Carrabungla (Ca)

A study of the land in the Catchment of Gippsland Lakes - Vol 2 - land system Carrabungla- geo

Area: 169 sq. km (0.9%)

This land system occurs mainly on a variety of acidic, volcanic rocks, including the Wellington Rhyolites and the Snowy River Volcanics. The terrain is mountainous with steep, rocky slopes and a ridge-and-ravine topography. In these respects the land is similar to Elizabeth land system, but Carrabungla occurs where it is much drier, mostly at lower elevations. Small levees and alluvial flats, similar to those in Walnut land system. occur occasionally along a few major st^reams, notably Wilkinson Creek.

The shallow soils reflect a combination of dry climate, steep slopes and parent materials that are resistant to weathering. Leaching of bases has produced moderately-acidic soils. Surface soils have a crumb structure while the subsoils are often apedal.

The vegetation is mainly open forest II, often shrubby with sparse ground cover. Forests with slightly denser understoreys occur where moisture supply is greater. due to altitude, aspect or protection by adjacent slopes.

A study of the land in the Catchment of Gippsland Lakes - Vol 2 - land system Carrabungla- image

A steep rocky slope with drier vegetation and patches of bare earth and litter characteristic of Carrabungla land system.

CLIMATE Rainfall, mean (mm) Temperature, mean (°C) Seasonal growth limitations	Annual 700) - 1200); lowest January or February (40 - 80), highest October (100) - 150) Annual 8 - 12; lowest July (3 - 7), highest February (16 - 20) Temperature <10°C (av.): May - September Rainfall < potential evapotranspiration: December – February
GEOLOGY Age, lithology	Devonian rhyolites, rhyodacites (Wellington Rhyolites, Snowy River Volcanics); minor Silurian intercalated siltstones, conglomerates, sandstones and basalts
PHYSIOGRAPHY Landscape Elevation range (m) Relative relief (m) Drainage pattern Drainage density (km/km²)	Steep mountains with ridge-and-ravine topography 220 - 1000 140 - 600 Dendritic 1.4
PRESENT LAND USE	Mostly uncleared: hardwood forestry (minor timber products); apiculture (very limited); bush grazing of cattle (very limited)

A study of the land in the Catchment of Gippsland Lakes - Vol 2 - land system Carrabungla- graph

LAND COMPONENT Percentage of land system Diagnostic features	1 85 Slopes with very dry forest	2 15 Slopes with more vigorous forest, mostly on protected upper slopes
PHYSIOGRAPHY Slope %, typical and (range) Slope shape	30 - 40, (20 - 80) Straight but uneven	30 - 40, (20 - 50) Straight
SOIL
Parent material	Mainly rhyolite and rhyodacite	Mainly rhyolite and rhyodacite
Description	Dark brown sandy loam to sandy clay loam grading into dark reddish brown or brown sandy clay loam or clay; generally stony. Somewhat shallow	Dark greyish brown to black loam to sandy clay loam grading into dark reddish brown or brown sandy clay loam or clay loam; generally stony, somewhat shallow
Classification	Brown Earths, Lithosols Um l.42, Um4.23; also Um5.51, Gn2.81, Gn3.51	Brown Earths, Lithosols Um4.13. Um5.52. Uc6.14
Surface texture	Sandy loam to sandy clay loam	Loam to sandy clay loam
Surface consistence	Soft to slightly hard when dry, friable when moist	Soft when dry, friable when moist
Depth (m)	0.3 - 1.2	0.5 - 1.5
Nutrient status	Low to moderate	Low to moderate
Available soil water capacity	Low to moderate	Moderate
Perviousness to water	Moderate	Rapid
Drainage	Good	Good
Exposed stone (%)	10 - 80	0 - 20
Sampled profile number	12	-
NATIVE VEGETATION Structure of vegetation and characteristic species of dominant stratum (+ Predominant species)	Open forest II, sometimes shrubby: Mixed forests with composition and predominant species variable (one of which usually predominant), E. mannifera, E. goniocalyx, elevations. E. pauciflora: Xanthorrhoea	Open forest II, III, often shrubby: including E. dives, E. sieberi, E. macrorhyncha. E. consideniana E. polyanthemos, E. rubida, E. baxteri, E. muellerana and, at higher australis occurs occasionally

Disturbance	Affected process and trend	Primary resultant deterioration			Casual activities	Primary off-site process
Disturbance	Affected process and trend	Form	Susceptibility of components	Incidence with components	Casual activities	Primary off-site process
Alteration of vegetation: — reduction in leaf area, rooting depth and/or perenniality	Reduced transpiration, resulting in increased deep percolation.	Nutrient loss	Not determined	Not determined	Removal of trees	Increased movement of water to groundwater; increased base-flow of streams
Increased exposure of surface soil	Increased overland flow and soil detachment	Sheet and rill erosion	1.2; high	Not determined	Clearing, logging, burning, road building and other earth-moving activities	Increased flash flows and sediment load.
Increased physical pressure on soil	Increased compaction With reduced infiltration	Structure decline Sheet and rill erosion	12; low - moderate 1,2; high	Not determined Not determined	Loss of organic matter from topsoil As for sheet and rill erosion above	- Increased flash flows
Increased soil disruption	Increased soil break-up	Gully erosion	1.2; moderate	Not determined	As for sheet and rill erosion above	Increased sediment load.
Comments: No observations of deterioration

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