Soil/Landform Unit 67

Pocket of cleared land on an upper slope overlooking uncleared open forest

Area:

3286 ha

0.25% of CMA region

Deeply dissected hills north and west of Gellibrand possess Paleogene sands and clays on the higher parts of the landscape and outcrops of

Cretaceous

sediments on the steeper and lower parts. The soils become heavier and more fertile on the Cretaceous sediments and this is reflected in the occurrence of

Eucalyptus obliqua

and

E. viminalis

open forests with dense understoreys. Most areas are too steep for agriculture, and remain forested with native hardwoods or pines. Clearing operations necessary for pine conversion and hardwood harvesting may result in severe scour gullying and landslips on the steep parts of the landscape. Access tracks are difficult to site and prone to scouring. In general, careful land management is required.

The steep land and irregular nature of the terrain makes these areas difficult to manage
	Low woodland of the gentle slopes

Component	1	2	3	4	5
Proportion of soil-landform unit	25%	20%	40%	9%	6%
CLIMATE Rainfall (mm)	Annual: 900-1050, lowest January (45), highest August (130)
Temperature (^oC)	Annual: 12, lowest July (7), highest February (18)
Seasonal growth limitations	Temperature: less than 10^oC (av.) June-August Precipitation: less than potential evapotranspiration early November-late March
GEOLOGY Age and lithology	Paeogene unconsolidated marine sand, silt and clay		Lower Cretaceous sandstone and mudstone	Paleogene unconsolidated carbonaceous sand, silt and clay
Geomorphology	3.2.2 Dissected upland ranges of the Southern Uplands
LANDUSE	Uncleared areas: Hardwood forestry for posts and ples, some sawlogs on better soils; nature conservation; water supply; gravel extraction; softwood plantations Cleared areas: Beef cattle and sheep grazing on mainly unimproved pastures; water supply
TOPOGRAPHY Landscape	Deeply dissected hills abutting the Gellibrand River to teh west of Love Creek
Elevation range (m)	60-290
Local relief (m)	95
Drainage pattern	Dendritic with some radial areas
Drainage density (km/km²)	2.2
Landform	Hills
Landform element	Crest and upper slope	Slope	Steep lower slope	Gentle slope	Broad crest and upper slope
Slope and range (%)	20 (5-35)	30 (20-35)	45 (30-65)	15 (4-20)	13 (1-20)
Slope shape	Convex	Convex	Linear	Concave	Convex
NATIVE VEGETATION Structure	Woodland	Open forest	Open forest	Low woodland	Woodland
Dominant species	E. nitida, E. radiata, E. baxteri	E. baxteri, E. obliqua	E. obliqua, E. ovata, E. viminalis, E. aromaphloia on southern aspect E. cypellocarpa	E. nitida, E. ovata, E. baxteri	E. radiata, E. baxteri, E. nitida, E. obliqua
SOIL Parent material	Sand	Sand, silt and clay	In situ weathered rock	Sand	Quartz gravel, some clay, sand and silt
Description (Corangamite Soil Group)	Grey sand soils (29)	Brown, grey or yellow gradational soils, weak structure (29, 17)	Brown gradational soil (7)	Grey sand soils with hardpans (29)	Stony brown, grey or yellow gradational soils (29)
Soil type sites	OTR742	OTR479, OTR741	OTR414, COF01, OTR736	OTR608	-
Surface texture	Loamy sand	Sandy loam	Loam	Loamy sand	Loamy sand
Permeability	Very high	High	Moderate	Very low	Very high
Depth (m)	>2	>2	0-9	0-5	>2
LAND CHARACTERISTICS, POTENTIAL AND LIMITATIONS	Low inherent fertility and high permeability lead to leaching and nutrient decline. When disturbed and compacted, steeper slopes are prone to sheet, rill and gully erosion (scouring).	Low inherent fertility and high permeability lead to nutrient decline. Weakly structured surface soils are prone to sheet erosion on steeper slopes.	Steeper slopes are prone to sheet and rill erosion. Clay subsoils subject to periodic saturation are prone to landslips.	Low inherent fertility leads to nutrient decline. Hardpans restrict vertical drainage leading to seasonal waterlogging.	Very low inherent fertility and high permeability lead to leaching and nutrient decline.

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