Soil/Landform Unit 2

Landform Unit Description

Scarps and steep slopes are very typical within this landscape	Area: 47 185 ha 3.53 % of CMA region
	This land unit is situated in the north of the Corangamite catchment (Midlands) within the Western Uplands and consists of rolling low hills. The broad rounded topography is in association with a Neogene capping of sands and other unconsolidated deposits, particularly in the south of the unit. The main vegetation classes of this rolling landscape includes Heathy Dry Forest, Grassy Dry Forest, Herb-rich Foothill Forest and Valley Grassy Forest. This unit, which is predominantly a single mass, forms part of the northern (and eastern) boundary of the Corangamite catchment with well defined dendritic drainage falling to the south. The broad crests may be associated with short steep slopes and the side slopes are rolling though some slopes have deep soil and others shallower. The upland basalts form a significant border. The soils generally have a significant silt component, are shallow and strongly acidic on crests and wetter areas, and are generally low in nutrients. They are susceptible to gully and sheet erosion in cleared areas.

Upper slopes leading to deeply dissected valleys and drainage depressions
	Plantation of Pinus radiata within a native vegetation stand at Garibaldi

Component	1	2	3	4	5	6
Proportion of soil-landform unit	20%	15%	35%	23%	2%	5%
CLIMATE Rainfall (mm)	Annual: 710
CLIMATE Rainfall (mm)	Annual: 710
Temperature (^oC)	Minimum 7, Maximum 18
Precipitation less than potential evapotranspiration	October-March
GEOLOGY Age and lithology	Cambro-Ordovician marine sandstone and shale, minor Quaternary basalt and Neogene clay, sand and gravel.
GEOLOGY Age and lithology
Geomorphology	2.1.1 Dissected Western Uplands associated with Palaeozoic sedimentary and metamorphic rocks
LANDUSE	Uncleared: Nature conservation; sport and recreation; residential development, softwood plantations. Cleared: Softwood plantation; residential developement; sheep and beef cattle grazing
LANDUSE
TOPOGRAPHY Landscape	Rolling low hills and ridges
TOPOGRAPHY Landscape	Rolling low hills and ridges
Elevation range (m)	180-670
Local relief (m)	100
Drainage pattern	Dendritic
Drainage density (km/km²)	3.1
Landform	Hills				Drainage line	Ridges
Landform element	Broad crests	Gentle plains and rises	Rolling hills	Moderately steep slopes	Drainage line	Ridge/ravine
Slope and range (%)	4(1-7)	4(2-7)	5(2-9)	11(3-15)	4(2-9)	25(0-50)
Slope shape	Convex	Convex	Convex	Straight	Concave	Convex
NATIVE VEGETATION Ecological Vegetation Class	Heathy Dry Forest (36.5%); Grassy Dry Forest (5.2%); Herb-rich Foothill Forest (2.6%); Valley Grassy Forest (2.5%); Creekline Herb-rich Woodland (1.2%); Plains Grassy Woodland (1.2%)
NATIVE VEGETATION Ecological Vegetation Class
SOIL Parent material	In situ weathered sandstone and shale	In situ weathered sandstone and shale	In situ weathered sandstone and shale	In situ weathered sandstone and shale	Alluvium colluvium clay, silt, sand and gravel	In situ weathered sandstone and shale
SOIL Parent material	In situ weathered sandstone and shale	In situ weathered sandstone and shale	In situ weathered sandstone and shale	In situ weathered sandstone and shale	Alluvium colluvium clay, silt, sand and gravel	In situ weathered sandstone and shale
Description (Corangamite Soil Group)	Acid and neutral mottled brown, grey or yellow texture contrast soils and shallow light texture soils (25)	Acid and neutral mottled brown, grey or yellow texture contrast soils (25,26)	Acid and neutral mottled brown, grey or yellow texture contrast soils (25,26)	Acid and neutral mottled brown, grey or yellow texture contrast soils and shallow light texture soils (25)	Acid and neutral mottled brown, grey or yellow texture contrast soils (26) and brown gradational soils (34)	Shallow light textured soils and acid and neutral mottled brown, grey or yellow texture contrast soils (25)
Soil type sites	CLRA53, CLRA58, BD10	BD13, CLRA54, BD10	CLRA53, CLRA58, BD13	CLRA53, CLRA58, BD10	BD13, CLRA54, CLRA15	CLRA53, CLRA58, BD10
Surface texture	Gravelly loam	Fine sandy loam to clay loam	Fine sandy loam to clay loam	Gravelly loam	Clay loam	Gravelly loam
Permeability	High	Moderate	Moderate	High	Moderate	High
Depth (m)	<0.1	<2	<1.5	<1.5	2	<0.7
LAND CHARACTERISTICS, POTENTIAL AND LIMITATIONS	Gentle slopes with low permeability leads to overland flow. This flow often creates sheet and rill erosion with major rainfall events. Leaching of salts also occur	Gentle slopes with low permeability lead to overland flow. This flow often creates sheet and rill erosion with major rainfall events. Leaching of nutrients and salts also occur.	Slopes and overland flow combine to increase the likelihood of leaching, sheet erosion and nutrient decline.	Steep slopes and overland flow combine to increase the likelihood of leaching, sheet erosion and nutrient decline	Moderate permeability soils. Overland flow often creates sheet and rill erosion wth major rainfall events. Waterlogging is periodic and gully erosion is most common here.	Steep slopes and overland flow continue to increase the likelihood of leaching, sheet erosion and nutrient decline.