User:Scruffy Bay Morton/sandbox
| Scruffy Bay Morton/sandbox | |
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| Species: | A. cupressoides
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| Athrotaxis cupressoides | |
Athrotaxis cupressoides, commonly known as the Pencil pine, is one of 3 species of Athrotaxis within the conifers in the cypress family, Cupressaceace. The genus and species are endemic to Tasmania in Australia. It is an evergreen coniferous tree that can grow up to 10–20 m tall or as an erect shrub under 6 m. Athrotaxis cupressoides habitat range is largely restricted to 700 – 1,300 m altitude [1] which is subalpine and open alpine vegetation, however it can also occur as a rainforest tree. In the genus Athrotaxis the leaves are single-veined, scale-like, spirally arranged and display woody cones [2].
Description
[edit]The genus Athrotaxis has spirally arranged, single veined leaves [3]. The leaves of Athrotaxis cupressoides are small (2-3 mm long and wide), with leaves that are scale-like, and spirally arranged. The free part of the leaf is shorter than the decurrent base. The leaves that have stomata on them are amphistomatic. The leaves are also closely appressed to the stem and the whole shoot is smooth in outline [4]. This particular species of tree has a distinct conical shape, which has led to its name Pencil pine. Athrotaxis cupressoides is often observed growing in open montane environments or sub-alpine vegetation. It rarely attains the height of a tall tree (can grow up to 10-20 m tall), but can achieve monumental trunk sizes (with diameters >1.5 m) and live for more than 1000 years [5]. Female cones are produced on terminal side shoots, are spherical with pointed bract scales and typically about 12-15 mm in diameter [6]. Male cones are much smaller and are produced on the tips of branchlets and are 3mm long, with 2-4 pollen sacs. Seeds produced have 2 even wings with 2 cotyledons and germination is epigeal [7]. The bark is brown to gray in color and can be slightly tattered.
Taxonomy and Naming
[edit]David Don was a scottish botanist who first described Athrotaxis cupressoides in 1838. The origins of the word Athrotaxis come from a Greek word athros meaning crowded, and taxis meaning arrangement. This is due to the overlapping arrangement of the leaves. The name of the species cupressoides is a Greek word meaning ‘resembling cypress’ [8].
Hybrids
[edit]Due to the overlapping ranges of distribution and being of the same genus Athrotaxis, Athrotaxis cupressoides and Athrotaxis selaginoides are potentially interbreeding species (reference Jamie k pat). The hybrid produced is named Athrotaxis laxifola or more commonly known as the Intermediate pine. It is the rarest of the Athrotaxis species and occurs as a uncommon plant with Athrotaxis cupressoides and Athrotaxis selaginoides growing in adjacent areas [9].
Distribution
[edit]
Athrotaxis cupressoides is restricted to sub-alpine environments or open montane habitats (700 – 1,500m a s l) and is confined to Tasmania, Australia. It occurs mainly on the Central Plateau, the Great Western Tier and westward mountaintops. It has a much more scattered distribution in the southwest region of the island. Due to the limited range of habitat types that Athrotaxis can inhabit, the total range of occupancy for vegetation types that Athrotaxis cupressoides occurs in are considerably small with estimates around 24,279ha [10]. Athrotaxis cupressoides is often found growing in areas that are protected from fire or have never been burnt, such as tarns, bogs, elevated dolerite boulders, alongside streams or damp depressions [11]. It also frequently occurs alongside other conifers such as Diselma archeri and Pherosphaera hookeriana, as well as with angiosperms such as Nothofagus gunnii, Richea scoparia, Richea pandnifolia and Eucalyptus coccifera [12].
Threats
[edit]There are a number of threats to this species of plant, such as the effects of Dieback from the oomycete genus Phytophtora that can infect it via its root system. However, there is no greater threat to this species then fire. Athrotaxis cuppresoides is extremely fire sensitive and fires on the Central Plateau killed a huge amount of the total population size in 1960/61 [13].
References
[edit]
- ^ Farjon, A. (2005). Monograph of Cupressaceae and Sciadopitys. Royal Botanic Gardens, Kew. ISBN 1-84246-068-4
- ^ http://www.utas.edu.au/dicotkey/dicotkey/CONIFERS/sAthrotaxis_cup.htm
- ^ http://www.utas.edu.au/dicotkey/dicotkey/CONIFERS/sAthrotaxis_cup.htm
- ^ School of Biological Sciences 2014, KPA 210 Plants of Tasmania, field key to the Tasmanian conifers, University of Tasmania, Hobart.
- ^ http://www.utas.edu.au/dicotkey/dicotkey/CONIFERS/sAthrotaxis_cup.htm
- ^ Ogden, John. 1985. Past, present and future: studies on the population dynamics of some long-lived trees. P. 3-16 in James White (ed.), Studies on plant demography: A festschrift for John L. Harper. London: Academic Press
- ^ Ogden, John. 1985. Past, present and future: studies on the population dynamics of some long-lived trees. P. 3-16 in James White (ed.), Studies on plant demography: A festschrift for John L. Harper. London: Academic Press
- ^ Wapstra, M, Wapstra, A & Wapstra, H 2010, Tasmanian plant names unraveled, 1st edn, Fullers Bookshop, Launceston, Tasmania, Australia. ISBN 978-09804720-2-8
- ^ http://www.utas.edu.au/dicotkey/dicotkey/CONIFERS/sAthrotaxis_cup.htm
- ^ Balmer, J., Whinam, J., Kelman, J., Kirkpatrick, J.B. & Lazarus, E. (2004). A review of the floristic values of the Tasmanian Wilderness World Heritage Area. Nature Conservation Report 2004/3.
- ^ http://threatenedconifers.rbge.org.uk/taxa/details/athrotaxis-cupressoides
- ^ http://threatenedconifers.rbge.org.uk/taxa/details/athrotaxis-cupressoides
- ^ http://www.iucnredlist.org/details/32054/0
Category:Cupressaceae Category:Pinales of Australia Category:Vulnerable flora of Australia Category:Trees of mild maritime climate Category:Ornamental trees Category:Trees of Australia Category:Flora of Tasmania Category:Endemic flora of Tasmania