coefficients of variation (CVg = 20%, 16% and 41% for DBH, height and volume respectively) shows that substantial gains can be made through selection. Combined-site Type B genetic correlations for DBH, height and volume were 0.71, 0.68 and 0.65 respectively, indicating that there was notable genotype by environment interaction. Pairwise comparisons of rBg for volume showed large variation in the correlations of clonal rankings between trials, with rBg ranging from 0.0 to 0.90.
大桉与黑桉杂交产生的后代旨在结合双亲的有利性状。巨叶菊具有良好的生长、茎型、木材特性和无性繁殖生根能力。耐寒性好，耐霜雪性好，木材密度高。专为提高耐寒性而培育的桉树杂交种往往比亚热带的桉树杂交种产生更少的可存活的杂交后代和更顽强的根系。为了克服这些挑战，开发了一种新的测试策略，并用于确定有希望进行商业部署的品种。结果，通过控制授粉，培育出了大量的大e × E. nitens杂交品种，并通过微型扦插繁殖，在南非夸祖鲁-纳塔尔省和姆普马兰加省共进行了21次田间试验，以调查其生长和适应性。通过分析胸径、树高和体积3个生长性状的遗传参数，确定了3个性状的遗传参数。胸径、高度和体积的组合广义遗传力分别为0.39、0.46和0.35，表明遗传控制处于中等水平。这与大的遗传变异系数(胸径、高度和体积的CVg分别为20%、16%和41%)相结合，表明通过选择可以获得可观的收益。组合位点B型遗传相关系数分别为0.71、0.68和0.65，表明存在显著的环境互作基因型。rBg对体积的两两比较显示，试验之间克隆排名的相关性差异很大，rBg在0.0到0.90之间。
{"title":"Estimation of genetic parameters for growth in a population of Eucalyptus grandis × Eucalyptus nitens hybrids in KwaZulu-Natal and Mpumalanga","authors":"W. Brink, G. van den Berg, A. Nel, B. du Toit","doi":"10.2989/20702620.2023.2218561","DOIUrl":"https://doi.org/10.2989/20702620.2023.2218561","url":null,"abstract":"Hybridising Eucalyptus grandis with Eucalyptus nitens produces progeny intended to combine the favourable traits of both parents. E. grandis exhibits good growth, stem form, wood properties and rooting ability for vegetative propagation. E. nitens displays superior cold tolerance, including superior frost and snow tolerance, and high wood density. Eucalypt hybrids developed specifically for improved cold tolerance tend to produce fewer viable hybrid progeny and are more recalcitrant rooters than their sub-tropical counterparts. To overcome these challenges, a novel testing strategy was developed and used to identify promising varieties for commercial deployment. As a result, a large population of E. grandis × E. nitens hybrids was developed through controlled pollinations, propagated via mini-cuttings and established in a total of 21 field trials, across the KwaZulu-Natal and Mpumalanga provinces of South Africa, to investigate growth and adaptability. Data of three growth traits, namely diameter at breast height (DBH), total tree height and volume were analysed to determine the genetic parameters of these traits. Combined-site broad sense heritability for DBH, height and volume were 0.39, 0.46 and 0.35 respectively, indicating a moderate level of genetic control. This, in conjunction with large genetic coefficients of variation (CVg = 20%, 16% and 41% for DBH, height and volume respectively) shows that substantial gains can be made through selection. Combined-site Type B genetic correlations for DBH, height and volume were 0.71, 0.68 and 0.65 respectively, indicating that there was notable genotype by environment interaction. Pairwise comparisons of rBg for volume showed large variation in the correlations of clonal rankings between trials, with rBg ranging from 0.0 to 0.90.","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87598969","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 : 2023-04-03DOI: 10.2989/20702620.2023.2216857
Victor Alexandre Hardt Ferreira dos Santos, Ana Flávia Monteiro de Souza, Bruna de Oliveira dos Santos, A. Grandis, M. Ferreira
We investigated the morphophysiological mechanisms indicative of resource uses behind net primary production in seedlings of three valuable forest species of socio-economic value in the Amazon:mahogany (Swietenia macrophylla), Brazil nut (Bertholletia excelsa) and Laurel (Cordia alliodora). The hypotheses tested were: (i) the three species will grow better under mild to high light but with different magnitudes of response; and (ii) the three species will show different mechanisms to reach a better growth under mild to high light We measured biomass production and a set of morphophysiological leaf traits and calculated the relative growth rates (diameter and height) of seedlings subjected to low(0.9), moderate (11.3) and high (45.0 mol m-2 day-1) irradiance for 80 days. For all species, biomass and growth increase with irradiance and the magnitude of the effect were species-dependent. The changes in total biomass by irradiance varied 1.5-fold (B. excelsa) and twofold (S. macrophylla). Light-induced changes in biomass partitioning and morphophysiological traits varied among species. S. macrophylla and C. alliodora significantly increased root/aboveground mass ratio (R/A) under high irradiance. Gas exchange increased with irradiance for C. alliodora and B. excelsa. The non-structural carbohydrates of C. alliodora and S. macrophylla were greater in high (total soluble sugars) and moderate (starch) light environments. The traits associated with total biomass were starch, stomatal conductance and transpiration for B. excelsa; leaf area ratio, leaf area root mass ratio, total soluble sugars and starch for C. alliodora; and RIA, leaf area ratio, and leaf area root mass ratio for S. macrophylla. The species obtained a high total biomass under mild to high irradiance but following different morphophysiological mechanisms. We discussed the potential to use these mechanisms in silvicultural systems designed to supply the plants with intermediate to high levels of light, for example enrichment planting in secondary forests or reforestation on degraded areas.
{"title":"The morphophysiological mechanisms of light-induced net primary production of Amazonian tree species","authors":"Victor Alexandre Hardt Ferreira dos Santos, Ana Flávia Monteiro de Souza, Bruna de Oliveira dos Santos, A. Grandis, M. Ferreira","doi":"10.2989/20702620.2023.2216857","DOIUrl":"https://doi.org/10.2989/20702620.2023.2216857","url":null,"abstract":"We investigated the morphophysiological mechanisms indicative of resource uses behind net primary production in seedlings of three valuable forest species of socio-economic value in the Amazon:mahogany (Swietenia macrophylla), Brazil nut (Bertholletia excelsa) and Laurel (Cordia alliodora). The hypotheses tested were: (i) the three species will grow better under mild to high light but with different magnitudes of response; and (ii) the three species will show different mechanisms to reach a better growth under mild to high light We measured biomass production and a set of morphophysiological leaf traits and calculated the relative growth rates (diameter and height) of seedlings subjected to low(0.9), moderate (11.3) and high (45.0 mol m-2 day-1) irradiance for 80 days. For all species, biomass and growth increase with irradiance and the magnitude of the effect were species-dependent. The changes in total biomass by irradiance varied 1.5-fold (B. excelsa) and twofold (S. macrophylla). Light-induced changes in biomass partitioning and morphophysiological traits varied among species. S. macrophylla and C. alliodora significantly increased root/aboveground mass ratio (R/A) under high irradiance. Gas exchange increased with irradiance for C. alliodora and B. excelsa. The non-structural carbohydrates of C. alliodora and S. macrophylla were greater in high (total soluble sugars) and moderate (starch) light environments. The traits associated with total biomass were starch, stomatal conductance and transpiration for B. excelsa; leaf area ratio, leaf area root mass ratio, total soluble sugars and starch for C. alliodora; and RIA, leaf area ratio, and leaf area root mass ratio for S. macrophylla. The species obtained a high total biomass under mild to high irradiance but following different morphophysiological mechanisms. We discussed the potential to use these mechanisms in silvicultural systems designed to supply the plants with intermediate to high levels of light, for example enrichment planting in secondary forests or reforestation on degraded areas.","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74806610","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 : 2023-04-03DOI: 10.2989/20702620.2023.2216858
F. Guilherme, D. L. Machado, G. E. Silva, Natanael Moreira Nascimento, Gustavo Luz Ferreira, Kaila de Assis Ressel Pereira, Ana Paula de Souza, Pollyana de Godoy Borges, Laura Rezende Souza, James Dean Leal Rocha, C. P. Coelho, Everton A. Maciel, W. C. Ferreira, M. Zórtea, Steffan Eduardo Silva Carneiro
This study aimed to compare the floristic and tree structure of two dry forests patches located in a forest remnant encompassed in Cerrado biome, south Goiás state, Brazil. In semideciduous (SF) and deciduous (DF) dry forests, we allocated 25 permanent plots (20 × 20 m), including trees and palms individuals with diameter at breast height (DBH1.3m) ≥ 5.0 cm. The whole survey showed 2 614 individuals, 146 species and 46 families. SF showed higher basal area and average height, but DF had higher density. Due to the low equitability and smaller species richness found in DF (87 species) than in SF (113), the Shannon diversity in SF was significantly higher. Both vegetation types showed low qualitative (Jaccard, 36%) and quantitative (Morisita, 19%) similarity, as only three of the 25 species regarded as having the highest importance/value were common in both dry forests. Fabaceae predominated in the number of species and density, especially in DF. Zoochory was more abundant, although it was not different between vegetation types, whereas both anemochory and autochory dispersion mechanisms were higher in DF. Although the surveys are geographically close, differences in the vegetation structure between dry forests showed strong heterogeneity and environmental complexity, reflecting an increase in local diversity, and reinforcing the need for conservation of these forest remnants in Cerrado.
{"title":"Fine-scale variation reveals high structure and floristic heterogeneity in dry forests of the Cerrado","authors":"F. Guilherme, D. L. Machado, G. E. Silva, Natanael Moreira Nascimento, Gustavo Luz Ferreira, Kaila de Assis Ressel Pereira, Ana Paula de Souza, Pollyana de Godoy Borges, Laura Rezende Souza, James Dean Leal Rocha, C. P. Coelho, Everton A. Maciel, W. C. Ferreira, M. Zórtea, Steffan Eduardo Silva Carneiro","doi":"10.2989/20702620.2023.2216858","DOIUrl":"https://doi.org/10.2989/20702620.2023.2216858","url":null,"abstract":"This study aimed to compare the floristic and tree structure of two dry forests patches located in a forest remnant encompassed in Cerrado biome, south Goiás state, Brazil. In semideciduous (SF) and deciduous (DF) dry forests, we allocated 25 permanent plots (20 × 20 m), including trees and palms individuals with diameter at breast height (DBH1.3m) ≥ 5.0 cm. The whole survey showed 2 614 individuals, 146 species and 46 families. SF showed higher basal area and average height, but DF had higher density. Due to the low equitability and smaller species richness found in DF (87 species) than in SF (113), the Shannon diversity in SF was significantly higher. Both vegetation types showed low qualitative (Jaccard, 36%) and quantitative (Morisita, 19%) similarity, as only three of the 25 species regarded as having the highest importance/value were common in both dry forests. Fabaceae predominated in the number of species and density, especially in DF. Zoochory was more abundant, although it was not different between vegetation types, whereas both anemochory and autochory dispersion mechanisms were higher in DF. Although the surveys are geographically close, differences in the vegetation structure between dry forests showed strong heterogeneity and environmental complexity, reflecting an increase in local diversity, and reinforcing the need for conservation of these forest remnants in Cerrado.","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73910162","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 : 2023-04-03DOI: 10.2989/20702620.2023.2199164
Regardt Ferreira, Kabir Peerbhay, Josua Louw, Ilaria Germishuizen, Andrew Morris, Romano Lottering
AbstractCommercial forest plantations in South Africa are homogeneous monocultures of highly bred exotic species grown to deliver timber products of the best potential quality. As such, these stands are susceptible to adverse effects of biotic and abiotic factors, and therefore require intense management to mitigate these risks. A sustainable forest monitoring system that can detect real-time changes in the physiological state of these plantations is needed for timeous management intervention to reduce losses. The use of machine learning algorithms has recently become popular, with acceptable levels of success. This study explores the application of deep learning neural networks for early detection of damage caused by baboons in evergreen plantations of Pinus species. Using PlanetScope imagery (spectral band 590–860 nm), which is captured by a constellation of Dove nanosatellites, with a high temporal resolution available daily at 3 m spatial resolution, the study achieved an overall accuracy of 81.54%, with a kappa value of 0.69, using a deep neural network. In comparison, using a random-forest classifier produced 74.04% accuracy and a kappa value of 0.62. The study successfully mapped different levels of baboon damage within commercial pine forests. We provide a repeatable method for daily monitoring initiatives, and attest to the utility of higher-resolution imagery such as PlanetScope for mapping health and damage severity at the tree level.Keywords: evergreen forestforest disturbancemonitoringPlanetScope imageryreal-time detectionremote sensingSouth Africa
{"title":"A tree-level analysis of baboon damage in commercial forest stands using deep learning techniques","authors":"Regardt Ferreira, Kabir Peerbhay, Josua Louw, Ilaria Germishuizen, Andrew Morris, Romano Lottering","doi":"10.2989/20702620.2023.2199164","DOIUrl":"https://doi.org/10.2989/20702620.2023.2199164","url":null,"abstract":"AbstractCommercial forest plantations in South Africa are homogeneous monocultures of highly bred exotic species grown to deliver timber products of the best potential quality. As such, these stands are susceptible to adverse effects of biotic and abiotic factors, and therefore require intense management to mitigate these risks. A sustainable forest monitoring system that can detect real-time changes in the physiological state of these plantations is needed for timeous management intervention to reduce losses. The use of machine learning algorithms has recently become popular, with acceptable levels of success. This study explores the application of deep learning neural networks for early detection of damage caused by baboons in evergreen plantations of Pinus species. Using PlanetScope imagery (spectral band 590–860 nm), which is captured by a constellation of Dove nanosatellites, with a high temporal resolution available daily at 3 m spatial resolution, the study achieved an overall accuracy of 81.54%, with a kappa value of 0.69, using a deep neural network. In comparison, using a random-forest classifier produced 74.04% accuracy and a kappa value of 0.62. The study successfully mapped different levels of baboon damage within commercial pine forests. We provide a repeatable method for daily monitoring initiatives, and attest to the utility of higher-resolution imagery such as PlanetScope for mapping health and damage severity at the tree level.Keywords: evergreen forestforest disturbancemonitoringPlanetScope imageryreal-time detectionremote sensingSouth Africa","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135718355","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 : 2023-04-03DOI: 10.2989/20702620.2023.2198093
T. Kraaij, J. Baard, B. Adriaan Grobler, Bayleigh Miles
The alien tree Acacia melanoxylon (R.Br.) occurs extensively in the Southern Cape Afrotemperate Forest (South Africa). Concerns exist about its potential negative effects on indigenous tree sapling communities, ultimately with implications for forest composition and structure. We investigated whether Acacia melanoxylon affects Afrotemperate forest tree sapling composition in the Garden Route National Park. Using a paired plot design, we compared sapling species richness, diversity and density underneath 30 overstorey Acacia melanoxylon trees and 30 indigenous counterparts of the species Podocarpus latifolius (Thunb.) R.Br. ex Mirb, Afrocarpus falcatus (Thunb.) C.N.Page, or Olea capensis macrocarpa (C.H.Wright) I.Verd. We recorded 2 503 tree saplings from 27 indigenous species and only three Acacia melanoxylon saplings in the 60 plots. There were no significant differences in the richness, diversity or density of saplings underneath Acacia melanoxylon trees versus their indigenous counterparts. Non-metric multidimensional scaling and cluster analysis accordingly showed only minor differences in sapling species composition and abundance between Acacia melanoxylon and indigenous overstorey trees. We concluded that indigenous tree sapling composition is not significantly altered by the presence of Acacia melanoxylon trees at the densities (< 3 trees ha−1) at which this species commonly occurs in Afrotemperate forest in the Garden Route National Park. However, populations of Acacia melanoxylon in the forest interior act as a source of propagules for invasion in forest margins, riparian areas and neighbouring fynbos shrubland, while at high density the species may alter forest gap-forming dynamics. These invasive attributes need to be considered in the management of the species in the region.
{"title":"Effects of Acacia melanoxylon, an alien tree species to South Africa, on Afrotemperate forest tree sapling composition","authors":"T. Kraaij, J. Baard, B. Adriaan Grobler, Bayleigh Miles","doi":"10.2989/20702620.2023.2198093","DOIUrl":"https://doi.org/10.2989/20702620.2023.2198093","url":null,"abstract":"The alien tree Acacia melanoxylon (R.Br.) occurs extensively in the Southern Cape Afrotemperate Forest (South Africa). Concerns exist about its potential negative effects on indigenous tree sapling communities, ultimately with implications for forest composition and structure. We investigated whether Acacia melanoxylon affects Afrotemperate forest tree sapling composition in the Garden Route National Park. Using a paired plot design, we compared sapling species richness, diversity and density underneath 30 overstorey Acacia melanoxylon trees and 30 indigenous counterparts of the species Podocarpus latifolius (Thunb.) R.Br. ex Mirb, Afrocarpus falcatus (Thunb.) C.N.Page, or Olea capensis macrocarpa (C.H.Wright) I.Verd. We recorded 2 503 tree saplings from 27 indigenous species and only three Acacia melanoxylon saplings in the 60 plots. There were no significant differences in the richness, diversity or density of saplings underneath Acacia melanoxylon trees versus their indigenous counterparts. Non-metric multidimensional scaling and cluster analysis accordingly showed only minor differences in sapling species composition and abundance between Acacia melanoxylon and indigenous overstorey trees. We concluded that indigenous tree sapling composition is not significantly altered by the presence of Acacia melanoxylon trees at the densities (< 3 trees ha−1) at which this species commonly occurs in Afrotemperate forest in the Garden Route National Park. However, populations of Acacia melanoxylon in the forest interior act as a source of propagules for invasion in forest margins, riparian areas and neighbouring fynbos shrubland, while at high density the species may alter forest gap-forming dynamics. These invasive attributes need to be considered in the management of the species in the region.","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75552085","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 : 2023-01-02DOI: 10.2989/20702620.2023.2169084
Matheus Oliveira Teixeira, A. Ribeiro, G. W. Ferreira, Maurício Sangiogo, A. C. F. Filho
African mahogany plantations are increasing in Brazil, especially those planted with the species Khaya grandifoliola C. DC. Despite the interest in establishing plantations, there is a lack of studies in management practices for the genus. This makes it difficult to improve methodologies that optimise forest inventory activities, which are essential to support forest management decisions. Therefore, this study aimed to evaluate the effect of the number of trees selected to determine the mean dominant height, and to verify its impact on site classification of African mahogany stands. This will then optimise height sampling and ensure correct site index estimation. To determine the dominant height, 11 treatments were tested, with the selection of 1st to 11th thickest trees per plot, representing between 9 and 102 dominant trees per hectare. The effect of the treatments was evaluated using the values of the mean dominant height and metrics regarding site index classification (stability, stratification capacity and relationship with stand growth). Treatments with inclusion of more dominant trees resulted in a more stable site classification at the expense of a lower correlation with stand growth. Treatments using fewer dominant trees resulted in a greater allocation of plots in the upper site classes, showing that the number of trees used to calculate the dominant height influences the distribution of plots in different site classes. We concluded that Treatments 3 (27 trees ha−1) to 6 (55 trees ha−1) had the best performance, guaranteeing adequate site index estimation. The selection of at least 27 and a maximum of 55 dominant trees per hectare is recommended for African mahogany plantations with low planting densities.
{"title":"Dominant tree selection for height estimation and its impact on site classification for African mahogany stands","authors":"Matheus Oliveira Teixeira, A. Ribeiro, G. W. Ferreira, Maurício Sangiogo, A. C. F. Filho","doi":"10.2989/20702620.2023.2169084","DOIUrl":"https://doi.org/10.2989/20702620.2023.2169084","url":null,"abstract":"African mahogany plantations are increasing in Brazil, especially those planted with the species Khaya grandifoliola C. DC. Despite the interest in establishing plantations, there is a lack of studies in management practices for the genus. This makes it difficult to improve methodologies that optimise forest inventory activities, which are essential to support forest management decisions. Therefore, this study aimed to evaluate the effect of the number of trees selected to determine the mean dominant height, and to verify its impact on site classification of African mahogany stands. This will then optimise height sampling and ensure correct site index estimation. To determine the dominant height, 11 treatments were tested, with the selection of 1st to 11th thickest trees per plot, representing between 9 and 102 dominant trees per hectare. The effect of the treatments was evaluated using the values of the mean dominant height and metrics regarding site index classification (stability, stratification capacity and relationship with stand growth). Treatments with inclusion of more dominant trees resulted in a more stable site classification at the expense of a lower correlation with stand growth. Treatments using fewer dominant trees resulted in a greater allocation of plots in the upper site classes, showing that the number of trees used to calculate the dominant height influences the distribution of plots in different site classes. We concluded that Treatments 3 (27 trees ha−1) to 6 (55 trees ha−1) had the best performance, guaranteeing adequate site index estimation. The selection of at least 27 and a maximum of 55 dominant trees per hectare is recommended for African mahogany plantations with low planting densities.","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76683305","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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