Soil/Landform Unit 90

Private land is mainly used for pasture production in dairy. Much of this land abuts forests of the Otway Range.

Area:

5122 ha

0.38% of CMA region

Rolling hills with occasional steep slopes and broad drainage lines are found in the vicinity of Kawarren. The landscape has several components, including some areas of red stony brown gradational soils developed on outcrops of basalt. However, old soils on deeply weathered Paleogene clay and sand tend to dominate the landscape. Other soil-landforms with similar soils and parent material are found to the east and west of this unit. However, this unit is a rolling landscape whereas the others are gently undulating to flat. The Barongarook unit (Unit

) to the east has a slightly lower rainfall and

Eucalyptus baxteri

has not been observed in this area. Clearing has been common and the main land uses are dairy farming and grazing of beef cattle and sheep. Some forested areas, such as the old Beech Forest railway easement, are popular for bushwalking. Pine establishment is common on private land. Sheet erosion and landslips have occurred on steeper slopes.

Rolling slopes used for grazing and cropping
	Most of the cleared areas are used for dairy

Component	1	2	3	4	5
Proportion of soil-landform unit	15%	10%	60%	10%	5%
CLIMATE Rainfall (mm)	Annual: 850-1100, lowest January (40), highest August (120)
Temperature (^oC)	Annual: 12, lowest July (8), highest February (18)
Seasonal growth limitations	Temperature: less than 10^oC (av.) June-September Precipitation: less than potential evapotranspiration Novembr-March
GEOLOGY Age and lithology	Neogene marine and calcarenite; Paleogene marine carbonaceous clay, siltstone, sandstone and minor basalt
Geomorphology	3.3.2 Dissected low hills rolling hills of the Southern Uplands
LANDUSE	Uncleared areas: Hardwood forestry for sawlogs, posts and poles; softwood plantations; nature conservation; passive recreation; water supply; forest grazing Cleared areas: Beef and cattle and sheep grazing; dairy farming; water supply
TOPOGRAPHY Landscape	Rolliing hills in the northern upper reaches of the Gellibrand River catchment
Elevation range (m)	75-210
Local relief (m)	60
Drainage pattern	Dendritic with some radial areas
Drainage density (km/km²)	2.6
Landform	Hills				Valley floors
Landform element	Steep slope	Crest and upper slope	Crest and slope	Slope	-
Slope and range (%)	20 (10-45)	12 (3-15)	9 (1-15)	13 (6-15)	1 (0-2)
Slope shape	Linear	Convex	Convex	Linear	Concave
NATIVE VEGETATION Structure	Open forest	Woodland	Open forest	Open forest	Low woodland
Dominant species	E. obliqua, E. radiata, E. viminalis	E. radiata, E. obliqua, E. nitida, E. ovata	E. obliqua, E. radiata, E. viminalis, occasionally E. ovata	E. aromaphloia, E. obliqua, E. radiata, occasionally E. ovata	E. ovata, E. radiata, Melaleuca squarrosa
SOIL Parent material	Clay, silt and sand	Colluvial sand on unconsolidated clay	Clay, silt and sand	Clay, silt and sand	Alluvial clay, sand and silt
Description (Corangamite Soil Group)	Brown, grey or yellow gradational soils, weak structure (29, 17)	Grey sand soils, structured clay underlay (29)	Mottled brown, grey, yellow and red gradational soils (29, 17)	Yellow-brown gradational soils, coarse structure (29, 17)	Grey gradational soils (29)
Soil type sites	OTR497, OTR41	OTR737	OTR746	OTR750, SW32	SW33
Surface texture	Sandy loam	Sandy loam	Fine sandy loam	Fine sandy loam	Fine sandy loam
Permeability	High	Low	Moderate	Low	Very low
Depth (m)	>2	>2	>2	>2	>2
LAND CHARACTERISTICS, POTENTIAL AND LIMITATIONS	Clay subsoils on steep slopes subject to periodic saturation are prone to landslips. Steep slopes are prone to sheet and rill erosion.	Low subsoil permeabilities lead to seasonal waterlogging. Low inherent fertility and permeable surface horizons lead to nutrient decline.	Low inherent fertility and phosphorus fixation lead to nutrient decline.	Dispersible clay subsoils of low permeability are prone to gully erosion. Clay subsoils on steeper slopes subjec to periodic saturation are prone to landslips.	Low permeabilities and high watertables lead to seasonal waterlogging. High discharge rates along watercourses lead to some flooding and gully erosion.

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