Salt Creek (SC)

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

Area: 194 sq. km (1.0%)

Salt Creek land system occurs in the main rain-shadow area of the lowlands to the east of Lake Glenmaggie, on hills and Eastern steep slopes cut into Tertiary and Pleistocene deposits. It is usually found along incised drainage lines but it also includes the dissected coastal edge of the Pleistocene plains mapped in Redgum 1 land system. The rounded hills with moderate slopes and a broad dissection pattern are similar to those in Anderson 1 and 2 and Stockdale land systems. However the vegetation of Anderson 1 or 2 does not contain redgums and in Stockdale the parent materials are sandier.

Clayey parent materials and duplex soils dominate and significant amounts of quartz gravels may occur in the upper horizons. Due to low rainfall and the lack of leaching the subsoils are commonly neutral to slightly alkaline at depth and may be susceptible to gullying. Some areas of deep sands occur.

The native vegetation, now almost entirely removed, was a grassy open forest II of E. tereticornis, sometimes accompanied by E. globoidea on areas of higher elevation, higher rainfall or better drainage.

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

Low rounded spurs produced by dissection of the Tertiary plateau

CLIMATE Rainfall, mean (mm) Temperature, mean (°C) Seasonal growth limitations	Annual 500 - 800; lowest July (30 - 50), highest October (50 - 80) Annual 12 - 14; lowest July (8 - 10), highest February (19 - 21) Temperature <10°C (av.): June - August Rainfall < potential evapotranspiration: November – March
GEOLOGY Age, lithology	Mainly Tertiary but some Pleistocene colluvial and alluvial deposits of gravels, sands, silts, clays; minor marine limestones (Seaspray Group)
PHYSIOGRAPHY Landscape Elevation range (m) Relative relief (m) Drainage pattern Drainage density (km/km²)	Hilly terrain or short relatively steep marginal slopes 0 - 120 10 - 60 Dendritic 1.7
PRESENT LAND USE	Cleared: grazing of sheep and beef cattle on improved pastures

A study of the land in the Catchment of Gippsland Lakes - Vol 2 - land system Salt Creek - cs

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

LAND COMPONENT Percentage of land system Diagnostic features	1 50 Short, steep slopes, often gravelly; minor cliffs	2 20 Gentle slopes	3 10 Drainage depressions	4 10 Steep slopes on limestone in lower parts of deep valleys	\ - Fans da10 dudror1
PHYSIOGRAPHY Slope %, typical and (range) Slope shape	10 - 20, (10 - 50) Straight	3 - 5, (1 - 10) Concave	2, (0 - 5) Straight to concave	12 - 18, (10 - 40) Straight or convex	10 - j Conca,e21
SOIL
Parent material	Gravel, sand, silt and clay		Alluvium	Limestone	Variable colluvium
Description	Dark greyish brown loamy sand to sandy clay loam topsoil, often gravelly; abrupt change to yellowish brown or reddish brown, blocky structured clay subsoil		Limited observations — pr over mottled greyish loam brown clay	Dark reddish brown clay loam to clay over red blocky alkaline clay; may be gravelly	Variable: includes deep pale coloured sands and mottled yellowish brown duplex soils
Classification	Soloths, Solodic Soils Dy2.21, Dy2.42, Dy3.21, Dy3.41, Dr3.21		Humic Gleys	Terra Rossa Soils	Earthy Sands, Solodic Soils Uc4.11, Dy3.22
Surface texture	Loamy sand to sandy clay loam		Probably silty loam to silty clay loam	Clay loam to clay	Variable
Surface consistence	Mostly slightly hard when dry, but hard for heavier soils		-	Friable to firm when moist	Variable
Depth (m)	>2.0		>2.0	0.3 - 1.0	>2.0
Nutrient status	Low to moderate		Low	Moderate	Variable
Available soil water capacity	Low		High	Moderate	Variable
Perviousness to water	Slow		Rapid	Moderate	Variable
Drainage	Mostly moderately good		Mostly poor	Good	Variable
Exposed stone (%)	0		0	0	0
Sampled profile number	-	62, 63	-	13	-
NATIVE VEGETATION Structure of vegetation and characteristic species of dominant stratum (+ Predominant species)	Grassy open forest II: Mostly E. tereticornis+, occasionally E. globoidea+ (better drained sites) or E. polyanthemos+; E. cypellocarpa and E. bridgesiana localities associated in some		Grassy open forest II: Limited data — probably E. tereticornis+ Clearing has made it difficult to determine if any other tree species predominant or associated

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 and leaching	Nutrient loss	1,2,4,5; low	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; high 2,5; moderate 3; low 4; moderate - high	Common: on cleared land	Clearing, cultivation, burning, overgrazing, road and dam building and other earth-moving activities, rabbit burrowing, trafficking by stock and vehicles.	Increased flash flows and sediment load.
Increased physical pressure on soil	Increased compaction With Reduced infiltration	Structure decline Sheet and rill erosion	1,2,5; low 3; high 4; moderate 1; high 2,5; moderate 3; low 4; moderate - high	Uncommon Common: on cleared land	Increased trafficking, cultivation, overgrazing, export of organic matter As for sheet and rill erosion above	- Increased flash flows
Increased soil disruption	Increased soil break-up	Gully erosion	1; moderate - high 2; moderate 3,4,5; low	Uncommon: but with severe local occurrences	As for sheet and rill erosion above	Increased sediment load.
Comments: -

Page top