The paper which this Corrigendum refers to is available here: Sectional measurement of trees: A rationalised method

A possible explanation for the failure of much past pruning to achieve the objective of having all final crop trees pruned is that the method of selecting trees for pruning could have excluded many potential final crop trees. This study compares two variants (including and excluding missing trees) of six selection methods for low pruning (below ca. 2.4m (8 ft) in two stands of radiata pine (Pinus radiata D. Don).

As measured by the total number of normal dominants selected, the order of efficiency of the methods tested was: best of 2 trees in 4; best of 1 tree in 2, and 1 tree in 3 "Queensland" (both more or less equal); best of 1 tree in 4 "Queensland"; best of 1 tree in 3; best of 1 tree in 4. Even when perfectly applied no method could guarantee that every normal dominant would be selected. The only means of ensuring this would be to adopt a system in which all acceptable stems are selected irrespective of spacing. Including or excluding missing trees had little effect on the comparisons.

An analysis of the reasons for variations between experienced workers showed that misinterpretation of priorities was the most common fault. Also important were failure to see malformation, choices between trees of more or less equal status, and differences in the assessment of the relative significance of types of malformation.

An X-ray source was used to produce a radiograph of 5.1mm wood cores. Ring widths were measured much faster and more accurately from the radiograph than directly from the wood core. Where the density variation between earlywood and latewood was not great enough, radio-opaque solutions were infused into the latewood cells to improve contrast on the radiograph. A wood moisture content of 30% gave the best results without any shrinkage. The radiographic method had a maximum inherent error of less than 0.3%, due to linear deformation.

Light and electron microscope studies of cambium in young trees of Pinus radiata D. Don sampled during the few weeks following the winter solstice have shown that this tissue does not become completely dormant. Cell division is actively proceeding throughout this period in the fusiform and ray initials of the secondary meristem. Evidence suggests that no tracheids aife being formed, and that cell divisions are actively involved in the production of phloem. The cytoplasm of developing tracheids is markedly different from that of young phloem cells, the former being involved mainly in wall thickening, the latter in production and storage of protein in addition to wall formation. P. radiata is different both in appearance and degree of activity during the winter, from P. strobus L. growing in the United States, and described by other authors. Preliminary work has suggested that New Zealand-grown P. strobus is similar in appearance and activity to that grown in USA. This work suggests that dormancy in the pines is as dependent on internal factors which vary among species as on climatic or day length factors.

Data are presented on liberations, establishment, dispersal, and increase of red deer during the period 1851-1988 throughout northern South Island districts. Thirty-two liberations, at 20 places, between 1851 and 1922 of five different strains of red deer, are recorded. Red deer were initially established at Nelson in 1861 from Thorndon Hall stock, England, and later, three comparatively small herds were established near Reefton, Bainham, and Westport from Windsor, Thorndon, and mixed stocks respectively. Distributions are mapped for the period 1861-1900, at decade intervals until 1940, and for the period 1940-68. By 1920 almost 70% of the total area of 14,234 sq miles had been occupied and the remainder was colonised by 1950. Maximum rates of dispersal occurred between 1910 and 1920 at 7 linear miles, or 637 sq miles per year. Prior to 1915, but rarely thereafter, stags were commonly seen outside the range of hinds. Routes and rates of dispersal were influenced primarily by topography and vegetation; in the Marlborough Sounds, Kaikoura region and the Paparoa range a considerable delay in occupation occurred.

Requirements for advanced generation breeding populations in forest trees are considered in terms of initial selection of parent genotypes, mating designs, and the nature of progeny plantings.

Large numbers of parent genotypes, 200 or more, are considered desirable, to minimise inbreeding, and to avoid loss of uncommon genes which might eventually prove valuable.

Mating designs should combine immediate efficiency of genetic gain with maintenance of effective population size. Several mating designs, commonly used to test parent genotypes or to estimate genetic parameters, are unsuitable for producing advanced generation breeding populations.

The most promising designs appear to be single-pair matings, and some modifications of the polycross. These are considered in detail, but further study is needed of the effects of non-additive genetic variance on their expected efficiencies. Final choice of mating design, however, may depend on availability of certain information from existing progeny trials, and on the possible need to fulfil other objectives, such as testing parental genotypes.

Progeny plantings could, in some circumstances, be designed entirely for efficient evaluation of individuals in relation to their family means. Clonal replication of seedlings should be explored as a procedure in selecting for traits with "all-or-none" expression.

End-grain pressure treatment of green softwood poles has been shown by previous workers to be improved by cutting away discs equal in thickness to the tracheid length. Xylem sap in the conducting sapwood of young trees which are felled for use as poles is under a hydrostatic tension and therefore retreats away from the cut surface and is replaced by air. In hardwoods with long xylem vessels this air forms a barrier to any solution forced in under pressure and is demonstrated to be very difficult to remove.

The degree of control of Dothistroma pini Hulbary was determined for 16 different monthly spray schedules of high volume applications of cuprous oxide at 0.2% active ingredient copper. Pinus radiata D. Don. seedlings exposed to heavy natural infection for one year were hand sprayed and the differences in the degree of defoliation with treatment were compared. For a single spray schedule it was found that the most effective time of application was November, and December was almost as effective. Applications in either August, September, or October were too early and those in January, February, or March were too late to be effective.

Only those two-spray schedules which included a November or December application provided effective control and the best of these was the October + December schedule. The combination of an October spray with the December application improved its effectiveness but the combination with a February spray did not enhance the effect of the December application. Similarly the September + November schedule was more effective than the single November application while the combination with a January application had little effect. This increase in effectiveness of the two-spray schedules as against the single sprays was due to a more gradual build-up in initial defoliation levels rather than to a large difference in the final levels reached.

Fifteen pruned dominants (mean d.b.h. 23.4in.) of a 26-year-old radiata pine second rotation stand were sawn predominantly to boards. The stand sampled had received intensive silvicultural management following natural regeneration but the results presented are not representative of the stand as a whole. Altogether, seventy-four 18ft logs were sawn, the average conversion factor being 6.7. Butt logs yielded a percentage average grade out-turn of 37% Clear and 32% Factory grades. The entire sample yielded 13% Clear and 23% Factory grades. A regression for the total clear wood available from the butt logs was calculated:

clear wood volume (in bd ft) = 92.26 B.A. - 44.49

where B.A. = tree basal area (in sq ft).

The incidence of defects was generally consistent with earlier studies on older crops but large bark encased knots were few.

Heartwood of Nothofagus fusca (Hook, f.) Oerst was examined in transmission and scanning electron microscopes to determine the effect of steaming on the fine structure of green wood; the implications of this in drying were considered. The most obvious changes were seen in materials lining cell lumina and pit areas; in natural condition, these occluding materials formed relatively uniform layers whereas, after steaming, they were more irregular because of flowing, blistering, or formation of rounded bodies. These changes could account for the increase found in drying rate after steaming.

The composition and structure of the forests and scrublands of northern Fiordland were recorded at 1,053 sample points. The vegetation at each sample point was classified into one of 16 associations using a combination of Sorensen's 'k' index of similarity, and a multi-linkage cluster analysis. The associations were related to habitat and the distribution of each was determined.

The influence of the introduced ungulates, red deer and wapiti, on the forests and scrublands was determined. Stand structure was analysed to provide information on the susceptibility of the vegetation to damage from browsing and on the history of ungulate utilisation of the vegetation. Browse indices were calculated to provide information on current ungulate utilisation of the vegetation.

Hypothetical diameters of geometric solids are used to compare volume estimates when frusta are considered in turn to be paraboloidal, conoidal, or neiloidal. Comparison shows that only very small differences exist between estimates, that the traditional concept of a generalised tree shape has no bearing in this context, and that it is better to choose representative and repeatable measuring points along a stem at regular drops in diameter, if a reproducible and realistic index of volume is to be obtained. A procedure for taking sectional measurements is suggested.

A Corrigendum to this paper is available here: Corrigendum for Whyte. A.G.D. 1971: Sectional measurement of trees: A rationalised method

The major requirements for framing timber are restriction of knot diameter to under 1.33in., straight grain, minimal distortion, and lengths of 16ft to 18ft. Silvilculture to ensure these requirements over two 18ft log lengths, if logs are not pruned, needs close (8ft X 5ft or 6ft X 6ft) initial spacing to be maintained until stand height is at least 60ft. Current framing production is from stands grown without thinning, but No. 1 Framing grade out-turn rarely exceeds 40%. On site indices of 95ft, about 850 bd ft of No. 1 Framing grade can be produced per acre per year from either a "framing regime" of 8ft X 5ft spacing, thinning to 150 s.p.a. at 60ft, and clear-felling at 19in. d.b.h., age 34yr; or from finger-jointing clearwood from a board regime. As with Douglas fir, the suppressed growth rate of the "framing regime", that accompanies restriction of branch size reduces final log size, with concomitant increases in logging and sawing costs. A rational solution would be to concentrate framing timber production on sites where branch size is naturally limited. The best framing grade potential appears to be in Northland.

The apparent reluctance of industry to season framing is considered to account for the negligible volume (200,000 bd ft) exported annually. Present supplies of framing timber from the 500,000 acres plus of first rotation stands of all species are abundant.

The future cost of production and proportion of framing timber required remain to be evaluated. Different methods of building construction may be a more favourable alternative for second rotation plantation utilisation.

Ground distribution of aerially applied fertiliser was studied by means of line and random sampling points. The pattern varied considerably. Application rates over sampling areas, flown at an intended rate of 5cwt/acre, varied from 0.56 to 14.16 cwt/acre in one forest and from 1.59 to 7.16 cwt/acre in another. Uneven spacing between successive flight lines accounted for most of the variation, but an uneven release rate from the hopper contributed to a lesser extent. Multiple applications failed to improve distribution patterns appreciably.

Half Value, a new criterion for testing the evenness of ground distribution during aerial topdressing is proposed and examined. It is defined as "the percentage of sampling points which receive less than half the designated rate of application.'' Values of 10 or less are proposed as acceptable. Those for several aerial topdressing operations ranged from 5 to 65.

Tracheids are much longer and wider in the root wood than in the stem wood of Pinus radiata D. Don. The tracheids in the root, in contrast to those in the stem, are larger in the rings close to the organic centre than in outer rings. The occurrence of spiral thickening, callitrisoid thickening, and true axial parenchyma are recorded. The axial resin ducts are associated with a single layer of epithelium together with inner short and outer long parenchyma cells. Compression wood is absent from the root wood. The occurrence of a perforated axial tracheid in a horizontal root is recorded.

The relative effectiveness of six phosphorus (P) fertilisers for growth of radiata pine seedlings was examined by means of an intensive cropping technique in which three successive crops of pine seedlings were raised, under glass (a) in pots of a P-deficient clay soil without added P fertiliser, and (b) in pots of the same soil, each with one of the six fertilisers applied at a rate equivalent to 120 kg total P per ha, or 1,250 kg superphosphate per ha (10 cwt superphosphate per acre).

The net percentages of applied P recovered from the soil of the various treatments and the order of fertiliser effectiveness based on yields, height growth, P concentration, and P uptake from fertiliser for successive crops were:

(1) dolomite-reverted superphosphate (1:1 mixture), 20;

(2) superphosphate, 15;

(3) calcined Christmas Island "C" phosphate ore (Calciphos), 11;

(4) spent bone char, 8;

(5) Christmas Island "C" phosphate ore, 4;

(6) red phosphorus, 2.

The trial results suggest that Calciphos, with a higher total P content than superphosphate (about 13% compared with 9%), would be slightly more effective than superphosphate on a fertiliser weight-for-weight basis. This is of particular interest since outlets are sought for the stockpiled "C" phosphate ore, which is unsuitable for superphosphate manufacture.

Growth of female strobili of Pinus radiata D. Don from central North Island of New Zealand is described and illustrated with photographs. The two-and-a-half year period from strobilus emergence until cone maturity comprises a seasonal period of growth in which pollination occurs, a second period of seasonal growth in which fertilisation occurs, and finally a period of cone maturation. The periods of rapid growth do not appear to result directly from either pollination or fertilisation, and the seasonal growth periods have some similarity to those of vegetative growth. The time taken to reach cone maturity in P. radiata (a closed-cone pine) is six months longer than that frequently described for other species of Pinus.

Four methods were used in a trial to establish Deladenus siricidicola Bedding, parasitic nematodes of Sirex noctilio (F.), in three forests in the South Island. All gave positive results. The most promising and the easiest for future use is to extract the Deladenus from wood, to place them in test tubes filled with wood chips and subsequently to insert the contents of the tubes in holes drilled in trees that have been successfully attacked by the woodwasp.