Discrimination among potential buloke (Allocasuarina leuhmannii) feeding trees by the endangered south-eastern red-tailed black-cockatoo (Calyptorhynchus banksii graptogyne)

2004 ◽  
Vol 31 (3) ◽  
pp. 311 ◽  
Author(s):  
Martine Maron ◽  
Alan Lill
Keyword(s):  
Food Resource ◽  
Model Performance ◽  
Dry Mass ◽  
Foraging Efficiency ◽  
Tree Diameter ◽  
Breast Height ◽  
South Eastern ◽  
Second Year ◽  
Individual Trees ◽  
Number Of Seeds

Remnant buloke (Allocasuarina luehmannii) woodland and scattered buloke trees appear to provide an important seasonal food resource for the endangered south-eastern red-tailed black-cockatoo (Calyptorhynchus banksii graptogyne). The factors that differed between buloke trees in which the cockatoos fed and those in which they did not feed were investigated in two consecutive years (Season 1 and Season 2). Tree diameter at breast height (DBH), individual mean seed dry mass, individual mean cone dry mass, mean number of seeds per cone, and proportion of total cone mass comprising seeds (seed ratio) were all significantly greater in feeding than non-feeding trees in both Season 1 and Season 2. A predictive model incorporating these five variables correctly classified 83% of trees measured in Season 1 as either feeding or non-feeding trees. Validation of predictive models with new data is essential in evaluating model performance, so the model was used to classify the feeding and non-feeding trees from which the variables were recorded during Season 2. The model, although derived only from the data collected during Season 1, was equally as effective in predicting the feeding status of trees in Season 2, despite the fact that the trees in which the cockatoos fed during the second year were not the same individual trees as those used in the previous year. The differences between feeding and non-feeding trees suggested that cockatoos choose to feed in trees in which they are able to optimise their foraging efficiency. As individual buloke trees appear to vary in their suitability for cockatoo foraging from year to year, it is not possible to exclude any buloke within the range of the cockatoo as a potential future food resource for this endangered bird.

Mechanistically based, allometric models to predict tree diameter and height in even-aged monoculture of Eucalyptusregnans F. Muell.

1989 ◽  
Vol 19 (2) ◽  
pp. 270-273 ◽  
Author(s):  
P. W. West ◽  
C. L. Beadle ◽  
C. R. A. Turnbull
Keyword(s):  
Tree Height ◽  
Allometric Relationships ◽  
Allometric Models ◽  
Tree Diameter ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Vertical Stability ◽  
Structural Argument ◽  
Individual Trees ◽  
Geometrical Argument

A randomly selected sample of 22 trees was felled in a stand in a 20-year-old monoculture of Eucalyptusregnans F. Muell. in southern Tasmania. One-half of the trees were from a section of the stand that had been heavily thinned 10 years previously, and the remainder were from the unthinned section. The trees were sectioned and the fresh weights of their stems (including bark) and crowns (leaves plus branches) determined. By combining a geometrical argument about the shape of tree stems with a structural argument about their vertical stability, allometric relationships were established relating tree diameter at breast height or tree height to total aboveground weight and the ratio of crown to stem weight. These relationships were found to hold in both the thinned and unthinned sections of the experiment. When combined with a model to predict biomass of individual trees, these models can be used to predict diameter or height of individual trees in E. regnans monoculture.

Jack pine cone quality and cache sizes of red squirrels in southern New Brunswick, Canada

1997 ◽  
Vol 75 (2) ◽  
pp. 332-335 ◽  
Author(s):  
Michael A. Setterington ◽  
Daniel M. Keppie
Keyword(s):  
New Brunswick ◽  
Pinus Banksiana ◽  
Seed Mass ◽  
Dry Mass ◽  
Jack Pine ◽  
Tamiasciurus Hudsonicus ◽  
Red Squirrels ◽  
Length Width ◽  
Total Seed ◽  
Number Of Seeds

Relationships between external cone characteristics (length, width, wet and dry mass), cone quality (total seed mass as a proportion of cone mass, total number of seeds per cone, total seed mass per cone), and number of cones in caches were evaluated for caches of jack pine (Pinus banksiana) cones belonging to red squirrels (Tamiasciurus hudsonicus) in two plantations in southern New Brunswick. Cone length and mass were good predictors of the total number of seeds per cone and total seed mass per cone. Length accounted for a small proportion of the variance of total seed mass as a proportion of cone mass. There was no relationship between the number of seeds or total seed mass per cone and the number of cones per cache.

Ethanol in ponderosa pine as an indicator of physiological injury from fire and its relationship to secondary beetles

2003 ◽  
Vol 33 (5) ◽  
pp. 870-884 ◽  
Author(s):  
Rick G Kelsey ◽  
Gladwin Joseph
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Xylem Sap ◽  
Upward Movement ◽  
Stem Base ◽  
Breast Height ◽  
Dead Trees ◽  
Crown Scorch ◽  
Second Year ◽  
The Relationship

Sixteen days after a September wildfire, ethanol and water were measured in phloem and sapwood at breast height and the base of Pinus ponderosa Dougl. ex P. & C. Laws. with zero (control), moderate, heavy, and severe crown scorch. The quantity of ethanol increased with each level of injury, resulting in trees with severe scorch containing 15 and 53 times more phloem and sapwood ethanol, respectively, than controls. Ethanol concentrations in the sapwood and adjacent phloem were related, probably as a result of diffusion. Upward movement in xylem sap was most likely responsible for the relationship between sapwood ethanol concentrations at breast height and the stem base. As trees recovered from their heat injuries, the ethanol concentrations declined. In contrast, ethanol accumulated in dead trees that lost their entire crowns in the fire. Various bark and xylophagous beetles landed in greater numbers on fire-damaged trees than on controls the following spring and summer, suggesting that ethanol was being released to the atmosphere and influencing beetle behavior. Beetle landing was more strongly related to sapwood ethanol concentrations the previous September than in May. Sapwood ethanol measured 16 days after the fire was the best predictor of second-year mortality for trees with heavy and severe crown scorch.

Extraordinary Heterosis Found In A Forage Grass Hybrid, Festuca apennina × F. pratensis

2020 ◽  
Author(s):  
Beat Boller ◽  
David Kopecký
Keyword(s):  
Chromosome Doubling ◽  
Artificial Chromosome ◽  
Dry Mass ◽  
Hybrid Vigor ◽  
Hybrid Breeding ◽  
Forage Grass ◽  
Breeding Programs ◽  
The Third ◽  
Specific Trait ◽  
Second Year

Abstract Background: Heterosis (or hybrid vigor) is the over-performance of a hybrid over its parents in a specific trait or a set of traits. As such, hybrid breeding serves as a tool to efficiently trigger gains in breeding programs. Moreover, hybrids of genetically distant landraces, varieties or even species may become evolutionary successful. In Swiss alpine swards, we observed frequent prevalence of triploid hybrids of Festuca pratensis × F. apennina with outstanding competitiveness relative to their parental species in the sites of sympatric occurrence. Results: Observations of these highly vigorous hybrids prompted the study on their heterosis across various environmental conditions. Phenotypic observations during three years at four locations at different altitudes (from 200 m a.s.l. to 1850 m a.s.l.) have shown significant heterosis for dry biomass production at all sites during the first and second year, and at the mid- and high altitude sites also in the third year. At mid-altitude (1000 m a.s.l.), heterosis increased steadily and reached a maximum of +508 % for annual yield (+626% for a single cut) in the third year. This is by far the highest value of heterosis ever reported for annual dry mass yield of a forage grass. Conclusions: Further utilization of triploid hybrids in forage grass breeding is hampered by their sterility hence a need for vegetative propagation. However, artificial chromosome doubling of triploids to create fertile hexaploids, or seeking ways to propagate them vegetatively at an industrial scale might overcome this limitation.

Arbuscular mycorrhizae of American ginseng (Panax quinquefolius) in cultivated field plots: plant age affects the development of a colonization lag phase

1999 ◽  
Vol 77 (7) ◽  
pp. 1028-1034 ◽  
Author(s):  
T P McGonigle ◽  
J P Hovius ◽  
R L Peterson
Keyword(s):  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizae ◽  
Dry Mass ◽  
American Ginseng ◽  
Panax Quinquefolius ◽  
Root Turnover ◽  
Lag Phase ◽  
Seed Collection ◽  
Second Year ◽  
Hyphal Coils

Temporal patterns of colonization of roots of perennials by arbuscular mycorrhizal fungi are poorly understood because annual crops are more often studied. The objective was to monitor in detail the growth and mycorrhizae of the perennial American ginseng (Panax quinquefolius L.) over the first 2 years after seeding. In particular, the extent of carry-over of colonization into the second year was examined. Delayed germination of some seeds caused by chance-driven variability in the time needed for seed maturation after seed collection provided an opportunity to compare first- and second-year plants under identical conditions in the second year. For all plants, development of arbuscules rose to a maximum in mid-August, falling partially thereafter. Production of hyphal coils proceeded more slowly but steadily, so that end-of-season colonization was composed equally of arbuscules and hyphal coils. Between seasons, taproot dry mass was reduced by 18%, whereas lateral root length increased by 15%. These changes were probably caused by root turnover, which left little initial colonization of roots at the start of the second year. Strikingly, second-year plants did not exhibit a colonization lag phase, whereas a lag of 43 days was seen for the first-year plants alongside. Possible reasons for this difference are discussed.Key words: perennial, arbuscules, hyphal coils, taproot, Ontario.

Uptake by grass and transfer to soil of nitrogen from 15N-labelled legume materials applied to a Rhodes grass pasture

1983 ◽  
Vol 34 (4) ◽  
pp. 367 ◽  
Author(s):  
I Vallis
Keyword(s):  
Linear Relationship ◽  
Dry Matter ◽  
Soil Surface ◽  
First Year ◽  
Rhodes Grass ◽  
Leaf Material ◽  
South Eastern ◽  
Non Linear ◽  
Second Year

Unground legume materials labelled with 15N were applied to the soil surface under a Rhodes grass pasture in south-eastern Queensland and the recovery of the applied 15N was followed over periods of 1-3 years. Comparisons were made between two legumes, Macroptiliurn atropurpureurn cv. Siratro and Desrnodiurn intorturn cv. Greenleaf, between leaf and stem materials of different nitrogen (N) concentrations (0.5-3.8% N), and between fresh and dried materials. After 1 year, 15N in the applied materials had decreased by 25-91%, and 7-25% was recovered in the Rhodes grass. Except for leaf material of Greenleaf, these changes showed a positive, non-linear relationship to the percentage of N (%N) in the applied materials. The changes for leaves of Greenleaf were less than would be predicted from their %N. Drying Siratro leaves and stems before applying them to the soil surface did not significantly affect the above changes. For N-poor materials (0.5-1.8% N) applied at 380-1360 g dry matter m-2, uptake of 15N by Rhodes grass was greater in the second year than in the first year, whereas for N-rich materials (3.8%N) applied at 140 g dry matter m-2 uptake of 15N in the second and third years was only 23 and 12% respectively of that in the first year.

Estimating Breast Height Diameters from Stump Measurements in British Columbia

1982 ◽  
Vol 58 (3) ◽  
pp. 143-145 ◽  
Author(s):  
Julien P. Demaerschalk ◽  
Stephen A. Y. Omule
Keyword(s):  
British Columbia ◽  
Prediction Model ◽  
Tree Species ◽  
Prediction System ◽  
Tree Diameter ◽  
Local Volume ◽  
Breast Height ◽  
Central Canada ◽  
Volume Equation ◽  
Stump Diameter

A means of estimating tree diameter at breast height from stump measurements has many applications. In this paper, metric equations are derived for estimating diameters at breast height from measured stump heights for all commercial tree species in British Columbia by age class and biogeoclimatic zones. The model found best was the same one as used by Alemdag and Honer (1977) for eleven tree species from eastern and central Canada. This prediction system can be incorporated into any local volume equation to derive a tree volume prediction model based on stump diameter and stump height.

Seed production in Cardiocrium cordatum: effects of nitrogen and dry mass availability of a plant

2006 ◽  
Vol 84 (5) ◽  
pp. 805-812
Author(s):  
Satoki Sakai ◽  
Akiko Sakai ◽  
Kohta Fujioka
Keyword(s):  
Mass Loss ◽  
Seed Production ◽  
Plant Size ◽  
Dry Mass ◽  
Stem Diameter ◽  
N Content ◽  
N Concentration ◽  
The Mean ◽  
Number Of Seeds

To clarify how seed production depends on the relative N and dry mass availability, we examined the number and size of seeds, and the loss of dry mass in Cardiocrium cordatum (Thunb.) Makaino plants that differed naturally in overall size and stem N content. After adjusting for plant size (basal stem diameter was used as a criterion of plant size), the amount of dry mass lost because of respiration in a plant decreased with an increase in the stem N content of the plant, whereas the total dry mass of seeds of a plant increased with an increase in the stem N content. Plants with a high stem N content relative to dry mass status used dry mass resources more efficiently in seed production by reducing the loss of dry mass. Plants with a higher stem N content produced a greater number of seeds, and the amount of dry mass lost decreased with an increase in the number of seeds of the plant, possibly because the resources allocated to seed production are consumed rapidly, if numerous seeds simultaneously absorb those resources. However, the stem N content of a plant had no influence on the mean seed dry mass, seed N content, and the seed N concentration, and the latter three parameters did not affect respiration loss of dry mass. We concluded that plants undergoing seed production reduce dry mass loss if their relative N to dry mass availability is high, through an increase in the numbers of seeds they produce.

Effect of sowing time on the establishment and early production of tropical and temperate pasture mixtures under irrigation in south-eastern Queensland

1981 ◽  
Vol 21 (111) ◽  
pp. 410
Author(s):  
KF Lowe ◽  
TM Bowdler ◽  
JC Mulder
Keyword(s):  
Dry Matter ◽  
Temperate Species ◽  
Considerable Proportion ◽  
Tropical Species ◽  
Sowing Time ◽  
South Eastern ◽  
Early Production ◽  
Grass Establishment ◽  
Second Year ◽  
Tropical Grass

The most effective time to sow irrigated perennial pastures containing tropical and temperate species was investigated over three years at Gatton, south-eastern Queensland. Three mixtures were sown each month between September and June and in split sowings where the tropical species were sown in September or March, and the temperate species in May. Autumn sowings produced the most seedlings of sown species 40 d after sowing. Of the autumn months, May was the most suitable, with an establishment of 181 plants/m2 and a weed population of only 19 plants/m2. Tropical grass establishment was less than 8 plants/m2 from all sowing times. A considerable proportion of tropical grass sown in autumn appeared in spring. Split sowings were not as effective as autumn sowings and favoured the tropical species, which were sown first. Dry matter yield of sown species in the establishment year varied from 0.9 t/ha for February sowings to 12.0 t/ha for April sowings; weed yields varied from 5.8 t/ha for September sowings to 0.8 t/ha for May sowings. Tropical grass contribution was greatest from the split sowing in which the tropical species were sown in September. Temperate species yields were highest from May sowings. In the second year yields of temperate species declined substantially, mainly because of poor persistence of ryegrass. Although tropical grass yields increased in all treatments, this increase was not sufficient in the autumn sowings to compensate for the low ryegrass yields.

Biomass of jack pine and mixed hardwood stands in northeastern New Brunswick

1976 ◽  
Vol 6 (4) ◽  
pp. 441-447 ◽  
Author(s):  
David A. MacLean ◽  
Ross W. Wein
Keyword(s):  
New Brunswick ◽  
Tree Species ◽  
Biomass Accumulation ◽  
Jack Pine ◽  
Tree Crown ◽  
Tree Diameter ◽  
Stem Biomass ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Fire Origin

Biomass accumulation in 12 jack pine and 11 mixed hardwood stands of fire origin ranging in age from 7 to 57 years is presented. Logarithmic equations relating aboveground tree, crown, and stem biomass to tree diameter at breast height are given for eight tree species.

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