Growth Rings, Age and Taxonomy of Dacrydium (Podocarpaceae) in Fiji

1986 ◽  
Vol 34 (2) ◽  
pp. 197 ◽  
Author(s):  
J Ash
Keyword(s):  
Growth Rate ◽  
Radiocarbon Dating ◽  
Shoot Growth ◽  
Diameter Growth ◽  
Wet Season ◽  
Growth Rings ◽  
North West ◽  
Trunk Diameter ◽  
Naked Eye ◽  
Annual Frequency

The anatomy of growth rings in Dacrydium (Podocarpaceae) from Fiji is described. Fungal staining may mask the heartwood growth rings and generally prevents observation of rings on either roughly cut logs or sanded sections with the naked eye. Earlywood is formed during the wet season and coincides with a peak of leaf and shoot growth. Radiocarbon dating of three trees indicates that growth rings have an approximately annual frequency. The average trunk diameter growth rate is estimated as 2.6 mm year-1. Life expectancy of established trees is estimated as 49 year. It is suggested that the endemic species D. nausoriense de Laub. may be an ecotype of D. nidulum de Laub. adapted to the drier climate of north-west Viti Levu.

Growth Rings and Longevity of Agathis vitiensis (Seemann) Benth. & Hook. F. ex Drake in Fiji

1985 ◽  
Vol 33 (1) ◽  
pp. 81 ◽  
Author(s):  
J Ash
Keyword(s):  
Annual Ring ◽  
Shoot Growth ◽  
Cambial Activity ◽  
Size Class ◽  
Confidence Limits ◽  
Wet Season ◽  
Growth Rings ◽  
Trunk Diameter ◽  
Canopy Trees ◽  
Class Frequency

The anatomy of growth rings in Agathis vitiensls (Araucariaceae; Gymnospermae) in Fiji is described, and also the eccentricities in ring formation produced by variations in cambial activity. Latewood is formed during the dry season, and earlywood coincides with leaf and shoot growth during the hotter wet season. Radiocarbon dating of five trees indicates an approximately annual ring frequency. A relationship between trunk diameter and age is defined, with 95% confidence limits: age (years) ͭ6 25 + 3.7 (diam. of trunk, cm), ± 32%. The size-class frequency distribution of trunk diameters is consistent with a constant mortality amongst canopy trees. A cyclone caused seed cones to disintegrate, dispersing the seeds and establishing a transient seedling population.

scholarly journals Effect of Cyclic Irrigation on Growth of Magnolias Produced Using Five In-ground Systems

2003 ◽  
Vol 21 (3) ◽  
pp. 148-152
Author(s):  
R. C. Beeson ◽  
K. Keller
Keyword(s):  
Growth Rates ◽  
Shoot Growth ◽  
Similar Rate ◽  
Height Growth ◽  
Irrigation Event ◽  
The Other ◽  
Diameter Growth ◽  
Trunk Diameter ◽  
Magnolia Grandiflora ◽  
Ground Systems

Abstract Five in-ground systems were evaluated based on shoot growth and marketability for the production of 2.17 m (7 ft) tall and 5.08 cm (2 in) trunk diameter Magnolia grandiflora cv. ‘Symmes Select’. Systems evaluated were Root Control Bags, Geo-Cell bags, and #25 containers in pot-in-pot in Experiment 1, and Agro-liners in socket pots and directly in-ground in Experiment 2. Each system was either cyclically irrigated or given a single irrigation event daily. In Experiment 1, cyclic irrigation increased the rate of height growth and trunk diameter compared to a single irrigation. Trees in Root Control Bags and pot-in-pot grew at a similar rate and faster than those in Geo-Cell bags. Faster growth rates with cyclic irrigation resulted in earlier marketability compared to single irrigation daily, except for pot-in-pot. In Experiment 2, cyclic irrigation increased the rate of trunk diameter growth, and Agro-liners in pots had greater height and trunk diameter growth rates than those directly in ground. Trees grown in the in-ground pot systems, whether in Agro-liners or black polyethylene containers, grew similarly to trees in Root Control Bags. Trees grown in Geo-cells or Agro-liners in-ground had significantly slower growth than the other treatments.

scholarly journals RELATIONSHIP BETWEEN CLIMATE VARIABLES, TRUNK GROWTH RATE AND WOOD DENSITY OF Eucalyptus grandis W. Mill ex Maiden TREES

2016 ◽  
Vol 40 (2) ◽  
pp. 337-346 ◽  
Author(s):  
Carlos Roberto Sette Jr ◽  
Mario Tomazello F ◽  
José Luis Lousada ◽  
Domingos Lopes ◽  
Jean Paul Laclau
Keyword(s):  
Growth Rate ◽  
Wood Density ◽  
Eucalyptus Grandis ◽  
Basal Area ◽  
High Sensitivity ◽  
Cambial Activity ◽  
Climatic Conditions ◽  
Diameter Growth ◽  
Climate Variables ◽  
Trunk Diameter

ABSTRACT Climatic conditions stimulates the cambial activity of plants, and cause significant changes in trunk diameter growth and wood characteristics. The objective of this study was to evaluate the influence of climate variables in the diameter growth rate of the stem and the wood density of Eucalyptus grandis trees in different classes of the basal area. A total of 25 Eucalyptus trees at 22 months of age were selected according to the basal area distribution. Dendrometer bands were installed at the height of 1.30 meters (DBH) to monitor the diameter growth every 14 days, for 26 months. After measuring growth, the trees were felled and wood discs were removed at the DBH level to determine the radial density profile through x-ray microdensitometry and then re-scale the average values every 14 days. Climatic variables for the monitoring period were obtained and grouped every 14 days. The effect of the climate variables was determined by maximum and minimum growth periods in assessing trunk growth. These growth periods were related with precipitation, average temperature and relative air humidity. The re-scaled wood density values, calculated using the radial growth of the tree trunks measured accurately with steel dendrometers, enabled the determination of the relationship of small changes in wood density and the effect of the climatic variations and growth rate of eucalyptus tree trunks. A high sensitivity of the wood density to variation in precipitation levels was found.

scholarly journals The effect of different pasture management strategies in north-west Queensland on liveweight gain and wool growth rate of several groups of young sheep.

1985 ◽  
Vol 7 (2) ◽  
pp. 75 ◽  
Author(s):  
RGA Stephenson ◽  
DA Pritchard ◽  
PM Pepper ◽  
PT Connelly
Keyword(s):  
Growth Rate ◽  
Dry Matter ◽  
Management Strategies ◽  
Live Weight ◽  
Dry Season ◽  
Wet Season ◽  
Pasture Management ◽  
North West ◽  
Wool Growth ◽  
Significant Difference

The effect of three different pasture management strategies on liveweight gain and wool growth rate of young(weaner) sheep was examined immediately after weaning on Mitchell grass-Flinders grass pastures during the dry season of north-west Queensland. The pasture management strategies were designed to mimic various industry situations, while the performance of four different progeny groups was compared and used to provide an overall assessment of pasture quality. Pasture treatments (experiment 1) consisted of three paddocks, a harvested (c. 8% of pasture harvested and baled) and spelled, a spelled, and a continuously grazed paddock. Spelled paddocks were not grazed during and after the wet season for a period of six months while the continuously grazed paddock was continuously stocked before the experiment. Experiment 2 consisted of spelled and continuously grazed paddocks. Pastures were evaluated by measuring the changes in composition and quality (experiment 1) and the responses in liveweight gain (experiments 1 and 2) and wool growth of the weaners (experiment 1). Marked improvements (c. 100%) in weaner growth rates occurred in the spelled paddocks. Greasy wool production by three groups of ewes in experiment I was about 14% greater in the harvested paddock than in the others. At the start of the trial there were no significant differences in dry matter yield but a significant difference in botanical composition occurred between paddocks. The changes in dry matter that occurred between the beginning and end of grazing were not significantly different between paddocks. Before gazing, forbs made up approximately 16%, 4% and 1% of pastures in harvested, spelled and continuously grazed paddocks respectively. The change in the percentage forbs that occurred between the beginning and end of the grazing period was significantly greater in the harvested paddock than in the other paddocks indicating preferential selection and intake by sheep. The differences in weaner live weight and wool growth between paddocks suggest that paddock management can improve weaner productivity. The study also indicates that paddock management could be successfully used to increase the percentage of forbs and quality of the pasture during the dry season. The superior wool growth of two progeny groups also suggests that improved productivity of breeding flocks in the tropics is possible if superior sheep can be identified. The results highlight the importance of preferential management of pasture for weaners so that productivity advantages can be exploited.

scholarly journals Factors Limiting the Growth of Eucalyptus and the Characteristics of Growth and Water Use under Water and Fertilizer Management in the Dry Season of Leizhou Peninsula, China

Agronomy ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 590
Author(s):  
Zhichao Wang ◽  
Apeng Du ◽  
Yuxing Xu ◽  
Wankuan Zhu ◽  
Jing Zhang
Keyword(s):  
Growth Rate ◽  
Water Use ◽  
Gompertz Model ◽  
Atmospheric Temperature ◽  
Dry Season ◽  
Limiting Factors ◽  
Diameter Growth ◽  
Eucalyptus Urophylla ◽  
Fertilizer Management ◽  
Wet Season

The growth rate of eucalyptus in the dry season was significantly lower than that in the wet season. However, the limiting factors of eucalyptus growth in the dry season are not clear. In this paper, through the continuous monitoring of the diameter growth and environmental factors of 5.5-year-old Eucalyptus urophylla S. T. Blake × E. grandis W. Hill ex Maiden in the dry season, the diameter growth characteristics of eucalyptus during the dry season were studied and the limiting factors of eucalyptus growth in the dry season were determined. The water and fertilizer management activities in the dry season were evaluated to verify the growth and water use characteristics of Eucalyptus urophylla × E. grandis in the dry season under the conditions of mitigation limiting factors and provide the basis for further increasing the growth rate of eucalyptus. The results show that the diameter fluctuation of Eucalyptus urophylla × E. grandis is cyclical and the diameter cumulative growth during the dry season monitoring is consistent with the Gompertz model. Atmospheric temperature and soil water content are the main factors limiting the growth of Eucalyptus urophylla × E. grandis in the dry season. Irrigation and fertilization in the dry season can significantly increase the growth of diameter at breast height (DBH) and biomass growth and significantly improve the water use efficiency in the dry season.

The impact of light quality and leaf wetness on photosynthesis in north-west Andean tropical montane cloud forest

2005 ◽  
Vol 21 (5) ◽  
pp. 549-557 ◽  
Author(s):  
Matthew Guy Letts ◽  
Mark Mulligan
Keyword(s):  
Cloud Forest ◽  
Net Photosynthesis ◽  
Leaf Wetness ◽  
Total Solar Radiation ◽  
Wet Season ◽  
Lowland Rain Forest ◽  
North West ◽  
Montane Cloud Forest ◽  
The Impact ◽  
Trees And Shrubs

Photosynthesis was limited by low-intensity photosynthetically active radiation (PAR) and leaf wetness in a lower montane cloud forest (LMCF) of Cauca, Colombia. Mean PAR intensity remained below the saturation level for leaf-scale net photosynthesis (Pn) throughout the solar day during the wet season and for most of the solar day during the dry season. PAR represented a smaller fraction of total solar radiation (K↓) in LMCF than in lowland rain forest (LRF). In LMCF trees and shrubs, mean PAR-saturated Pn ranged from 4.3–10.6 μmol C m−2 s−1 at 1450 m, and from 3.5–10.2 μmol C m−2 s−1 at 2150 m. Pn was reduced by abaxial wetness in leaves of some trees and shrubs, and eliminated in others. This study indicates that persistent cloudiness and interception of cloud water by leaves limit LMCF productivity.

RADIOCARBON DATING OF MESOLITHIC OPEN-AIR SITES IN THE COVERSAND AREA OF THE NORTH-WEST EUROPEAN PLAIN: PROBLEMS AND PROSPECTS

Archaeometry ◽  
2012 ◽  
Vol 55 (3) ◽  
pp. 545-562 ◽  
Author(s):  
PH. CROMBÉ ◽  
E. ROBINSON ◽  
M. VAN STRYDONCK ◽  
M. BOUDIN
Keyword(s):  
Radiocarbon Dating ◽  
North West ◽  
The North ◽  
West European
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