Indices of interspecific plant competition for Pinus radiata in the central north island of New Zealand

1999 ◽  
Vol 29 (7) ◽  
pp. 898-905 ◽  
Author(s):  
Brian Richardson ◽  
Mark O Kimberley ◽  
John W Ray ◽  
Graham W Coker
Keyword(s):  
New Zealand ◽  
Tree Growth ◽  
Pinus Radiata ◽  
Plant Competition ◽  
Light Availability ◽  
Tree Height ◽  
Height Growth ◽  
Tree Age ◽  
Weed Species ◽  
Delayed Effect

Pinus radiata D. Don was grown on its own and with a range of densities of either buddleia (Buddleja davidii Franchet) or broom (Cytisus scoparius L.), two important forest weed species, in a field trial at Rotorua, New Zealand. Tree growth from the time of planting to age 3 was modelled as a function of tree size and a competition modifier. The competition modifier is, in effect, a multiplier that reduces tree growth according to the degree of competition defined by a competition index (CI). A range of CIs, with some sensitivity to both weed and tree growth and development over time, were individually incorporated into the modifier and evaluated. The "best" CI combined measures of weed height relative to tree height, proximity of the weed to the tree, and weed abundance, and was negatively correlated with an index of light availability. For a given value of CI, the effect on tree growth was independent of weed species. For diameter growth, the effect of CI was independent of tree age. However, for height growth the negative effect of a given CI value was much higher in year 3 than in years 1 and 2. This suggest that competition has an immediate effect on diameter but a delayed effect on height growth.

Importance of seasonal growth patterns in modelling interactions between radiata pine and some common weed species

2004 ◽  
Vol 34 (1) ◽  
pp. 184-194 ◽  
Author(s):  
Mark O Kimberley ◽  
Brian Richardson
Keyword(s):  
Fourier Series ◽  
Tree Growth ◽  
Tree Height ◽  
Height Growth ◽  
Growth Patterns ◽  
Seasonal Effects ◽  
Weibull Function ◽  
Seasonal Fluctuations ◽  
Weed Species ◽  
Weed Growth

Previously described weed competition models that use competition indices based on weed size relative to tree size (e.g., tree height divided by weed height) require models of weed growth and models of weed-free tree growth. A method is presented to model these using standard sigmoidal growth functions and to incorporate regular seasonal patterns of tree growth using Fourier series approximations. The method is tested against data from a field trial at Rotorua, New Zealand, in which Pinus radiata D. Don was grown both on its own and in competition with several common weed species. Weed and tree height were best modelled by a Weibull function, and tree ground line diameter by a Schumacher function. Seasonal fluctuations in both tree and weed growth were adequately modelled by a single-term Fourier series. All weed species showed very similar, strong seasonal fluctuations in height growth, peaking in February. Seasonal fluctuations in tree height growth, and especially diameter growth, were less marked and peaked earlier, in December. Simulations suggested that it is necessary to account for seasonal effects when modelling competition during the first year of growth, but that seasonal effects have less influence in subsequent years.

scholarly journals Production and interaction of pastures and shelterbelts in the central North Island

1993 ◽  
pp. 193-197 ◽  
Author(s):  
M.F. Hawke ◽  
J.D. Tombleson
Keyword(s):  
New Zealand ◽  
Tree Growth ◽  
Pinus Radiata ◽  
Dry Matter ◽  
Tree Height ◽  
Dry Matter Production ◽  
Nutrient Transfer ◽  
Pasture Production ◽  
Nutrient Levels ◽  
Matter Production

Many New Zealand farms contain shelterbelts which have generally been unmanaged, resulting in dubious shelter benefits and poor log values at harvest. The effect of a 6- and 7-row Pinus radiata shelterbelt on adjacent pasture production was monitored at Matea, Taupo during 1992193. Pasture production was measured at a range of distances parallel'to the shelterbelts on both sides and on open pasture. A 15% increase in pasture production was recorded at 0.7 tree height distance on both sides of the shelterbelts. There was also a gradual trend of increasing dry matter production as distance from the shelterbelts increased. However, on average, the sheltered zone produced slightly less dry matter than the open pasture. Increases in soil and herbage nutrient levels close to the shelterbelt suggest nutrient transfer by animals to the sheltered zones may have occurred. Shelterbelt tree growth was assessed and projected forward to maturity. Merchantable log volume at age 28 years was predicted to be 2300 m3/km of shelterbelt. Based on current log prices the 7-row shelterbelt was estimated at age 28 years to have a net value of $130 000/km Keywords: log value, nutrients, pasture production, pasture composition, Pinus radiata, shelter, shelterbelt, wood yields

Agroforestry in Eastern Otago: results from two long-term experiments

2000 ◽  
pp. 93-98
Author(s):  
G.G. Cossens ◽  
M.F. Hawke
Keyword(s):  
Soil Ph ◽  
Tree Growth ◽  
Pinus Radiata ◽  
Carrying Capacity ◽  
Livestock Grazing ◽  
Tree Age ◽  
Rapid Decline ◽  
Pasture Production ◽  
Clover Content ◽  
Pasture Yield

During the first 20 years of a Pinus radiata tree rotation, tree growth and pasture yield were assessed under a range of tree spacings at Invermay and Akatore, two coastal sites in Eastern Otago. Pasture yield in association with trees thinned to 100 stems per hectare (sph) was comparable to that from open pasture up to a tree age of 12 years. By the 19th year, however, pasture production declined to 63% of open pasture yield at Invermay and to 42% at Akatore. At 200 and 400 sph at Akatore, pasture yield was similar to that from open pasture at tree age 12 years but declined to 27% and 0% of open pasture yield respectively by year 20. At both Invermay and Akatore, the ryegrass and clover content of open pasture was relatively constant throughout the term of the trial. However, both the ryegrass and clover content of pasture beneath trees began to decline by tree age 12 years with a very rapid decline at Akatore in the number of pasture species at 200 sph by the 19th year. No pasture remained at 400 sph, after 19 years. Livestock carrying capacity with sheep on tree treatments at Invermay decreased from 100% of open pasture at year 6 to 60% by year 10. At Akatore, livestock carrying capacity averaged over the 20-year life of the trial was 4.1 stock units per hectare with a maximum of 8.1 stock units at a tree age of 8 years. Tree growth at both sites was similar, averaging between 1 and 1.1 m/year in height over 20 years, with trees at Invermay at 100 sph averaging 9% greater height and diameter growth than at Akatore. Increasing tree stocking from 100 to 200 to 400 sph at Akatore, resulted in increased tree height, but decreased diameter at breast height. A comparison of the East Otago trees with those in a similar trial at Tikitere (Rotorua) 900 km further north indicated that the southern trees were about 6 years later in their growth pattern by tree age 20 years. On both sites, soil pH tended to be lower in the presence of trees and was significantly lower than in open pasture by year 20. The results and comparisons with the Tikitere data suggest that, in an integrated agroforestry regime, there will be livestock grazing under the trees further into the tree rotation in Otago than in North Island sites. However, slower tree growth would result in a longer rotation time to harvest. Current recommendations to farmers are to plant trees on the less productive areas of the farm and adopt a tree stocking rate which fully utilises the site. Keywords: agroforestry, livestock, pasture, Pinus radiata, soil pH, tree stocking

Genetic improvement of resistance to cyclaneusma needle cast in Pinus radiata

2019 ◽  
Vol 49 (2) ◽  
pp. 128-133 ◽  
Author(s):  
Mari Suontama ◽  
Yongjun Li ◽  
Charlie B. Low ◽  
Heidi S. Dungey
Keyword(s):  
New Zealand ◽  
Pinus Radiata ◽  
Genetic Improvement ◽  
Genetic Correlations ◽  
Tree Height ◽  
Progeny Testing ◽  
Environment Interaction ◽  
Needle Cast ◽  
Genotype Environment Interaction ◽  
Selection For

Progeny testing of resistance to needle loss caused by Cyclaneusma minus (cyclaneusma needle cast) has been included in the needle disease resistance strategy of Pinus radiata D. Don in New Zealand since the late 1970s. Data on progeny trials, two in the North Island of New Zealand and one in Tasmania, Australia, were available to estimate heritability between trait genetic correlations and genotype × environment interaction. Resistance to cyclaneusma needle cast had moderate estimates of heritability (0.25 to 0.46) at all sites. Genetic correlations between the assessed traits indicated that selection for faster early growth, i.e., tree height at age 4 years and diameter at breast height at age 6 years, favours trees that are prone to Cyclaneusma infection, while a favourable genetic association between resistance to cyclaneusma needle cast and productivity was evident at a later assessment at age 9 years. No significant genotype × environment interaction was found for resistance to cyclaneusma needle cast; however, stability of genotypes across a wider range of environments and with a high genetic connectedness requires more research. Considerable genetic improvement can be achieved for resistance to cyclaneusma needle cast and indirect selection for the trait should be pursued by selecting for productivity and culling susceptible genotypes from breeding.

VERTICAL GROWTH RESPONSE OF PONDEROSA PINE INFESTED BY WESTERN PINE SHOOT BORER, EUCOSMA SONOMANA KEARFOTT (LEPIDOPTERA: OLETHREUTIDAE)

1990 ◽  
Vol 122 (2) ◽  
pp. 343-347 ◽  
Author(s):  
R.W. Thier ◽  
M.A. Marsden
Keyword(s):  
Tree Growth ◽  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Growth Response ◽  
Tree Height ◽  
Height Growth ◽  
National Forest ◽  
Needle Length ◽  
Shoot Borer ◽  
Reduced Height

AbstractIncidence of the western pine shoot borer, Eucosma sonomana Kearfott, and tree growth measurements from 5687 ponderosa pines, Pinus ponderosa Dougl. ex Laws., were recorded in the Calf Pen plantation Payette National Forest, ID. The percentage of trees infested by shoot borer generally increased as tree height increased.Infestation of the tree’s leader usually resulted in reduced height growth especially where needle length was shortened in the leader. Height growth of infested leaders was less than uninfested leaders. This difference in height growth increased with the total height of the tree as measured in the previous year.

Testing a juvenile tree growth model sensitive to competition from weeds, using Pinus radiata at two contrasting sites in New Zealand

2004 ◽  
Vol 34 (10) ◽  
pp. 1985-1992 ◽  
Author(s):  
Michael S Watt ◽  
Mark O Kimberley ◽  
Brian Richardson ◽  
David Whitehead ◽  
Euan G Mason
Keyword(s):  
Growth Model ◽  
Tree Growth ◽  
Pinus Radiata ◽  
Root Zone ◽  
Light Availability ◽  
Early Summer ◽  
Diameter Growth ◽  
Light Competition ◽  
Potential Growth ◽  
Tree Growth Model

A juvenile tree growth model sensitive to competition from weeds was developed and tested. Tree growth is predicted by reducing potential growth from an empirically determined optimum rate for the site (weed-free) using a seasonally estimated competition modifier, which accounts for the degree of weed competition for both water and light availability. The model was tested against data from a field trial at a dryland site, where juvenile Pinus radiata D. Don trees were grown with and without competition from the woody weed broom (Cytisus scoparius (L.) Link). For trees in plots without broom, seasonal fluctuations in growth were adequately modelled by a single-term Fourier series, which showed that maximum rates of diameter growth occurred during early summer. Diameter growth of trees in plots with broom was initially predicted by including a light-competition modifier into the model developed for weed-free plots on sites not subject to growth-limiting seasonal water deficit. Although the light modifier reduced growth from the weed-free state by 12% over the first year and 25% over the second year, modelled values still significantly exceeded measured diameter growth. To account for this overprediction a competition modifier based on modelled root-zone water storage was added into the model. Predictions of diameter growth using this modified model corresponded closely to measured diameter growth in both treatments.

The effect of silviculture on genetic gain in growth of Pinus radiata at one-third rotation

1999 ◽  
Vol 29 (12) ◽  
pp. 1979-1984 ◽  
Author(s):  
S D Carson ◽  
M O Kimberley ◽  
J D Hayes ◽  
M J Carson
Keyword(s):  
New Zealand ◽  
Tree Growth ◽  
Pinus Radiata ◽  
Genetic Gain ◽  
Genetic Improvement ◽  
Basal Area ◽  
Growth Modelling ◽  
Silvicultural Treatments ◽  
Genetic Potential ◽  
Silvicultural Treatment

A trial planted on six sites representing five growth modelling regions and a range of site qualities in New Zealand was used to examine the interaction of silviculture and genetic improvement in Pinus radiata D. Don. Four seed lots with differing genetic potential for growth were grown under four stocking treatments from 100 to 600 stems/ha, all with a thinning ratio of 5:2. In addition, two treatments were planted at 500 stems/ha, one pruned and one unpruned. Among sites, differences were large for mean top height (8.1-13.9 m), basal area (7.9-21.5 m2/ha), and volume (25-108 m3/ha) at 8 years from planting. Differences among silvicultural treatments were large for basal area (with a range of 4.3-18.8 m2/ha over sites) and volume (17-86 m3/ha) and smaller but statistically significant for mean top height (10.1-11.6 m). Differences among seed lots were statistically significant for all traits but larger for basal area (12.1-13.6 m2/ha) and volume (51-59 m3/ha) than for height (10.7-11.1 m). Genetically different seed lots performed similarly relative to each other over the range of sites and silvicultural treatment, with a slight trend for greater differences among seed lots in the faster growing silvicultural treatments. However, differences in tree growth were many times greater among sites and silvicultural treatment than among genetically different seed lots.

scholarly journals Modeling Effects of Overstory Density and Competing Vegetation on Tree Height Growth

2008 ◽  
Vol 54 (1) ◽  
pp. 107-122
Author(s):  
Christian Salas ◽  
Albert R. Stage ◽  
Andrew P. Robinson
Keyword(s):  
Habitat Type ◽  
Predictor Variable ◽  
Tree Height ◽  
Height Growth ◽  
Tree Age ◽  
Individual Tree ◽  
Vegetation Control ◽  
Index Site ◽  
Linear Differential ◽  
Tree Height Growth

Abstract We developed and evaluated an individual-tree height growth model for Douglas-fir [Pseudotsuga menziesii (Mirbel) Franco] in the Inland Northwest United States. The model predicts growth for all tree sizes continuously, rather than requiring a transition between independent models for juvenile and mature growth phases. The model predicts the effects of overstory and understory vegetative competition on height growth. Our model requires attained height rather than tree age as a predictor variable, thereby avoiding the problems of site index. Site effects are introduced as a function of ecological habitat type, elevation, aspect, and slope. We used six data sets totaling 3,785 trees in 314 plots. The structure of the data and the model indicated the need for a mixed-effects, nonlinear modeling approach using maximum likelihood in a linear differential equation with a power transformation. Behavior of the model was analyzed using a state-space approach. Our results show that both overstory and understory density affect height growth, allowing a manager to make informed decisions about vegetation control.

Effect of boron fertiliser, weed control and genotype on foliar nutrients and tree growth of juvenile Pinus radiata at two contrasting sites in New Zealand

2008 ◽  
Vol 255 (3-4) ◽  
pp. 1196-1209 ◽  
Author(s):  
Sonya T. Olykan ◽  
Jianming Xue ◽  
Peter W. Clinton ◽  
Malcolm F. Skinner ◽  
Doug J. Graham ◽  
...  
Keyword(s):  
New Zealand ◽  
Weed Control ◽  
Tree Growth ◽  
Pinus Radiata ◽  
Foliar Nutrients

scholarly journals Spring Freeze Damage of Pecan Bloom: A Review

Horticulturae ◽  
2020 ◽  
Vol 6 (4) ◽  
pp. 82
Author(s):  
Amandeep Kaur ◽  
Louise Ferguson ◽  
Niels Maness ◽  
Becky Carroll ◽  
William Reid ◽  
...  
Keyword(s):  
Tree Height ◽  
The United States ◽  
Reproductive Organs ◽  
Tree Age ◽  
The Us ◽  
Nut Production ◽  
Freeze Damage ◽  
Terminal Buds ◽  
And Function ◽  
The Impact

Pecan is native to the United States. The US is the world’s largest pecan producer with an average yearly production of 250 to 300 million pounds; 80 percent of the world’s supply. Georgia, New Mexico, Texas, Arizona, Oklahoma, California, Louisiana, and Florida are the major US pecan producing states. Pecan trees frequently suffer from spring freeze at bud break and bloom as the buds are quite sensitive to freeze damage. This leads to poor flower and nut production. This review focuses on the impact of spring freeze during bud differentiation and flower development. Spring freeze kills the primary terminal buds, the pecan tree has a second chance for growth and flowering through secondary buds. Unfortunately, secondary buds have less bloom potential than primary buds and nut yield is reduced. Spring freeze damage depends on severity of the freeze, bud growth stage, cultivar type and tree age, tree height and tree vigor. This review discusses the impact of temperature on structure and function of male and female reproductive organs. It also summarizes carbohydrate relations as another factor that may play an important role in spring growth and transition of primary and secondary buds to flowers.

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