Redgum 2 (R2)

A study of the land in the Catchment of Gippsland Lakes - Vol 2 - land system Redgum2- geo

Area: 331 sq. km (1.6%)

Redgum 2 also occurs on the earlier Pleistocene terraces and more distal parts of the Tertiary flood plain deposits, but differs from Redgum 1 land system in that it has suffered very little dissection. The original land surface is usually unchannelled and forms almost flat plains, commonly with low gilgai micro-relief.

Well-developed, duplex soils have formed on the flat terrain. Varying amounts of rounded gravels can occur within the profile. Erosion hazards are slight, but extensive clearing may aggravate waterlogging, particularly during winter and spring. The Redgum 2 land system is judged to have a moderate salinity hazard.

The native vegetation, mainly an E. tereticornis grassy open forest II, is now mostly cleared.

A study of the land in the Catchment of Gippsland Lakes - Vol 2 - land system Redgum2- image

Flat plain with reeds growing in the wetter depressions. The dead trees are indicative of the decline in the Eucalypt tereticornis (forest red gum) woodland which once covered most of this plain

CLIMATE Rainfall, mean (mm) Temperature, mean (°C) Seasonal growth limitations	Annual 500 - 800; lowest July or August (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	Lower Pleistocene gravels, sands, silts and clays; minor Tertiary alluvium
PHYSIOGRAPHY Landscape Elevation range (m) Relative relief (m) Drainage pattern Drainage density (km/km²)	Almost flat plains, residual Pleistocene terraces 20 - 90 0 - 5 Dendritic <0.1
PRESENT LAND USE	Approximately half the area cleared: grazing of sheep and cattle; cropping (limited) Uncleared portion: firewood extraction (limited)

A study of the land in the Catchment of Gippsland Lakes - Vol 2 - land system Redgum2- cs

A study of the land in the Catchment of Gippsland Lakes - Vol 2 - land system Redgum2- graph

LAND COMPONENT Percentage of land system Diagnostic features	1 95 Almost flat plains and slightly depressed areas with poorer drainage	2 5 Incised drainage depressions and bordering slopes
PHYSIOGRAPHY Slope %, typical and (range) Slope shape	1, (0 - 4) Straight	Variable, (0 - 10) Concave
SOIL
Parent material	Clay, silt, sand and gravel, often stratified	Locally derived alluvial lag deposits
Description	Very dark greyish brown sandy loam to sandy clay loam topsoil grading into greyish brown similarly textured subsurface soil, often mottled; abrupt change to strongly mottled yellowish brown clay subsoil, commonly alkaline at depth. Varying gravel content	No observations — probably mostly undifferentiated medium textured dark greyish brown topsoil, brown subsoil and appreciable gravel content
Classification	Solodic Soils, Solodized Solonetz Soils, Soloths Dy3.23, Dy3.22, Dy3.33, Dy3.21, Dy3.13, Dy3.31, Dy2.43	-
Surface texture	Sandy loam to sandy clay loam	-
Surface consistence	Slightly hard to hard when dry	-
Depth (m)	>2.0	-
Nutrient status	Low	>2.0
Available soil water capacity	Low to moderate	-
Perviousness to water	Slow	-
Drainage	Mainly somewhat poor, in places poor	-
Exposed stone (%)	0	-
Sampled profile number	61, 64, 65	-
NATIVE VEGETATION Structure of vegetation and characteristic species of dominant stratum (+ Predominant species)	Grassy open forest II: Mainly E. tereticornis+ Occasionally E. globoidea or E. melliodora (Heyfield, Seaton areas) predominant or associated Other species sometimes associated include E. bridgesiana, E. polyanthemos

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: a) increased deep percolation b) raised winter/spring watertable	Waterlogging Salting	1; moderate 1; moderate	Common: seasonally Common: localised areas	Removal of trees. Reduced plant-water use in catchment. Reduced plant water use in catchment	Increased movement of water to groundwater Increased salting in lower areas
Increased exposure of surface soil	Increased overland flow and soil detachment	Sheet and rill erosion	1; very low 2; low - moderate	Uncommon	Cultivating, overgrazing, road building and other earth-moving activities, rabbit burrowing, trafficking by stock and vehicles.	Increased run-on and sedimentation in lowest areas
Increased physical pressure on soil	Increased compaction With Reduced infiltration	Structure decline Waterlogging	1,2; low 1; low - moderate	Uncommon Common; localised areas	Increased trafficking, cultivation, overgrazing, export of organic matter As for structure decline above	- Increased run-on and ponding of water in low-lying areas
Increased soil disruption	Increased soil break-up	Gully erosion	2; low - moderate	Uncommon	As for sheet and rill erosion above	Increased sediment load and turbidity in steams
Comments: A salt-affected area occurs to the south of Rosedale; other occurrences are few and scattered.

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