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1.
Key message
Coppice stands result in slightly higher stump waste compared with planted stands, when felled mechanically by a harvester.Context
The large demand for wood fibre requires efficient production and cost-effective practices throughout the supply chain.Aims
The purpose of the study was to quantify the amount of volume lost to excessive stump height in coppiced and planted stands.Methods
Stump height was measured on similar eucalypt stands that differed only for their origin: coppiced or planted. The study sample comprised of 543 planted stems and 851 coppice stems; of which 365 grew as double stems and 486 as single.Results
Stump waste was highest for coppiced double stumps, smallest for coppiced single stumps and intermediate for planted tree stumps. All differences were statistically significant, but the difference between coppiced single stumps and planted tree stumps was much smaller (20%) than the difference between coppiced double stumps and the rest (220–260%). Regression analysis showed that stump waste volume increased with tree volume, and this effect was twice as large for coppiced double stumps compared with the other treatments. Stump waste seemed very small in both relative and absolute terms and is unlikely to offset the large benefits accrued through coppice management and mechanization.Conclusion
Comparison with previous stump height studies indicates that the results obtained in this experiment for planted eucalypt may have general value and could be extended to other coppice stands, although with caution.2.
《Southern Forests》2013,75(4):239-246
Due to the labour challenges in South Africa, mechanised forestry equipment has increasingly been required to operate in complex forest conditions – such as coppiced Eucalyptus compartments – where they have not operated before. For this reason, harvesters are either used in certain coppiced compartments with uncertain productivity expectations, or harvesters are not used in these compartments due to a lack of productivity knowledge. This research aimed to determine the influence of tree volume and tree form on the productivity of an excavator-based harvester in coppiced regrowth – with either double or single stems, or planted single stems – in Eucalyptus grandis pulpwood compartments. In addition, the stem felled first and the distance between stems were investigated for coppiced double stems. The stem felled first is whichever stem between the two coppiced double stems the harvester grabbed, felled and processed first. The tree volume was determined; thereafter the trees were classified into different form classes. The tree volume and the cycle time were used to determine productivity. The research results showed that planted trees had the highest productivity across all tree sizes, followed by coppiced single stems and then coppiced double stems. When harvesting a 0.2 m3 tree, the mean harvester productivity was 8.7 m3 per productive machine hour (PMH0) in coppiced double stems, 13.8 m3 per PMH0 in coppiced single stems and 16.1 m3 per PMH0 in planted trees. In coppiced double stems the productivity was significantly influenced by the size of the stem felled first. In coppiced double stems the productivity was not significantly influenced by the distance between stems. The productivity for both coppiced single stems and coppiced double stems was significantly influenced by stem form. The poorly formed trees had lower productivity compared to the trees with good form. 相似文献
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Rocha José Henrique T. Wenzel Andréa V. A. Melo Eduardo A. S. C. Lima Ângela Simone Freitag Hakamada Rodrigo Eiji de Vicente Ferraz Alexandre Arthur Junior José Carlos de Moraes Gonçalves José Leonardo Moreira Gabriela Gonçalves Antônio Natal 《New Forests》2019,50(5):717-731
Coppicing is a widely adopted management system for forest plantations; however, little information is available pertaining to responses to fertilizer application. Our objective was therefore to assess the effect of individual and conjunct omissions of N, P, K, Ca, Mg, B, and Cu on the growth of a highly productive Eucalyptus urophylla?×?E. grandis hybrid clone, managed for coppicing at the second rotation, in two soils of contrasting fertility in southeastern Brazil. Two commercial sites of approximately 7 years of age, one in an Arenosol and the other in a Ferralsol, were harvested and the experiments installed. At the Arenosol site, the yield from the fertilizer treatment in the coppice system (R2) was the same as determined for the first rotation (high forest; R1), at approximately 40 m3 ha?1 year?1 at 6 years old. In contrast, the yield from the fertilizer treatment in R2 at the Ferralsol site was 11% lower compared with R1. Despite some alterations in leaf nutrient concentrations, other than for K at the Arenosol site (where the K omission treatment reduced wood volume at 6 years by 21%), no yield reduction was found for any no-fertilizer treatments. Due to the widely distributed root system already established in coppiced plantations, ensuring a large volume of soil exploration, coppiced eucalypts only responded to K application. This is due to low soil K availability and the high K demand in eucalypt plantations.
相似文献5.
Luciano Rodrigo Lanssanova Sebastião do Amaral Machado Alexandre Techy de Almeida Garrett Izabel Passos Bonete Allan Libanio Pelissari Afonso Figueiredo Filho 《Southern Forests》2019,81(2):167-173
This study evaluated the efficiency of taper functions and the application of mixed-effect modelling for diameter estimation along the stems of Tectona grandis. We sampled 266 trees of Tectona grandis, measuring the diameter at relative heights for volume determination, grouping the data according to three form-factor classes. Six taper functions were fitted, selecting the function with better fit performance. Six taper functions were fitted, selecting the function with better fit performance. The selected function was fitted in its basic formulation, and with the mixed non-linear modelling technique in different scenarios, and for the stem stratified in three portions of the total height. The precision and selection of the adjusted models were evaluated regarding the coefficient of determination, standard error of estimate, the Akaike information criterion, bias, quadratic error and absolute bias. According to the statistical criteria used, the model of Kozak was selected for the adjustments. For diameter estimation, the scenario with two coefficients as random effects provided an accuracy increase of 11.91%, and the mixed non-linear modelling better estimated the stem diameter for the stratified stems. In conclusion, the model of Kozak can be used to describe the stem shape of Tectona grandis, and the mixed-effect non-linear model approach was the best technique to estimate diameter along the stem of Tectona grandis. 相似文献
6.
From the early 2000s there has been a general shift in South Africa in harvesting and extraction systems from the use of semi- to fully-mechanised systems. Any increase in mechanisation, as is occurring in Zululand, will need to take into consideration damage to stumps and the subsequent ability to regenerate by coppice. In 2002, four types of harvesting and extraction systems, arranged in a randomised complete block design, were used to clearfell a stand of E. grandis × E. urophylla. A motor-manual harvesting system was used to carry out the manual harvesting system (Man). The fully mechanised system (Mech) consisted of a single-grip harvesting head used with a tracked excavator to carry out all felling and processing operations. Two additional systems (Man_Mech_3W and Man_Mech_Flexi) had increased levels of mechanisation over that of the Man treatment. Both these harvesting systems made use of a Bell debarker, with loading carried out by a Bell three-wheeled loader in the Man_Mech_3W, and by a Flexiloader in the Man_Mech_Flexi treatments. Data collected from these four treatments were used to determine the effects of mechanised harvesting systems on type and severity of stump damage, coppicing potential and coppice growth over the rotation. Irrespective of harvesting system, more damage occurred to the top than bottom half of the stump, with a significant decrease in coppice regrowth with increasing stump damage. Most damage and least coppice regrowth occurred in the extraction rows where the damage recorded could be attributed to vehicle movement, tear-outs and/or log stripping. There was no significant difference between the harvesting systems in terms of stump mortality, final stem stocking and rotation-end volume. Thus, individual components within each harvesting system can have a larger impact than the overall harvesting system used. Future research should focus on these components, and where associated damage occurs for a specific component, this should be lessened through management intervention, training or technological improvements. 相似文献
7.
In South Africa, commercial eucalypt stands may be regenerated through the stepwise reduction of coppice shoots following felling. The development of secondary coppice regrowth following these reduction operations results in competition with the remaining stems, possibly resulting in a reduction in growth. Currently, secondary coppice regrowth is controlled manually, or through spraying with glyphosate at 0.6% when ca. 0.75?m in height. No research has been conducted to determine whether alternative rates and/or timing of application are possible or cost-effective. In 2006 a trial was implemented in Zululand, South Africa on a recently coppiced stand of Eucalyptus grandis × Eucalyptus urophylla so as to optimise rates of glyphosate application (0.6%, 1.2% and 1.8%) for the control of secondary coppice regrowth at various heights (0.5, 1.0 and 1.5?m). Tree and secondary coppice regrowth variates were measured annually until rotation-end (9 years, 3 months). The volume of herbicide used, the number of occasions each treatment was sprayed and associated costs were combined to provide an indication of the most cost-effective treatment. Although there were no significant differences in final coppice yield for the various rates of glyphosate and timing of application (as assessed by the size of the secondary coppice regrowth) tested, treatment efficacy in terms of treating secondary coppice regrowth increased with an increase in the rate of glypho- sate applied (0% < 0.6% < 1.2% < 1.8%), especially when treated at either 1.0 or 1.5?m in height. The use of glypho- sate, irrespective of rate and/or timing of application (as assessed by secondary coppice regrowth height), proved to be more cost-effective compared with manual control or the spraying of the secondary coppice regrowth at 0.75?m height with 0.6% glyphosate. The most cost-effective treatment was 1.2% glyphosate applied when the secondary coppice regrowth was 1.5?m. If reduced herbicide use is a major criterion within a company portfolio, then the secondary coppice regrowth can be manually removed when 1.5?m. 相似文献
8.
《Southern Forests》2013,75(3):149-154
Eucalyptus grandis is predominantly cultivated in the humid, warmer temperate, subtropical regions in South Africa for pulp and paper production because of its rapid growth and desirable wood properties. With forestry expanding into mid-altitude drier and warmer, or drier and colder sites, the growth of E. grandis has been compromised by unsuitable growing conditions and, therefore, the search to identify reasonably well-performing species/provenances for such sites has extended to summer rainfall provenances of E. cypellocarpa for pulp and paper production. Seed collected from New South Wales, Australia, comprising provenances from Hanging Rock, Nullo Mountain, Wingello State Forests and Kaputar Mountain National Park was established in provenance/progeny trials on three sites in South Africa (Windy Gap, Petrusvlei and Speenkoppies). Trials were planted at 1 667 stems ha?1, in single-row plots of six trees, with four replications in one balanced and two unbalanced lattice designs. Commercial seed of other eucalypts and clones was used as controls. Diameter at breast height and height were measured at 96 months at Windy Gap, and 72 months at both Petrusvlei and Speenkoppies. Basal areas and volumes were derived from these measurements. There were distinct family and provenance differences for growth at the different sites, with the Hanging Rock provenance generally performing well across all sites. A genotype × environment interaction was present between two sites, as indicated by low Type B correlations of 0.47 and 0.53 for basal area and volume, respectively. This indicated that different populations of E. cypellocarpa should be developed for the cold and warm sites. 相似文献
9.
Selected cut-stump (Cut_surface) and basal frill (Basal_frill) treatments were tested on Eucalyptus macarthurii cut stumps that had previously been coppiced multiple times. Treatments included the application of herbicide (triclopyr as an amine salt, 360 g L?1), either to the cut-surface or to a basal frill (cuts made through the bark and into the cambium at the base of the tree). These treatments were integrated with non-chemical control methods, where seedlings were planted either between each stump row or within the row, to determine whether such treatments could further reduce the level of coppicing. Stump mortality for both the Basal_frill and Cut_surface treatments were equally effective, with 87% of the stumps killed when assessed at 14 weeks following initial treatment. No significant treatment differences were detected for the various growth variates of the stand at rotation end (stocking, basal area and volume). This can be attributed to a lack of competition from any coppice regrowth due to good control on each occasion. As there were no significant differences between the treatments, the Cut_surface treatment would be preferable due to the lower overall costs. However, for this method to be most effective, it is important that the herbicide be applied to the cut-surface of the felled tree within one day of felling. This may pose a safety issue, especially with mechanised felling of a stand. Further research on extending the period for application to the cut-surface could be beneficial. However, if reduced herbicide use is a prerequisite, coppice regrowth can be manually removed. 相似文献
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对 5 5年生尾叶桉实生林砍伐后 ,保留不同萌条数量对其萌芽林生长和产量的影响开展了研究。结果表明 ,定株使桩的存活率明显下降 ,特别是保留单株 ,但保留一定的株数却有利于萌芽林的生长 ;萌芽林的高、径和单株材积生长随保留株数的减少而显著增加 ;3 5年生单位面积蓄积量和出材率 (顶木 )以保留 3株·桩- 1为最好 ,其次为 4株·桩- 1和 2株·桩 - 1,蓄积量分别为 4 5 4 9、4 4 2 1和4 2 5 1m3·hm- 2 ,分别是对照的 131 7%、12 8 0 %和 12 3.0 % ,出材率 (顶木 )分别是对照的 174 .3%、14 8.6 %和 15 5 .4 %。因此 ,在中等地力 ,种植密度为 3m× 2m的尾叶桉萌芽林 ,以纸浆材和顶木为主要经营目的的林分 ,建议其萌芽林的保留株数为 2 4株·桩 - 1。 相似文献
12.
Antti Otsamo Tjuk Sasmito Hadi Göran Ådjers Jussi Kuusipalo Risto Vuokko 《New Forests》1995,10(3):257-265
A species trial with 14 eucalypt species with randomized complete blocks design was planted on Imperata cylindrica dominated grassland in South Kalimantan, Indonesia in January 1987. The site was prepared mechanically. No fertilizers were used. At the age of three years E. camaldulensis had clearly the highest survival rate (95%) and mean annual increment (5.9 m3ha–1a–1) compared with the other species tried. It was followed by E. urophylla, E. deglupta, E. pellita, E. tereticornis, E. alba, E. torelliana, E. intermedia, E. grandis and E. pilularis. Four other species, E. phaeotricha, E. resinifera, E. cloeziana and E. microcorys died either in the nursery or immediately after planting. All the eucalypts tried had narrow crowns and open canopies. It is suggested that eucalypts are not recommendable for grassland reforestation under minimum plantation tending. Effects of intensive weeding, spacing, fertilizing and performance in second rotation or mixed stands should be tested to elaborate the suitability of eucalypts on grasslands. 相似文献
13.
Accurately and non-destructively quantifying the volume, mass or nutrient content of tree components is fundamental for assessing
the impact of site, treatment, and climate on biomass, carbon sequestration, and nutrient uptake of a growing plantation.
Typically, this has involved the application of allometric equations utilising diameter and height, but for accurate results,
these equations are often specific to species, site, and silvicultural treatment. In this study, we assessed the value of
incorporating a third piece of information: the height of diameter measurement. We derived a more general volume equation,
based on the conical approximation, using a diameter projected to the base of the tree. Common equations were developed which
allowed an accurate estimate of stem volume, dry weight and nutrient content across two key plantation grown eucalypt species,
Eucalyptus grandis W. Hill ex Maiden and Eucalyptus globulus (Labill.). The conical model was developed with plantation-grown E. grandis trees ranging from 0.28 to 15.85 m in height (1.05 g to 80.3 kg stem wood dry weight), and E. globulus trees ranging from 0.10 to 34.4 m in height (stem wood dry weight from 0.48 g to 652 kg), grown under a range of contrasting
cultural treatments, including spacing (E.
grandis), site (E.
globulus) and fertilization (nitrogen and phosphorus) for both species. With log transformed data the conical function (Vcon) was closely related to stem sectional volume over bark and stem weight (R2 = 0.996 and 0.990, respectively) for both E.
grandis and E.
globulus, and the same regressions can be applied to both species. Back transformed data compared with the original data yielded modelling
efficiencies of 0.99 and 0.97, respectively. Relationships between Vcon and bark dry weight differed for the two species, reflecting differing bark characteristics. Young trees with juvenile foliage
had a different form of relationship to older trees with intermediate or adult foliage, the change of slope corresponding
to heights about 1.5 m for E. grandis and age 1 year for E. globulus. The Vcon model proved to be robust, and unlike conventional models, does not need additional parameters for estimating biomass under
different cultural treatments. More than 99% of the statistical variance of the logarithm of biomass was accounted for in
the model. Vcon captures most of the change in stem taper associated with cultural treatments and some of the change in stem form that occurs
after the crown base has lifted appreciably. Fertilization increased N and P concentrations in stem wood and bark, and regressions
to estimate N and P contents (the products of biomass and concentration) were dependent on treatment. For instance, there
was a large growth response to N fertilization in E. globulus corresponding with a change (P < 0.05) in the intercept of the regression to estimate N content. 相似文献
14.
Three drought-tolerant eucalypt genotypes have been investigated for a broad spectrum of properties to provide a basis for comparison on their suitability for various end-uses. The genotypes included were a Eucalyptus grandis × E. camaldulensis hybrid, E. gomphocephala and E. cladocalyx, selected based on previous studies that indicated good potential to tolerate arid conditions, reasonably good volume growth and straightness of stems. In this study, information was added on differences between species and parts of stems in growth (volume and biomass) and properties of wood (density and stiffness), fibres (dimensions and microfibril angle) and vessels (size and numbers). We found high wood densities and stiffness values for E. cladocalyx and E. gomphcephala, making them suitable for construction wood. Logs from the mid-part of the stem had the best timber properties, as the butt logs showed the highest microfibril angle and lowest wood stiffness due to longitudinal juvenility. Such juvenility was also to some degree observed for wood density and fibre length. The information gained will be especially helpful for selecting species and processing options for small farm and community plantations for producing higher-value products that may be sold to generate much-needed income as well as for local uses, such as fuelwood and charcoal. 相似文献
15.
The effect of phosphite concentration on lesion development by Phytophthora cinnamomi in stems and roots of Banksia grandis and Eucalyptus marginata and in stems of Banksia coccinea was assessed during a 4.3 year period after stem injection of phosphite. Lesion length 6 weeks after inoculation was significantly less in roots of B. grandis trees that had been stem injected with three concentrations of phosphite (50, 100 and 200 g phosphite/l) at two rates (1 and 2 ml/cm of stem circumference) compared with the not‐injected control. With the exception of B. grandis trees injected with 50 g phosphite/l, lesion length for the high rate was not significantly different to the low rate. In roots of E. marginata, lesion development in response to phosphite was different to that in roots of B. grandis; lesion length in roots did not differ significantly between phosphite concentration and rate. Lesion length and girdling in stems of B. grandis and E. marginata was significantly less in those injected with phosphite than in not injected stems. One year after injection, callus tissue had contained lesions in stems injected with phosphite. By 4.3 years after injection of both hosts there was a steep significant negative linear relationship between phosphite concentration and either lesion length or girdling, with greatest lesion development in not injected stems and least in stems injected with 100 g phosphite/l. Recovery of P. cinnamomi from lesion margins 1 year after injection, was significantly less in trees injected with phosphite than in not injected trees. The amount of plant death reflected containment of lesion extension and girdling, and reduction of recovery of P. cinnamomi with phosphite concentration; 4.3 year after injection there was a steep significant negative linear relationship between phosphite concentration and percentage of plant death. In contrast to B. grandis and E. marginata, there was a U‐shaped non‐linear relationship between phosphite concentration and effectiveness of phosphite in controlling lesion extension and girdling in B. coccinea. Containment of lesion extension and girdling with time was greatest for B. coccinea stems injected with 25 g phosphite/l, least for stems not injected, and intermediate in stems injected with 50 and 100 g phosphite/l. As in B. grandis and E. marginata, containment of lesion extension and girdling in B. coccinea with phosphite concentration was reflected in the amount of plant death. The non‐linear response to phosphite of some plant species indicated that injected concentration for B. coccinea should not exceed 50 g phosphite/l, whereas injected concentrations of up to 100 g phosphite/l could be recommended for B. grandis. Longevity of action of phosphite for 4–5 years in native plant species after one injection makes phosphite injection a practical control option for the control of P. cinnamomi disease front extension and the protection of threatened flora. Research into the effect of factors affecting longevity of action of phosphite would facilitate optimization of timing of injection. 相似文献
16.
The effects on soil of canopy and roots of coppiced teak (Tectona grandis L.f.) regrowth in a maize-teak mixture were investigated experimentally by trenching and coppice shoot control. Nitrogen, potassium, magnesium and calcium content of soil were not significantly affected by either treatment throughout the first season of cropping the soil with maize. It is suggested that soil nutrient changes due to canopy or surface roots of coppiced teak regrowth are probably too small to influence the performance of intercropped maize in the first season following coppicing. 相似文献
17.
试论世界桉树栽培现状和我国桉树人工林发展策略 总被引：4，自引：0，他引：4
桉树是世界上热带、亚热带地区最重要的人工林树种之一,其面积已超过600万ha。文中着重介绍了巴西发展按树的经验,并提出了我国应采取的对策。 相似文献
18.
Yi-Qiang Wu Kazuo Hayashi Yuan Liu Yingchun Cai Masatoshi Sugimori 《Journal of Wood Science》2006,52(3):187-194
To explore the influence of the basic density on collapse-type shrinkage properties and to quantify the relationships of the
main anatomical features with shrinkage and collapse properties, all above-mentioned parameters were determined and analyzed
for three species of collapse-susceptible eucalypts, Eucalyptus urophylla, Eucalyptus grandis, and E. urophylla × E. grandis, planted in South China. The correlation coefficients were also determined and the corresponding regression equations were
established with the anatomical parameters measured by using multiple linear regression. The results indicated that: (1) basic
density was strongly positively linearly related to both unit tangential shrinkage (r = 0.970) and unit radial shrinkage (r = 0.959), weakly positively related to total shrinkage (r = 0.656 and 0.640 for tangential and radial, respectively), and weakly negatively related to residual collapse (r = 0.632 and 0.616 for tangential and radial, respectively). (2) The main factors affecting unit shrinkage were cell wall
proportion (WP), microfibril angle (MFA), and double fiber cell wall thickness (DWT); factors playing an important role in
total shrinkage were WP, ray parenchyma proportion (RP), and MFA, while RP had the highest effect on residual collapse (r = 0.949 and 0.860 for tangential and radial, respectively). (3) All corresponding regression models obtained were very suitable
for the evaluation of relationships between the anatomical parameters and unit shrinkage, total shrinkage, and residual collapse,
as measured using a moisture content of 28% as the fiber saturation point for all specimens. 相似文献
19.
J. Rishbeth 《Forest Pathology》1991,21(4):239-249
In an ancient broadleaved woodland in eastern England that had been coppiced regularly for over 700 years Armillaria mellea and A. gallica were common, A. tabescens was moderately frequent, whilst A ostoyae and A cepistipes were local. Fruit bodies were often abundant in areas coppiced the previous winter. The largest focus of A gallica occupied 9 ha and was probably over 500 years old. Large trees were rarely killed but A mellea caused some root decay in birches. The number of coppice shoots killed by Armillaria was small but became greater as the period since coppicing increased; A gallica was most often involved. Alder coppice was the most, and hazel coppice the least, affected. The productivity of coppiced woodland in general seemed little reduced by Armilaria. 相似文献
20.
Whole birch stems were cut off in order to determine how coppicing affects root and stump starch, glucose, fructose and sucrose concentrations and their correlation with shoot regeneration capacity. The Betula pubescens Ehrh. and B. pendula Roth studied included intact trees, trees that had been coppiced 8 years earlier, trees coppiced at the beginning of the experimental season, and birches that had been coppiced twice, 8 years earlier and at the beginning of the experimental season. Carbohydrate accumulation differed between 8 years earlier coppiced and intact trees. Recent coppicing clearly decreased the starch and sugar concentrations of the roots, which were often highest in the thin roots. The concentrations of these compounds in the stumps were always low, although the carbohydrate concentrations of stumps, in particular, correlated with shoot regeneration capacity. Starch was the most labile of the carbohydrates measured and most clearly reacted to coppicing. Differences in starch- and sugar-reserve dynamics indicate a difference between these birch species in the use and replenishing of root and stump reserves. This information may also be of help when the effects of other stresses, for example, severe animal damage or burning, on the regrowth of young birch stands are estimated. 相似文献