Esperance Plains
Esperance Plains Western Australia | |||||||||||||||
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Area | 29,213.27 km2 (11,279.3 sq mi) | ||||||||||||||
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Esperance Plains, also known as Eyre Botanical District, is a
Geography and geology
The Esperance Plains may be roughly approximated as the land within 40 kilometres (25 mi) of the coast between
The region's topography consists of a plain that rises from near sea level to an altitude of about 200 metres (660 ft), broken in places by outcrops of granite domes and quartzite ranges. The soil is Eocene sediments overlying clay or ironstone gravel derived from the Albany-Fraser Orogen.[2][3]
Climate
Esperance Plains has a warm, dry, Mediterranean climate, with five to six dry months. Rainfall in winter is typically between 500 and 700 millimetres (19–27 in).[3]
Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year | ||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Mean daily maximum temperature | 26.2°C 79.2°F |
26.2°C 79.2°F |
25.1°C 77.2°F |
23.2°C 73.8°F |
20.4°C 68.7°F |
18.0°C 64.4°F |
17.1°C 62.8°F |
17.7°C 63.8°F |
19.3°C 66.7°F |
21.0°C 69.8°F |
23.0°C 73.4°F |
24.5°C 76.1°F |
21.8°C 71.2°F | |
Mean daily minimum temperature | 15.5°C 59.9°F |
16.0°C 60.8°F |
15.0°C 59.0°F |
13.2°C 55.8°F |
11.0°C 51.8°F |
9.1°C 48.4°F |
8.3°C 46.9°F |
8.6°C 47.5°F |
9.5°C 49.1°F |
10.6°C 51.1°F |
12.6°C 54.7°F |
14.3°C 57.7°F |
12.0°C 53.6°F | |
Mean total rainfall | 21.7 mm 0.83 in |
27.3 mm 1.05 in |
28.8 mm 1.11 in |
42.7 mm 1.64 in |
74.2 mm 2.85 in |
81.1 mm 3.12 in |
99.6 mm 3.83 in |
84.1 mm 3.23 in |
59.9 mm 2.30 in |
48.4 mm 1.86 in |
34.7 mm 1.33 in |
18.1 mm 0.70 in |
620.6 mm 23.87 in | |
Mean number of rain days | 5.7 | 5.8 | 7.7 | 10.5 | 13.9 | 16.1 | 17.1 | 16.6 | 14.2 | 12.1 | 9.6 | 6.7 | 135.9 | |
Source: Bureau of Meteorology[4] |
Vegetation
The main vegetation formation of the Esperance Plains region is mallee-heath; this covers about 58% of the region. Other significant vegetation forms include mallee (17%), scrub-heath (13%) and coastal dune scrub (4%). There is very little woodland; the only woodland communities are some of Eucalyptus marginata (jarrah), Corymbia calophylla (marri) and E. wandoo (wandoo) in valleys of the Stirling Range (1%); and some E. loxophleba (York gum) and Eucalyptus occidentalis (flat-topped yate) woodland in low-lying areas. There is also a small amount of low forest on islands off the coast. 1.7% of the region is unvegetated.
As of 2007, the Esperance Plains is known to contain 3506 indigenous vascular plant species, and a further 294 naturalised alien species. The
Land use
Approximately 87% of the Esperance Plains region falls within what the
More than half of the remaining vegetation is now in
Biogeography
The first biogeographical regionalisation of Western Australia, that of
In 1980, John Stanley Beard published a phytogeographical regionalisation of the state based on data from the Vegetation Survey of Western Australia. This new regionalisation included a district that is essentially identical with the present-day Esperance Plains region, which Beard named "Eyre Botanical District" in honour of Edward John Eyre, first explorer of the area. By 1984, Beard's phytogeographic regions were being presented more generally as "natural regions", and as such were given more widely recognisable names. Thus the "Eyre Botanical District" became "Esperance Plains".
When the IBRA was published in the 1990s, Beard's regionalisation was used as the baseline for Western Australia. The Esperance Plains region was accepted as defined by Beard, and has since survived a number of revisions. Since Version 6.1, Esperance Plains is divided into two subregions, Fitzgerald and Recherche.
Under the
References
- ^ Beard, J. S. and B. S. Sprenger (1984). Geographical Data from the Vegetation Survey of Western Australia. Occasional Paper No. 2.
- Australian Government. Archived from the originalon 5 September 2006. Retrieved 31 January 2007.
- ^ a b c Beard, J. S. (1980). "A new phytogeographic map of Western Australia". Western Australian Herbarium Research Notes (3): 37–58.
- ^ "Averages for ESPERANCE". Bureau of Meteorology. Retrieved 7 February 2007.
- ^ "Florabase". Western Australian Herbarium, Department of Environment and Conservation, Government of Western Australia. Retrieved 31 January 2007.
- ^ Department of Agriculture and Food, Government of Western Australia. Archived from the original on 25 August 2006. Retrieved 31 January 2007.)
{{cite web}}
: CS1 maint: multiple names: authors list (link - ^ Jarvis, N. T., ed. (1979). Western Australia: An Atlas of Human Endeavour: 1829–1979. Government of Western Australia.
- ^ "Priority Bioregions for Developing National Reserve System". Department of Environment and Water Resources, Australian Government. Archived from the original on 3 July 2007. Retrieved 8 February 2007.
Further reading
- Hogarth, Valerie A. (1966). The Esperance plains research station and the development of the Esperance plains 1950-1966. Unpublished manuscript, lodged at the Battye Library.
- Thackway, R and I D Cresswell (1995) An interim biogeographic regionalisation for Australia : a framework for setting priorities in the National Reserves System Cooperative Program Version 4.0 Canberra : Australian Nature Conservation Agency, Reserve Systems Unit, 1995. ISBN 0-642-21371-2
- Young, Jennifer (2000). Hakeas of Western Australia: botanical districts of Roe and Eyre, the Mallee and the Esperance Plains. West Perth, Western Australia: J. Young. ISBN 0-9585778-1-1.