Barongarook Land System

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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. radiata. E. 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.

A Study of land in the catchments of the Otway Range and adjacent plains - barongarook

Poor site drainage and low soil permeability lead to waterlogging
and pugging of the soil by stock in many parts of this land system.

Area: 92 km²	Component and its proportion of land system
Area: 92 km²	1 8%	2 55%	3 15%	4 15%	5 7%
CLIMATE Rainfall, mm	Annual: 100 – 900, lowest January (40), highest August (80)
Temperature, 0^oC	Annual: 13, lowest July (8), highest February (18)
	Temperature: less than 10^oC (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. radiata occasionally 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.