Description
provided by eFloras
Trees, large. Bark at base of trunk rough and flaky, apically silvery white, smooth, and gradually exfoliating. Branchlets grayish white, ridged. Young leaves shortly petiolate; leaf blade broadly lanceolate to ovate, thinly leathery. Mature leaves with a ca. 2 cm petiole; leaf blade lanceolate, 13-20 × 2-2.5 cm, both surfaces with small glands, adaxially dark green and slightly glossy, secondary veins at an angle of 60°-70° from midvein. Inflorescences axillary, simple, umbels 3-10-flowered; peduncle 1-1.5 cm, compressed. Flower buds narrowly obovate, 8-10 × ca. 5 mm. Hypanthium obconic to campanulate; stipe 0-3 mm; calyptra semiglobose to conic, as long or slightly shorter than hypanthium, apex acute to apiculate. Stamens 8-10 mm; anthers oblong, nearly basifixed, dehiscing longitudinally, glands abaxial. Style shorter than stamens. Capsule gray, pyriform to awl-shaped, 7-8 × 6-8 mm; disk narrow; valves 4 or 5(or 6), exserted from hypanthium. Fl. winter-spring.
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Habitat & Distribution
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Cultivated in Guangdong, Guangxi, and Taiwan [native to E and NE Australia].
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Derivation of specific name
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grandis: of great size
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- Hyde, M.A., Wursten, B.T. and Ballings, P. (2002-2014). Eucalyptus grandis Maiden Flora of Zimbabwe website. Accessed 28 August 2014 at http://www.zimbabweflora.co.zw/speciesdata/species.php?species_id=142450
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- Mark Hyde
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- Petra Ballings
Description
provided by Flora of Zimbabwe
Tree. Bark smooth, white or glaucous. Leaves narrowly lanceolate, attenuate-acuminate. Umbels axillary, 3-10-flowered; peduncles c.1-1.2 cm, flattened; pedicels scarcely differentiated from the receptacle-tube. Operculum conical, shorter than broad. Fruit 7-8 mm, glaucous; valves 4-6, clearly visible at the mouth.
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- Hyde, M.A., Wursten, B.T. and Ballings, P. (2002-2014). Eucalyptus grandis Maiden Flora of Zimbabwe website. Accessed 28 August 2014 at http://www.zimbabweflora.co.zw/speciesdata/species.php?species_id=142450
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- Mark Hyde
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- Bart Wursten
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- Petra Ballings
Worldwide distribution
provided by Flora of Zimbabwe
Coastal parts of Queensland and New South Wales, Australia
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- Hyde, M.A., Wursten, B.T. and Ballings, P. (2002-2014). Eucalyptus grandis Maiden Flora of Zimbabwe website. Accessed 28 August 2014 at http://www.zimbabweflora.co.zw/speciesdata/species.php?species_id=142450
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- Mark Hyde
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- Bart Wursten
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- Petra Ballings
Associated Forest Cover
provided by Silvics of North America
In its native range, rose gum grows in tall, open forests
associated with the eucalypts E. intermedia, E. pilularis, E.
microcorys, E. resinifera, and E. saligna, as well as
Syncarpia glomulifera, Tristania conferta, and Casuarina
torulosa. Rose gum also commonly grows on the fringes of and
occasionally within rainforest (6). In Florida, rose gum
plantations are most frequently established on palmetto prairies.
The characteristic vegetation of palmetto prairies consists of a
ground cover of Serenoa repens, Aristida stricta, Andropogon
spp., Myrica pusilla, M. cerifera, Ilex glabra, and Quercus
minima, with the scattered trees, Sabal palmetto, Quercus
virginiana, and Pinus palustris (12).
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Climate
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The climate in the Australian native range of rose gum is humid
subtropical with mean minimum temperatures during the coldest
month ranging from 2 to 10° C (36 to 50° F) and mean
maximums near 29° C (85° F) during the hottest month.
Rainfall averages 1020 to 1780 mm (40 to 70 in); it is
concentrated in the summer, but monthly precipitation during the
dry season is at least 20 mm (0.8 in) (10,21). Coastal areas are
generally frost-free, but higher altitude, inland areas
experience occasional frosts (6).
Southwest Florida is humid and subtropical. Summers are long,
rainy, and warm; winters are dry and mild but with the threat of
damaging frost. Mean annual rainfall ranges from 1270 to 1400 mm
(50 to 55 in). Monthly precipitation during the rainy season,
June through September, averages about 180 to 200 mm (7 to 8 in).
Rainfall during the dry season, November through April or May,
averages 50 mm (2 in) per month (40). Dry-season rainfall is
unreliable, however. Daily maximum temperatures from late May
through September exceed 32° C (90° F) on most days but
rarely reach 38° C (100° F). During the coldest month,
daily maximum temperatures average near 24° C (75° F)
and daily minimums near 11° C (52° F) (27). But swift
continental cold fronts change balmy afternoons into dangerously
cold nights. The lowest temperatures recorded in each of 30
winters averaged -4.4° C (24° F) (22).
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Damaging Agents
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The greatest threat to rose gum survival
is a lapse in soil moisture at outplanting time. If this occurs,
managers must be prepared to stop planting until the rains begin
again. Severe nursery losses have been suffered from a
stem-girdling fungal canker caused by Cylindrocladium
scoparium, but alternating sprays of chlorothalonil and
benomyl prevent or control it (1).
Severe frost damages rose gum saplings even in the commercial
plantation zone, but they sprout and regrow vigorously. Frost has
cost a season's growth several times but never a plantation.
South Florida usually has inversion freezes, with lower
temperatures at ground level than at 2 m (6.6 ft). There is a
strong positive correlation between freeze resistance and rapid
early growth; resistant trees develop larger stems with thicker,
insulative bark close to the ground, and also elevate tender
terminal tissue into the higher, warmer air. Each additional year
of growth reduces the risk of frost damage. Since planting
research began in 1961, severe damage has been suffered 1 out of
3 years by seedlings in their first winter, I out of 5 years by
saplings in their second winter, and only 1 out of 19 years by
trees in their third winter or older.
Local plantations are suffering an increasing incidence of basal
cankers caused by the fungus Cryphonectria cubensis. Canker
incidence in the oldest pilot-scale plantation increased from 15
percent at age 7 to 50 percent at age 11 (2). Infected trees in
Florida do not seem debilitated, but mortality has been serious
in Brazil (30 percent) and Surinam (50 percent). Basal cankers
may appear in trees less that 2 years old.
Lightning occurs with an unusually high frequency in southwest
Florida (36). Over an 8.5-year rotation on a 67-ha (165-acre)
plantation, 4.4 percent of the sample trees suffered lightning
strikes or splashes and 2.5 percent actually died as a result.
No hurricane has struck southwest Florida since commercial
planting began, but there is a 10-percent hurricane probability
for any given year. A hurricane would cause serious windthrow, as
hurricane Allen did to Eucalyptus in Jamaica (41).
Termites which devour seedlings during the first years, have been
a serious problem in rose gum plantations in India (28). Also
worth mentioning is the serious tendency of rose gum logs to
end-split. Losses can be kept at a minimum by milling within 3
days of cutting, bucking to lengths as long as possible, and
sawing carefully (33).
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Flowering and Fruiting
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Rose gum, like all eucalypts,
bears perfect flowers. Buds form in axillary umbels with usually
seven buds per cluster. Each flower consists of a central style
surrounded by stamens standing about 8 mm (0.3 in) tall and
forming a bloom about 20 mm (0.8 in) in diameter. The puffy
clusters of creamy white blooms are attractive and conspicuous
but not of horticultural quality.
The main blooming season is mid-August through late September, but
some trees start blooming early in August and the latest finish
in mid-November. This blooming season of late summer-early fall
matches the low-elevation blooming season in South Africa but
contrasts with the late fall-early winter bloom at high
elevations (18) and the midwinter bloom in Australia (5). Each
tree blooms serially over a period of 5 to 10 weeks, with an
average of only 12 percent of a tree's bud crop in prime bloom
during a given week.
Foraging insects, particularly honeybees, pollinate the flowers.
In an individual flower, the stigma is not receptive until after
pollen shed, but because each tree blooms serially, there is,
unfortunately, ample opportunity for self-fertilization. In a
South African seed orchard, selfing occurred with a frequency of
10 to 38 percent, caused 10 recognizable detrimental
abnormalities, and depressed the height growth of outplanted
seedlings 8 to 49 percent compared to crossed progenies (19).
Flowering precocity is strongly inherited; a few families bloom
at plantation-age 1 year, many more at age 2, and 97 percent of
the orchard at age 3.
From 2 to 3 weeks after blooming, the stamens and style wither and
fall away, leaving a woody, urn-shaped seed capsule closed by
four to six valve covers. The capsules are about 8 mm long by 6
mm in diameter (0.3 by 0.25 in). Most umbels carry five to seven
capsules to maturity.
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Genetics
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Rose gum is most closely related to E. deanei and E.
saligna (6). No subspecies or varieties are recognized.
Rose gum trees planted in southwest Florida constitute a land race
developed through three generations of selection and progeny
testing in the local environment. Because of recurrent selection
for local adaptation, the trees perform better than progenies of
outstanding trees selected in Australia, South Africa, or
elsewhere.
A long-range breeding system calls for importing as many rose gum
seed lots as possible-preferably collections from selected single
trees in Australia-but some bulk lots and many lots from exotic
populations outside Australia have been included. Each seed lot
(family) contributes about 60 seedlings to a large outplanting
called the genetic base population. All individuals of all
families are completely randomized in single-tree plots. Trees
are measured for growth rate and scored for cold hardiness, stem
straightness, branch habit, and general adaptation. At 2.7 years
(one-third of the rotation age), the trees are selected and the
rest are rogued to convert the base population to a seedling seed
orchard. The best families usually contribute three or four
selects to the seedling seed orchard; most families contribute
only one or two; and about one-third of the families drop out of
the breeding population for lack of any worthy candidates.
Select trees exchange pollen in the first massive bloom at age 3+
years. The following spring the resultant seed is collected and
used to establish the next generation's base population, which
also is the progeny test of the seedling seed orchard. Thus, a
generation of selection is completed in 4 years. Progeny test
results identify the best commercial seed-orchard trees as well
as poor seed trees to be rogued from the orchard.
Each generation of selection enhances the land race's adaptation
to local conditions, but new families must be imported to broaden
the genetic base and minimize inbreeding depression.
In the current genetic base population, first-generation
Australian families average 7.5 dm³ (0.26 ft³) of stem
volume at 2.5 years. Compared with those Australian families,
second-generation Florida families average 95 percent more stem
volume (14.6 dm³ or 0.52 ft³); third-generation
families, 127 percent more (17.0 dm³ or 0.60 ft³); and
fourth-generation families, 163 percent more (19.7 dm³ or
0.70 ft³). A study designed to measure realized gain
compares the following three populations, each in replicated
block plantings:
Premier-Six advanced-generation families (average 3.5
generations of selection) that are top-ranked for the combined
traits of volume production, cold hardiness, form, and coppicing.
Commercial-The 33 advanced-generation families (average
2.9 generations) included in the seed mix for the 1979 commercial
season.
Ancestral-Four imported seed lots from which all
six premier families descend and 21 of the 33 commercial
families.
At age 1.5 years both premier and commercial trees significantly
exceeded the height of ancestral trees by 23 and 13 percent,
respectively. The three populations all differed significantly in
their cold hardiness. The premier families suffered mainly foliar
damage, while the commercial and ancestral families suffered
increasingly severe damage to foliage and woody parts.
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Growth and Yield
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Growth of rose gum on short rotations is
rapid. Mean height growth of 2 m/yr (6.5 ft) is common (29), and
a rate of 4 m/yr (13 ft) has been reported (35). Mean yields are
about 27 m³/ha/yr (386 ft³/acre/yr) (21). Wood
increment on the best sites is even more impressive:
Volume
of uncleaned seeds
Weight of
uncleaned seeds
Healthy
germinants
Healthy
germinats per tree
(liters)
(quarts)
(kg)
(lb)
(/gram)
(/ounce)
1.7
1.8
0.99
2.18
688
19,504
694,115
average 3.5 m (11.5 ft) annually for the first 4 years, then taper
off to average 2.4 in (7.9 ft) over an 8-year rotation.
Adequately stocked commercial plantations have not reached
harvest age, but preliminary growth data support the following
planning assumptions:
An 8-year seedling rotation.
Trees averaging about 18 in (60 ft) tall at age 8 years.
Annual yield for volume and weight in the following range:
Volume
Dry Weight
m³/ha
ft³/acre
t/ha
tons/acre
Pessimistic
12.9
184
5.4
2.4
Realistic
16.1
230
6.9
3.1
Optimistic
19.3
276
8.3
3.7
These indicated annual yields are well below world standards, and
are probably due to south Florida's infertile soils and
seasonally high water tables. Yields include about 18 percent
bark by volume and 14 percent by weight. Density averages about
0.45 g/cm³ (0.026 oz/in³) for wood and about 0.32 g/cm³
(0.018 oz/in³) for bark. Moisture content is about 0.50 g/cm³
(0.029 oz/in³) for wood and 0.72 g/cm³ (0.042 oz/in³)
for bark (14).
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Reaction to Competition
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Rose gum is intolerant of shade.
Seedlings can only develop in full or nearly full sunlight; trees
must maintain a dominant or codominant canopy position to long
survive. Suppressed trees quickly die and intermediate trees must
grow to an overstory position or eventually lose vigor and die.
Despite their startling growth capacity, newly planted rose gum
seedlings compete poorly with weedy vegetation, tolerating
neither root competition nor shading. In Florida, they need 3
months reasonably free of competition to grow about 1.5 in (5 ft)
tall and dominate the site. The local planting effort
concentrates on virgin prairies and cutover pineland where
chopping and bedding control the native ground cover sufficiently
to permit rose gum establishment without post-planting weed
control. However, early vegetative competition often retards
growth and probably contributes to large tree-to-tree variation
within stands. Post-planting weed control by herbicides and
cultivation is beneficial (37). An increase in volume at 5 years
of 48 to 55 percent was obtained by combinations of cultivation
and herbicide spraying during the first 24 months (30). Competing
vegetation also contributes to the fire danger. Rose gum
completely occupies suitable sites in Florida with adequate
stocking by plantation-age 2.5 years and herbaceous ground cover
mostly disappears. On poor sites, intense competition may
continue for 5 years.
Competitive relationships develop early among the plantation trees
and stay well defined throughout the 8-year rotation. In
Florida's first commercial plantation, 75 percent of the sample
trees that were in the top quartile for height at age 2.5 years
were still in the top quartile at age 8.5 years; and 73 percent
of the trees in the bottom quartile at age 2.5 were either dead
or still in the bottom quartile at 8.5 years. Similarly, out of
131 sample crop trees at 8.5 years, 85 percent had been predicted
as crop trees at 2.5 years; of 37 sample trees that were culls or
dead at 8.5 years, 68 percent had been predicted as culls at 2.5
years.
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Rooting Habit
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Natural seedlings develop a pronounced
taproot with few laterals if conditions permit. The roots of
containerized seedlings more or less assume their natural form
after being outplanted, regardless of previous restrictions (3).
Rose gum does not develop lignotubers (6).
The soils of south Florida drastically sculpture the root systems
of rose gum trees. These spodosols feature a thin, sandy A,
horizon with meager accumulations of nutrients and organic
matter. Below lies a strongly leached A2
horizon of white, sterile sand. The A2
changes abruptly to a B2h, the spodic
horizon, consisting of fine sand accreted with organic and
aluminum compounds. In some areas this spodic hardpan perches
water tables and resists root penetration both physically and by
aluminum toxicity (4). Typically, taproots penetrate about 50 cm
deep (20 in), then divide into two or more smaller taproots that
terminate barely into the spodic horizon (4). Excavated trees
show an abrupt fringe of dead lateral and feeder roots in the A2
horizon, apparently anoxia mortality from perched or raising
water tables during the summer rainy season (4). This shallow
anoxic zone restricts the exploitable soil during the prime
summer growing season, and the roots cannot penetrate the spodic
horizon to pursue the retreating water table during the long dry
season.
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Seed Production and Dissemination
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Seed capsules are
mature for harvest 6 or 7 months after flowering. However, the
capsules remain closed on the tree for at least 1 year after
maturity, so it is possible to gather two seed crops at a time by
harvesting in alternate years. Seed capsules should be harvested
by severing the umbel stalks; the alternative of clipping
seed-bearing twigs reduces the next flower crop.
The valves of the capsules dry out, open, and release seeds.
Capsules scattered loosely on a dry surface release their seeds
after about 2 hours in full sun. Commercial bulk lots can be
extracted in about I week in chambers equipped with open-mesh
shelves, heating from 30 to 35° C (86 to 95° F),
forced-air circulation, and dehumidification.
Individual trees bear from 3 to 25 sound seeds per capsule, with
an average near 8 (20) and a much greater mass of infertile
ovules called "chaff." Fertile seeds are tiny, only
about I min (0.04 in) in diameter. Chaff particles are lighter
colored and only minutely smaller and lighter than seeds. Seed
cleaning involves sorting by size and shape through multiple
sieves, then separating by weight in a pneumatic separator.
In Florida, operational quantities of seeds can be harvested from
an orchard at age 3.7 years and production increases annually to
a plateau at about age 10. Seed production is reliable year to
year, but there is great tree-to-tree variation in the quantity,
purity, and viability of seed crops. The 1-year seed crop from
some 7-year-old trees was as follows:
Seeds have been successfullly stored for 20 years by either
freezing at -8° C (18°F) or refrigerating at 10° C
(50° F). Rose gum seeds require no presowing treatment.
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Seedling Development
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Germination of rose gum is epigeal
and takes place in 7 to 14 days after sowing (44). Moist, bare
soil is required for natural regeneration; fire, erosion, and
flood deposits provide satisfactory seedbeds. In commercial
forests, the species is almost always regenerated by planting.
Seedlings are usually raised to 20 to 30 cm (7.8 to 11.8 in)
tall, which takes 3 to 5 months (29). Due to the sensitivity to
desiccation, seedlings are normally grown in containers. Rigid
containers with multiple cavities from which the seedlings are
removed with roots and soil intact are almost always used in
large operations. Seedlings are also grown in plastic nursery
bags. In the absence of frost and drought, seedlings can be
planted throughout the year. In many areas seedling production
and planting must be carefully timed. In Florida, planting must
coincide with summer rains to give sufficient time for seedlings
to grow into hardy saplings before facing winter frosts.
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Site Preparation and Planting in Florida
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Success in
establishing rose gum in plantations depends on double chopping
or cross disking to greatly reduce vegetative competition, then
broadcasting 1.12 t/ha (0.5 ton/acre) of ground rock phosphate to
overcome a severe natural phosphorus deficiency, and finally
bedding to elevate the seedlings out of the standing water during
the first rainy season (25). Saw-palmetto rhizomes are thick,
fibrous, and deeply rooted, requiring heavy equipment for
chopping and bedding. Landowners prepare sites in the spring when
the deepening drought enhances the kill from chopping or disking.
Also, spring offers little time or moisture for weed competition
to colonize the beds before summer planting starts.
Planting crews use high-clearance wheel tractors to straddle the
beds and pull planting machines fitted with racks holding four
cartons containing a total of 1,400 to 2,000 containerized
seedlings. This number is sufficient to traverse several rows as
long as I kin (0.6 mi). Recommended planting density is 1,495
seedlings per hectare (605 seedlings/acre) on beds spaced 3.7 in
(12 ft) apart and seedlings spaced 1.8 in (6 ft) along the beds
(26).
In the first 2 years of machine planting, survival averaged 86
percent in an extremely wet season and 75 percent in a dry year.
Survival after machine planting probably averages about 84
percent. Hand planting routinely achieves at least 95 percent
survival.
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Soils and Topography
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This species grows on flats or lower slopes of deep, fertile
valleys in Queensland and New South Wales. It grows best on
moist, well drained, deep, loamy soils of alluvial or volcanic
origin (6). Clayey soils are acceptable if they are well drained
(23).
The rose gum plantations in Florida lie in a physiographic region
known as the Western Flatlands (11). Topography is nearly flat;
elevations change almost imperceptibly from coastal sea level to
6, 12, or rarely 18 m (20 to 60 ft) elevation inland. Soils are
almost exclusively members of the sandy, siliceous hyperthermic
Haplaquods. Derived from marine deposits, these soils are mainly
sands, strongly acid, poorly drained, and underlain by spodic
horizons that are commonly impervious to root penetration and
water drainage. The combination of high seasonal rainfall, flat
topography, and low elevation results in high water tables,
shallow root zones, and local inundation during the rainy season.
Conversely, during the dry season these sandy soils rapidly
become moisture deficient.
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Special Uses
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The sapwood of rose gum is pale pink and the heartwood light to
dark red. The wood is straight grained, coarse textured, and
moderately strong (6). It is moderately durable at best, but the
sapwood is generally resistant to Lyctus spp. borers (6,7). The
specific gravity varies from 0.62 to 0.80 (6,7,23). Rose gum
timber is used for general construction, joinery, plywood,
panelling, boat building, flooring, utility poles, mine timbers,
and posts (6,7).
In 1972, rose gum wood harvested from an 8.5-ha (21-acre) research
planting supported a commercial-scale trial run in a Florida
pulpmill. A mixture of 70 percent rose gum and 30 percent native
hardwood was manufactured into quality facial tissue with
excellent properties of strength and softness (42). Earlier
laboratory tests showed that debarked rose gum wood gave screened
Yields of kraft bleached paper pulp equal to those of
representative native hardwood furnish at comparable kappa
numbers. Brightness of bleached pulp was equal or superior to
native hardwood controls at equivalent or slightly higher
processing costs (14). However, strength properties of handsheets
were generally inferior to those of native hardwood controls.
A pyrolysis test was conducted to determine the energy value that
could be recovered from whole-tree chips of 9-year-old rose gum
grown in southwest Florida. Seventy percent of the energy
contained in the dry chips could be recovered as char and oil,
which could be transported and stored. Twenty-one percent of the
trees' energy value was converted to noncondensed volatile oil
and low-energy gas that could only be used on site or sold to an
adjacent user (34).
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Vegetative Reproduction
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After harvest, under favorable
conditions, rose gum plantations regenerate by coppicing
(sprouting) from the stumps. Two or three coppice rotations are
commonly harvested before it is necessary to replant seedlings.
Coppice shoots initially grow faster than seedlings, but that
advantage is partially offset by stump mortality, which usually
runs about 5 percent per rotation in South Africa (39). In many
areas, coppice forms equally well regardless of the season of
harvest. In Florida, however, it was shown that summer harvests
(June-September) reduced coppicing ability.
Vegetative propagation has been a difficult challenge. Cuttings
from tiny seedlings root readily, but rooting capability ceases
before seedlings are 1 in (3 ft) tall because of natural rooting
inhibitors produced by adult leaves (32). However, even in adult
trees, cuttings from epicormic shoots induced at the base of the
tree by felling or girdling retain the ability to root. Rooting
success varies substantially among clones, and there are strong
seasonal influences and exacting cultural requirements for each
geographic area. The technique is particularly advantageous in
multiplying outstanding hybrid individuals. Starting in the
mid-1970's, some commercial plantations were propagated by rooted
cuttings in Brazil (8,17), where the method is now used to
establish major clonal plantations (9). Reproduction through
tissue culture techniques has also been demonstrated (38).
Clonal seed orchards have been produced by grafting in South
Africa, but delayed graft incompatibility is a common,
debilitating problem. Incompatibility can be greatly reduced by
grafting scions onto sibling or half-sibling rootstocks (45).
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Brief Summary
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Myrtaceae -- Myrtle family
George Meskimen and John K. Francis
Eucalyptus grandis is native to the east coast of
Australia. Its common name is rose gum or flooded gum (a
misnomer). Rose gum is one of the premier forest species in the
Australian States of Queensland and New South Wales where it
grows 43 to 55 m tall (140 to 180 ft) and 122 to 183 cm (48 to 72
in) in diameter (15). Its form is excellent with tall, straight,
clean holes up to two-thirds of the total height. The bark is
thin and deciduous, shedding in strips to expose a smooth surface
marked with flowing patterns of silvery white, slaty gray, terra
cotta, or light green. Occasionally a "stocking" of
light-gray, platelike or fissured bark persists over the basal I
to 2 m (3 to 6 ft) on the trunk.
Rose gum is one of the most important commercial eucalypts, with
more than one-half million hectares (1.3 million acres) planted
in tropical and subtropical areas on four continents. Massive
planting programs have been carried out in the Republic of South
Africa and Brazil, and there are substantial plantings in Angola,
Argentina, India, Uruguay, Zaire, Zambia, and Zimbabwe (21). In
southwest Florida rose gum may be an emerging commercial species
for plantations. It has been successfully tested for pulpwood and
fuel; and its wood has potential for poles, pallets, veneer, and
other products. In California, Hawaii, and Puerto Rico, rose gum
appears in some species trials and landscaping.
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Distribution
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Over its central range, rose gum grows on alluvial or volcanic
loams in valleys and flats within 160 krn (100 mi) of the coast,
straddling the Queensland-New South Wales border from latitude 26
to 33° S. Two outlier populations extend the range to the
Atherton Tablelands at latitude 13° S. (10,15).
In Florida, intensive research on rose gum began in 1961
and operational planting in 1972. Through the 1980 planting
season, it was commercially planted on 5,650 ha (14,000 acres) in
Glades, Hendry, and Charlotte Counties in southwest Florida
between latitude 26° 31' and 27° 02' N. and between
longitude 81° 31' and 81° 48' W. Outside that zone
there are numerous potential planting areas in south Florida.
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Eucalyptus grandis
provided by wikipedia EN
Eucalyptus grandis, commonly known as the flooded gum or rose gum,[2] is a tall tree with smooth bark, rough at the base fibrous or flaky, grey to grey-brown. At maturity, it reaches 50 metres (160 feet) tall, though the largest specimens can exceed 80 metres (260 feet) tall. It is found on coastal areas and sub-coastal ranges from Newcastle in New South Wales northwards to west of Daintree in Queensland, mainly on flat land and lower slopes, where it is the dominant tree of wet forests and on the margins of rainforests.
Description
Eucalyptus grandis grows as a straight and tall forest tree, reaching around 50 m (160 ft) tall,[3] with a dbh of 1.2 to 2 m (3.9 to 6.6 ft). The biggest trees can reach 75 m (246 ft) high and 3 m (9.8 ft) dbh,[2] the tallest recorded known as "The Grandis" near Bulahdelah, with a height of 86 m (282 ft) and a girth of 8.5 m (28 ft).[4] The bole is straight for 2/3 to 3/4 the height of the tree. The bark is smooth and powdery, pale- or blue-grey to white in colour, with a skirt of rough brownish bark for the bottom 1–4 m (3 ft 3 in – 13 ft 1 in) of the tree trunk.[2] The glossy dark green leaves are stalked, lanceolate to broad lanceolate, and paler on their undersides, 10 to 16 cm (3.9 to 6.3 in) long and 2–3 cm (0.79–1.18 in) wide. They are arranged alternately along the branches.[3] The secondary veins arise off the leaf midvein at a wide angle (61 degrees), and the leaf is dotted with around 800 oil glands per square centimetre.[5]
The flower buds are arranged in leaf axils in groups of seven, nine or eleven on an unbranched peduncle 10–18 mm (0.39–0.71 in) long, the individual buds sessile or on pedicels up to 5 mm (0.20 in) long. Mature buds are oval, pear-shaped or club-shaped, green to yellow or glaucous, 6–9 mm (0.24–0.35 in) long and 4–5 mm (0.16–0.20 in) wide. The white flowers appear from mid autumn to late winter from April to August. The flowers are followed by conical, pear- or cone-shaped fruit 4–10 mm (0.16–0.39 in) long and 5–8 mm (0.20–0.31 in) wide with the valves at rim level or slightly above.[3][6][7]
The Sydney blue gum (E. saligna) is very similar in appearance and overlaps E. grandis in the southern part of its range, but has narrower leaves and more bell-shaped gumnuts with protruding valves.[8] It also has a lignotuber. The mountain blue gum (E. deanei) can be distinguished by its entirely smooth bark and wider adult leaves.[2]
Taxonomy
Eucalyptus grandis was first formally described by Walter Hill in 1862 in Catalogue of the Natural and Industril Products of Queensland.[9] The species name grandis "large" relates to this tree's large size. It is commonly known as the flooded gum and as rose gum in Queensland.[2] It has been classified in the subgenus Symphyomyrtus, Section Latoangulatae, Series Transversae (eastern blue gums) by Brooker and Kleinig. Its two closest relatives are the Sydney blue gum (Eucalyptus saligna) and the mountain blue gum (E. deanei).[10]
Distribution and habitat
E. grandis is found on coastal areas and sub-coastal ranges from the vicinity of Newcastle in New South Wales northwards to Bundaberg in central Queensland with disjunct populations further north near Mackay, Townsville and Daintree in northern Queensland, mainly on flat land and lower slopes. The soils are deep fertile alluvial loams. The annual rainfall varies from 1100 to 3500 mm.[2] It is the dominant tree of wet forest and rain forest margins,[3] either growing in pure stands or mixed with trees such as blackbutt (E. pilularis), tallowwood (E. microcorys), red mahogany (E. resinifera), Sydney blue gum (E. saligna), pink bloodwood (Corymbia intermedia), turpentine (Syncarpia glomulifera), brush box (Lophostemon confertus) and forest oak (Allocasuarina torulosa).[2] E. grandis has been established in plantations in northern Uruguay and is sold under the trade name "Red Grandis".
Uses
Flooded gum is an attractive, straight-trunked tree much in demand outside Australia for timber and pulp, and extensive plantations exist in South Africa and Brazil.[4] Within Australia, plantations exist in northern New South Wales, where seedlings have put on 7 metres (23 feet) of growth in their first year.[8] The timber has a pinkish tinge and is used in joinery, flooring, boat building, panelling and plywood.[4] It has a straight grain, moderate durability and strength, and is resistant to Lyctus borers.[2] Hybrids with river red gum (Eucalyptus camaldulensis) are used to combat salinity.[4] Eucalyptus grandis is a food plant of paropsine beetles of the family Chrysomelidae and Christmas beetles, the latter often defoliating trees of Australia's east coast. Clones of Eucalyptus grandis have been selected and bred on the basis of unpalatability to the brown Christmas beetle (Anoplognathus chloropyrus) to minimise damage to plantations.[11]
Other insect pests include the steelblue sawfly (Perga dorsalis) and the leafblister sawfly (Phylacteophaga froggatti), both of which prefer young trees.[12]
Eucalyptus grandis has been grown successfully in plantations in wetter areas of Sri Lanka, particularly in the Badulla and Nuwara Eliya Districts. Plantations have also been successful in Uruguay where lumber is being exported to the United States under the trade name "Red Grandis".[13] Many parameters of climate and soil are similar to eastern Australia, and it has grown well on plains as well as hills previously used for growing tea. Grown for its wood and ease of cultivation, it is the fastest growing eucalypt in the country.[14]
The tree is too large for most gardens, but makes an attractive tree for large parks and farms, and can be used in riverbank stabilisation.[15]
The saligna gum is grown extensively in plantations in South Africa in areas that formerly offered indifferent bee forage. At the onset of flowering each year an extraordinarily large number of colonies move into these plantations where thousands are decoyed into hives by beekeepers. The flowers have a strong scent and beekeepers assert that bees travel at least 32 km (20 miles) to some plantations.
Pulpwood
References
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^ "Eucalyptus grandis". Australian Plant Census. Retrieved 22 July 2019.
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^ a b c d e f g h Boland, Douglas J.; Brooker, M. I. H.; Chippendale, G. M.; McDonald, Maurice William (2006). Forest trees of Australia. Collingwood, Victoria: CSIRO Publishing. p. 83. ISBN 0-643-06969-0.
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^ a b c d Hill, Ken. "New South Wales Flora Online: Eucalyptus grandis". Royal Botanic Gardens & Domain Trust, Sydney, Australia.
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^ a b c d Wrigley, John; Fagg, Murray (2010). Eucalypts: A Celebration. Allen & Unwin. pp. 84, 157, 217. ISBN 978-1-74175-924-2.
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^ Brooker, Ian; Nicolle, Dean (2013). Atlas of Leaf Venation and Oil Gland Patterns in the Eucalypts. Collingwood, VIctoria: Csiro Publishing. p. 57. ISBN 9780643109865.
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^ "Eucalyptus grandis". Euclid: Centre for Australian National Biodiversity Research. Retrieved 2 June 2020.
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^ Chippendale, George M. "Eucalyptus grandis". Flora of Australia. Australian Biological Resources Study, Department of the Environment and Energy, Canberra. Retrieved 22 July 2019.
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^ a b Holliday, Ivan (1989). A Field Guide to Australian Trees. Melbourne: Hamlyn Australia. p. 198. ISBN 0-947334-08-4.
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^ "Eucalyptus grandis". APNI. Retrieved 22 July 2019.
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^ Brooker, M.I.H.; Kleinig, D. A. (1999). Field Guide to Eucalypts. Vol. 1: South-eastern Australia. Melbourne, Victoria: Bloomings Books. pp. 69–72. ISBN 1-876473-03-7.
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^ Johns, Caitlin V.; Stone, Christine; Hughes, Lesley (2004). "Feeding preferences of the Christmas beetle Anoplognathus chloropyrus (Coleoptera: Scarabaeidae) and four paropsine species (Coleoptera: Chrysomelidae) on selected Eucalyptus grandis clonal foliage" (PDF). Australian Forestry. 67 (3): 184–90. doi:10.1080/00049158.2004.10674932. S2CID 84280012.
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^ Stone, C. (1993). "Insect pest problems of eucalypt plantations in Australia 2. New South Wales". Australian Forestry. 56 (4): 363–69. doi:10.1080/00049158.1993.10674627.
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^ "URUFOR".
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^ Sivananthawerl, T.; Mitlohner, R. (2011). "Eucalyptus grandis and other important Eucalyptus species". In Sven G. Nter; Sven Günter; Michael Weber; Bernd Stimm; Reinhard Mosandl (eds.). Silviculture in the Tropics. Springer. pp. 465–70. ISBN 978-3-642-19985-1.
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^ Elliot, Rodger W.; Jones, David L.; Blake, Trevor (1992). Encyclopaedia of Australian Plants Suitable for Cultivation: Vol. 4: Eu-Go. Port Melbourne: Lothian Press. pp. 108–09. ISBN 0-85091-213-X.
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Eucalyptus grandis: Brief Summary
provided by wikipedia EN
Eucalyptus grandis, commonly known as the flooded gum or rose gum, is a tall tree with smooth bark, rough at the base fibrous or flaky, grey to grey-brown. At maturity, it reaches 50 metres (160 feet) tall, though the largest specimens can exceed 80 metres (260 feet) tall. It is found on coastal areas and sub-coastal ranges from Newcastle in New South Wales northwards to west of Daintree in Queensland, mainly on flat land and lower slopes, where it is the dominant tree of wet forests and on the margins of rainforests.
lower trunk showing rough "skirt",
Sunshine Coast flower buds
fruit
cultivated specimen in
Maranoa Gardens
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