Glenmaggie (Ge)

Area: 174 sq. km (0.9%)

This land system is mapped on hilly terrain with Carboniferous sediments and occurs close to the lower margin of the East Victorian Uplands and along some of the major river valleys. The ridge-and-ravine topography has moderately long, steep slopes prone to soil creep and rock outcrop is common. Small alluvial terraces similar to those mapped in Walnut land system occur in the major drainage corridors, for example along the Avon River. Glenmaggie is similar to Avon and Turton land systems in that it occurs on similar lithology in the less-humid areas, but is intermediate in relief and degree of dissection. Turton land system has the greatest relief and dissection and Avon the least.

Shallow, stony soils dominate because of high, natural erosion rates on the steep slopes, slow rates of soil formation on the siliceous, sedimentary parent rocks and moderate rainfall. The soils are acidic and tend to have little structural development except in the topsoils and those subsoils that are clayey.

Open forest II dominates with some open forest III on protected hill slopes and in major drainage corridors.

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

The lower relief and more gentle, cleared slopes of Glenmaggie land system contrast with the higher relief and steeper, forested slopes of Turton land system

CLIMATE Rainfall, mean (mm) Temperature, mean (°C) Seasonal growth limitations	Annual 600 - 900; lowest July (40 - 70), highest October (60 - 90) Annual 8 - 12; lowest July (3 - 7), highest February (16 - 20) Temperature <10°C (av.): May - September Rainfall < potential evapotranspiration: November – March
GEOLOGY Age, lithology	Carboniferous siltstones, minor sandstones and conglomerates, often red (Snowy Plains Formation)
PHYSIOGRAPHY Landscape Elevation range (m) Relative relief (m) Drainage pattern Drainage density (km/km²)	Hilly terrain with ridge-and-ravine topography 150 - 520 80 - 360 Dendritic 1.8
PRESENT LAND USE	Mostly uncleared: hardwood forestry (mainly minor products); apiculture (limited); bush grazing of cattle Minor proportion cleared: grazing of beef cattle and sheep

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

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

LAND COMPONENT Percentage of land system Diagnostic features	1 75 Exposed slopes, often with outcrops of sub-horizontal beds	2 15 Protected slopes	3 10 Discontinuous terraces of major drainage corridors
PHYSIOGRAPHY Slope %, typical and (range) Slope shape	25 - 35, (20 - 60) Straight	25 - 35, (20 - 60) Straight	<5, (0 - 10) Mostly straight
SOIL
Parent material	Siltstone, sandstone and conglomerate		Stony alluvium
Description	Limited observations — mostly shallow and stony with very dark greyish brown sandy loam topsoil merging into yellowish brown or reddish brown sandy loam; topsoil sometimes resting on yellowish brown clay		Limited observations — little differentiated and stratified soils varying from sandy loam to clay loam, often stony
Classification	Lithosols, Brown Podzolic Soils Uc1.41, Uc4.13, Dy2.41		Alluvial Soils Um1.41
Surface texture	Mainly lighter textures, e.g. sandy loam		Variable
Surface consistence	Slightly hard when dry, friable to firm when moist		Variable
Depth (m)	Probably 0.5 - 0.8, but deeper in pockets		>2.0
Nutrient status	Low to moderate		Low to moderate
Available soil water capacity	Moderate		Moderate
Perviousness to water	Moderate		Moderate
Drainage	Good		Mostly good
Exposed stone (%)	Variable; <50		<20
Sampled profile number	-		-
NATIVE VEGETATION Structure of vegetation and characteristic species of dominant stratum (+ Predominant species)	Open forest II: Mixed forests with variable composition — including E. macrorhyncha+, E. polyanthemos+, E. consideniana, E. muellerana, E. sieberi	Open forest II, III: Mixed forests with variable composition — including E. cypellocarpa+, E. globoidea+, E. polyanthemos+, E. goniocalyx	Shrubby open forest II, III: E. melliodora+ and/or E. viminalis+

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 — reduction in density of tree roots	Reduced transpiration, resulting in: a) increased deep percolation b) increased regolith wetness Decreased root-binding	Nutrient loss Soil creep Soil creep	Not determined 1,2; high 1,2; high	Not determined Common: on steep slopes Common: on steep slopes	Removal of trees Accelerated by clearing of native vegetation Accelerated by clearing of native vegetation	Increased movement of water to groundwater; increased base-flow of streams Increased sediment load Increased sediment load
Increased exposure of surface soil	Increased overland flow and soil detachment	Sheet and rill erosion	1,2; high	Common; on cleared land	Clearing, road 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	1,3; low 2; moderate 1,2; high	Not determined Not determined	Increased trafficking export of organic matter As for sheet and rill erosion above	- Increased flash flows
Increased soil disruption	Increased soil break-up	Gully erosion Streambank erosion	1,2; high 3; high	Common: locally severe in major drainage corridors Common: locally severe in major drainage corridors	As for sheet and rill erosion above As for sheet and rill erosion above	Increased sediment load. Increased turbidity of streams
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