Your gateway to a wide range of natural resources information and associated maps

Victorian Resources Online

Wellington (Wn)

A study of the land in the Catchment of Gippsland Lakes - Vol 2 - land system Wellington- geoArea: 418 sq. km (2.0%)

Wellington land system occurs below the subalpine tract in the East Victorian Uplands, on partially-dissected, prior-landscape remnants that probably predate the Older Volcanics. These remnants have not yet been affected by erosion associated with entrenchment of the modern drainage network. The topography is hilly to undulating and plateau tops are almost accordant. Lithology varies but acid volcanics, metamorphic rocks and slightly-weathered, sedimentary rocks are well represented. Jamieson land system is also mapped on hilly to undulating, prior land surfaces that probably predate the Older Volcanics and which are below the subalpine tract. Plateaux in Wellington land system differ from those in Jamieson, having greater relief and being more humid and densely forested, particularly in the west. The soils have developed on moderately steep slopes and under high rainfall on a variety of parent rocks. There is a predominance of gradational, leached, acidic soils of intermediate texture, moderately to strongly structured throughout. Where slopes are steeper, or the rocks are more resistant to weathering, the soils tend to be shallow and uniform in texture.

Most of the area is covered by open forest II or III, often shrubby or layered, with less vigorous stands on shallow, rocky soils.
A study of the land in the Catchment of Gippsland Lakes - Vol 2 - land system Wellington- image
View across to the gentle to moderate slopes of the plateau suirface

CLIMATE
Rainfall, mean (mm)
Temperature, mean (C)
Seasonal growth limitations

    Annual 900 - 1600; lowest January or February (50 - 90), highest August or September (120 - 180)

    Annual 8 - 12; lowest July (3 - 7), highest February (16 - 20)
    Temperature <10C (av.): April - October
    Rainfall < potential evapotranspiration: February; frequent winter snow
GEOLOGY
    Age, lithology
    Variable; mainly Ordovician undifferentiated sandstones, mudstones and shales, often metamorphosed; Devonian rhyolites and rhyodacites
PHYSIOGRAPHY
Landscape
Elevation range (m)
Relative relief (m)
Drainage pattern
Drainage density (km/km2)

    Partially dissected hilly to undulating prior landscape residuals

    560 - 1460
    100 - 500
    Dendritic
    0.9
PRESENT LAND USE
    Uncleared: hardwood forestry (mostly ash timber with some timber for general construction); bush grazing of cattle; apiculture

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

LAND COMPONENT
Percentage of land system
Diagnostic features
1
40
Moderate slopes with deeper
soils; sedimentary or igneous
rocks
2
40
Gentle slopes with deeper soils;
sedimentary or igneous rocks
3
15
Slopes of any gradient with
shallow rocky soils; mainly
Ordovician sediments
4
5
Drainage depressions,
often with minor swamps
PHYSIOGRAPHY
Slope %, typical and (range)
Slope shape
20 - 30, (15 - 50)
Straight to concave
5 - 10, (2 - 15)
Mainly concave
20 - 30, (15 - 50)
Straight to convex
Variable, (10 - 40)
Straight, some concave
SOIL
Parent material
Variable; mostly rhyolite, rhyodacite, and siltstone; minor granodiorite
Sandstone, mudstone and shale
Colluvium and alluvium
Description
Mainly dark brown sandy clay loam grading into yellowish brown to reddish brown sandy clay loam to light clay with fine structure, commonly stony; topsoil often deep
Mainly shallow brown stony sandy
loam to sandy clay loam
Limited observations — probably
dark, undifferentiated with much
organic matter and variable
texture
Classification
Red and Brown Earths; Krasnozems
Gn4.11, Gn4.31, Gn3.11, Gn2.11, Gn4.81, Um4.21, Um6.11, Um6.12, Um6.23, Um7.11
Lithosols, Brown Earths
Um-, Um6.23, Uc1.44
Humic Gleys
Uc1.24
Surface texture
Sandy clay loam, sometimes loam or clay loam
Sandy loam to sandy clay loam
-
Surface consistence
Soft when dry, friable when moist
Friable when moist
-
Depth (m)
Generally 1.0 - 2.0
<0.8
-
Nutrient status
Low to moderate
Low
Probably low
Available soil water capacity
Moderate
Low
Probably moderate
Perviousness to water
Rapid
Slow to moderate
Probably rapid
Drainage
Good
Good
Very poor to poor on alluvium;
better on colluvium
Exposed stone (%)
Often 0, but 5 - 30 not uncommon
Probably >10
Probably 0
Sampled profile number
32
-
-
-
NATIVE VEGETATION
Structure of vegetation and
characteristic species of
dominant stratum
(+ Predominant species)
Mostly open forest II, III, often shrubby or layered:
Mixed or pure stands with composition dependent on elevation and aspect;
Higher elevations — E. delegatensis, E. dives, E. pauciflora, E. radiata, E. rubida
Lower elevations — E. cypellocarpa, E. dives, E. obliqua, E. regnans,
Open forest I or II:
species including — and occasionally E. nitens, E. viminalis
Limited observations — probably open forest I of Leptospermum grandifolium

Disturbance
Affected process and trend
Primary resultant deterioration
Causal activities
Primary off-site process
Form
Susceptibility of
components
Incidence within
components
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




Not determined




Soil creep




Soil creep




Not determined




1; moderate




1; moderate




Not determined




Uncommon: observed occasionally on steep slopes as a natural process

Uncommon: observed occasionally on steep slopes as a natural process




Removal of trees




Usually after the removal of trees from steeper land


Accelerated by major disturbance to the native vegetation




Increased movement of water to groundwater; increased base-flow of streams

Increased sediment load




Increased sediment load

Increased exposure of surface soilIncreased overland flow and soil detachmentSheet and rill erosion1,3; moderate
2; low - moderate
Uncommon: locally severeClearing, logging, burning, overgrazing, road building and other earth-moving activities, trafficking by stock.Increased flash flows and sediment load.
Increased physical pressure on soilIncreased compaction

With

Reduced infiltration
Structure decline



Sheet and rill erosion
1,2; moderate
3; low
4; moderate – high

1,3; moderate
2; low - moderate
Uncommon



Uncommon: locally severe
Increased trafficking, export of organic matter


As for sheet and rill erosion above
-



Increased flash flows
Increased soil disruptionIncreased soil break-upGully erosion1,2,3,4; moderateUncommonAs for sheet and rill erosion aboveIncreased sediment load.
Comments: -
Page top