Pub Date : 2022-06-30DOI: 10.33494/nzjfs522022x211x
S. Fraser, M. Baker, Grant D. Pearse, C. Todoroki, H. Estarija, I. Hood, L. Bulman, C. Somchit, C. Rolando
Background: Red needle cast (RNC) is a foliar disease of radiata pine (Pinus radiata D.Don), caused by Phytophthora pluvialis Reeser, Sutton & E.Hansen and occasionally Phytophthora kernoviae Brasier, Beales & S.A.Kirk. The disease has impacted plantations in New Zealand since at least 2008. To develop management recommendations for red needle cast, research has focused on identifying chemical control options and understanding pathogen epidemiology to guide optimal timing of spray application. The objectives of this study were to: (1) assess the efficacy of aerial copper fungicide application for the control of red needle cast in mature radiata pine plantations; and (2) investigate optimal spray timing. Methods: To address these objectives, three operational-scale field trials were undertaken in successive years between 2017 and 2019 at a forest in the Central North Island of New Zealand. RNC severity was assessed in canopies of forest blocks exposed to cuprous oxide applied at 0.855 kg ha-1 active ingredient in low-volume aerial spray at different times of the year (November, February and April (or May)). Needle cast from plantation trees and infection levels on trap plants were also assessed in some years. Results: Application of cuprous oxide significantly reduced RNC severity in all three trials. As well as reducing disease severity, application of cuprous oxide also tended to reduce needle cast from plantation trees and infection on trap plants in years when these were also assessed. No consistent effect of spray timing was observed. Generally, all three spray timings reduced disease severity compared to the unsprayed control, but differences were not always significant, and few differences were detected between different spray timings. Conclusions: The results reported here are the first to show that low-volume aerial applications of cuprous oxide applied at 0.855 kg ha-1 active ingredient can reduce the severity of RNC in commercial radiata pine plantations. No consistent effect of spray timing was detected. These findings support the development of management recommendations for RNC.
背景：红针病（RNC）是辐射松（Pinus radiata D.Don）的一种叶部疾病，由雨疫病（Phytophthora pluvialis Reeser）、萨顿和汉森（Sutton&E.Hansen）引起，偶尔也会由克氏疫霉（Phytophora kernoviae Brasier）、比尔斯和柯克（Beales&S.a.Kirk）引起。该疾病至少自2008年以来就影响了新西兰的种植园。为了制定红针铸型的管理建议，研究的重点是确定化学控制选项和了解病原体流行病学，以指导最佳喷雾时间。本研究的目的是：（1）评估气载铜杀菌剂在成熟辐射松人工林中防治红针病的效果；以及（2）研究最佳喷射时间。方法：为了实现这些目标，2017年至2019年间，在新西兰中北岛的一处森林连续进行了三次操作规模的实地试验。在一年中的不同时间（11月、2月和4月（或5月），在暴露于低容量空中喷雾中施用0.855 kg ha-1活性成分的氧化亚铜的林区树冠中评估RNC的严重程度。几年来，还评估了人工林树木的针刺和诱捕植物的感染水平。结果：在所有三项试验中，氧化亚铜的应用显著降低了RNC的严重程度。除了降低疾病的严重程度外，氧化亚铜的施用也有助于减少种植树的针刺和陷阱植物的感染。没有观察到喷雾时间的一致影响。一般来说，与未喷雾的对照相比，所有三种喷雾时间都降低了疾病的严重程度，但差异并不总是显著的，并且在不同的喷雾时间之间几乎没有发现差异。结论：本文报道的结果首次表明，在商业辐射松人工林中，低体积空中施用0.855kg ha-1活性成分的氧化亚铜可以降低RNC的严重程度。未检测到喷雾时间的一致影响。这些发现支持RNC管理建议的制定。
{"title":"Efficacy and optimal timing of low-volume aerial applications of copper fungicides for the control of red needle cast of pine","authors":"S. Fraser, M. Baker, Grant D. Pearse, C. Todoroki, H. Estarija, I. Hood, L. Bulman, C. Somchit, C. Rolando","doi":"10.33494/nzjfs522022x211x","DOIUrl":"https://doi.org/10.33494/nzjfs522022x211x","url":null,"abstract":"Background: Red needle cast (RNC) is a foliar disease of radiata pine (Pinus radiata D.Don), caused by Phytophthora pluvialis Reeser, Sutton & E.Hansen and occasionally Phytophthora kernoviae Brasier, Beales & S.A.Kirk. The disease has impacted plantations in New Zealand since at least 2008. To develop management recommendations for red needle cast, research has focused on identifying chemical control options and understanding pathogen epidemiology to guide optimal timing of spray application. The objectives of this study were to: (1) assess the efficacy of aerial copper fungicide application for the control of red needle cast in mature radiata pine plantations; and (2) investigate optimal spray timing.\u0000Methods: To address these objectives, three operational-scale field trials were undertaken in successive years between 2017 and 2019 at a forest in the Central North Island of New Zealand. RNC severity was assessed in canopies of forest blocks exposed to cuprous oxide applied at 0.855 kg ha-1 active ingredient in low-volume aerial spray at different times of the year (November, February and April (or May)). Needle cast from plantation trees and infection levels on trap plants were also assessed in some years.\u0000Results: Application of cuprous oxide significantly reduced RNC severity in all three trials. As well as reducing disease severity, application of cuprous oxide also tended to reduce needle cast from plantation trees and infection on trap plants in years when these were also assessed. No consistent effect of spray timing was observed. Generally, all three spray timings reduced disease severity compared to the unsprayed control, but differences were not always significant, and few differences were detected between different spray timings.\u0000Conclusions: The results reported here are the first to show that low-volume aerial applications of cuprous oxide applied at 0.855 kg ha-1 active ingredient can reduce the severity of RNC in commercial radiata pine plantations. No consistent effect of spray timing was detected. These findings support the development of management recommendations for RNC.","PeriodicalId":19172,"journal":{"name":"New Zealand Journal of Forestry Science","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44657343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-28DOI: 10.33494/nzjfs522022x224x
I. Hood, S. Husheer, J. Gardner, Tony W. Evanson, Gordon Tieman, Catherine Banham, Liam C. Wright, S. Fraser
Background: Red needle cast caused by Phytophthora pluvialis Reeser, Sutton & E. Hansen, and less frequently P. kernoviae Brasier, Beales & S.A.Kirk, is an important foliar disease of Pinus radiata D.Don (radiata pine) in plantations throughout parts of New Zealand. Significant growth loss occurs following years when severe outbreaks occur. Aerial spraying with a copper-based fungicide has potential for disease control. Research is being carried out to optimise application timing, supported by complementary studies to understand RNC epidemiology. Methods: In order to determine the pathogen infection periods, a field trial was conducted over two years at two forests in the Central North Island of New Zealand. Batches of potted radiata pine seedlings were placed beneath diseased pine stands at fortnightly intervals, before returning them to an open nursery area for assessments of infection every two weeks (based on visual symptoms and qPCR) over a period of three months. A hybrid modelling approach was employed to establish relationships between the proportion of plants showing symptoms and weather conditions during the fortnight of exposure and previous fortnights. Gradient boosting machine learning analyses were used to identify the most important weather variables, followed by analysis of these by generalised mixed effects models, generalised least square models and ordinary least square models. Results: Development of RNC symptoms and detection of Phytophthora pluvialis and P. kernoviae on exchange seedlings was greatest for those exposed between April and September (Southern Hemisphere mid-autumn to early-spring). At this time, temperatures, solar radiation and evapotranspiration were lower, and rainfall and foliage wetness were plentiful. Modelling identified temperature and relative humidity several months before the date of exposure as the most important weather variables explaining infection. Conclusions: Because of autocorrelation, it was not possible to determine those variables that drive sporulation, dispersal, infection and symptom development. This will require more detailed exchange plant studies together with controlled environment inoculation experiments. Nevertheless, results of this and earlier work complement recent research indicating that it may be possible to manage RNC by fungicide applications made in late summer or autumn, early in the annual disease cycle.
{"title":"Infection periods of Phytophthora pluvialis and Phytophthora kernoviae in relation to weather variables and season in Pinus radiata forests in New Zealand","authors":"I. Hood, S. Husheer, J. Gardner, Tony W. Evanson, Gordon Tieman, Catherine Banham, Liam C. Wright, S. Fraser","doi":"10.33494/nzjfs522022x224x","DOIUrl":"https://doi.org/10.33494/nzjfs522022x224x","url":null,"abstract":"Background: Red needle cast caused by Phytophthora pluvialis Reeser, Sutton & E. Hansen, and less frequently P. kernoviae Brasier, Beales & S.A.Kirk, is an important foliar disease of Pinus radiata D.Don (radiata pine) in plantations throughout parts of New Zealand. Significant growth loss occurs following years when severe outbreaks occur. Aerial spraying with a copper-based fungicide has potential for disease control. Research is being carried out to optimise application timing, supported by complementary studies to understand RNC epidemiology.\u0000Methods: In order to determine the pathogen infection periods, a field trial was conducted over two years at two forests in the Central North Island of New Zealand. Batches of potted radiata pine seedlings were placed beneath diseased pine stands at fortnightly intervals, before returning them to an open nursery area for assessments of infection every two weeks (based on visual symptoms and qPCR) over a period of three months. A hybrid modelling approach was employed to establish relationships between the proportion of plants showing symptoms and weather conditions during the fortnight of exposure and previous fortnights. Gradient boosting machine learning analyses were used to identify the most important weather variables, followed by analysis of these by generalised mixed effects models, generalised least square models and ordinary least square models.\u0000Results: Development of RNC symptoms and detection of Phytophthora pluvialis and P. kernoviae on exchange seedlings was greatest for those exposed between April and September (Southern Hemisphere mid-autumn to early-spring). At this time, temperatures, solar radiation and evapotranspiration were lower, and rainfall and foliage wetness were plentiful. Modelling identified temperature and relative humidity several months before the date of exposure as the most important weather variables explaining infection.\u0000Conclusions: Because of autocorrelation, it was not possible to determine those variables that drive sporulation, dispersal, infection and symptom development. This will require more detailed exchange plant studies together with controlled environment inoculation experiments. Nevertheless, results of this and earlier work complement recent research indicating that it may be possible to manage RNC by fungicide applications made in late summer or autumn, early in the annual disease cycle.\u0000 ","PeriodicalId":19172,"journal":{"name":"New Zealand Journal of Forestry Science","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46636767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-24DOI: 10.33494/nzjfs522022x181x
J. Valverde, R. Rubilar, A. Medina, O. Mardones, Verónica Emhart, Daniel Bozo, Yosselin Espinoza, Octavio Campoe
Background: Compatible taper and volume equations are key for traditional growth and yield and current process-based or hybrid models. However, most equations do not consider variables such as genotype, water regime and their interaction, limiting the development of general equations for species or regions. Our research investigated taper and individual tree volume equations for eight Eucalyptus genotypes (E. nitens, E. badjensis, E. smithii, E. camaldulensis x globulus and two varieties of low and high productivity of E. globulus and E. nitens x globulus), all materials are growing under summer irrigated vs. no irrigated conditions. Methods: A 7-year old Eucalyptus plantation experiment was sampled considering four representative trees per genotype x water regime combination treatment. Four non-linear taper equations were evaluated: Kozak (2004), Kozak et al. (1969), Ormerod (1973) and Max and Burkhart (1976). In addition, total and merchantable volume was evaluated with the Schumacher and Hall (1933) equation. The effect of genotype, irrigation regime and interaction were evaluated for each equation. Then, the best taper equation was selected from adjusted coefficient of determination, mean square error, and AIC and BIC parameters. Finally, the validation of evaluations was carried out with the Leave-One-Out Jackknife method. Results: Genotype, irrigation regime, or the interaction were not statistically significant for all evaluated taper - volume equations and a generalised model equation was obtained. The best taper equation was Kozak (2004) which showed the best fit and adaptation to irregular boles. Regarding volume equations, all showed a trend to underestimate volume (total and merchantable) in trees with a volume greater than 0.22 m3. Validation of the equations showed reduced bias suggesting that the equations can be used to predict taper and volume regardless of Eucalyptus genotype x irrigation regimen combinations. Conclusions: Our results suggest a negligible or minor effect of irrigation (water resource availability) and genotype (for tested taxas and genotypes) on taper and individual tree volume equations. A generalised taper and volume equation (total and merchantable) may be used for all tested genotypes, regardless of water regime (site water availability). This generalised model would simplify Eucalyptus estimates required for stand management and projection.
背景:兼容的锥度和体积方程是传统生长和产量以及当前基于过程或混合模型的关键。然而，大多数方程没有考虑诸如基因型、水分状况及其相互作用等变量，限制了物种或地区一般方程的发展。研究了8个桉树基因型(nitens、badjensis、smithii、camaldulensis x globulus和两个高产和低产量品种)的锥度和单株体积方程，所有材料在夏季灌溉和无灌溉条件下均有生长。方法:选取一个7年生桉树人工林进行试验，每个基因型和水分组合处理4棵有代表性的树。评估了四个非线性锥度方程:Kozak (2004)， Kozak等人(1969)，Ormerod(1973)和Max和Burkhart(1976)。此外，用舒马赫和霍尔(1933)方程评估了总体积和可销售体积。评估了基因型、灌溉方式和相互作用对每个方程的影响。然后，从调整后的决定系数、均方误差、AIC和BIC参数中选择最佳锥度方程。最后，采用留一刀法对评价结果进行验证。结果:基因型、灌溉方式或相互作用对所有评估的锥度-体积方程都没有统计学意义，并获得了一个广义模型方程。最佳锥度方程为Kozak(2004)，对不规则孔具有最佳的拟合和适应性。在体积方程方面，所有研究都显示出低估体积大于0.22 m3的树木的体积(总体积和可销售体积)的趋势。对方程的验证表明，偏差减小，表明该方程可用于预测锥度和体积，而不考虑桉树基因型x灌溉方案组合。结论:我们的研究结果表明，灌溉(水资源可用性)和基因型(对于测试的分类群和基因型)对锥度和单株树体积方程的影响可以忽略不计或很小。广义的锥度和体积方程(总量和可销售)可用于所有测试的基因型，而不考虑水状况(现场水供应情况)。这种广义模型将简化林分管理和预测所需的桉树估算。
{"title":"Taper and individual tree volume equations of Eucalyptus varieties under contrasting irrigation regimes","authors":"J. Valverde, R. Rubilar, A. Medina, O. Mardones, Verónica Emhart, Daniel Bozo, Yosselin Espinoza, Octavio Campoe","doi":"10.33494/nzjfs522022x181x","DOIUrl":"https://doi.org/10.33494/nzjfs522022x181x","url":null,"abstract":"Background: Compatible taper and volume equations are key for traditional growth and yield and current process-based or hybrid models. However, most equations do not consider variables such as genotype, water regime and their interaction, limiting the development of general equations for species or regions. Our research investigated taper and individual tree volume equations for eight Eucalyptus genotypes (E. nitens, E. badjensis, E. smithii, E. camaldulensis x globulus and two varieties of low and high productivity of E. globulus and E. nitens x globulus), all materials are growing under summer irrigated vs. no irrigated conditions.\u0000Methods: A 7-year old Eucalyptus plantation experiment was sampled considering four representative trees per genotype x water regime combination treatment. Four non-linear taper equations were evaluated: Kozak (2004), Kozak et al. (1969), Ormerod (1973) and Max and Burkhart (1976). In addition, total and merchantable volume was evaluated with the Schumacher and Hall (1933) equation. The effect of genotype, irrigation regime and interaction were evaluated for each equation. Then, the best taper equation was selected from adjusted coefficient of determination, mean square error, and AIC and BIC parameters. Finally, the validation of evaluations was carried out with the Leave-One-Out Jackknife method.\u0000Results: Genotype, irrigation regime, or the interaction were not statistically significant for all evaluated taper - volume equations and a generalised model equation was obtained. The best taper equation was Kozak (2004) which showed the best fit and adaptation to irregular boles. Regarding volume equations, all showed a trend to underestimate volume (total and merchantable) in trees with a volume greater than 0.22 m3. Validation of the equations showed reduced bias suggesting that the equations can be used to predict taper and volume regardless of Eucalyptus genotype x irrigation regimen combinations.\u0000Conclusions: Our results suggest a negligible or minor effect of irrigation (water resource availability) and genotype (for tested taxas and genotypes) on taper and individual tree volume equations. A generalised taper and volume equation (total and merchantable) may be used for all tested genotypes, regardless of water regime (site water availability). This generalised model would simplify Eucalyptus estimates required for stand management and projection.","PeriodicalId":19172,"journal":{"name":"New Zealand Journal of Forestry Science","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47182565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-03DOI: 10.33494/nzjfs522022x196x
T. Jones, J. Yang, D. Mcconchie, G. Downes
Background: Resin pockets and blemishes in pruned logs of radiata pine (Pinus radiata D.Don) can reduce the value of clear and moulding grades of lumber. External resin features (ERF) on the bark of the logs have proved an effective method of predicting the incidence of resin pockets in the lumber. Resin canals have been associated with resin blemishes in radiata pine, and could prove useful in improving the prediction of the grade recovery of lumber. Methods: Pruned butt logs of radiata pine trees from two forests in the North Island, New Zealand, were selected for low, moderate, and severe levels of external resin features (ERF) on the bark, and for low, average, and high resin canal diameter, frequency and brightness from breast height increment cores. The relationships were evaluated between these properties, and the lumber resin features and grade recovery of the logs. Results: The number of resin pockets, the blemish rating, and the percentage of boards with resin streaks and resinous heartwood increased, and the recovery of clears and moulding grade boards and the lumber value declined, with the severity of the ERF class of the logs. Multiple regression models gave good predictions of the grade recovery and loss of lumber value, using the log ERF class, volume, heartwood content, and number of Type 1 resin pockets on the ends of the logs, as independent variables. The resin canal properties did not improve the regression models. Resin blemishes were associated with Type 2 resin pockets, and were more frequent in the forest where false growth rings were present. This suggests the constitutive resin flow from resin canals, rather than the resin canal size and frequency, is more important in determining the incidence of resin blemishes. Conclusions: The prediction of the grade recovery of lumber using the ERFs of radiata pine logs, was supplemented by the log volume, heartwood content and number of Type 1 resin pockets on the ends of the logs. The environmental factors that drive the constitutive resin enrichment of resin canals, such as drought conditions that give rise to false growth rings, could be useful in improving the prediction of grade recovery for forest stands.
{"title":"Predicting resin pockets and blemishes in radiata pine lumber from log properties","authors":"T. Jones, J. Yang, D. Mcconchie, G. Downes","doi":"10.33494/nzjfs522022x196x","DOIUrl":"https://doi.org/10.33494/nzjfs522022x196x","url":null,"abstract":"Background: Resin pockets and blemishes in pruned logs of radiata pine (Pinus radiata D.Don) can reduce the value of clear and moulding grades of lumber. External resin features (ERF) on the bark of the logs have proved an effective method of predicting the incidence of resin pockets in the lumber. Resin canals have been associated with resin blemishes in radiata pine, and could prove useful in improving the prediction of the grade recovery of lumber.\u0000Methods: Pruned butt logs of radiata pine trees from two forests in the North Island, New Zealand, were selected for low, moderate, and severe levels of external resin features (ERF) on the bark, and for low, average, and high resin canal diameter, frequency and brightness from breast height increment cores. The relationships were evaluated between these properties, and the lumber resin features and grade recovery of the logs.\u0000Results: The number of resin pockets, the blemish rating, and the percentage of boards with resin streaks and resinous heartwood increased, and the recovery of clears and moulding grade boards and the lumber value declined, with the severity of the ERF class of the logs. Multiple regression models gave good predictions of the grade recovery and loss of lumber value, using the log ERF class, volume, heartwood content, and number of Type 1 resin pockets on the ends of the logs, as independent variables. The resin canal properties did not improve the regression models. Resin blemishes were associated with Type 2 resin pockets, and were more frequent in the forest where false growth rings were present. This suggests the constitutive resin flow from resin canals, rather than the resin canal size and frequency, is more important in determining the incidence of resin blemishes.\u0000Conclusions: The prediction of the grade recovery of lumber using the ERFs of radiata pine logs, was supplemented by the log volume, heartwood content and number of Type 1 resin pockets on the ends of the logs. The environmental factors that drive the constitutive resin enrichment of resin canals, such as drought conditions that give rise to false growth rings, could be useful in improving the prediction of grade recovery for forest stands.","PeriodicalId":19172,"journal":{"name":"New Zealand Journal of Forestry Science","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47919832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-27DOI: 10.33494/nzjfs522022x172x
E. Iyiola, C. Altaner, L. Apiolaza
Background: Eucalyptus globoidea Blakely produces ground-durable (Class 2) and stiff wood and has the potential to be grown in New Zealand to supply high-value environmentally-friendly timber for use as posts in the agricultural sector and stiff veneers for the LVL industry. The New Zealand Dryland Forests Initiative (NZDFI) has established a breeding programme for this species. The objective of this study was to identify trees with superior wood properties for commercial propagation enabling the establishment of a domestic plantation resource of ground-durable timber. Methods: The genetic variation in wood properties at mid-rotation age (8-year-old) of 141 E. globoidea families was assessed for the following traits: heartwood diameter, diameter under bark at ~0.5 m height, combined sapwood diameter, heartwood collapse, sapwood collapse, standing tree acoustic velocity and extractive content in the heartwood. Families were ranked and genotypes with large heartwood diameter, high extractive content and stiffness as well as low collapse were identified. Results: Heartwood diameter (h2 = 0.51) and extractive content (h2 = 1.16) showed good heritability, which in combination with high variation are promising traits for a breeding programme. The high heritability for extractive content indicated a closer relatedness within the population than the assumption of unrelated families of half-siblings. The unfavourable correlation between the heartwood diameter and extractive content (genetic correlation (rg) = −0.45) indicated that a compromise is required for simultaneous improvement of both traits. Heritability estimates for heartwood collapse (h2 = 0.30) and acoustic velocity (h2 = 0.36) were moderate. Conclusions: Genetic selection for wood quality traits of E. globoidea is practically feasible. Superior individuals with above average performance for multiple traits were present in the breeding populations, however, this was dependent on the intended end use of the timber.
{"title":"Genetic variation in wood properties of mid-rotation age Eucalyptus globoidea","authors":"E. Iyiola, C. Altaner, L. Apiolaza","doi":"10.33494/nzjfs522022x172x","DOIUrl":"https://doi.org/10.33494/nzjfs522022x172x","url":null,"abstract":"Background: Eucalyptus globoidea Blakely produces ground-durable (Class 2) and stiff wood and has the potential to be grown in New Zealand to supply high-value environmentally-friendly timber for use as posts in the agricultural sector and stiff veneers for the LVL industry. The New Zealand Dryland Forests Initiative (NZDFI) has established a breeding programme for this species. The objective of this study was to identify trees with superior wood properties for commercial propagation enabling the establishment of a domestic plantation resource of ground-durable timber.\u0000Methods: The genetic variation in wood properties at mid-rotation age (8-year-old) of 141 E. globoidea families was assessed for the following traits: heartwood diameter, diameter under bark at ~0.5 m height, combined sapwood diameter, heartwood collapse, sapwood collapse, standing tree acoustic velocity and extractive content in the heartwood. Families were ranked and genotypes with large heartwood diameter, high extractive content and stiffness as well as low collapse were identified.\u0000Results: Heartwood diameter (h2 = 0.51) and extractive content (h2 = 1.16) showed good heritability, which in combination with high variation are promising traits for a breeding programme. The high heritability for extractive content indicated a closer relatedness within the population than the assumption of unrelated families of half-siblings. The unfavourable correlation between the heartwood diameter and extractive content (genetic correlation (rg) = −0.45) indicated that a compromise is required for simultaneous improvement of both traits. Heritability estimates for heartwood collapse (h2 = 0.30) and acoustic velocity (h2 = 0.36) were moderate.\u0000Conclusions: Genetic selection for wood quality traits of E. globoidea is practically feasible. Superior individuals with above average performance for multiple traits were present in the breeding populations, however, this was dependent on the intended end use of the timber.","PeriodicalId":19172,"journal":{"name":"New Zealand Journal of Forestry Science","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46553799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-13DOI: 10.33494/nzjfs522022x186x
Campbell Harvey
Background: When harvesting plantation forests of Pinus radiata (D.Don) in New Zealand, large residue piles commonly accumulate on or adjacent to processing sites. While the merchantable volume that is transported to market is carefully measured, little is known of the quantity of the piled, residual material. A working knowledge of residues is becoming more important as it is not only a potentially merchantable product for the bioenergy market, but when stored in perpetuity it can present a risk of self-ignition, and specifically on steep slopes, it presents a mobilisation risk if not stored correctly. Methods: The area, bulk volume and depth of residue piles at 16 recently harvested steepland sites were measured from a wide geographic spread across New Zealand. Unmanned Aerial Vehicle imagery was used to build georeferenced photogrammetric models of residue piles (94 per cent of the studied volume). Pile area was determined from interpreting boundaries from orthophotos and volumes determined by interpolating the obscured terrain surfaces on duplicate photogrammetric models. The remaining 6 per cent of pile volume was measured with handheld GPS tracking of the perimeters and on-site estimation of average pile depth. Results: For a mean harvest area of 18.9 ha, there was a mean of 2.4 piles per harvest site, 2600 m3 bulk volume and 2900 m2 of area covered. For every hectare harvested, a bulk volume of 170 m3 is piled at the landing, or alternatively, 0.23 m3 of bulk pile volume per tonne harvested. The manual terrain interpolation methodology was tested against collecting georeferenced pre-harvest terrain surfaces, yielding an average difference of 19% across two sites and six residue piles. Conclusions: This research demonstrates the ability to investigate the bulk volume and site coverage of landing residue piles with equipment and software tools available to today’s forester. Mean values for pile area and volume are presented to reflect the current state of knowledge and can be a reference point for future initiatives.
{"title":"Measuring harvest residue accumulations at New Zealand’s steepland log-making sites","authors":"Campbell Harvey","doi":"10.33494/nzjfs522022x186x","DOIUrl":"https://doi.org/10.33494/nzjfs522022x186x","url":null,"abstract":"Background: When harvesting plantation forests of Pinus radiata (D.Don) in New Zealand, large residue piles commonly accumulate on or adjacent to processing sites. While the merchantable volume that is transported to market is carefully measured, little is known of the quantity of the piled, residual material. A working knowledge of residues is becoming more important as it is not only a potentially merchantable product for the bioenergy market, but when stored in perpetuity it can present a risk of self-ignition, and specifically on steep slopes, it presents a mobilisation risk if not stored correctly.\u0000Methods: The area, bulk volume and depth of residue piles at 16 recently harvested steepland sites were measured from a wide geographic spread across New Zealand. Unmanned Aerial Vehicle imagery was used to build georeferenced photogrammetric models of residue piles (94 per cent of the studied volume). Pile area was determined from interpreting boundaries from orthophotos and volumes determined by interpolating the obscured terrain surfaces on duplicate photogrammetric models. The remaining 6 per cent of pile volume was measured with handheld GPS tracking of the perimeters and on-site estimation of average pile depth.\u0000Results: For a mean harvest area of 18.9 ha, there was a mean of 2.4 piles per harvest site, 2600 m3 bulk volume and 2900 m2 of area covered. For every hectare harvested, a bulk volume of 170 m3 is piled at the landing, or alternatively, 0.23 m3 of bulk pile volume per tonne harvested. The manual terrain interpolation methodology was tested against collecting georeferenced pre-harvest terrain surfaces, yielding an average difference of 19% across two sites and six residue piles.\u0000Conclusions: This research demonstrates the ability to investigate the bulk volume and site coverage of landing residue piles with equipment and software tools available to today’s forester. Mean values for pile area and volume are presented to reflect the current state of knowledge and can be a reference point for future initiatives.","PeriodicalId":19172,"journal":{"name":"New Zealand Journal of Forestry Science","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45360559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-07DOI: 10.33494/nzjfs522022x139x
Júlio Cézar Tannure Faria, Caius Ribeiro-Kumara, R. R. Costa, E. Nieri, D. de Carvalho, J. P. Pinto, A. R. S. Neto, G. E. Brondani
Background: Micropropagation, an in vitro vegetative propagation technique using small propagules is one of the main applications of plant tissue culture. It can be used to clone specific plants with desired traits and reduce the cost of plant propagation. In this study, we developed a protocol for micropropagation of Eucalyptus microcorys F.Muell using a selected mature tree, in which we tested various combinations of different culture media and evaluated the use of biodegradable polyester-based microvessels during the adventitious rooting and acclimatisation phases. Methods: Epicormic shoots were used as an explant source. After the in vitro explant establishment and multiplication, we tested 8 combinations of BAP, NAA and IBA in the elongation phase. Three types of microvessels were tested in the adventitious rooting phase and acclimatisation of the microcuttings. Results: Epicormic shoots had an establishment percentage of 40.6% and a total of 820 explants were generated by the 11th subculture, with an average of 12 buds per explant. Best shoot elongation results were achieved with BAP (0.05 mg L-1) + NAA (1 mg L-1) and BAP (0.05 mg L-1) + NAA (1 mg L-1) + IBA (1 mg L-1) combinations, whereas microvessel types M2 and M3 provided higher rooting and acclimatisation. According to the results of ISSR markers, at the end of 535 days of in vitro cultivation, cloning was successful between acclimatised micro-plantlets and the parent plant. Conclusions: The micropropagation protocol using microvessels was efficient in producing E. microcorys clonal micro-plantlets and is recommended for further studies with this species, and for testing in the micropropagation of other species.
{"title":"Use of biodegradable polyester-based microvessels for micropropagation of mature Eucalyptus microcorys","authors":"Júlio Cézar Tannure Faria, Caius Ribeiro-Kumara, R. R. Costa, E. Nieri, D. de Carvalho, J. P. Pinto, A. R. S. Neto, G. E. Brondani","doi":"10.33494/nzjfs522022x139x","DOIUrl":"https://doi.org/10.33494/nzjfs522022x139x","url":null,"abstract":"Background: Micropropagation, an in vitro vegetative propagation technique using small propagules is one of the main applications of plant tissue culture. It can be used to clone specific plants with desired traits and reduce the cost of plant propagation. In this study, we developed a protocol for micropropagation of Eucalyptus microcorys F.Muell using a selected mature tree, in which we tested various combinations of different culture media and evaluated the use of biodegradable polyester-based microvessels during the adventitious rooting and acclimatisation phases.\u0000Methods: Epicormic shoots were used as an explant source. After the in vitro explant establishment and multiplication, we tested 8 combinations of BAP, NAA and IBA in the elongation phase. Three types of microvessels were tested in the adventitious rooting phase and acclimatisation of the microcuttings.\u0000Results: Epicormic shoots had an establishment percentage of 40.6% and a total of 820 explants were generated by the 11th subculture, with an average of 12 buds per explant. Best shoot elongation results were achieved with BAP (0.05 mg L-1) + NAA (1 mg L-1) and BAP (0.05 mg L-1) + NAA (1 mg L-1) + IBA (1 mg L-1) combinations, whereas microvessel types M2 and M3 provided higher rooting and acclimatisation. According to the results of ISSR markers, at the end of 535 days of in vitro cultivation, cloning was successful between acclimatised micro-plantlets and the parent plant.\u0000Conclusions: The micropropagation protocol using microvessels was efficient in producing E. microcorys clonal micro-plantlets and is recommended for further studies with this species, and for testing in the micropropagation of other species.","PeriodicalId":19172,"journal":{"name":"New Zealand Journal of Forestry Science","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45361351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-06DOI: 10.33494/nzjfs522022x203x
S. Dodd, F. Shah, M. Kimberley, C. Somchit, Ian Hood
Background: Armillaria novae-zelandiae and A. limonea occur naturally as wood decay fungi in native forests in New Zealand. As pathogens they are responsible for significant root disease in trees and shrubs in plantations, crops and urban parks and gardens. A thorough understanding of their population dynamics entails knowledge of the spatial arrangement of their individual mycelia or genets. In previous work the distributions of vegetative compatibility groups (VCGs) of these fungi were mapped in an area of native forest prior to and after replacement by a young Pinus radiata plantation. With the advent of molecular technology, it has become possible to test species identities made earlier using culture techniques and to verify whether or not their VCGs, determined by incompatibility reactions between paired cultures, represent distinct individual genets. Methods: Stock subcultures of isolates representing each VCG were recovered from storage in order to obtain DNA. Extracted DNA was subjected to a polymerase chain reaction procedure (UP-PCR) using 11 universal primers to assess genetic variation between subcultures. Bands were scored as either present or absent for each primer-subculture combination and cluster analysis was undertaken by generating dendrogram trees to reveal genetic groupings among subcultures. Results: DNA cluster analysis divided subcultures of isolates into two species groups, A. novae-zelandiae and A. limonea, corresponding to identities determined through culture morphology. Within species, subcultures grouped into clusters that matched VCGs determined by earlier culture pairing. There was little indication of genetic variation within VCGs, except for one of A. limonea, which comprised two sub-clusters. Conclusions: The Armillaria species and VCGs identified by culture techniques in the laboratory were verified by independent molecular methodology. In general, the VCGs represent discrete individual genets or colonies in the field. Techniques that differentiate isolates based on differences in their DNA sequence provide a quick alternative to time-consuming laboratory culture methods for resolving population spatial structure. However, some complementary isolate pairing may be necessary when rationalising the significance of groupings in dendrogram trees.
{"title":"Differentiating individuals of Armillaria species in New Zealand forests","authors":"S. Dodd, F. Shah, M. Kimberley, C. Somchit, Ian Hood","doi":"10.33494/nzjfs522022x203x","DOIUrl":"https://doi.org/10.33494/nzjfs522022x203x","url":null,"abstract":"Background: Armillaria novae-zelandiae and A. limonea occur naturally as wood decay fungi in native forests in New Zealand. As pathogens they are responsible for significant root disease in trees and shrubs in plantations, crops and urban parks and gardens. A thorough understanding of their population dynamics entails knowledge of the spatial arrangement of their individual mycelia or genets. In previous work the distributions of vegetative compatibility groups (VCGs) of these fungi were mapped in an area of native forest prior to and after replacement by a young Pinus radiata plantation. With the advent of molecular technology, it has become possible to test species identities made earlier using culture techniques and to verify whether or not their VCGs, determined by incompatibility reactions between paired cultures, represent distinct individual genets.\u0000Methods: Stock subcultures of isolates representing each VCG were recovered from storage in order to obtain DNA. Extracted DNA was subjected to a polymerase chain reaction procedure (UP-PCR) using 11 universal primers to assess genetic variation between subcultures. Bands were scored as either present or absent for each primer-subculture combination and cluster analysis was undertaken by generating dendrogram trees to reveal genetic groupings among subcultures. \u0000Results: DNA cluster analysis divided subcultures of isolates into two species groups, A. novae-zelandiae and A. limonea, corresponding to identities determined through culture morphology. Within species, subcultures grouped into clusters that matched VCGs determined by earlier culture pairing. There was little indication of genetic variation within VCGs, except for one of A. limonea, which comprised two sub-clusters.\u0000Conclusions: The Armillaria species and VCGs identified by culture techniques in the laboratory were verified by independent molecular methodology. In general, the VCGs represent discrete individual genets or colonies in the field. Techniques that differentiate isolates based on differences in their DNA sequence provide a quick alternative to time-consuming laboratory culture methods for resolving population spatial structure. However, some complementary isolate pairing may be necessary when rationalising the significance of groupings in dendrogram trees.","PeriodicalId":19172,"journal":{"name":"New Zealand Journal of Forestry Science","volume":"1 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41504122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-24DOI: 10.33494/nzjfs522022x182x
M. McGlone, P. Bellingham, S. Richardson
Background: Over 80% of New Zealand’s indigenous forests are in public ownership with logging prohibited, and logging of private indigenous forests is restricted to sustainable harvesting only. Such limitations are highly unusual globally and were imposed only in the last few decades of the 20th century. Previously, the national goal had been indigenous wood production in perpetuity. Here we review the role of forestry science in this outcome, and in particular in relation to the policies and practices adopted by the New Zealand Forest Service. Methods: Literature review Results: As early as 1900, it was recognised that economically viable management of indigenous forests for timber production was marginal at best. Nevertheless, the Forest Service, from its formation in 1919 to its abolition in 1987, advocated sustainable commercial management of indigenous forests. However, it failed to bring any significant areas under such management nor prevented conversion of substantial tracts of old-growth forest to exotic plantations or agriculture. Indigenous forest logging would have continued until commercial exhaustion of tall conifer species if a confluence of factors (urbanization, political upheaval, rise of an assertive conservation movement, and declining economic contribution) had not weakened the influence of provincial logging advocacy. Forestry research played a minor role in this saga as it focused on the technical issues of indigenous silviculture (e.g., coupe vs group vs single-tree harvesting methods) while the main drivers of change were economic, social, and cultural. Conclusions: Commercially valuable indigenous forests were protected only when the political cost of continuing logging was greater than that of halting it. However, it is an open question if the current policy settings will remain. Changes in governance (including increased Māori participation), land use change, planted indigenous forests and formation of exotic-indigenous forest communities will affect public attitudes as regards their use. If indigenous forestry science is to be of more consequence than in the past, New Zealand will need clear forestry goals and policies to deal with these changed circumstances, and the will to implement them.
{"title":"Science, policy, and sustainable indigenous forestry in New Zealand","authors":"M. McGlone, P. Bellingham, S. Richardson","doi":"10.33494/nzjfs522022x182x","DOIUrl":"https://doi.org/10.33494/nzjfs522022x182x","url":null,"abstract":"Background: Over 80% of New Zealand’s indigenous forests are in public ownership with logging prohibited, and logging of private indigenous forests is restricted to sustainable harvesting only. Such limitations are highly unusual globally and were imposed only in the last few decades of the 20th century. Previously, the national goal had been indigenous wood production in perpetuity. Here we review the role of forestry science in this outcome, and in particular in relation to the policies and practices adopted by the New Zealand Forest Service.\u0000Methods: Literature review\u0000Results: As early as 1900, it was recognised that economically viable management of indigenous forests for timber production was marginal at best. Nevertheless, the Forest Service, from its formation in 1919 to its abolition in 1987, advocated sustainable commercial management of indigenous forests. However, it failed to bring any significant areas under such management nor prevented conversion of substantial tracts of old-growth forest to exotic plantations or agriculture. Indigenous forest logging would have continued until commercial exhaustion of tall conifer species if a confluence of factors (urbanization, political upheaval, rise of an assertive conservation movement, and declining economic contribution) had not weakened the influence of provincial logging advocacy. Forestry research played a minor role in this saga as it focused on the technical issues of indigenous silviculture (e.g., coupe vs group vs single-tree harvesting methods) while the main drivers of change were economic, social, and cultural.\u0000Conclusions: Commercially valuable indigenous forests were protected only when the political cost of continuing logging was greater than that of halting it. However, it is an open question if the current policy settings will remain. Changes in governance (including increased Māori participation), land use change, planted indigenous forests and formation of exotic-indigenous forest communities will affect public attitudes as regards their use. If indigenous forestry science is to be of more consequence than in the past, New Zealand will need clear forestry goals and policies to deal with these changed circumstances, and the will to implement them.","PeriodicalId":19172,"journal":{"name":"New Zealand Journal of Forestry Science","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48441977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-24DOI: 10.33494/nzjfs522022x174x
Campbell Harvey, R. Visser
Background: Timber harvesting in New Zealand’s plantation forests results in relatively large volumes of woody residues being generated. While a proportion of these residues are concentrated at the landings where the trees are processed, the majority of residues are distributed throughout the cutover. Harvest residues present a biomass market opportunity, however managing un-merchantable residues remains essential as the material can present a mass mobilisation risk. Quantifying cutover residues in terms of volume provides an important step for marketing and for improving post-harvest management. Methods: A refined Line Intersect Sampling (LIS) method was used to measure the cutover residues at 17 recently harvested steepland sites. These covered a range of whole tree harvesting systems, silviculture and geographical locations. The harvesting sites varied in size from 2.3 to 41.1 ha, with an average of 11x 60 m LIS transect plots completed at each site. Woody harvest residues >25 mm in diameter were measured. Results: The median volume of woody residues was 88 m3/ha, ranging from 0 m3/ha in an area swept bare, up to 580 m3/ha in an area severely impacted by windthrow prior to harvest. A distribution of volumes by plot showed a positive skew with an interquartile range of 87 m3/ha. Timber that was considered merchantable as a log at the time of harvest, being >10 cm in small end diameter and >4 m in length, accounted for a median of 11 m3/ha. Residues >10 cm in small end diameter and >80 cm in length that could make a viable biomass product, described as ‘binwood’, accounted for a further 19 m3/ha at the median. Cutovers harvested with cable-based systems had greater median total residue volumes than those harvested with ground-based systems (110 m3/ha versus 68 m3/ha) however the felling method employed made no significant difference to total residue volumes. Conclusions: This study provides cutover residue measurements that can be used to improve post-harvest management, as both a substantial opportunity for improved crop utilisation and also for reducing mobilisation risk. It also provides a contemporary benchmark against which to measure change as harvesting technology or methodology develops.
背景：新西兰人工林的木材采伐导致产生相对大量的木质残留物。虽然这些残留物的一部分集中在树木加工的着陆处，但大多数残留物分布在整个割地。收获残留物提供了生物质市场机会，但管理不可销售的残留物仍然至关重要，因为该材料可能存在大规模动员风险。从数量上量化割草残留物为营销和改进收获后管理提供了重要的一步。方法：采用改良的直线交叉抽样（LIS）方法对17个近期收获的陡坡地的割草残留物进行测量。这些措施涵盖了一系列整树采伐系统、造林和地理位置。收获地点的面积从2.3公顷到41.1公顷不等，每个地点平均完成11 x 60米的LIS样带。测量直径大于25mm的木质收获残留物。结果：木质残留物的中位体积为88立方米/公顷，从裸露地区的0立方米/公顷到收获前受风吹严重影响地区的580立方米/公顷不等。按地块划分的体积分布显示出正偏斜，四分位间距为87 m3/ha。采伐时被视为可作为原木出售的木材，小端直径>10厘米，长度>4米，平均占11立方米/公顷。小端直径>10厘米、长度>80厘米的残留物可以制成可行的生物质产品，被称为“垃圾木”，在中位数处又占了19立方米/公顷。与地面系统相比，使用电缆系统收获的路堑的中值总残留量更大（110 m3/ha与68 m3/ha），但所采用的砍伐方法对总残留量没有显著差异。结论：这项研究提供了可用于改善收获后管理的割草残留物测量，这既是提高作物利用率的重要机会，也是降低动员风险的重要机会。它还提供了一个当代基准，用来衡量收割技术或方法发展过程中的变化。
{"title":"Characterisation of harvest residues on New Zealand’s steepland plantation cutovers","authors":"Campbell Harvey, R. Visser","doi":"10.33494/nzjfs522022x174x","DOIUrl":"https://doi.org/10.33494/nzjfs522022x174x","url":null,"abstract":"Background: Timber harvesting in New Zealand’s plantation forests results in relatively large volumes of woody residues being generated. While a proportion of these residues are concentrated at the landings where the trees are processed, the majority of residues are distributed throughout the cutover. Harvest residues present a biomass market opportunity, however managing un-merchantable residues remains essential as the material can present a mass mobilisation risk. Quantifying cutover residues in terms of volume provides an important step for marketing and for improving post-harvest management.\u0000Methods: A refined Line Intersect Sampling (LIS) method was used to measure the cutover residues at 17 recently harvested steepland sites. These covered a range of whole tree harvesting systems, silviculture and geographical locations. The harvesting sites varied in size from 2.3 to 41.1 ha, with an average of 11x 60 m LIS transect plots completed at each site. Woody harvest residues >25 mm in diameter were measured.\u0000Results: The median volume of woody residues was 88 m3/ha, ranging from 0 m3/ha in an area swept bare, up to 580 m3/ha in an area severely impacted by windthrow prior to harvest. A distribution of volumes by plot showed a positive skew with an interquartile range of 87 m3/ha. Timber that was considered merchantable as a log at the time of harvest, being >10 cm in small end diameter and >4 m in length, accounted for a median of 11 m3/ha. Residues >10 cm in small end diameter and >80 cm in length that could make a viable biomass product, described as ‘binwood’, accounted for a further 19 m3/ha at the median. Cutovers harvested with cable-based systems had greater median total residue volumes than those harvested with ground-based systems (110 m3/ha versus 68 m3/ha) however the felling method employed made no significant difference to total residue volumes.\u0000Conclusions: This study provides cutover residue measurements that can be used to improve post-harvest management, as both a substantial opportunity for improved crop utilisation and also for reducing mobilisation risk. It also provides a contemporary benchmark against which to measure change as harvesting technology or methodology develops.","PeriodicalId":19172,"journal":{"name":"New Zealand Journal of Forestry Science","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45207064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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