Soil/Landform Unit 62

Large parts of this soil-landform unit at Cape Otway have been cleared and provide rough grazing for cattle on native grasses

Area:

4866 ha

0.36% of CMA region

In the vicinity of Cape Otway and extending discontinuously to the west is an elevated plain of coastal dunes. The coastal margins of the plain are generally fronted by 100 m cliffs of calcarenite with possibly small primary dunes at the base of the cliffs. Behind the cliffs, the plain has an irregular dune topography that may extend several kilometres inland. The demarcation to other land systems is very sharp and easily defined. Woodlands of

Eucalyptus viminalis

with open grassy understoreys used to cover most areas, although shrubs resistant to salt and sand-laden winds formerly colonised the coastal localities. Most areas have been cleared for grazing, but the establishment of improved pastures presents difficulties. Overgrazing has resulted in severe wind erosion in some areas, and reclamation is difficult and expensive.

Tussock grassland with a richly diverse heath stratum
	Calcarenite cliffs at Cape Otway

Component	1	2	3	4	5	6
Proportion of soil-landform unit	6%	4%	20%	20%	10%	40%
CLIMATE Rainfall (mm)	Annual: 900-1100, lowest January (45), highest July (105)
Temperature (^oC)	Annual: 14, lowest July (10), highest February (18)
Seasonal growth limitations	Temperature: less than 10^oC (av.) July Precipitation: less than potential evapotranspiration late November-February
GEOLOGY Age and lithology	Recent sand and shell grit on Neogene calcarenite basement
Geomorphology	6.2.5 Alluvium, alluvial terraces, floodplains and coastal plains of the Sedimentry Western Plains, and 3.1.2 Deeply dissected upland ranges of the Southern Uplands
LANDUSE	Cleared areas: Beef cattle grazing on unimproved patures; mining of calcarenite; residential; active recreation Uncleared areas: Forest grazing of beef cattle; active and passive recreation; nature conservation; landscape conservation
TOPOGRAPHY Landscape	Elevated longitudinal coastal dunes at and to the west of Cape Otway
Elevation range (m)	0-155
Local relief (m)	15
Drainage pattern	Mainly absent; some dendritic areas
Drainage density (km/km²)	0.7
Landform	Foredunes	Cliffs	Longitudinal dunes		Interdune corridors	Inland dunes
Landform element			Windward slopes	Leewrd slopes	-
Slope and range (%)	20 (15-40)	65 (50-100)	25 (5-50)	20 (5-50)	3 (0-9)	25 (3-60)
Slope shape	Convex	Linear	Convex	Convex	Concave	Concave
NATIVE VEGETATION Structure	Tussock grassland	Open scrub	Open scrub	Woodland	Open forest	Woodland
Dominant species	Spinifex hirsutus, Scirpus nodosus, Calocephalus brownii	Casuarine stricta, Cassinia longifolia, Alyxia buxifolia	Alyxia buxifolia, Leucopogon parviflorus, Cassinia longifolia, Acacia verticillata, Leptospermum juniperinum, Helichrysum paraluon	Casuarine stricta, E. viminalis, Leucopogon parviflorus	E. obliqua, E. viminalis	E. viminalis
SOIL Parent material	Coarse sand, shell grit	Calcarenite, aeolian sand	Sand with calcarenite basement	Sand with calcarenite basement	Sand with calcarenite basement	Sand with calcarenite basement
Description (Corangamite Soil Group)	Yellow calcareous sand soils (12)	Yellow calcareous sand soils - discontinuous (12)	Brown calcareous sand soils (12)	Brown calcareous sand soils (12)	Red-yellow calcareous sand soils (12)	Red-yellow calcareous sand soils (12)
Soil type sites	CLRA41, CLRA44, OTR415	CLRA41, CLRA44, OTR415	OTR415	CLRA41, CLRA44, OTR415	CLRA41, CLRA44, OTR415	CLRA41, CLRA44, OTR415
Surface texture	Coarse sand	Coarse sand	Loamy sand	Loamy sand	Loamy sand	Loamy sand
Permeability	Very high	Very high	Very high	Very high	Very high	Very high
Depth (m)	>2	0.3	>2	>2	>2	1.9
LAND CHARACTERISTICS, POTENTIAL AND LIMITATIONS	Dunes inherently unstable due to cyclical marine erosion. Low fertility, low water holding capacity and vegetation sensitive to disturbance lead to wind erosion and leaching of nutrients	Weakly structured sand soils of low water holding capacity on steep slopes with vegetation sensitive to disturbance and salt pruning are pone to sheet erosion by wind and water.	Weakly structured soils with low water holding capacities, subjected to strong on-shore winds are prone to wind erosion. Low inherent fertility, high alkalinity and rapid leaching lead to nutrient decline.	Weakly structured sand soils with low water holding capacities are prone to wind erosion. Low inherent fertility, high alkalinity and rapid leaching lead to nutrient decline.	Low inherent fertility and high permeability lead to nutrient decline.	Weakly structured sand soils with low water holding capacities are prone to wind erosion. Low inherent fertility and high permeability lead to nutrient decline.

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