26 results for Apiolaza, L.A.

  • Inheritance of Antioxidants in a New Zealand Blackcurrant (Ribes nigrum L.) population

    Currie, A.; Langford, G.; McGhie, T.; Apiolaza, L.A.; Snelling, C.; Braithewaite, B.; Vather, R. (2006)

    Conference Contributions - Published
    University of Canterbury Library

    Proceedings on CD ROM

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  • Very early screening of wood quality for radiata pine: pushing the envelope

    Apiolaza, L.A.; Walker, J.C.F.; Nair, H.; Butterfield, B.G. (2008)

    Conference Contributions - Published
    University of Canterbury Library

    For many years, breeding of Pinus radiata for structural wood relied on improving basic density assessed at age 7 or 8 years old, with little progress. Current efforts have moved to acoustic screening for stiffness at similar age. Breeding cycles are still too long. An alternative is to screen out the worst trees even earlier: shorter breeding cycles should outweigh the lower accuracy due to early selection. Besides genetic effects, there is also evidence that wood stiffness is affected by wind, particularly for stands with low stocking and trees in forest margins. A glasshouse experiment was setup for early selection considering two factors: tree position and clone. Tree positions were straight (control), leaning (30° from the vertical) and rocked (15 minutes every hour, simulating 10 km h-1 wind). Four clones were used covering a range of wood stiffness and replication was 12 plants per treatment. The response variables at 8 months were squared acoustic velocity (v2, surrogate of stiffness), basic density, collar diameter, diameter asymmetry and compression wood. There were significant differences of v2 for treatments and clones. Straight trees had the higher v2 (2.15 km2 s-2), followed by leaning trees (1.95 km2 s-2) and rocked trees (1.74 km2 s-2). The 19% v2 reduction from straight to rocking trees is consistent with observations on the effect of forest margins. Clonal means ranged from 1.53 to 2.11 km2 s-2. Basic density showed significant differences between treatments but not for clones, with higher values for leaning trees (408.0 kg m-3), followed by rocked trees (370.2 kg m-3) and straight trees (358.3 kg m-3). There was zero correlation between v2 and basic density. Straight and rocked trees formed little compression wood in thin arcs at random within the cross-section. Leaning trees formed continuous compression wood on the underside of the leaning stem. We discuss the implications for tree improvement.

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  • Revisiting eucalypts—a strategic assessment

    Apiolaza, L.A.; Chauhan, S.; Walker, J.C.F. (2009)

    Conference Contributions - Published
    University of Canterbury Library

    A prolonged recession is as good a time as any to re-examine one’s premises: to identify what is excellent and what is failing. For too long pine foresters have been involved in an industry that – like airlines, computer hardware and semiconductors – it has on aggregate suffered a loss of capital during the last decade. Over the last 50 years the State has invested $1 billion on forest R&D – and most of that on pine. This has not provided the expected returns because it failed to appreciate the huge natural variability with respect to wood quality, and especially in the corewood of pine. The intrinsic wood properties of today’s pine are little better than that of 80 years ago. The belated recognition that all species are unimproved with regard to intrinsic wood properties puts eucalypt and pine on an equal footing in that both face the same challenge of getting the best out of the existing resource, as well as of developing greatly improved breeds. Eucalypts, and alternative species generally, have been ignored by most forest companies with support coming largely from farm foresters and small investors. Many have been on the receiving end of the question “Why bother?” when pressing the case for the possibility of planting eucalypts. Too often this is followed by a condescending explanation of past failures, and that in the old days the Forest Service tested hundreds of species and that radiata pine was the winner. We tried, they did not work out. Yet any professional gambler will tell you that “you don't bet on the horse you think is gonna win, you bet on the horse that’s got the best odds”; and that you spread your bets/investments (alternative species) and hedge against uncertainties. Our failure to develop a large eucalypt estate is in stark contrast to other Southern Hemisphere countries (Table 1), both in temperate and sub-tropical regions. Most of these plantations are being established by the private sector, which is looking to maximize profit. Many of the new projects involve very high biomass productivity (either for pulp or energy production). These are cutthroat businesses where New Zealand has little prospect of competing on equal terms with countries like Brazil or Uruguay. However around the world there has been less progress with solid wood products and therein lies an opportunity.

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  • Exploiting different scales of variability in a generic Eucalyptus species

    Apiolaza, L.A. (2009)

    Conference Contributions - Published
    University of Canterbury Library

    This paper tackles a simple question: How should we go about starting a breeding program for a generic eucalypt? I posit that the failure of many attempts is directly related to their lack of focus and small population size, which made very difficult to select and breed trees that showed superiority for multiple-traits. I describe the exploitation of variability at three levels: between populations, within populations and within trees. Taking advantage of within-tree variability would make very early selection for intrinsic wood quality feasible. I use stochastic simulation to study the effect of sample size when dealing with a multiple-trait situation. Arising from this analysis I suggest using a strategy based on openpollination, enriched with controlled crosses making use of low cost techniques like Artificially Induced Protogyny. Finally, the testing scheme would target very specific environments, considering that we ought to be breeding niche species that take account of a particular site/environment and a specific endproduct.

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  • Why are breeders not using economic breeding objectives?

    Apiolaza, L.A.; Greaves, B.L. (2001)

    Conference Contributions - Published
    University of Canterbury Library

    The direction of progress for a tree improvement program is determined by a formerly defined objective, that is the linear combination of traits to improve multiplied by their respective economic weights. These weights are derived from production functions, which simply describe the impact of trait change on some economic measure (usually profit). In this sense, they have relevance to both silviculture and breeding. Nevertheless, often objectives in forestry have either not been quantified or have been imprecisely defined, being more the expression of wishful thinking than the product of economic analysis. The CRC for Sustainable Production Forestry (CRC-SPF) has been at the forefront of the development of such objectives for vertically integrated Eucalyptus globulus and Pinus radiata industries. We review basic theory, the current status of breeding objectives development and explore several issues that hinder their usefulness. Some of the problems affect the construction of the objective function (e.g. poor knowledge of the relationship between biological traits and end-product properties, uncertainty on both cost structure and future market prices), other problems affect the application of the objective in the selection process (e.g. lack of good estimates of relationship between selection criteria and objective traits) and, finally, some problems impact on transforming gain in the objective into economic advantage for the industry (e.g. poor market signals between layers of the industry). We discuss these problems and suggest ways to overcome them and/or flag them as areas for further research. It seems to be that the major obstacle for developing formal breeding objectives is uncertainty. We postulate that breeders already have enough information to develop and use sensible breeding objectives.

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  • Carbon revenues and economic breeding objectives in Eucalyptus globulus pulpwood plantations

    Whittock, S.P.; Apiolaza, L.A.; Dutkowski, G.W.; Greaves, B.L.; Potts, B.M. (2004)

    Conference Contributions - Published
    University of Canterbury Library

    This paper investigates the integration of carbon revenues into production system models used to define economic breeding objectives for the genetic improvement of Eucalyptus globulus pulp-wood plantations. A model was used to estimate that carbon dioxide equivalent accumulation in biomass in the Australian Eucalyptus globulus plantation estate established between 2004 and 2012 was in the order of ~146 t CO₂e ha⁻¹, of which 62 t CO₂e ha⁻¹ were tradable in 2012 and a further 30 t CO₂e ha⁻¹ were tradable in 2016. By considering a system where revenues for carbon sequestration are directly dependant upon biomass production in a plantation, it was possible to determine whether economic breeding objectives for the genetic improvement of E. globulus will be sensitive to the revenue from carbon sequestration. The correlated response of breeding objectives with and without carbon ( ΔcGH₁ ) never fell below 0.86 in sensitivity analysis, and the mean was 0.93. As such, where economic breeding objectives for the genetic improvement of Eucalyptus globulus for pulpwood plantations are based on maximizing NPV by increasing biomass production, the consideration of carbon in economic breeding objectives will provide no significant gains in NPV.

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  • Exploration of the Eucalyptus globulus gene pool

    Potts, B.M.; Vaillancourt, R.E.; Jordan, G.; Dutkowski, G.W.; McKinnon, G.; Steane, D.; Volker, P.; Lopez, G.A.; Apiolaza, L.A.; Li, Y.; Marques, C.; Borralho, N.M.G.; Costa e Silva, J. (2004)

    Conference Contributions - Published
    University of Canterbury Library

    The first Europeans to discover Eucalyptus globulus were French explorers in 1792. Its seed was rapidly spread throughout the world in the 19th century and this was the species by which much of the world first knew the genus. However, it was in the industrial forests of the 20th century that this species, once considered the ‘Prince of Eucalypts’, achieved greatest prominence due to its fast growth and superior pulp qualities. Formal breeding first commenced in 1966 in Portugal and in the late 1980’s large base population trials from open-pollinated seed collections from native stands were established in many countries. These trials have provided unprecedented insights into the quantitative genetic control of numerous traits of economic and ecological importance and how this variation is spatially distributed in the native range of the species. However with large, fully pedigreed breeding populations becoming available for quantitative analysis and the rapidly expanding knowledge of DNA sequence variation, we are now at the threshold of a new understanding of this important eucalypt gene pool. Indications of the significance of non-additive genetic effects are becoming available. The E. globulus chloroplast genome has now been sequenced and several genome maps have been published. Studies of the variation in nuclear microsatellites and the lignin biosynthesis gene CCR confirm the complex, spatially structured nature of the native gene pool. Strong spatial structuring of the chloroplast genome has provided a tool for tracking seed migration and the geographic origin of exotic landraces. Highly divergent lineages of chloroplast DNA have been discovered and studies of the hypervariable JLA+ region argue that some components of the E. globulus gene pool have been assimilated from other species following hybridisation.

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  • Developing a genetic evaluation system for forest tree improvement – the making of TREEPLAN®

    Kerr, R.J.; Dutkowski, G.W.; Apiolaza, L.A.; McRae, T.A.; Tier, B. (2002)

    Conference Contributions - Published
    University of Canterbury Library

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  • TREEPLAN - A genetic evaluation system for forest trees

    McRae, T.A.; Apiolaza, L.A.; Dutkowski, G.W.; Kerr, R.J.; Pilbeam, D.J.; Powell, M.B.; Tier, B. (2003)

    Conference Contributions - Published
    University of Canterbury Library

    The TREEPLAN® genetic evaluation system is designed specifically for the efficient and accurate prediction of breeding and other genetic values in trees. TREEPLAN® uses the preferred statistical method of best linear unbiased prediction (BLUP) using an individual tree additive genetic effect. Although BLUP methods are well developed theoretically, other software is suitable only for breeding value estimation and prediction on small and/or highly structured (balanced) data sets. Packages such as ASREML and SAS have hardware and software limitations that make them unsuitable for routine prediction on large data sets with complex pedigree structures and overlapping generations. TREEPLAN® fits a reduced individual tree model for purposes of efficiency. TREEPLAN® can model multiple genetic groups, handle clonal data, fit multi-trait models with more than 50 traits, accommodate heterogeneous variances, fit site specific statistical and genetic models, and also weights information across environments (accounts for genotype by environment interaction) and time (allows for age:age correlations). The Southern Tree Breeding Association (STBA) is routinely using TREEPLAN® for genetic evaluation in Australian tree improvement programs for Pinus radiata, Eucalyptus globulus and E. nitens. TREEPLAN® has allowed data across generations and years to be combined in a multi-trait analysis to produce single lists of breeding values for each trait and environment combination. TREEPLAN® is easy to use and has the ‘industrial strength’ to handle large amounts of unbalanced data with the complex pedigree structures that are usually associated with national or regional tree improvement programs. TREEPLAN® is fully integrated with a web based data management system that efficiently handles data and pedigree information. The analytical power and flexibility of the TREEPLAN® system has made routine genetic evaluation in trees a straightforward process.

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  • TREEPLAN A genetic evaluation system for forest tree improvement

    Kerr, R.J.; Tier, B.; McRae, T.A.; Dutkowski, G.W.; Apiolaza, L.A. (2001)

    Conference Contributions - Published
    University of Canterbury Library

    TREEPLAN® is a genetic evaluation system for forest tree improvement. The system is designed specifically for the efficient and accurate prediction of genetic values of trees for breeding and deployment purposes. TREEPLAN® uses best linear unbiased prediction (BLUP). BLUP has important statistical advantages over the more traditional methods used in tree breeding as BLUP allows for the comparison of individuals across space and time, regardless of the environment in which the trees are grown. Although BLUP methods are well developed theoretically, software currently available is suitable only for breeding value estimation and prediction on ‘small’ and/or ‘well structured’ (balanced) data sets. Packages such as ASREML (Gilmour et al. 1999) and SAS/STATS (1991) have hardware and software limitations that make them unsuitable for the routine prediction of breeding values on very large data sets. The Southern Tree Breeding Association (STBA) implements breeding programs in Australasia for Pinus radiata and Eucalyptus globulus. A feature of these programs is a ‘rolling front’ strategy with overlapping generations. Without suitable BLUP software it is difficult to combine information across locations, years and generations, particularly where the pedigree is complex. A lack of suitable BLUP software may have acted as an impediment to genetic progress in many tree improvement programs internationally. The STBA and the Animal Genetics and Breeding Unit (AGBU) have developed TREEPLAN® as an ‘industrial strength’ system for breeding value prediction using technologies developed and routinely used in animal breeding and livestock improvement.

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  • Heritability and fitness-related consequences of squid personality traits

    Sinn, D.L.; Apiolaza, L.A.; Moltschaniwskyj, N.A. (2006)

    Journal Articles
    University of Canterbury Library

    Dumpling squid, Euprymna tasmanica, show consistent individual differences in behaviour that can be classified according to indices reflecting shy–bold, activity and reactivity responses. Using crosses of wild-caught single males to multiple females with known behavioural phenotypes, this study estimated patterns of additive genetic and residual variance in these behavioural traits from offspring of squid in two contexts, a threat (antipredator) and feeding (foraging) test. Genetic contributions to behavioural expression were dependent on test context. Behaviours in antipredator contexts had significant heritabilities (h² = 0.2-0.8) while behaviours from foraging contexts had lesser additive genetic and greater residual components (h² = 0.05-0.08). Personality trait variation in females was not related to her fecundity. Female boldness in foraging situations, which co-varied with body size, explained small but significant variation ( 21%) in brood hatching success, while successful fertilization was determined by positive assortion of mate pairs according to their shy–bold phenotype. These results are discussed in terms of the ecological and evolutionary significance of animal 'personality' traits in wild populations of animals.

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  • Breeding objectives for three silvicultural regimes of radiata pine

    Apiolaza, L.A.; Garrick, D.J. (2001)

    Journal Articles
    University of Canterbury Library

    A generic vertically integrated firm, comprising a production forest, a sawmill, and a pulp mill was modelled under three silvicultural regimes: direct to pulp, intermediate (includes production thinning), and intensive (includes production thinnings and pruning). The harvest age traits included in the breeding objective were total volume (m³/ha) and average wood density (kg/m³). Economic values for each trait were calculated as the difference in discounted profit for a unit marginal increase of volume or density, and expressed as relative weights to facilitate comparisons between the objectives. The methodology was applied to a Chilean case study using representative economic and production circumstances. The breeding objectives so derived were 1vol + 2.4den for pulp, 1vol + 1.1den for intermediate, and 1vol + 1.2den for the intensive regime, where vol and den are the breeding values for volume and density, respectively. The firm was profitable under all regimes. Genetic correlations between the objectives for each regime were higher than 0.9, indicating that a single breeding strategy with objective 1vol + 1.5den could be adopted, with almost no loss of genetic gain relative to selecting for a particular silvicultural regime.

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  • Maternal and carryover effects on early growth of Eucalyptus globulus

    Lopez, G.A.; Potts, B.M.; Vaillancourt, R.E.; Apiolaza, L.A. (2003)

    Journal Articles
    University of Canterbury Library

    Maternal and nonmaternal reciprocal effects were compared with nuclear genetic and carryover effects using a diallel mating amongst eight Eucalyptus globulus Labill. wild parents from northeastern and southern Tasmania races. Seed mass exhibited a significant maternal effect, increasing seed germinative capacity but not germination rate. After accounting for variation in seed mass, both germinative capacity and germination rate exhibited significant reciprocal effects, but these were nonmaternal in origin. Rapid germination and large seeds resulted in significantly larger seedlings in the nursery, but these carryover effects diminished with age. In contrast, the expression of genetic effects increased with age. Significant additive genetic variation was detected for growth by age 3 years and significant reciprocal differences were detected at the race level after 2 years in field trials. If common, such reciprocal effects could bias genetic parameters and impact on the choice of cross-direction in deployment programs. Failure to account for carryover effects in genetic analyses may inflate estimates of genetic variation for growth during early stages of the life cycle.

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  • Basic density of radiata pine in New Zealand: genetic and environmental factors

    Apiolaza, L.A. (2011)

    Journal Articles
    University of Canterbury Library

    Wood basic density is among the selection criteria for many fast-grown tree species, including Pinus radiata D. Don in New Zealand. Basic density was assessed in 23,330 stem cores from 18 trials to study the heritability, the relevance of environmental effects and the magnitude of genotype-by-environment (GxE) interaction. Site differences in annual average temperature dominated variability in this dataset, with lower latitude and altitude (i.e. warmer) sites displaying higher average density. Between highest- and lowestdensity sites there was an 18% difference (302.7 vs. 358.4 kg m-3) for the linear mean for cores of rings 1–5 and a 39% difference (329.7 vs. 459.1 kg m-3) for the linear mean of rings 6–10. The estimated heritabilities fluctuated between 0.28 and 0.94 (mean, 0.6); however, basic density displayed little within-site variability (phenotypic coefficient of variation, <8%). Bivariate analyses were used to estimate between-site genetic correlations as an indication of GxE interaction. Only 57 out of the 153 pairs of trials contained enough information to estimate the between-site genetic correlations and, out of those, 15 estimates were not statistically significant. Moderate to high (0.46–0.96) significant genetic correlation estimates indicated that there was little interaction for basic density, suggesting no need to modify the breeding strategy to account for differential performance in this trait. Poor connectedness between trials could be depressing estimates of genetic correlations. This situation should be considered when designing genetic testing schemes, particularly when purposely inducing imbalance as in rolling front strategies.

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  • Compromises in the genetic evaluation system of radiata pine in New Zealand

    Apiolaza, L.A. (2014)

    Conference Contributions - Other
    University of Canterbury Library

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  • Screening eucalypts for growth-strain

    Davies, N.T.; Sharma, M.; Altaner, C.M.; Apiolaza, L.A. (2015)

    Conference Contributions - Other
    University of Canterbury Library

    Eucalypt species are fast-growing and can produce high quality timber for appearance and structural products including Laminated Veneer Lumber (LVL). Eucalypts can contain large growth-strains which are associated with log splitting, warp, collapse and brittleheart. These impose substantial costs on processing (Yamamoto 2007). Costly, and only partially effective, mitigation strategies have been developed to reduce wood defects induced by growth-strain. As growth-strain is highly heritable, an alternative approach is to select and grow individuals which display low growth-strain. Until now measurement of growth-strain has been difficult, time consuming and expensive, preventing the assessment of the large number of trees needed by a breeding programme (Altaner 2015). As an example, the largest sample number in any reported growth-strain study was smaller than 230 trees (Solorzano Naranjo 2011). Traditionally selections are made when trees are older, not only increasing costs (e.g. trial management, sample handling) but also substantially extending the breeding cycle and delaying the deployment of improved germplasm (Altaner 2015). Developments at the University of Canterbury have resulted in a unique growth-strain measurement method supported by theoretical analysis (Entwistle 2014) - dubbed the “Splitting” test. It allows for rapid growth-strain assessment on young trees (Chauhan 2010).

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  • Sampling tree breeding trials

    Apiolaza, L.A.; Moltchanova, E. (2016)

    Conference Contributions - Other
    University of Canterbury Library

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  • Variance modelling of longitudinal height data from a Pinus radiata progeny test

    Apiolaza, L.A.; Gilmour, A.P.; Garrick, D.J. (2000)

    Journal Articles
    University of Canterbury Library

    Variance components were estimated using alternative structures for the additive genetic covariance matrix (G₀), for height (m) of trees measured at 10 unequally spaced ages in an open-pollinated progeny test. These structures reflected unstructured, autoregressive, banded correlation and random regressions models. The residual matrix (R₀) was unstructured, and the block and plot strata matrices were autoregressive. The best model for G₀ considering the likelihood value and number of parameters was the autoregressive correlation form with age-specific variances and time on a natural logarithm basis. The genetic correlation between successive measures ranged from 0.93 at age 1 to 0.99 at age 14 years. Heritability increased with age from 0.09 (age 1) to 0.24 (age 7) and then declined to 0.13 at age 15. Heritabilities from the unstructured model were similar, while heritabilities assuming banded correlations were lower after age 7. The covariance structure implicit in the random regressions model was considered unsatisfactory. Using structures in G₀ facilitated model fitting and convergence of the likelihood maximisation algorithm. Fitting a structured matrix that reflects the relationships present in repeated measures may overcome problems of nonpositive definiteness of unstructured matrices from longitudinal data, especially when genetic variation is small.

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  • Integrating revenues from carbon sequestration into economic breeding objectives for Eucalyptus globulus pulpwood production

    Whittock, S.P.; Dutkowski, G.W.; Greaves, B.L.; Apiolaza, L.A. (2007)

    Journal Articles
    University of Canterbury Library

    A system where carbon sequestration was directly dependent upon biomass production in a plantation was modelled to assess whether economic breeding objectives for the genetic improvement of Eucalyptus globulus were sensitive to potential revenues from carbon sequestration. Carbon dioxide equivalent accumulation in the biomass (CO2e) of the Australian E. globulus plantation estate established between 2004 and 2012 was estimated. Total carbon dioxide equivalent (CO2e) accumulation was in the order of 146 t CO2e ha-1, of which 62 t CO2e ha-1 were tradable in 2012 (the 1st Kyoto Protocol commitment period) and a further 30 t CO2e ha-1 were tradable in 2016 (a hypothetical second Kyoto protocol commitment period). The correlated response of breeding objectives with and without carbon revenues ( never fell below 0.86 in sensitivity analysis, and the mean was 0.93. Where economic breeding objectives for the genetic improvement of Eucalyptus globulus for pulpwood plantations are based on maximizing net present value by increasing biomass production, the consideration of carbon revenues in economic breeding objectives will have no significant effect on the relative economic weights of the key economic traits, wood basic density and standing volume at harvest.

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  • Effects of cultivation method on the early growth of Pinus radiata on a low-quality site in north-eastern Tasmania

    Laffan, M.; Rees, S.; Apiolaza, L.A. (2008)

    Journal Articles
    University of Canterbury Library

    Survival and growth of Pinus radiata on a low-quality texture-contrast soil in north-eastern Tasmania were compared over a five-year period following five different cultivation treatments: no cultivation, ripping, mounding, ripping + mounding or spot cultivation. Soil penetration resistance after two years, and root abundance after 4.5 years, were also measured. After five years, there were no significant differences in survival between treatments. Ripping + mounding produced the best height growth after five years, followed by mounding, ripping, spot cultivation and lastly no cultivation. However, only mounding and ripping + mounding produced significantly greater height growth compared to no cultivation. Comparisons of plot mean basal area (m2) and volume per hectare (m3 ha-1) showed trends similar to mean height after five years, with ripping + mounding producing the highest basal area and volume. However, only the differences between ripping + mounding and no cultivation were significant. Soil penetration resistance, measured after two years, was significantly lower at depths <45 cm following either ripping + mounding or spot cultivation compared to no cultivation. Root abundance after 4.5 years was significantly higher following ripping + mounding compared to the other four treatments. Growth was therefore consistently superior following ripping + mounding when compared to the other treatments, although the results indicate that any type of cultivation is preferable to no cultivation at all. On highly erodible soils, such as those at the trial site, spot cultivation might be preferable to continuous cultivation (ripping and/or mounding) in order to minimise the risk of erosion and subsequent pollution of waterways by suspended sediments.

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