Eucalyptus nitens (Deane & Maiden) Maiden is widely planted in temperate regions of the southern hemisphere, principally for pulpwood production. Eucalyptus denticulata I.O. Cook & P.Y. Ladiges was previously recognised as an informal variant of E. nitens and, accordingly, was included in many ‘E. nitens’ field trials. We reviewed data from 85 E. nitens/E. denticulata field trials, located in Australia, Chile, China, Italy, Lesotho, New Zealand, South Africa and Zimbabwe and ranging in age from less than one year to 14 years, to investigate racial (among population groups) genetic variation in growth, wood-property, tree-architecture, fitness and morphological / developmental traits. Meta-analyses were undertaken on these data to gauge the significance of differences among races across trials. Race × rainfall zone interaction was also investigated by categorising field trials as summer-rainfall, winter-rainfall or nursery-based. Race × rainfall zone interaction was significant for growth traits only. In general, Central Victorian E. nitens populations outperformed New South Wales E. nitens populations in winter-rainfall zones, but this ranking was reversed in summer-rainfall zones. On average, E. denticulata grew less rapidly than the best-performing E. nitens races, particularly in winter-rainfall zones. Differences among races were detected in basic density, a commercially important trait, but these differences were small in magnitude. Significant differences among races were also evident in branch size and stem form (straightness). Eucalyptus denticulata races had significantly thinner branches than all E. nitens races except Southern Central Victorian, and Central Victorian E. nitens races generally had the straightest stems. The small number of trials represented for most traits limited the power of meta-analyses but significant differences among races detected in our study are likely to represent consistent and robust differences across a broad range of environments.

Dothistroma needle blight is a very damaging foliar disease of Pinus species. An existing model for predicting spatial variation in Dothistroma needle blight severity was used to predict disease severity (S_sev) under current and future climate.

Spatial predictions of S_sev under current climate varied widely throughout New Zealand. Values of S_sev were highest in moderately warm wet environments in the North Island and on the west coast of the South Island. In contrast, relatively low values of S_sev were predicted in drier eastern and southern regions of New Zealand.

Changes in S_sev from current climate were predicted to be low to moderate under climates projected for 2040. However, over the longer term, to 2090, projected changes in S_sev, resulting from climate change, ranged from moderate to high. Over both projection periods, S_sev was predicted to decline in the North Island and increase within the South Island. Surfaces such as those presented here are a critical element for decision support systems that provide information on site suitability for plantation species under increasing rates of global warming.

Small-footprint, discrete return airborne laser scanning (ALS or lidar) data is increasingly being used by forest managers to assist forest inventories. In this study, airborne lidar and plot-based data were collected from a 5 000 ha study site within Green Hills State Forest, a Pinus radiata D.Don plantation in southern New South Wales, Australia. A series of area-based lidar metrics were extracted and modelled against four inventory attributes (mean tree height, stem density, basal area and stand volume) obtained from 63 ground plots. For all response variables, regression tree models had the best model fit compared to Random Forest and Bayesian Model Averaging modelling techniques. The best regression tree models were based on the lidar metrics: the 5^th and 95^th height percentiles, minimum vegetation height, density of non-ground returns and a measure of spatial variation, the rumple index. All these metrics can be easily derived from the lidar data. The best regression tree models for each inventory attribute produced the following R² values: for mean tree height (m), R² = 0.94; stocking (trees ha^-1), R² = 0.85; basal area (m² ha^-1), R² = 0.81 and for stand volume, R² = 0.81 (m³ ha^-1) while the corresponding relative RMSEs were 5.8%, 23.4%, 15.5% and 22.3%, respectively. These models were then used to produce prediction maps over a 50 m grid across the 5 000 ha study site. Results from this study support the operational inclusion of airborne lidar data within P. radiata resource inventory systems.

A plot based inventory system in conjunction with models is being used to facilitate predictions of carbon stocks and changes in New Zealand’s planted forests. The models include the 300 Index Growth Model for Pinus radiata D.Don to predict stem gross and net volume under bark over a rotation using plot data, linked with a wood density model to convert stem volume to carbon, and C_Change to calculate carbon stocks annually in four pools - above-ground biomass, below-ground biomass, dead wood and litter. This linked suite of models is called the Forest Carbon Predictor version 3.

This model validation paper aims to empirically determine the accuracy and precision of carbon stock and change estimates and predictions from the Forest Carbon Predictor, using independent above-ground biomass measurements acquired at permanent plots located in 39 stands throughout New Zealand and dead organic matter measurements from 14 stands. Model error was assessed using plot inventory data acquired in the same year that biomass measurements were made (model estimation error), and using plot measurements made nominally 5 years before or 5 years after the biomass measurement (model prediction error).

Model bias and 95% confidence interval of the bias averaged -1.2% ± 2.6 m³ ha^-1 for stem volume, -0.8% ± 1.9 kg m^-3 for wood density, 3.7% ± 7.9 t ha^-1 for total carbon (excluding mineral soil carbon), -0.9% ± 5.6 t ha^-1 for above-ground biomass carbon, and 4.7% ± 12.6 t ha^-1 for dead organic matter. The model prediction error was similar to the model estimation error over growth projection intervals of ± 5 years. Total carbon stock estimates at the inventory date and stock change projections over a 5 year interval are expected to average within 5% of actual values.

The herbicides terbuthylazine and hexazinone are widely used by the New Zealand forest industry to control a range of weeds during first year vegetation management operations. These herbicides do not comply with certain eco-certification criteria and have been placed on a list of prohibited pesticides by the Forest Stewardship Council (FSC). Currently they cannot be used on FSC-certified land unless an approval is obtained. A pot trial was conducted to test for a combination of herbicides, not currently prohibited by FSC, that might have the potential to provide control of a wide range of weeds, including both broadleaves and grasses, with low phytotoxicity to Pinus radiata D.Don. Two groups of active ingredients were included in mixes used in the trial: (1) triclopyr, clopyralid and picloram for control of broadleaves; and (2) haloxyfop and quizalofop for control of grasses. Terbuthylazine was also included in the trial in the event that an approval is obtained for continued use there-of in New Zealand. We tested the herbicide combinations at 25%, 50%, 75% and 100% of recommended rates on six species: Pinus radiata, Cytisus scoparius L. (broom), Buddleja davidii Franchet (buddleja), Ulex europaeus L. (gorse), Holcus lanatus L. (fogg grass) and Cortaderia selloana (Schult) Asch. et Graeb. (pampas).

The results indicated that potential replacements for hexazinone and terbuthylazine during year one for the control of fogg grass, pampas, broom and gorse are haloxyfop, clopyralid, triclopyr and picloram. Terbuthylazine used in combination with triclopyr and picloram was the only combination of herbicides tested that caused mortality of buddleja. The herbicide combinations and rates require further testing both in pot and field trials before robust recommendations for field application can be made.

McIvor et al. (pp.151-163) trialled four experimental Populus maximowiczii × P. nigra clones in six different climatic zones. The results suggest that these clones are particularly suitable for colder sites subject to severe winter frosts and to warmer sites with regular rainfall, where their high rust resistance is an advantage. These clones also showed a high tolerance to wind. They are less suited to sites prone to salt spray and to summer drought.

In New Zealand, poplars are commonly planted on moist, unstable pastoral hill country to combat soil erosion. Four Populus maximowiczii × P. nigra experimental clones, bred for soil stabilisation, were trialled on pastoral land in six different climatic zones. The experimental clones (identified as NZ5033, NZ5034, NZ5035, NZ5036) were planted together with six New Zealand-bred commercially available clones (four P. deltoides × P. nigra clones, either ‘Toa’ (P. × euramericana × P. yunnanensis) or ‘Kawa’ (P. deltoides × P. yunnanensis), and ‘Shinsei’ (P. nigra × P. maximowiczii)). The clones were planted as unrooted 3-m poles on open, generally sloping (and often broken) terrain. Replication was 5 or 10 poles per clone/site/year subclass. Survival, height and diameter at breast height (DBH) were measured six to eight years after establishment. Survival of the experimental clones was similar to that of the commercial clones. For height and DBH, NZ5034 was a superior clone, NZ5035 was an average clone, NZ5033 was an average to below-average clone, and NZ5036 was a below-average clone, compared with the commercial clones tested in the trials.

The P. maximowiczii × P. nigra clones are considered particularly suitable for colder sites subject to severe winter frosts and to warmer sites with regular rainfall, where their high rust resistance is an advantage. They also showed a high tolerance to wind. They are less suited to sites prone to salt spray and to summer drought.

Resin pockets are found in the xylem of conifers belonging to four main genera and can generally be classified into two types. Type 1 are radially narrow discontinuities in the wood while type 2 are radially flattened, contain less callus tissue, and are open to the external environment at early stages in their development. Although resin pockets are a major cause of degrade for appearance grade timber little is known about how the frequency of type-1 and type-2 resin pockets varies within trees and within rings.

In this study, we collected data from 15- to 18-year-old Pinus radiata D.Don stands at four sites covering a wide environmental gradient. Resin pocket frequency was determined by cutting the lower 5 m of six trees at each site into 50 mm sections. Each of these sections was then imaged. Resin pockets were identified as type 1 or type 2 and the location of the resin pockets in three dimensions was recorded. Using these detailed measurements, the objectives of this study were to characterise: (i) three-dimensional variation in type-1 and type-2 resin pocket frequency within trees; and (ii) the position of type-1 and type-2 resin pockets within rings.

The frequency of type-2 resin pockets was double that of type-1 resin pockets, and this ratio did not vary significantly between sites. Within trees, resin pocket density varied markedly in the radial but not the longitudinal or circumferential dimensions. At all four sites, variation in the radial dimension was characterised by an absence of resin pockets in the inner rings and fluctuating resin pocket densities in the outer rings. The age at which substantial resin pocket formation began ranged from 4 years on the fastest growing site to 8 years on the slowest growing site. On the driest sites, resin pocket incidence consistently peaked in the latter part of the growth ring in all trees, but on the windiest and wettest site the distribution was more irregular and varied between trees. The distribution of type-1 and type-2 resin pockets was highly segregated within the growth ring with mean positions occurring respectively at ca. the 30th and 80th percentile of the growth ring width.

The demand for carbon credits to offset greenhouse gas emissions is likely to stimulate afforestation rates throughout the world. The development of maps that describe suitable new areas for plantation forestry and quantify potential productivity for these regions will be of considerable value to planners and growers. Using nationally available spatial data sets, the objectives of this study were to: (i) identify areas within New Zealand that could be afforested in the future; and (ii) compare productivity between current Pinus radiata D.Don plantations and potential areas suitable for afforestation. Productivity for P. radiata was defined by 300 Index, which describes the stem volume mean annual increment at age 30 years under a reference regime of 300 stems ha^-1.

Within New Zealand, three potential afforestation scenarios were developed in which delineated areas ranged from ca. 0.7 million ha (Scenario 1) to 1.1 M ha (Scenario 2) and 2.9 M ha (Scenario 3). All three scenarios targeted non-arable land classes for afforestation that have limitations for sustainable use under perennial vegetation. For the current plantations the mean national 300 Index was 27.4 m3 ha-1 yr -1. Compared to the current plantations, at the national level, 2 to 6% increases in 300 Index were predicted for areas established under these three scenarios. Such afforestation would also significantly reduce the rate of soil loss by erosion.

The principal aim of this investigation was to test improved methods for initiation of embryogenic cell lines developed with open-pollinated seeds, on control-pollinated material, and furthermore to improve early cell line proliferation prior to cryopreservation. A total of 20 control-pollinated seed families, many with unrelated parents, were tested. Three cone collections were made between 15 December 2008 and 5 January 2009. Two zygotic embryo explant-preparation techniques were tested; embryos with retained megagametophytes, and excised embryos. Initiation medium was a modified Litvay medium (Glitz). Following initiation, growth of embryogenic tissue was tested on two proliferation media; a modified Litvay medium (Glitz2) and a modified Verhagen and Wann medium (BLG1). Initiation was obtained from both explant-preparation techniques. The best initiation treatment used excised embryos, with 52% of all explants from all collections and all families giving rise to proliferating embryogenic tissue. At the optimum collection time for each of the families, this treatment resulted in a range of 44% – 93% initiation success with a mean of 70% per family. Continued proliferation of initiated cell lines was high with 99% of cell lines initiated from excised embryos continuing to proliferate. After 28 days of growth on the two tested media, Glitz2 and BLG1, the embryogenic mass showed mean increases of 25 and 29 fold, respectively. This represents a major improvement over our previous work.

The paper which this Corrigendum refers to is available here: Alternatives to Pinus radiata in the New Zealand high-country: early growth and survival of P. radiata, P. attenuata and their F1 hybrid

Gadgil and Dick (pp. 87-94) describe a number of fungi that have been recorded but not fully described from New Zealand.

The fungi described in this paper have been recorded but not fully described from New Zealand. The fungi are:
Caulicolous Ascomycota: Heptameria obesa (Durieu & Montagne) Saccardo on Pittosporum tenuifolium Solander ex Gaertner; Pseudovalsa lanciformis (Fries) Cesati & De Notaris on Betula pendula Roth; Pseudovalsa longipes (Tulasne) Saccardo on Quercus cerris f. laciniata (Loudon) C.K.Schneider.
Corticolous coelomycetes: Diplodia scrobiculata J.de Wet, Slippers & M.J.Wingfield on Pinus radiata D.Don.
Foliicolous Ascomycota: Guignardia sp. (aff. Guignardia aesculi (Peck) Stewart) on Macropiper excelsum (G. Forster) Miquel.
Xylophilous hyphomycetes: Phaeoacremonium rubrigenum W.Gams, Crous & M.J. Wingfield on Melia azedarach Linnaeus.

Carbon stocks in two Pinus radiata (D.Don) stands in the North Island of New Zealand were determined at 5-years-old and again at mid-rotation (15-years-old at Kinleith; 16-years-old at Tarawera). Above-ground tree biomass was measured at both ages. At the mid-rotation, dead organic matter pools were also assessed. Below-ground live roots were not directly measured but estimated from a published root/shoot ratio to indicate the relative sizes of the stand carbon pools. At Kinleith (15-years-old) and Tarawera (16-years-old), carbon in the four pools: above-ground biomass; live below-ground biomass; dead wood; and forest floor litter; were estimated to be 79.4 t/ha and 105.6 t/ha, 15.9 t/ha and 21.1 t/ha, 17.2 t/ha and 23.6 t/ha, 13.7 t/ha and 14.6 t/ha, respectively. The total carbon stocks at Kinleith (15-years-old) and Tarawera (16-years-old) were 126 (± 5.1) t/ha and 165 (± 5.5) t/ha, respectively. At mid-rotation, 63 – 64% of total carbon stock at both sites was in live above-ground biomass plus attached dead branches; 16% was in stems, live and dead stumps, dead roots and branch woody debris from the second thinning operation, 7 – 8% was in the forest-floor litter, and 13% was estimated to be in live roots. Carbon (C) accumulation in above-ground biomass averaged 5.3 t C/ha/year by age 15-years at Kinleith and 6.6 t C/ha/year by age 16-years at Tarawera, and increased to 6.4 t C/ha/year at Kinleith and 7.9 t C/ha/year at Tarawera when Pinus radiata live root biomass was included. Further, when dead organic matter pools were included with the Pinus radiata biomass, the mean C accumulation rate increased to 8.4 t C/ha/year at Kinleith and 10.4 t C/ha/year at Tarawera. Overall weighted mean carbon concentration of above-ground biomass was estimated as 51.4 g/100 g and 52.0 g/100 g of dry matter at Kinleith and Tarawera, respectively. At Kinleith (15-years-old) and Tarawera (16-years-old) respectively, mean diameter at breast height was 27.1 cm and 30.8 cm, mean total height was 22.7 m and 28.2 m, mean basal area was 33.1 m²/ha and 39.4 m²/ha, and mean volume inside bark was 299 m³/ha and 397 m³/ha.

Fifteen families of each of Pinus attenuata × P. radiata hybrids and their open-pollinated pure-species controls were tested across three trial sites in the South Island of New Zealand. These hybrids were produced to combine the cold and snow resistance of P. attenuata with the faster growth of P. radiata.

At ages four and eight, the hybrids were the tallest taxon at the two semi-continental sites and had the most acceptable crop trees when compared with the pure species. At the mildest site, P. radiata was the tallest and P. attenuata was the shortest. After an exceptional snowfall, snow damage was recorded to be the greatest in P. radiata, P. attenuata had the least, and the hybrids had damage recorded which was intermediate between the two parent species.

The P. attenuata ×

In pine trees, resin is formed in an interconnecting system of tube-like structures known as resin canals. In radiata pine (Pinus radiata D.Don) these are most common in the earlywood/latewood transition zone and within the latewood. Within- and between-tree variation in resin canal occurrence has been poorly documented and little is known about factors controlling canal frequency or the relationship between canal distribution and the formation of timber blemishes. The presence of resin canals is often associated with the formation of resinous defects of various kinds which can cause major losses in timber production of particularly appearance-grade wood products.

This review summarises recent studies of radiata pine, which have shown that:

the formation of resin canals and resinous blemishes on stems and in wood is more frequent in hotter, drier sites subject to water stress. It is also influenced by silvicultural procedures (stocking rate and thinning) and genetic constitution;

external signs of resin bleeding on stems may indicate the presence of internal resin blemishes that degrade timber products. Some companies now record external resin bleeding in forest inventory systems in order to improve harvest planning. Such data are used to guide pruning intensity and the selection of genotypes in breeding programmes;

resinous blemishes on log ends can be an indication of internal defects in radiata pine timber. These include resin pockets, resin patches, galls, blemishes and intra-ring checks. Some companies now segregate logs in the log yard by visual inspection of log ends; and

certain types of resin features are sometimes associated with external lesions and dimpling on the log surface.

It is a challenge for farmers to manage sustainable development in order to achieve financial, social and environmental objectives feasibly and simultaneously. This paper describes the use of a systems-approach framework for addressing such a complex problem. Three farms were evaluated using this framework. The model used simultaneously optimised financial, social and environmental objectives by selecting from a range of land use and management alternatives over a specified period of time. The result was a financial performance that could be linked to the environmental benefits rather than a simple balance sheet. It contained not only financial information but also an account of both environmental impacts and implicit social and cultural concerns of the farms' manager and owners. The results obtained from this evaluation are now in the process of being implemented to all three farms. These positive results indicate that a systems-approach framework could be successfully applied to resolving other complex land use situations.