Hedonic prices for structural wood attributes of radiata pine logs in New Zealand

This paper presents an estimation of the economic values of attributes for the production of structural timber from Pinus radiata logs. A hedonic prices approach was used to obtain economic values, using conversion return instead of log price as the dependent variable. A comparison between these log values is presented to illustrate the pertinence of the conversion return for the purposes of this study. Data were provided by the Wood Quality Initiative as a sample of 71 second and third unpruned logs. Attributes included in the hedonic models were small end diameter, stiffness, basic density, and branches and the corresponding hedonic prices were 0.11, 0.029, 0.37 and -0.55 NZ $/m3 respectively. Additionally, an efficiency analysis was used to identify the mix of wood attributes that define an efficient log for structural purposes, from a technical and economic point of view. The application of data envelopment analysis showed that a third log is the most efficient to produce structural grade MSG8+. This log also presented the highest difference between conversion return and its corresponding price. Trends observed in the cost efficiency index, as well as correlations between this and the log conversion return were useful for validating the economic values of the wood attributes

Very early selection for solid wood quality: screening for early winners

This article reviews the theoretical basis for indirect selection – where early selection is an example – and how correlated response is calculated. The review is followed by a description of issues as to the choice of selection criteria that could explain the lack of substantial progress on breeding for wood quality. These include: the autoregressive nature of selection criteria, overemphasizing the importance of basic density as selection criterion, ignoring age-related trends of wood properties, using rotation age rather than technical thresholds as objective traits and ignoring that not all grades have identical marginal economic value. Three data sets are either analyzed for the first time or reanalyzed under different assumptions, to explore the importance of these criticisms. Finally, the use of critical value thresholds as very early selection criteria is suggested and discussed in the context of improving intrinsic corewood quality

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

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

Exploiting different scales of variability in a generic Eucalyptus species

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

Modeling wood quality using random regression splines

During the last five years there has been a surge of wood quality data describing variation from pith to bark. This data has been generated by low-cost repeated assessment of individuals or by SilviScan-type analyses of increment cores. Traditionally, breeders have used multiple univariate analyses to study the evolution of genetic control and estimate age-age correlations. In this paper I random regression splines to model longitudinal data. After introducing theoretical considerations, I apply the method to two SilviScan data sets from open-pollinated progeny trials, using microfibril angle (°) for 188 trees from an 11 year old Eucalyptus globulus trial in Australia and basic density for 425 trees from an 28 year old Pinus radiata trial in New Zealand. The random regressions approach permits modeling the mean wood quality curve and individual curves at the family and tree level. These curves show significant variation from the mean, which can be exploited for selection purposes, particularly when quality thresholds are important. In addition, their use produces a smoothed additive genetic covariance matrix

Genotype by environment interaction of Pinus radiata in New Zealand

In New Zealand, a formal tree improvement and breeding programme for Pinus radiata (D.Don) commenced in 1952. A countrywide series of progeny trials was progressively established on over sixty sites, and is managed by the Radiata Pine Breeding Company. Diameter at breast height data from the series was used to investigate genotype by environment interaction with a view to establishing the need for partitioning breeding and deployment efforts for P. radiata. More than 280,000 measurements made this study one of the largest for genotype by environment interaction ever done. Bivariate analyses were conducted between all pairs of sites to determine genetic correlations between sites. This enabled construction of a proximity matrix by subtracting each correlation from unity. The process of constructing the matrix highlighted issues of connectedness between sites. Multiple regression on resemblance matrices was carried out by regressing a number of environmental correlation matrices on the diameter at breast height correlation matrix. Genotype by environment interactions were found to be driven by total rainfall and extreme maximum and minimum temperatures. In addition, a method from Graph Theory using proximity thresholds was utilised as a form of clustering. However, in this study, minimal grouping of sites was observed. Future work, incorporating ASReml to conduct the univariate and bivariate analyses, is expected to produce clearer results than experienced in this pilot study

Comment on sustainability and innovation in staple crop production in the US Midwest

Freely available online.In a recent article Heinemann et al. (2013) focused “on the US staple crop agrobiodiversity, particularly maize” using the contrast between the yield of Western Europe and United States as a proxy for the comparison between genetically modified (GM) maize versus non-GM maize. They found no yield benefit from using GM maize when comparing the United States to Western Europe. In addition, Heinemann et al. contrasted wheat yields across United States and Western Europe to highlight the superiority of the European biotechnological package from a sustainability viewpoint. I am compelled to comment on two aspects that led the authors to draw incorrect conclusions on these issues. My statistical code and data are available as supplementary material

Revisiting eucalypts—a strategic assessment

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