Interactions between influences of genotype and grass competition on growth and wood stiffness of juvenile radiata pine in a summer-dry environment

2006 ◽  
Vol 36 (10) ◽  
pp. 2454-2463 ◽  
Author(s):  
Euan G Mason

Clones of radiata pine (Pinus radiata D. Don) were established in two experiments on two contrasting pasture sites in Canterbury, New Zealand, with four levels of competition from grass as main plots within each experiment. Control was extended over the first 5 years at one site, whereas grass at the other site was controlled by a single herbicidal spray immediately after planting. At the latter site, 1 m diameter spots cleared with herbicide were compared with the same size spot created using a woven mat. Grass competition added up to 3 years to a rotation, and the gain from control was correlated with spot size. Competition control was most critical during the first year after planting. Trees grown within spots cleared by mats grew more slowly than those in weed-free spots cleared with herbicide. Green dynamic modulus of elasticity was related to genotype and increased with both slenderness and higher levels of pruning. Significant interactions between genotype and level of competition were observed for growth, indicating that choice of genotype can be a useful way of coping with pasture competition if managers wish to reduce the use of herbicides.

1999 ◽  
Vol 29 (7) ◽  
pp. 934-939 ◽  
Author(s):  
E G Mason ◽  
B Kirongo

An experiment comprising seven clones with four levels of weed competition was established on a semiarid site on the Canterbury plains, New Zealand, during September 1996. Previous experiments showed that trees subjected to little competition from weeds did not always respond to their favourable environments, resulting in more variation among individuals subjected to less competition. The aim of this experiment was to determine whether the variable response to competitive environment is partly a genetic effect. The main plots consisted of four levels of competition: no competition and cleared spots: 3.14, 0.75, and 0.03 m2. Within each plot there were 10 individuals of each clone. Trees generally grew more rapidly with increasing amounts of clear ground, but increasing spots beyond 3.14 m2 did not increase growth during the first year. Variation, expressed as coefficient of variation, was greater among trees subjected to more competition. Within clone coefficient of variation was not related to level of competition.


2005 ◽  
Vol 83 (3) ◽  
pp. 272-278 ◽  
Author(s):  
Gyu-Hyeok Kim ◽  
Jae-Jin Kim ◽  
Young Woon Lim ◽  
Colette Breuil

Ophiostomatoid fungi discolor lumber, logs, and tree sapwood. Stained wood has a lower market value and can be refused by importing customers because such products can potentially carry pathogenic fungi. Little information is available on the ophiostomatoid fungi that colonize Pinus radiata D. Don (radiata pine) logs imported from New Zealand into Korea. In this work, we attempted to identify the native and non-native fungi colonizing wood imported into Korea. At least 12 species of ophiostomatoid fungi, including an unknown Ophiostoma sp. A, were identified among the fungi-staining radiata pine. They were Leptographium procerum (Kendr.) Wingf., Leptographium bistatum Kim & Kim, Ophiostoma floccosum Mathiesen, Ophiostoma huntii (Rob.) Hoog & Scheff., Ophiostoma ips (Rumbold) Nannf., Ophiostoma nigrocarpum (David.) Hoog, Ophiostoma piceae (Münch) H. & P. Sydow, Ophiostoma piliferum (Fries) H. & P. Sydow, Ophiostoma quercus (Georgév.) Nannf., Ophiostoma radiaticola Kim et al., and Ophiostoma setosum Uzunovic et al. Of these species, O. floccosum was the dominant species in both logs and boards. We confirmed that many of the sapstain species that we isolated have been previously reported in Korea. However, four species, O. radiatcola, O. setosum, O. huntii, and O. nigrocarpum have not been reported previously in Korea. We also found the new species, L. bistatum, along with an unknown Ophiostoma sp. A.Key words: radiata pine, ophiostomatoid fungi, New Zealand, non-native organisms, β-tubulin gene.


2009 ◽  
Vol 58 (1-6) ◽  
pp. 28-38 ◽  
Author(s):  
H. S. Dungey ◽  
J. T. Brawner ◽  
F. Burger ◽  
M. Carson ◽  
M. Henson ◽  
...  

Abstract A new breeding strategy is presented for the Radiata Pine Breeding Company, a New Zealand based research consortium, that drives the breeding program for Pinus radiata for both the New Zealand and New South Wales based Australian forest plantation industry. The new strategy builds on the existing base for P. radiata, and on the last strategy review in 2000. The new strategy comprises a large open-pollinated (OP) Main Population (MP) with 500 female parents and two sublines (250 female parents per subline). The MP will be tested using alpha designs, single-tree plots and incomplete blocks to maximise efficiency. Each subline will be tested on four sites, geographically distant from the other subline. The MP will be managed in discrete generations. Selection of the next generation will be using a combination of backward and forward selection, but the strict control of inbreeding with identified lineage will rely on the development of parental reconstruction for OP progeny. There are alternatives to this, however, such as estimating the group coancestry and accepting some additional increase in inbreeding. This is a new and significant departure from previous breeding strategies for P. radiata in New Zealand. There will also be a single, small Elite Population (EP), tested 50% as progeny and 50% as clones. Twenty four parents will be tested each year as clones and 24 as seedling progeny with some overlap between the two. It is expected that the clonal population will capture the greatest gains in traits with low heritabilities, and the half-sib progeny will capture the greatest gains in traits with high heritabilities. The two sublines will be maintained in the EP, and breeding will be managed as a rolling front with trials established every year, while trials of the MP will be established every 10 years.


2004 ◽  
Vol 34 (12) ◽  
pp. 2601-2610 ◽  
Author(s):  
Satish Kumar

Data from two separate experiments were used to estimate genetic parameters for different wood properties of Pinus radiata D. Don in New Zealand. In experiment 1, 72 and 60 open-pollinated families were sampled at two sites, Kinleith and Paengaroa, respectively. Fifty-nine such families were common to both sites. In experiment 2, 62 and 29 pollen-parent families were sampled from a female-tester trial at two sites, Kaingaroa and Warrengong (the latter in Australia), respectively. Twenty-nine such families were common to both sites. Clearwood stiffness (MOE) and strength (MOR), wood density (DEN), acoustic stiffness on standing trees (IMLH), acoustic stiffness in 5-m logs (HITMAN), external resin bleeding (ERB), internal checking from discs taken at 1.3-m and 3.0-m height (CHEK_B and CHEK_U), and diameter at breast height (DBH) were assessed. Within-site narrow-sense heritability (h2) estimates of various wood properties were consistent, particularly within New Zealand. Across-sites estimates of h2 of HITMAN, CHEK_B, and DEN were, respectively, 0.24, 0.40, and 0.62 in experiment 1 and 0.21, 0.16, and 0.38 in experiment 2. Estimated type B genetic correlations were generally high for all traits except DBH. DEN showed strong positive genetic correlation with all direct and acoustic measures of stiffness (MOE, HITMAN, and IMLH). DEN and all measures of stiffness showed low to moderate negative genetic correlations with DBH.


Author(s):  
Mohan KC ◽  
Euan G. Mason ◽  
Horacio E. Bown

AbstractSilvicultural practices applied in managed forest plantations may help counteract the effects of climate change by influencing soil surface CO2 efflux (Fs). Understanding the effects of silvicultural practices on Fs will provide unbiased estimates of carbon fluxes and allow better silvicultural decisions for carbon sequestration. Therefore, we assessed how Fs differed seasonally across silvicultural practices (i.e., stocking levels, clone, fertilization and weed control treatments) and evaluated the effects of soil temperature (Ts) and soil volumetric water content (θv) on Fs across these practices for a mid-rotation (14 year-old) Pinus radiata plantation in the Canterbury region of New Zealand. There were significant differences in Fs (p < 0.05) over the four seasons, three levels of stocking, and five clones. The effects of fertilization and weed control applied 12 years previously on Fs were insignificant. Annual estimate of Fs (mean ± 1 standard deviation) from the study site was 22.7 ± 7.1 t ha−1 a−1 in the form of CO2 (6.2 ± 2.1 t ha−1 a−1 in the form of C). Fs values were consistently higher in plots with 1250 stems ha−1 compared to 2500 stems ha−1, which may be related to a strong soil resource limitation because of the close spacing in the latter plantation. Significant differences in Fs across clones suggest that variations in carbon partitioning might explain their growth performance. Silvicultural treatments influenced Fs response to soil temperature (p < 0.05), resulting in models explaining 28–49% of the total variance in Fs. These findings provide insights into how silvicultural management decisions may impact Fs in mid-rotation radiata pine plantations, contributing towards developing more precise and unbiased plantation carbon budgets.


2003 ◽  
Vol 56 ◽  
pp. 56-60
Author(s):  
S.F. Gous ◽  
B. Richardson ◽  
M.O. Kimberley

A trial was established in the South Island of New Zealand to investigate the response of Pinus radiata to varying the area and duration of weed control around individual trees Results after six years demonstrated that weed control was essential to ensure maximum survival and growth of Pinus radiata seedlings Maintaining weed control for two seasons following planting resulted in marginally higher stand productivity than where weed control was applied in the year of planting only A modelling approach was used to determine treatment effects in terms of a time difference and to make inferences on longterm treatment effects Without weed control tree volume six years after planting was more than 15 years behind trees given complete weed control Spot vegetation control resulted in similar tree growth to total control as long as the area and duration of weed control was greater than a 1 m spot maintained for 1 year


2011 ◽  
Vol 60 (1-6) ◽  
pp. 276-285 ◽  
Author(s):  
L. Bian ◽  
W. J. Gapare ◽  
M. Ivković ◽  
P. Jefferson ◽  
H. X. Wu

AbstractA total of 1226 increment cores were sampled from two provenance trials of Pinus radiata D. Don planted in New Zealand (Kaingaroa) and Australia (Kangaroovale), to study variation and inheritance of wood density in selections from three mainland California natural populations: Año Nuevo, Monterey and Cambria. The study represents a back-to-back comparison of the same provenance and family material on contrasting sites between New Zealand and Australia. Monterey was significantly different to Año Nuevo and Cambria at Kaingaroa (p<0.05), and had slightly higher density, whereas all provenances were almost identical and not significantly different at Kangaroovale. However, there were significant differences for wood density at family level for Año Nuevo and Cambria at Kangaroovale. No significant provenance or family differences were detected for core length at either site. The estimates of heritability for wood density were all above 0.50 and generally higher at Kaingaroa than at Kangaroovale. Estimates of additive genetic correlations between wood density and core length were imprecise. Genotype × site interactions for density appeared minor (estimated type-B genetic correlation= 0.70) despite substantial differences in rainfall and soils. The similarity of Cambria to Año Nuevo for density is an interesting result because the genetic base of the present Australian and New Zealand plantations has been shown to be from Año Nuevo and Monterey. Infusion of Cambria material would increase the overall genetic base of the radiata pine breeding programs, with potential long-term benefits, despite the often disappointing growth performance of material collected from Cambria.


2008 ◽  
Vol 38 (11) ◽  
pp. 2870-2879 ◽  
Author(s):  
Carolyn A. Raymond ◽  
Bill Joe ◽  
Dean W. Anderson ◽  
Duncan J. Watt

The effect of thinning on the relationship of wood quality traits measured on standing trees (dynamic modulus of elasticity (MOE) and outerwood density) and traits measured on logs or short clear specimens was determined using data collected from radiata pine ( Pinus radiata D. Don) trees growing in 22 unthinned and 16 thinned plots of harvest age trees in New South Wales, Australia. Stiffness showed a linear decrease along the stem. Trees growing on thinned sites were, on average, 3% lower in stiffness at each height in the stem. MOE measured on short clear specimens was moderately related to standing tree MOE (R2 = 0.62) and outerwood density (R2 = 0.56) but less well related to MOE of the adjacent log (R2 = 0.30). Standing tree MOE was a better predictor of whole stem MOE for the thinned sites (R2 = 0.60) than for the unthinned sites (R2 = 0.31). Stiffness and density appear to follow different patterns of variation and results for density may not be extrapolated to stiffness. Outerwood density was a very poor predictor of mean whole stem stiffness (R2 = 0.14). Overall, the acoustic tool, TreeTap, was a better predictor of whole stem stiffness than outerwood density, particularly for the thinned sites.


1999 ◽  
Vol 29 (7) ◽  
pp. 985-992 ◽  
Author(s):  
E G Mason ◽  
P G Milne

Two factorial experiments examining effects of weed control, fertilization, and soil cultivation on Pinus radiata D. Don growth were established in the Canterbury region of New Zealand during 1983. The experiments were measured every year for the first 5 years, during which effects of both weed control and fertilization were detected. Midrotation measurements of height and diameter at breast height were taken. Growth in subplot mean height and basal area per unit area over 3 years in one case and 4 years in the other, up to ages 13 and 14, respectively, was analysed. Results showed that the initial time gain due to weed control and fertilization was preserved at midrotation and that there was no continuing divergence between treated and untreated subplots after weed control. There was, however, continuing divergence after fertilization on one site where topsoil had been shifted into heaps during land clearing. Modelling revealed that effects of weed control and fertilization on basal area growth and yield of stands could be represented by the same difference equation with an additive term to represent the effects of treatments. On the other hand an existing regional growth and yield model failed to represent these effects properly.


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