Jamieson (Jn)

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

Area: 109 sq. km (0.8%)

During late Tertiary and Pleistocene times major rejuvenation of drainage and hillslopes occurred through most of the East Victorian Uplands. However, some north-south trending interfluves have not yet been dissected by the modern drainage network and prior landscape residuals, probably pre-dating the Older Volcanics, are preserved. Those mapped in Jamieson land system are relatively undissected plateaux, mainly on Ordovician sediments, at high elevations but below the subalpine tract. Residuals within the subalpine tract are in Bennison land system. More dissected residuals are in Bulltown Spur land system and those with denser, more-humid forests in Wellington land system.

The dominant gentle slopes reduce natural erosion rates and relatively deep soils have resulted from the weathering of moderately-resistant parent rocks under high rainfall and a cool climate. The soils tend to have a well-developed, fine structure and are moderately to strongly acidic.

The dominant vegetation is open forest II or III, often shrubby or layered, with ferny open forest I or sedgey woodland I on valley floors.

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

Steeper, timbered slopes typical of the peripheral sloping areas

CLIMATE Rainfall, mean (mm) Temperature Seasonal growth limitations, mean (°C)	Annual 800 - 1400; lowest January or February (50 - 90), highest August or September (120 - 180) Annual 8 - 12; lowest July (3 - 7), highest February (16 - 20) Temperature <10°C (av.): April - October Rainfall < potential evapotranspiration: December - February; occasional winter snow
GEOLOGY Age, lithology	Mainly Ordovician mudstones and sandstones
PHYSIOGRAPHY Landscape Elevation range (m) Relative relief (m) Drainage pattern Drainage density (km/km²)	Relatively undissected prior landscape remnants, mainly pre-dating the Older Volcanics 400 – 1360 40 – 320 Dendritic 1.1
PRESENT LAND USE	Uncleared: hardwood forestry (variable timber); bush grazing of cattle; apiculture

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

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

LAND COMPONENT Percentage of land system Diagnostic features	1 70 Undulating and sloping plateaux remnants with less humid forest then in component 3	2 15 Peripheral steeper slopes with less humid forest than in component 3	3 10 Protected slopes with vigorous humid forest	4 5 Valley flats
PHYSIOGRAPHY Slope %, typical and (range) Slope shape	8-15 (0-20) Straight or slightly convex	25-30 (20-40) Convex	15-25 (10-40) Straight	<5 (0-10) Concave, straight
SOIL
Parent material	Mudstone, sandstone; some metamorphic rock			Colluvium and locally derived alluvium
Description	Black to dark brown loam to clay loam grading into reddish brown or brown loam to light clay, acid and usually finely structured throughout; sometimes shallow and stony, particularly in component 2.		Limited observations – as in components 1 and 2 but thicker dark coloured topsoil; shallow soil less common	Dark greyish brown to dark grey sandy loam to sandy clay loam; mottled subsoil
Classification	Red and Brown Earths; less commonly, Lithosols Gn2.11, Gn2.21, Gn4.14, Um6.13, Um6.24, Um5.52		Krasnozems Gn4.11	Alluvial Soils; possibly Humic Gleys Um6.23, Gn4.51
Surface texture	Loam to sandy clay loam		Loam to sandy clay loam	Sandy loam to sandy clay loam
Surface consistence	Friable to firm when moist	Friable to firm when moist	Very friable when moist	Variable
Depth (m)	1.2-1.8	<0.8	>1.2	>2.0
Nutrient status	Low to moderate		Low to moderate	Low to moderate
Available soil water capacity	Moderate		Moderate	High
Perviousness to water	Rapid		Rapid	Rapid
Drainage	Good		Good	Poor to somewhat poor
Exposed stone (%)	Usually 0		0	0
Sampled profile number	-		36	-
NATIVE VEGETATION Structure of vegetation and characteristic species of dominant stratum (+ Predominant species)	Open forest II, III, often shrubby or layered: E. pauciflora and E. rubida, with or without E. dives, at highest elevations; elsewhere, pure or mixed stands with species including E. dives, E. rubida, E. obliqua, E. baxteri		Limited observations – probably layered open forest III: Higher elevations – E. delegatensis+; with or without E. rubida+ Lower elevations – E. obliqua+, with or without E. regnans	Sedgey woodland I: E. camphora, Carex appressa Occasional fern open forest I: E. neglecta

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	1,3; low 2; moderate	Not determined	Clearing, logging, burning, road building activities, trafficking by stock and vehicles.	Increased flash flows and sediment load. and other earth-moving
Increased physical pressure on soil	Increased compaction With Reduced infiltration	Structure decline Sheet and rill erosion	1,2; low 3,4; moderate – high 1,3; low 2; moderate	Not determined Not determined	Increased trafficking, 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; low 2,3; moderate	Not determined	As for sheet and rill erosion above	Increased sediment load.
Comments: No observations of soil deterioration

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