Pub Date : 2021-07-03DOI: 10.2989/20702620.2021.1934180
M. Siddique, M. Hossain, S. R. Rubaiot Abdullah, Md. Zaheer Iqbal, M. Akhter, G. Sola, L. Saint-André, M. Henry
Mangroves are recognised as an important carbon sequester and therefore demand accurate biomass and carbon stock estimations. This study aimed to develop additive biomass models for Heritiera fomes, the most dominant tree species of the Sundarbans Reserved Forest in Bangladesh. Using a non-destructive method, 219 small branches (diameter < 7 cm) were harvested from 97 individual trees to develop biomass models for leaves and smaller branches. The biomass of bigger branches (diameter > 7 cm) and stem was calculated from the volume and mean wood density value after debarking while the biomass of all other components was derived from the determined fresh to oven dry weight conversion ratio. Finally, the biomass of one individual tree was calculated by adding the biomass of trimmed and untrimmed leaves, small and large branches, foliage and stem. An independent data set was used to validate the best-fit model. A component-wise (leaves, branches, bark and stem) biomass model was developed by recovering subsequent cross-component correlations which were then aggregated using the weighted Gaussian maximum likelihood estimation method. Among the components model, D (diameter at breast height) alone performed best for leaves and branches while the product of D and H (total tree height) proved the better results for stem and bark. Our best-fit model (Biomass = 0.0389D 2.3773 H 0.4178 + 0.0492D 2.3027 + 0.0112D 1.1144 H 1.4572 + 0.0306D 1.8507) showed the highest model efficiency with the lowest AIC, RMSE%, MAE, and MPE values. The efficiency of our non-destructive model has shown that it is as effective as other widely used pan-tropical models. Our built models can therefore be used for accurate estimation of biomass and carbon stock in H. fomes of the Sundarbans Reserved Forest, Bangladesh.
{"title":"Additive biomass model for Heritiera fomes (Buch.-Hum.) in the Sundarbans Reserved Forest, Bangladesh","authors":"M. Siddique, M. Hossain, S. R. Rubaiot Abdullah, Md. Zaheer Iqbal, M. Akhter, G. Sola, L. Saint-André, M. Henry","doi":"10.2989/20702620.2021.1934180","DOIUrl":"https://doi.org/10.2989/20702620.2021.1934180","url":null,"abstract":"Mangroves are recognised as an important carbon sequester and therefore demand accurate biomass and carbon stock estimations. This study aimed to develop additive biomass models for Heritiera fomes, the most dominant tree species of the Sundarbans Reserved Forest in Bangladesh. Using a non-destructive method, 219 small branches (diameter < 7 cm) were harvested from 97 individual trees to develop biomass models for leaves and smaller branches. The biomass of bigger branches (diameter > 7 cm) and stem was calculated from the volume and mean wood density value after debarking while the biomass of all other components was derived from the determined fresh to oven dry weight conversion ratio. Finally, the biomass of one individual tree was calculated by adding the biomass of trimmed and untrimmed leaves, small and large branches, foliage and stem. An independent data set was used to validate the best-fit model. A component-wise (leaves, branches, bark and stem) biomass model was developed by recovering subsequent cross-component correlations which were then aggregated using the weighted Gaussian maximum likelihood estimation method. Among the components model, D (diameter at breast height) alone performed best for leaves and branches while the product of D and H (total tree height) proved the better results for stem and bark. Our best-fit model (Biomass = 0.0389D 2.3773 H 0.4178 + 0.0492D 2.3027 + 0.0112D 1.1144 H 1.4572 + 0.0306D 1.8507) showed the highest model efficiency with the lowest AIC, RMSE%, MAE, and MPE values. The efficiency of our non-destructive model has shown that it is as effective as other widely used pan-tropical models. Our built models can therefore be used for accurate estimation of biomass and carbon stock in H. fomes of the Sundarbans Reserved Forest, Bangladesh.","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":"5 1","pages":"185 - 195"},"PeriodicalIF":0.0,"publicationDate":"2021-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81600654","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 : 2021-04-03DOI: 10.2989/20702620.2021.1896958
K. Little
Black wattle is planted on 110 000 ha in South Africa, and considered economically important for both private and commercial growers. Black wattle is intensively managed, with protection from abiotic and biotic risk factors forming an important component of any management strategy. Of the various pests and diseases, brown wattle mirid and wattle rust have a negative impact on early wattle growth. Although pesticides have been shown to be effective for their management, the opportunity to combine an insecticide and fungicide in the same tank and applied as a mix would reduce operations. In November 2017 four trials were initiated on contrasting black wattle sites in KwaZulu- Natal, South Africa. Azoxystrobin + tebuconazole (Custodia®) were tested at varying rates, timing (November or January) and in combination with cypermethrin (Kemprin®) for the control of the wattle mirid and rust on different site types. Azoxystrobin + difenoconazole (AmistarTop®) were included as a reference standard, and an untreated control for comparative purposes. Tree growth, tree condition and disease/insect expression assessments over one growing season were used to determine optimum treatments. The fungicides and rates at which they were tested were equally effective for the control of wattle rust. Custodia® when applied at either 1.2 or 2 L ha−1 showed similar trends to AmistarTop® (1 L ha−1) in terms of optimum tree performance/condition, together with fewest wattle rust symptoms. Although there were tree performance benefits associated with the curative application of a fungicide after infestation (January 2018), spraying before infestation (November 2017) provided the greatest benefits. Wattle mirid presence in three trials indicated tree performance benefits when controlled with an insecticide. However, greater benefits were obtained when combined with a fungicide for the control of both wattle mirid and rust. Applying the two as a tank mixture would reduce costs without a noticeable impact on the efficacy for either active ingredient.
黑荆花在南非的种植面积为11万公顷，被认为对私人和商业种植者都具有重要的经济意义。黑荆是集约化管理，与非生物和生物风险因素的保护形成任何管理策略的重要组成部分。在各种病虫害中，金合欢褐斑病和金合欢锈病对金合欢的早期生长有不利影响。虽然已证明杀虫剂对其管理是有效的，但将杀虫剂和杀菌剂混合在同一个罐中并作为混合物施用的机会将减少操作。2017年11月，在南非夸祖鲁-纳塔尔省对比鲜明的黑荆树遗址上启动了四项试验。在不同的剂量、时间(11月或1月)以及与氯氰菊酯(Kemprin®)联合使用的情况下，对不同地点类型的金合欢螟和锈病进行了试验。偶氮唑虫酯+异苯唑(AmistarTop®)作为参考标准，并作为未经处理的对照进行比较。通过一个生长季节的树木生长、树木状况和病虫表达评估来确定最佳处理。所测试的杀菌剂和杀菌率对控制金曲锈病同样有效。当使用1.2或2 L ha - 1时，Custodia®与AmistarTop®(1 L ha - 1)在最佳树木性能/条件方面表现出相似的趋势，以及最少的金曲锈病症状。尽管在虫害发生后(2018年1月)施用杀菌剂对树木的性能有好处，但在虫害发生前(2017年11月)喷洒杀菌剂带来的好处最大。在三个试验中，金合欢线虫的存在表明，用杀虫剂控制树木的性能会有所改善。然而，当与杀菌剂联合使用时，可以获得更大的效益，以控制金合欢病和锈病。将这两种药物混合使用将降低成本，而不会对任何一种活性成分的功效产生明显影响。
{"title":"Fungicides and an insecticide tested for the control of wattle rust and brown wattle mirid in Acacia mearnsii plantations","authors":"K. Little","doi":"10.2989/20702620.2021.1896958","DOIUrl":"https://doi.org/10.2989/20702620.2021.1896958","url":null,"abstract":"Black wattle is planted on 110 000 ha in South Africa, and considered economically important for both private and commercial growers. Black wattle is intensively managed, with protection from abiotic and biotic risk factors forming an important component of any management strategy. Of the various pests and diseases, brown wattle mirid and wattle rust have a negative impact on early wattle growth. Although pesticides have been shown to be effective for their management, the opportunity to combine an insecticide and fungicide in the same tank and applied as a mix would reduce operations. In November 2017 four trials were initiated on contrasting black wattle sites in KwaZulu- Natal, South Africa. Azoxystrobin + tebuconazole (Custodia®) were tested at varying rates, timing (November or January) and in combination with cypermethrin (Kemprin®) for the control of the wattle mirid and rust on different site types. Azoxystrobin + difenoconazole (AmistarTop®) were included as a reference standard, and an untreated control for comparative purposes. Tree growth, tree condition and disease/insect expression assessments over one growing season were used to determine optimum treatments. The fungicides and rates at which they were tested were equally effective for the control of wattle rust. Custodia® when applied at either 1.2 or 2 L ha−1 showed similar trends to AmistarTop® (1 L ha−1) in terms of optimum tree performance/condition, together with fewest wattle rust symptoms. Although there were tree performance benefits associated with the curative application of a fungicide after infestation (January 2018), spraying before infestation (November 2017) provided the greatest benefits. Wattle mirid presence in three trials indicated tree performance benefits when controlled with an insecticide. However, greater benefits were obtained when combined with a fungicide for the control of both wattle mirid and rust. Applying the two as a tank mixture would reduce costs without a noticeable impact on the efficacy for either active ingredient.","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":"7 1","pages":"144 - 157"},"PeriodicalIF":0.0,"publicationDate":"2021-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87899352","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 : 2021-04-03DOI: 10.2989/20702620.2021.1894538
R. Gardner, David J. Lee
During August 2013, two ‘new’ eucalypt taxa × site interaction trials were established in northern coastal Zululand. The main purpose of these trials was to investigate the commercial forestry potential of a range of Corymbia inter-specific hybrids for the region. Two sites contrasting in mean annual precipitation (850 mm and 1 155 mm respectively) and productivity potential, namely Mfezi (Mtubatuba) and Flatcrown (Kwambonambi), were selected for these trials. The 28 Corymbia hybrid seedlots comprised controlled crosses between C. torelliana and C. citriodora subsp citriodora, C. citriodora subsp variegata and C. henryi. Trees were assessed annually for the presence of pests and diseases and at mid-rotation (48 months) comprehensively measured for growth. By mid-rotation, none of the Corymbia hybrid families showed susceptibility to the suite of insect pests plaguing many of the commercial Eucalyptus hybrid clones in the region. Furthermore, no noteworthy disease infection symptoms were observed in any of the Corymbia or Eucalyptus species and hybrids in the trials. At the drier site of the two (Mfezi), at 24 months following 2 successive dry (<700 mm rainfall) years, trees of some of the Corymbia hybrid families manifested drought stress symptoms in the form of mild to moderate kino exudations from stems and branches. However, by mid-rotation, most of the Corymbia hybrid families in the trial showed excellent tree health, survival and stem volume relative to that of the commercial hybrid controls. At both sites, the seven top-ranking treatments for volume were Corymbia hybrid families. Based on the overall excellent growth performances of several of the Corymbia hybrid families in the two trials, more intensive investigations, for example in the areas of wood properties, vegetative propagation and clonal performance testing, would appear well-warranted.
{"title":"Investigating the wood production and adaptability potential of Corymbia hybrid progeny in northern coastal Zululand, South Africa","authors":"R. Gardner, David J. Lee","doi":"10.2989/20702620.2021.1894538","DOIUrl":"https://doi.org/10.2989/20702620.2021.1894538","url":null,"abstract":"During August 2013, two ‘new’ eucalypt taxa × site interaction trials were established in northern coastal Zululand. The main purpose of these trials was to investigate the commercial forestry potential of a range of Corymbia inter-specific hybrids for the region. Two sites contrasting in mean annual precipitation (850 mm and 1 155 mm respectively) and productivity potential, namely Mfezi (Mtubatuba) and Flatcrown (Kwambonambi), were selected for these trials. The 28 Corymbia hybrid seedlots comprised controlled crosses between C. torelliana and C. citriodora subsp citriodora, C. citriodora subsp variegata and C. henryi. Trees were assessed annually for the presence of pests and diseases and at mid-rotation (48 months) comprehensively measured for growth. By mid-rotation, none of the Corymbia hybrid families showed susceptibility to the suite of insect pests plaguing many of the commercial Eucalyptus hybrid clones in the region. Furthermore, no noteworthy disease infection symptoms were observed in any of the Corymbia or Eucalyptus species and hybrids in the trials. At the drier site of the two (Mfezi), at 24 months following 2 successive dry (<700 mm rainfall) years, trees of some of the Corymbia hybrid families manifested drought stress symptoms in the form of mild to moderate kino exudations from stems and branches. However, by mid-rotation, most of the Corymbia hybrid families in the trial showed excellent tree health, survival and stem volume relative to that of the commercial hybrid controls. At both sites, the seven top-ranking treatments for volume were Corymbia hybrid families. Based on the overall excellent growth performances of several of the Corymbia hybrid families in the two trials, more intensive investigations, for example in the areas of wood properties, vegetative propagation and clonal performance testing, would appear well-warranted.","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":"10 1","pages":"135 - 143"},"PeriodicalIF":0.0,"publicationDate":"2021-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81314213","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 : 2021-04-03DOI: 10.2989/20702620.2021.1911590
H. Pretzsch, A. Rais, Deon Malherbe, A. Ruano, H. Lambrechts, E. Uhl, B. du Toit
Currently, silvicultural prescriptions such as thinning monospecific stands from above and transitioning from monospecific to mixed-species stands are scrutinised regarding their ability to reduce stress and damage. That the quantity and quality of the trees harvested by intermediate and final cuts will vary depending on the chosen prescription is likely but more or less neglected so far. Here we analyse 60 Pinus radiata (D. Don) trees earmarked for removal from the Jonkershoek thinning experiment at the West Cape, South Africa. The experiment comprises both thinning from above and below allowing for comparison of the structure and growth of dominant and subdominant trees removed at 11 years old. Thinning from above removed mainly dominant trees which were on average 44.3% larger in tree diameter, only 8.5% larger in tree height, but 83% larger in crown projection area and more than 25% tapering than subdominant trees extracted by thinning from below. The courses of diameter growth over age of the dominant trees were degressively asymptotic; those of subdominant trees were S-shaped, due to competitive pressure. The volume growth was exponential in both groups. However, the dominant trees achieved 2–3 times higher stem volumes at 10 years of age. Tree structure and growth were highly correlated: the mean annual volume increment showed a Pearson correlation of r = 0.64 with crown length, r = −0.76 with the current ratio of stem slenderness, and r = −0.70 with the competition index by Hegyi. Thus, crown length, slenderness and the competition index were most relevant in explaining tree growth. The analysis of the mode of competition indicated in both groups and in total a sub-proportional increase of stem growth with increasing size. Interestingly, growing space efficiency in terms of mean annual volume growth per crown projection area was similar in both groups.
{"title":"Structure, growth and growing space efficiency of Pinus radiata (D. Don) trees as affected by their social position","authors":"H. Pretzsch, A. Rais, Deon Malherbe, A. Ruano, H. Lambrechts, E. Uhl, B. du Toit","doi":"10.2989/20702620.2021.1911590","DOIUrl":"https://doi.org/10.2989/20702620.2021.1911590","url":null,"abstract":"Currently, silvicultural prescriptions such as thinning monospecific stands from above and transitioning from monospecific to mixed-species stands are scrutinised regarding their ability to reduce stress and damage. That the quantity and quality of the trees harvested by intermediate and final cuts will vary depending on the chosen prescription is likely but more or less neglected so far. Here we analyse 60 Pinus radiata (D. Don) trees earmarked for removal from the Jonkershoek thinning experiment at the West Cape, South Africa. The experiment comprises both thinning from above and below allowing for comparison of the structure and growth of dominant and subdominant trees removed at 11 years old. Thinning from above removed mainly dominant trees which were on average 44.3% larger in tree diameter, only 8.5% larger in tree height, but 83% larger in crown projection area and more than 25% tapering than subdominant trees extracted by thinning from below. The courses of diameter growth over age of the dominant trees were degressively asymptotic; those of subdominant trees were S-shaped, due to competitive pressure. The volume growth was exponential in both groups. However, the dominant trees achieved 2–3 times higher stem volumes at 10 years of age. Tree structure and growth were highly correlated: the mean annual volume increment showed a Pearson correlation of r = 0.64 with crown length, r = −0.76 with the current ratio of stem slenderness, and r = −0.70 with the competition index by Hegyi. Thus, crown length, slenderness and the competition index were most relevant in explaining tree growth. The analysis of the mode of competition indicated in both groups and in total a sub-proportional increase of stem growth with increasing size. Interestingly, growing space efficiency in terms of mean annual volume growth per crown projection area was similar in both groups.","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":"34 1","pages":"158 - 169"},"PeriodicalIF":0.0,"publicationDate":"2021-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80295669","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 : 2021-04-03DOI: 10.2989/20702620.2021.1886575
G. C. Maas, C. Sanquetta, R. Marques, S. Machado, Mateus NI Sanquetta, A. P. D. Corte, I. M. Barberena
Forests play an important role in climate change, acting as a source or sink of carbon. There is, however, a lack of data regarding the carbon production from litterfall in tropical forests. The Atlantic Forest is one of the most distinguished forest types in Brazil, encompassing the Araucaria Forest. In this study, we assessed the seasonal carbon production from litterfall. Data were collected every season from 27 litter traps. Dry matter and carbon fraction were investigated and confronted with meteorological variables. Litterfall components were stratified into Brazilian pine leaves and twigs: broadleaved leaves, twigs, bark, reproductive material, and other material (miscellaneous). The Tukey test indicated significant differences among the carbon fractions for litter components. Seven key species were determinant in litterfall production. Brazilian pine leaves and twigs were the primary carbon source to the forest, followed by leaves and twigs from broadleaved species. Most carbon input from litterfall comes during spring and summer. We concluded that litterfall is a source of carbon and nutrient to the ecosystem. This study contributes to improving the Brazilian national greenhouse inventory and related reports addressed to climate change mitigation.
{"title":"Carbon production from seasonal litterfall in the Brazilian Atlantic Forest","authors":"G. C. Maas, C. Sanquetta, R. Marques, S. Machado, Mateus NI Sanquetta, A. P. D. Corte, I. M. Barberena","doi":"10.2989/20702620.2021.1886575","DOIUrl":"https://doi.org/10.2989/20702620.2021.1886575","url":null,"abstract":"Forests play an important role in climate change, acting as a source or sink of carbon. There is, however, a lack of data regarding the carbon production from litterfall in tropical forests. The Atlantic Forest is one of the most distinguished forest types in Brazil, encompassing the Araucaria Forest. In this study, we assessed the seasonal carbon production from litterfall. Data were collected every season from 27 litter traps. Dry matter and carbon fraction were investigated and confronted with meteorological variables. Litterfall components were stratified into Brazilian pine leaves and twigs: broadleaved leaves, twigs, bark, reproductive material, and other material (miscellaneous). The Tukey test indicated significant differences among the carbon fractions for litter components. Seven key species were determinant in litterfall production. Brazilian pine leaves and twigs were the primary carbon source to the forest, followed by leaves and twigs from broadleaved species. Most carbon input from litterfall comes during spring and summer. We concluded that litterfall is a source of carbon and nutrient to the ecosystem. This study contributes to improving the Brazilian national greenhouse inventory and related reports addressed to climate change mitigation.","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":"32 1","pages":"128 - 134"},"PeriodicalIF":0.0,"publicationDate":"2021-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75188256","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 : 2021-04-03DOI: 10.2989/20702620.2020.1848344
K. Little, Raw Gardner
From the 1980s, Eucalyptus grandis × E. camaldulensis (GC) and E. grandis × E. urophylla (GU) were planted as alternatives to E. grandis for improved productivity in the Zululand coastal regions of South Africa. Although these hybrid combinations provided a degree of drought and/or disease tolerance together with the ability to regenerate the stand via the management of coppice growth, there was the need to test better-suited species for the drier, northern parts of coastal Zululand. Species, provenances and inter-specific hybrid clones of the genera Eucalyptus, Corymbia, Acacia and Casuarina were tested as alternatives to GC and GU in four site × species trials over one rotation (1996 to 2006). Although E. longirostrata, Corymbia henryi, C. citriodora subsp. variegata and E. argophloia showed promise as alternatives to GC and GU, their coppicing ability remained unknown. To determine this, one of the trials (Palm Ridge) was re-implemented and managed for regeneration via coppice over a second rotation (2R). Coppicing ability, growth and susceptibility to pests and disease data were compared for the 16 species at Palm Ridge over the two successive rotations (1R — planted = 8.9 years; 2R — coppiced = 8.2 years). Except for E. argophloia and one E. camaldulensis provenance, all treatments had equivalent, or improved stem stocking in 2R relative to 1R (trial mean: 1R = 1 174 stems ha-1; 2R = 1 288 stems ha−1). The two commercial hybrid clones had the highest volumes in both the 1R (GU = 174 m3 ha−1; GC 163 m3 ha−1) and 2R (GU = 149 m3 ha−1; GC 124 m3 ha−1) rotations. The mean annual volume increments (MAI in m3 ha−1 y−1) were not significantly different between rotations (1R = 10.74 m3 ha−1 y−1; 2R = 9.95 m3 ha−1 y−1), nor were there any significant rotation × treatment interactions indicating that the treatments performed in a similar manner over both rotations. Although there were differences among provenances within taxa, these were not as great as the differences amongst the taxa tested: GC/GC > C. citriodora subsp. variegata > E. logirostrata > C. henryi, with E. tereticornis, E. camaldulensis, E. argophloia and E. watsoniana not performing well over both rotations. Despite the higher rainfall recorded over 2R (837 mm y−1) relative to 1R (765 mm y−1), the incidence of pests and diseases that was not recorded in 1R most likely contributed to the reduced growth of the coppiced trees. Most notable of these were Leptocybe invasa on the GC, E. tereticornis and E. camaldulensis treatments, Botryosphaeria spp. on all but the Corymbia treatments, kino on the Corymbia treatments, and Coniothyrium spp on the GU treatment. Relative to the two commercial hybrid clones (GC and GU), E. longirostrata, and C. henryi were the most promising of the alternative species tested over both rotations (planted and coppiced), with C. citriodora subsp. variegata also showing promise. Although all treatments were affected by pest(s) or disease(s), some of the species show
20世纪80年代以来，为了提高南非祖鲁兰沿海地区的生产力，人们开始种植大桉树(GC)和大桉树(GU)作为大桉树的替代品。虽然这些杂交组合提供了一定程度的耐旱和/或抗病能力，以及通过管理灌木林生长使林分再生的能力，但仍有必要测试更适合祖鲁兰沿海北部干旱地区的物种。1996 ~ 2006年，在一个轮作的4个点×种试验中，对桉树、山茱萸、金合欢和木麻黄属植物的种、种源和种间杂交克隆作为GC和GU的替代品进行了试验。虽然长叶蛾、凤梨蛾、柠檬蛾亚属。variegata和E. argophloia是GC和GU的替代品，但它们的复制能力尚不清楚。为了确定这一点，其中一个试验(棕榈岭)被重新实施，并通过第二轮(2R)通过灌木林进行再生管理。对棕榈岭16种植物在2个连续轮作(1R -种植= 8.9年;2R -复制= 8.2年)。除石竹种源和1个山竹种源外，所有处理在2R的茎存储量均与1R相当或有所改善(试验平均值:1R = 1 174茎ha-1;2R = 1 288根ha−1)。两个商业杂交无性系的1R体积均最高(GU = 174 m3 ha - 1;GC = 163 m3 ha - 1)和2R (GU = 149 m3 ha - 1;GC 124 m3 ha−1)旋转。平均年体积增量(MAI，单位:m3 ha - 1 y - 1)在不同的轮作中无显著差异(1R = 10.74 m3 ha - 1 y - 1;2R = 9.95 m3 ha - 1 y - 1)，也没有任何显著的旋转与处理的相互作用，表明在两个旋转中处理的方式相似。尽管在分类群内种源间存在差异，但其差异并不如在分类群间差异大:GC/GC > C. citriodora subsp。在两个轮作中，杂交种的表现都不太好，其中，长角菊、山竹菊、石竹菊和水仙菊的表现不太好。尽管2R记录的降雨量(837毫米/年)高于1R(765毫米/年)，但1R未记录的病虫害发生率很可能是导致覆被树木生长减少的原因。其中最显著的是GC组的入侵细鳞虫(Leptocybe invasa)、E. tereticornis和E. camaldulensis，除Corymbia组外，其余组均为Botryosphaeria, Corymbia组为kino, GU组为Coniothyrium。相对于两个商业杂交无性系(GC和GU)，在两个轮作(种植和套作)试验中，长叶稻和亨利稻是最有希望的替代物种。Variegata也显示出希望。虽然所有的处理方法都受到病虫害的影响，但有些品种表现出抗性，其来源在品种耐受范围内，这表明有可能通过选择来减少生物风险。
{"title":"Relative performance of coppice versus seedlings of 16 eucalypt taxa over two rotations in northern coastal Zululand, South Africa","authors":"K. Little, Raw Gardner","doi":"10.2989/20702620.2020.1848344","DOIUrl":"https://doi.org/10.2989/20702620.2020.1848344","url":null,"abstract":"From the 1980s, Eucalyptus grandis × E. camaldulensis (GC) and E. grandis × E. urophylla (GU) were planted as alternatives to E. grandis for improved productivity in the Zululand coastal regions of South Africa. Although these hybrid combinations provided a degree of drought and/or disease tolerance together with the ability to regenerate the stand via the management of coppice growth, there was the need to test better-suited species for the drier, northern parts of coastal Zululand. Species, provenances and inter-specific hybrid clones of the genera Eucalyptus, Corymbia, Acacia and Casuarina were tested as alternatives to GC and GU in four site × species trials over one rotation (1996 to 2006). Although E. longirostrata, Corymbia henryi, C. citriodora subsp. variegata and E. argophloia showed promise as alternatives to GC and GU, their coppicing ability remained unknown. To determine this, one of the trials (Palm Ridge) was re-implemented and managed for regeneration via coppice over a second rotation (2R). Coppicing ability, growth and susceptibility to pests and disease data were compared for the 16 species at Palm Ridge over the two successive rotations (1R — planted = 8.9 years; 2R — coppiced = 8.2 years). Except for E. argophloia and one E. camaldulensis provenance, all treatments had equivalent, or improved stem stocking in 2R relative to 1R (trial mean: 1R = 1 174 stems ha-1; 2R = 1 288 stems ha−1). The two commercial hybrid clones had the highest volumes in both the 1R (GU = 174 m3 ha−1; GC 163 m3 ha−1) and 2R (GU = 149 m3 ha−1; GC 124 m3 ha−1) rotations. The mean annual volume increments (MAI in m3 ha−1 y−1) were not significantly different between rotations (1R = 10.74 m3 ha−1 y−1; 2R = 9.95 m3 ha−1 y−1), nor were there any significant rotation × treatment interactions indicating that the treatments performed in a similar manner over both rotations. Although there were differences among provenances within taxa, these were not as great as the differences amongst the taxa tested: GC/GC > C. citriodora subsp. variegata > E. logirostrata > C. henryi, with E. tereticornis, E. camaldulensis, E. argophloia and E. watsoniana not performing well over both rotations. Despite the higher rainfall recorded over 2R (837 mm y−1) relative to 1R (765 mm y−1), the incidence of pests and diseases that was not recorded in 1R most likely contributed to the reduced growth of the coppiced trees. Most notable of these were Leptocybe invasa on the GC, E. tereticornis and E. camaldulensis treatments, Botryosphaeria spp. on all but the Corymbia treatments, kino on the Corymbia treatments, and Coniothyrium spp on the GU treatment. Relative to the two commercial hybrid clones (GC and GU), E. longirostrata, and C. henryi were the most promising of the alternative species tested over both rotations (planted and coppiced), with C. citriodora subsp. variegata also showing promise. Although all treatments were affected by pest(s) or disease(s), some of the species show","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":"4 1","pages":"99 - 110"},"PeriodicalIF":0.0,"publicationDate":"2021-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88725249","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 : 2021-04-03DOI: 10.2989/20702620.2021.1926370
A. Nel, J. Acosta, G. Hodge
The hybrid between Pinus patula and P. tecunumanii low elevation (PPTL) and high elevation (PPTH) sources was developed in the 1990s in South Africa and commercialised during the 2000s in response to high post-establishment mortality of P. patula caused by Fusarium circinatum. The growth and wood properties for these hybrids are also superior to the parental species. This study describes an experiment where F1 hybrid families and F2 advanced hybrid families of the Pinus patula × P. tecunumanii low elevation hybrid were compared in a progeny field experiment. Seed yield and early growth at three years is reported. The early results from this study indicate that there were no significant differences in growth between the F1 and F2 PPTL hybrid and both the F1 and F2 hybrid outperformed the pure P. patula control. These early results should be monitored further to determine if this trend continues. The F2 hybrid offers the opportunity to obtain tolerance of F. circinatum and better growth than P. patula at a much lower cost than that of deployment of the F1 PPTL hybrid.
patula与P. tecunumanii低海拔(PPTL)和高海拔(PPTH)源的杂交品种于20世纪90年代在南非开发，并于21世纪初商业化，以应对环形镰刀菌(Fusarium circinatum)引起的patula高死亡率。这些杂交品种的生长和木材性能也优于亲本品种。本研究通过后代田间试验，对低海拔黑松(patula × P. tecunumanii) F1杂交科和F2高级杂交科进行了比较。报道了三年种子产量和早期生长情况。本研究的早期结果表明，F1和F2 PPTL杂交后代的生长没有显著差异，F1和F2杂交后代的生长表现都优于纯的卷叶松对照。应该进一步监测这些早期结果，以确定这种趋势是否会继续下去。与F1 PPTL杂交品种相比，F2杂交品种有机会获得对圆叶线虫的耐受性，并且生长速度比斑马病好，而且成本要低得多。
{"title":"Initial growth results comparing first generation F1 and advanced-generation F2 Pinus patula × Pinus tecunumanii interspecific hybrid families","authors":"A. Nel, J. Acosta, G. Hodge","doi":"10.2989/20702620.2021.1926370","DOIUrl":"https://doi.org/10.2989/20702620.2021.1926370","url":null,"abstract":"The hybrid between Pinus patula and P. tecunumanii low elevation (PPTL) and high elevation (PPTH) sources was developed in the 1990s in South Africa and commercialised during the 2000s in response to high post-establishment mortality of P. patula caused by Fusarium circinatum. The growth and wood properties for these hybrids are also superior to the parental species. This study describes an experiment where F1 hybrid families and F2 advanced hybrid families of the Pinus patula × P. tecunumanii low elevation hybrid were compared in a progeny field experiment. Seed yield and early growth at three years is reported. The early results from this study indicate that there were no significant differences in growth between the F1 and F2 PPTL hybrid and both the F1 and F2 hybrid outperformed the pure P. patula control. These early results should be monitored further to determine if this trend continues. The F2 hybrid offers the opportunity to obtain tolerance of F. circinatum and better growth than P. patula at a much lower cost than that of deployment of the F1 PPTL hybrid.","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":"44 1","pages":"170 - 176"},"PeriodicalIF":0.0,"publicationDate":"2021-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73476659","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 : 2021-04-03DOI: 10.2989/20702620.2020.1862634
Lailla Sabrina Queiroz Nazareno, A. Ribeiro, Mylla Vyctória Coutinho Sousa, Cynthia Wanick Vieira, A. C. Ferraz Filho
Prediction of aboveground wood volume is one of most important stages when conducting a forest inventory and making forest management decisions. This is more difficult for native forest than for plantations given the high variability of the former (trees of different species and age groups). The objective of this work was to evaluate different strategies to estimate aboveground standing tree wood volume (v) using its diameter at breast height (DBH) and total height (h), comparing the use of form factors, volume equations fitted by ordinary least squares and mixed modelling, as well as the options from the literature. To achieve this, 351 trees were scaled during field campaigns, with 158 felled trees and 193 measured using Criterion equipment. The data collected from each scaled tree was: h, DBH, v and identification of the botanical species. We found that the best application of form factors occurred when the trees were divided by diameter classes. However, regression models, regardless of the fitting technique, presented better volume estimates than form factors. Mixed models, with either the species or diameter class as the random variable, provided the lowest errors when estimating tree volume. Thus, we recommend the use of mixed models as the best strategy to estimate volume of standing trees. The following equation can be used to estimate aboveground wood volume for trees from vegetation types similar to the ones of this study: ln(v) = −9.06013 + 1.91756 ln(DBH) + 0.69846 ln(h).
{"title":"Wood volume estimation strategies for trees from a Dry Forest/Savannah transition area in Piauí, Brazil","authors":"Lailla Sabrina Queiroz Nazareno, A. Ribeiro, Mylla Vyctória Coutinho Sousa, Cynthia Wanick Vieira, A. C. Ferraz Filho","doi":"10.2989/20702620.2020.1862634","DOIUrl":"https://doi.org/10.2989/20702620.2020.1862634","url":null,"abstract":"Prediction of aboveground wood volume is one of most important stages when conducting a forest inventory and making forest management decisions. This is more difficult for native forest than for plantations given the high variability of the former (trees of different species and age groups). The objective of this work was to evaluate different strategies to estimate aboveground standing tree wood volume (v) using its diameter at breast height (DBH) and total height (h), comparing the use of form factors, volume equations fitted by ordinary least squares and mixed modelling, as well as the options from the literature. To achieve this, 351 trees were scaled during field campaigns, with 158 felled trees and 193 measured using Criterion equipment. The data collected from each scaled tree was: h, DBH, v and identification of the botanical species. We found that the best application of form factors occurred when the trees were divided by diameter classes. However, regression models, regardless of the fitting technique, presented better volume estimates than form factors. Mixed models, with either the species or diameter class as the random variable, provided the lowest errors when estimating tree volume. Thus, we recommend the use of mixed models as the best strategy to estimate volume of standing trees. The following equation can be used to estimate aboveground wood volume for trees from vegetation types similar to the ones of this study: ln(v) = −9.06013 + 1.91756 ln(DBH) + 0.69846 ln(h).","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":"2012 1","pages":"111 - 119"},"PeriodicalIF":0.0,"publicationDate":"2021-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87858880","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 : 2021-04-03DOI: 10.2989/20702620.2021.1928566
M. Mielke, L. S. Lobo, Geane Santos da Costa, A. Schilling, M. S. dos Santos, Â. Dalmolin
The segmentation of digital images in red, green and blue (RGB) components is a low-cost method for monitoring leaf chlorophyll concentrations and seedling quality. The two congeneric species, Cariniana legalis and C. estrellensis, are distinguished based on differences in bark texture and the colour of their new leaves. We compared indices based on leaf colour segmentation in RGB to predict total chlorophyll concentrations (Chlt) in the leaves of seedlings of these two species. Mature leaves were digitalised in a flatbed scanner and segmented in red (R), green (G) and blue (B). The relationships between the three RGB indices and Chlt were tested. Additionally, we calculated the anthocyanin content-chroma basic (ACcb). The mean value of ACcb was significantly higher in C. legalis than in C. estrellensis, demonstrating a higher anthocyanin concentration in C. legalis leaves. Based on the highest coefficients of determination (R 2) and lowest prediction errors (PE), for all indices, the best results were obtained for C. estrellensis. The presence of anthocyanins in the leaves of C. legalis and the limitation of the RGB colour segmentation indices for separating all leaf pigments might be the main causes of the differences in Chlt prediction in the leaves of these two congeneric tree species.
{"title":"Predictions of chlorophyll concentrations in the leaves of seedlings of two congeneric tropical trees from RGB digital image components","authors":"M. Mielke, L. S. Lobo, Geane Santos da Costa, A. Schilling, M. S. dos Santos, Â. Dalmolin","doi":"10.2989/20702620.2021.1928566","DOIUrl":"https://doi.org/10.2989/20702620.2021.1928566","url":null,"abstract":"The segmentation of digital images in red, green and blue (RGB) components is a low-cost method for monitoring leaf chlorophyll concentrations and seedling quality. The two congeneric species, Cariniana legalis and C. estrellensis, are distinguished based on differences in bark texture and the colour of their new leaves. We compared indices based on leaf colour segmentation in RGB to predict total chlorophyll concentrations (Chlt) in the leaves of seedlings of these two species. Mature leaves were digitalised in a flatbed scanner and segmented in red (R), green (G) and blue (B). The relationships between the three RGB indices and Chlt were tested. Additionally, we calculated the anthocyanin content-chroma basic (ACcb). The mean value of ACcb was significantly higher in C. legalis than in C. estrellensis, demonstrating a higher anthocyanin concentration in C. legalis leaves. Based on the highest coefficients of determination (R 2) and lowest prediction errors (PE), for all indices, the best results were obtained for C. estrellensis. The presence of anthocyanins in the leaves of C. legalis and the limitation of the RGB colour segmentation indices for separating all leaf pigments might be the main causes of the differences in Chlt prediction in the leaves of these two congeneric tree species.","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":"93 1","pages":"177 - 184"},"PeriodicalIF":0.0,"publicationDate":"2021-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84936527","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 : 2021-04-03DOI: 10.2989/20702620.2021.1877094
M. D. M. Queiroz, S. Caldeira, A. Sebbenn, D. A. Arriel
Teak (Tectona grandis) is a tree species native to South-east Asia and widely cultivated in Latin America. In Mato Grosso state, Brazil, teak is the second-most planted forest species due to its high productivity resulting from high adaptability to the soil and climate conditions of the region. However, there is little information about the genetic diversity of improved genotypes cultivated in the state. Thus, the objective of this study was to quantify, through ISSR (inter-simple sequence repeat) molecular markers, the genetic diversity of improved teak genotypes used in different plantations in Mato Grosso state. For this, 31 ISSR primers were tested on 113 genotypes separated into nine populations. Six primers were selected to perform the analyses, resulting in 55 amplified loci. All selected primers showed a high polymorphic information content. Considering all genotypes in the Mato Grosso population, the percentage of polymorphic loci (P) was 96.4%, the genetic diversity according to Nei՚s genetic diversity index (H) was 1.96, and according to Shannon՚s information/diversity index (I), it was 0.53. Considering each population individually, P varied from 50.9% to 90.9%, H from 0.21 to 0.33, and I from 0.30 to 0.49. Most of the genetic diversity observed was within populations (86%). Four genetic groups were identified, with a high level of admixture among them. The existence of a considerable genetic diversity within populations indicates the possibility of exploring this variation in genetic improvement programmes. However, the introduction of new genetic materials is recommended to increase the genetic base of this species in Brazil.
{"title":"Genetic diversity of improved genotypes of Tectona grandis in the state of Mato Grosso, Brazil","authors":"M. D. M. Queiroz, S. Caldeira, A. Sebbenn, D. A. Arriel","doi":"10.2989/20702620.2021.1877094","DOIUrl":"https://doi.org/10.2989/20702620.2021.1877094","url":null,"abstract":"Teak (Tectona grandis) is a tree species native to South-east Asia and widely cultivated in Latin America. In Mato Grosso state, Brazil, teak is the second-most planted forest species due to its high productivity resulting from high adaptability to the soil and climate conditions of the region. However, there is little information about the genetic diversity of improved genotypes cultivated in the state. Thus, the objective of this study was to quantify, through ISSR (inter-simple sequence repeat) molecular markers, the genetic diversity of improved teak genotypes used in different plantations in Mato Grosso state. For this, 31 ISSR primers were tested on 113 genotypes separated into nine populations. Six primers were selected to perform the analyses, resulting in 55 amplified loci. All selected primers showed a high polymorphic information content. Considering all genotypes in the Mato Grosso population, the percentage of polymorphic loci (P) was 96.4%, the genetic diversity according to Nei՚s genetic diversity index (H) was 1.96, and according to Shannon՚s information/diversity index (I), it was 0.53. Considering each population individually, P varied from 50.9% to 90.9%, H from 0.21 to 0.33, and I from 0.30 to 0.49. Most of the genetic diversity observed was within populations (86%). Four genetic groups were identified, with a high level of admixture among them. The existence of a considerable genetic diversity within populations indicates the possibility of exploring this variation in genetic improvement programmes. However, the introduction of new genetic materials is recommended to increase the genetic base of this species in Brazil.","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":"15 1","pages":"120 - 127"},"PeriodicalIF":0.0,"publicationDate":"2021-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85355551","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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