Tasmanian snow gum | |
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Eucalyptus coccifera tree line in Mt. Field National Park. | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Clade: | Rosids |
Order: | Myrtales |
Family: | Myrtaceae |
Genus: | Eucalyptus |
Species: | E. coccifera |
Binomial name | |
Eucalyptus coccifera | |
Eucalyptus coccifera, commonly known as the Tasmanian snow gum, [3] is a small to medium-sized tree in the Eucalyptus genus, endemic to Tasmania. It has smooth, grey and cream-coloured bark, elliptic to lance-shaped adult leaves, flower buds in groups of between three and nine, usually white flowers and conical, hemispherical or cup-shaped fruit.
Eucalyptus coccifera is a tree that typically grows to a height of 15 metres (49 ft) but is sometimes a mallee to 5 m (16 ft). The bark is smooth and light grey to white, with streaks of tan. Young plants and coppice regrowth have sessile, blue-green, elliptic to heart-shaped leaves 15–45 mm (0.59–1.77 in) long and 7–23 mm (0.28–0.91 in) wide. Adult leaves are arranged alternately, elliptic to lance-shaped, the same glossy green to bluish on both sides, 50–100 mm (2.0–3.9 in) long and 10–20 mm (0.39–0.79 in) wide on a petiole 8–22 mm (0.31–0.87 in) long. The flowers are borne in groups of three, seven or nine in leaf axils on a peduncle 4–12 mm (0.16–0.47 in) long, the individual buds on a pedicel 1–7 mm (0.039–0.276 in) long. Mature buds are oval, glaucous, 5–8 mm (0.20–0.31 in) long and 4–7 mm (0.16–0.28 in) wide with a warty, hemispherical to more less flattened operculum. Flowering occurs between December and February and the flower are white, or rarely, pink. The fruit is a woody conical, hemispherical or cup-shaped capsule 6–12 mm (0.24–0.47 in) long and 8–13 mm (0.31–0.51 in) wide. [3] [4] [5] [6]
Eucalyptus coccifera was first formally described in 1847 by Joseph Dalton Hooker and the description was published in William Jackson Hooker's London Journal of Botany. [7] [8] The specific epithet (coccifera) is derived from the Neo-Latin coccus, from ancient Greek kokkos (κόκκος), "seed of tree fruit" and Latin ferre, "to carry", [9] referring to the leaves having a Coccus infection. [3]
Eucalyptus coccifera is a member of the peppermint group (series Piperitae) within subgenus Eucalyptus (formerly Monocalyptus). [5] It is endemic to central and southern Tasmania, where it generally occupies sub-alpine habitats above 800 metres (2,600 ft) in altitude. [4] [10] [11]
Eucalyptus coccifera is endemic to Tasmania, and is the dominant species of many exposed, rocky, dolerite rich sub-alpine regions in Tasmania's south and Central Plateau. [4] [5] [11]
Eucalyptus flower buds generally take around a year to fully develop, however development takes longer in E. coccifera and other high altitude species. Insects and birds pollinate the emergent flowers, and fertilization can take up to 20 days after pollination. E. coccifera flowering typically occurs between November and February. [5] After fertilization, the hard woody capsule develops. Seeds are released through the capsule valves, which open when the capsule dries. This drying out is either caused by extreme heat and drought, or by fire. Dispersal of seed relies partially on wind, but mostly on gravity: the seeds will usually fall within a couple of metres of the parent tree. [5] E. coccifera is also known to regenerate from underground lignotubers after fire. [12]
The distribution of E. coccifera is limited by altitude: rarely will it be found lower than 800 metres (2,600 ft), or higher than 1,300 metres (4,300 ft) above sea level. Around 1,300 metres (4,300 ft) the tree line is often unclear, and E. coccifera can be found in small stands or even as solitary trees. At these altitudes, E. coccifera generally grows to heights below 10 metres (33 ft), often blending into the alpine shrubbery at the highest reaches of its distribution. [5] [13] A strong correlation has been found between increasing altitude and declining stem growth rate in E. coccifera. [14]
At the lower range of its altitudinal cline, E. coccifera has been observed growing to 40 metres (130 ft) in height, but it is more commonly measured at around 20 metres (66 ft), especially in sheltered sites on the Central Plateau and in Mt. Field National Park. [11]
Whilst individual and population tree height is the primary change in Eucalyptus coccifera at higher altitudes, observational studies have shown that with increasing altitude, the degree of leaf and bud glaucousness intensifies. [5] This is most likely linked to the increased frost resistance of E. coccifera with increasing altitude. [12] The juvenile foliage of E. coccifera is also more likely to persist for longer at high altitude. [5]
The dominant bedrock underlying both the Mt. Field and Mt. Wellington sub-alpine habitats is Jurassic dolerite. Dolerite is also a feature of the geology of the Central Plateau. These dolerite-rich substrates provide sufficient drainage for the establishment of E. coccifera populations, which prefers well-drained soils. They also offer a potentially rich nutrient source to the sub-alpine plant communities, but the slow rate at which dolerite weathers results in soil of only moderate fertility. [10]
It is generally accepted that in Tasmania annual rainfall increases with altitude, and thus the most exposed E. coccifera populations must contend with high annual rainfall (greater than 1,300 mm [51 in] on Mt. Wellington, and around 2,500 mm [98 in] at Mt. Field). [10] Despite this, water availability can often be an issue for E. coccifera and other subalpine species. This is due to the sporadic nature of Tasmanian rainfall, and a number of other factors including soil type, slope and wind action. [10]
The rocky substrates of sub-alpine Mt. Field and Mt. Wellington drain very effectively, therefore waterlogging isn’t generally a problem. However, it has been shown that waterlogging is a limiting factor on the growth rate of E. coccifera and can, as a consequence, affect the success of the species in susceptible areas. [13] [14]
Eucalyptus coccifera has a high tolerance to frost and to drought, allowing it to occupy very exposed substrates at high altitude. E. coccifera must contend with hot and dry temperatures during the peak of summer, as well as very cold, frosty conditions in winter. [10] [11]
At 1,250 metres (4,100 ft) above sea level on Mt. Wellington, the mean maximum temperature in July is 1.9 °C (35.4 °F), and the mean minimum is −2.0 °C (28.4 °F). In January, the mean maximum is 12.8 °C (55 °F) and the mean minimum is 4.4 °C (39.9 °F). [14] There is a stronger maritime effect (oceanic climate) on Mt. Wellington, due to its closer proximity to the ocean, than at Mt. Field. This results in milder temperatures, especially in summer. Despite the increased exposure of sites at very high altitudes, solar radiation is not thought to markedly affect temperatures, nor does it have much impact on the growth rate of E. coccifera. [14]
Whilst E. coccifera is considered fairly frost-hardy, rare extreme frost events are thought to be one of the principle determinants of subalpine species distribution. [12] Similarly, the duration of snow lie dictates, to a large extent, the species that can persist in alpine/sub-alpine habitats. As snow lie in Tasmania is not permanent, woody species such as E. coccifera and its underlying shrub population can persist at higher altitudes. [10] [15]
Another factor that can impact on the growth of E. coccifera is mist. Mist is generally more prevalent with increasing altitude, particularly in the colder months, and can affect the ability of eucalypts (and other plants) to photosynthesize by decreasing light penetration and increasing condensation on leaves. [10] [14]
Altitude and coordinates | Eucalypt species present | Vegetation type |
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250 metres (820 ft) E4755 S52743 | Eucalyptus obliqua , Eucalyptus regnans (dominant) | Wet sclerophyll forest |
700 metres (2,300 ft) E4728 S52746 | Eucalyptus delegatensis (subsp. tasmaniensis) | Mixed forest |
1,000 metres (3,300 ft) E4695 S52746 | Eucalyptus coccifera (dominant), Eucalyptus subcrenulata (dominant), Eucalyptus urnigera | Subalpine woodland |
1,200 metres (3,900 ft) E4657 S52742 | Eucalyptus coccifera | Subalpine sclerophyll heath |
Table 1. Showing changes in eucalypt species with increasing altitude in Mt. Field National Park. [16]
The understorey of subalpine habitats is typically dominated by woody shrubs of the families Ericaceae (genera Richea , Epacris and Cyathodes ) and Proteaceae ( Orites acicularis , Orites revoluta ). [10] [11] [16] Low-lying conifers of the Cupressaceae ( Diselma archerii ) and Podocarpaceae ( Microachrys tetragona , Phaerosphaera hookeriana ) are also common in these sclerophyllous heaths. [10] [15] [16]
At lower altitudes, other eucalypt species such as E. subcrenulata (Mt. Field), E. urnigera (Mt. Field and Mt. Wellington) and E. delegatensis (Mt. Field and Mt. Wellington) become increasingly common in E. coccifera woodland. [11]
Reid, J.B., Robert, S.H., Brown, M.J., & Hovenden, M.J. (editors) (1999). ‘Vegetation of Tasmania’, Australian Biological Resources Study.
Hartz Mountains National Park is located in the south of Tasmania, Australia. It is one of 19 Tasmanian National Parks, and in 1989 it was included in the Tasmanian Wilderness World Heritage Area, in recognition of its natural and cultural values. The Hartz Mountains were named after the Harz mountain range in Germany.
Eucalyptus regnans, known variously as mountain ash, giant ash or swamp gum, or stringy gum, is a species of very tall forest tree that is native to the Australia states of Tasmania and Victoria. It is a straight-trunked tree with smooth grey bark, but with a stocking of rough brown bark at the base, glossy green, lance-shaped to curved adult leaves, flower buds in groups of between nine and fifteen, white flowers, and cup-shaped or conical fruit. It is the tallest of all flowering plants; the tallest measured living specimen, named Centurion, stands 100 metres tall in Tasmania.
Eucalyptus delegatensis, commonly known as alpine ash, gum-topped stringybark, white-top and in Victoria as woollybutt, is a species of tree that is endemic to southeastern Australia. It has a straight trunk with rough, fibrous to stringy bark on the lower half of the trunk, smooth white bark above, lance-shaped to curved adult leaves, flower buds in groups of between seven and fifteen, white flowers and barrel-shaped or hemispherical fruit.
Eucalyptus pauciflora, commonly known as snow gum, cabbage gum or white sally, is a species of tree or mallee that is native to eastern Australia. It has smooth bark, lance-shaped to elliptical leaves, flower buds in clusters of between seven and fifteen, white flowers and cup-shaped, conical or hemispherical fruit. It is widespread and locally common in woodland in cold sites above 700 m (2,300 ft) altitude.
Nothofagus gunnii, the tanglefoot or deciduous beech, is a deciduous shrub or small tree endemic to the highlands of Tasmania, Australia. It was described in 1847 by R.C Gunn N. gunnii is a small woody tree with a shrubby appearance known to grow up to 8 metres (26 ft). It lives only on mountains due to temperature limitations within the Tasmanian maritime climate and mainly grows at altitudes greater than 800 metres (2,600 ft) above sea level. It grows in alpine and sub-alpine regions in the central portions of the island. Though capable of reaching the size of a small tree, it is most common as a thick shrub or woody ground cover, hence its common name of "tanglefoot".
Eucalyptus gunnii, commonly known as cider gum, is a species of large tree in the flowering plant family Myrtaceae. It is endemic to the island of Tasmania, Australia. It has mostly smooth bark, lance-shaped to egg-shaped adult leaves, flower buds in groups of three, white flowers and cylindrical to barrel-shaped fruit.
Eucalyptus obliqua, commonly known as messmate stringybark or messmate, but also known as brown top, brown top stringbark, stringybark or Tasmanian oak, is a species of tree that is endemic to south-eastern Australia. It has rough, stringy or fibrous bark on the trunk and larger branches, smooth greyish bark on the thinnest branches, lance-shaped to curved adult leaves, flower buds in groups of seven to fifteen or more, white flowers and cup-shaped or barrel-shaped fruit.
Eucalyptus nitens, commonly known as shining gum or silvertop, is a species of tall tree native to Victoria and eastern New South Wales. It has smooth greyish bark, sometimes with thin, rough bark near the base, lance-shaped adult leaves, flower buds in groups of seven or nine, white flowers and cup-shaped, barrel-shaped or cylindrical fruit. It grows in wet forests and rainforest margins on fertile soils in cool, high-rainfall areas.
Eucalyptus vernicosa, commonly known as varnished gum, is a species of shrub or a mallee that is endemic to mountainous areas of Tasmania. It has smooth greyish bark, crowded, egg-shaped to elliptical or round leaves, flower buds singly or in groups of three in leaf axils, white flowers and hemispherical or bell-shaped fruit.
Dracophyllum milliganii is a species of angiosperm in the family Ericaceae and the sub-family Epacridoideae. It is a distinctive alpine shrub, endemic to western Tasmania.
Eucalyptus kybeanensis, commonly known as the Kybean mallee ash, is a species of mallee or tree that is endemic to south eastern Australia. It has smooth, white or greyish bark, lance-shaped adult leaves, flower buds in groups of seven, nine or eleven, white flowers and conical or hemispherical fruit.
Eucalyptus brookeriana, commonly known as Brooker's gum, is a tree species that is endemic to south-eastern Australia. It has rough, fibrous bark on the lower part of its trunk, smooth bark higher up, lance-shaped, egg-shaped or curved adult leaves, flower buds usually arranged in groups of seven, white flowers and cup-shaped, conical or bell-shaped fruit.
Orites revolutus, also known as narrow-leaf orites, is a Tasmanian endemic plant species in the family Proteaceae. Scottish botanist Robert Brown formally described the species in Transactions of the Linnean Society of London in 1810 from a specimen collected at Lake St Clair. Abundant in alpine and subalpine heath, it is a small to medium shrub 0.5 to 1.5 m tall, with relatively small, blunt leaves with strongly revolute margins. The white flowers grow on terminal spikes during summer. Being proteaceaous, O. revolutus is likely to provide a substantial food source for nectivorous animal species within its range.
Leptospermum rupestre, commonly known as alpine tea-tree or prostrate tea-tree, is a flowering shrub in the myrtle family, Myrtaceae. It is endemic to Tasmania. In alpine areas it assumes a prostrate habit while in subalpine areas it appears as a large shrub.
Eucalyptus pulchella, commonly known as the white peppermint or narrow-leaved peppermint, is a species of small to medium-sized tree that is endemic to Tasmania. it has smooth bark, sometimes with rough fibrous bark on older trees, linear leaves, flower buds in groups of nine to twenty or more, white flowers and cup-shaped to shortened spherical fruit.
Eucalyptus guilfoylei, commonly known as yellow tingle or dingul dingul, is a species of tall tree that is endemic to Western Australia. The trunk is straight with fibrous, greyish brown bark and it has lance-shaped leaves, flower buds in groups of seven, white flowers and barrel-shaped fruit.
Eucalyptus subcrenulata, commonly known as Tasmanian alpine yellow gum, is a species of small to medium-sized tree that is endemic to the highlands of Tasmania. It has smooth bark, glossy green, lance-shaped to egg-shaped adult leaves, flower buds in groups of three, white flowers and hemispherical to bell-shaped fruit. It is similar to E. johnstonii, E. vernicosa and E. urnigera.
Eucalyptus longicornis, commonly known as red morrel, morryl, poot or pu, is a species of large tree that is endemic to the south-west of Western Australia. It has rough, fibrous, fissured bark on the trunk, smooth greyish bark above, flower buds in groups of seven or more, white flowers and shortened spherical fruit.
Eucalyptus kabiana, commonly known as Mt Beerwah mallee, is a species of mallee, rarely a small tree, that is endemic to Queensland. It has smooth white to grey bark, sometimes with a short stocking of rough, fibrous bark at the base. The adult leaves are lance-shaped or curved, the flower buds are arranged in groups of between seven and eleven, the flowers are white and the fruit is hemispherical with protruding valves.
Eucalyptus urnigera, commonly known as urn tree, is a species of small to medium-sized tree that is endemic to Tasmania. It has smooth bark, lance-shaped or elliptical leaves, flower buds in groups of three, white flowers and urn-shaped fruit.