Profile

Barongarook

Area: 92 km2

Component and its proportion of land system

1
8%

2
55%

3
15%

4
15%

5
7%

CLIMATE
Rainfall, mm

Annual: 100 – 900, lowest January (40), highest August (80)

Temperature, 0oC

Annual: 13, lowest July (8), highest February (18)

Temperature: less than 10oC (av.) June – August

Precipitation: less than potential evapotranspiration late October – early April

GEOLOGY
Age, lithology

Pliocene unconsolidated clay, silt and sand

Recent sand veneer

TOPOGRAPHY
Landscape

Gently undulating to rolling plain in the western parts of the Barwon catchment

Elevation, m

120 –280

Local relief, m

30

Drainage pattern

Dendritic

Drainage density, km/km2

1.2

Land form

Undulating plan

Land form element

Steep slope

Crest, upper slope

Upper and middle slope

Lower slope

Drainage line

Slope (and range), %

25 (15-40)

5 (0-10)

5 (0-10)

7 (1-15)

1 (10-2)

Slope shape

Linear

Convex

Convex

Linear

Concave

NATIVE VEGETATION
Structure

Open forest

Open forest

Open forest

Woodland

Woodland

Dominant species

E. obliqua, E. radiata, 
E. viminalis

E. obliqua, E. radiata,occasionally E. ovata, 
E. viminalis

E. radiata, E. obliqua, 
E. nitida

E. radiata, E. nitida

E. ovata, E. radiataoccasionally 
E. aromaphloia

SOIL
Parent material

Clay, silt and sand

Clay, silt and sand

Clay, silt and sand with quartz sand veneer

Clay, silt and sand with quartz sand veneer

Alluvium

Description

Yellow gradational soils, weak structure

Mottled yellow and red gradational soils

Grey sand soils, structured clay underlay

Grey sand soils, weakly structured clay underlay

Mottled yellow and grey gradational soils

Surface texture

Sandy loam

Loam

Sandy loam

Sandy loam

Loam

Permeability

High

Moderate

Low

Low

Moderate

Depth, m

>2

>2

>2

>2

>2

LAND USE

Cleared areas: Sheep and beef cattle grazing; dairy farming.
Uncleared areas: Hardwood forestry for sawlogs, post and poles; nature conservation; active and passive recreation; softwood forestry; forest grazing.

SOIL DETERIORATION HAZARD
Critical land features, processes, forms

Steeper slopes with weak-structured surfaces are prone to sheet erosion.

Low inherent fertility and phosphorus fixation lead to nutrient decline.

Low inherent fertility with leaching of permeable surface horizons lead to nutrient decline.

Low permeability and seasonal perched water table lead to waterlogging and soil compaction.

High seasonal water table leads to waterlogging and soil compaction.

 

North of Forrest and extending towards Colac, undulating plains with often deeply weathered soils are found. The geology is mainly Tertiary clay with minor outcrops of sand. Redistribution of surface sand has resulted in polygenetic soils over much of the landscape, with weak hardpan development and impeded drainage. Surface soils seem to be naturally low in plant nutrients.

Many areas remain uncleared and support open forests dominated by Eucalyptus obliqua and E. radiataE. baxteri is notably absent in this slightly drier region. Other areas have been cleared for agriculture or converted to pines. The main hazards to land use are loss of soil structure, by compaction, and leaching of nutrients.

DPI website 2012, http://vro.dpi.vic.gov.au/dpi/vro/coranregn.nsf/pages/corangamite_landsystems_barongarook

Bioregion – Otway Plains, Warrnambool Plains and Otway Ranges, Some High and Medium Native Veg Conservation Significance (CCMA 2006)