Soil/Landform Unit 200

The Moolap Sunklands have a very diverse range of wildlife and habitats in this very unique wetlands within the Corangamite CMA region

Area:

7186 ha

0.54% of CMA region

Across the dissected sedimentary plains of the Western Plains are numerous swamps and closed depressions that host a wide variety of flora and fauna. These permanent swamps have been identified as occurring south of Geelong on Recent clay, sand and gravels, coastal sand dunes and minor basalt. Many of the swamps have been cleared previously with some untouched by land clearance. Vegetation classes of these swamps include Coastal Saltmarsh, Reed Swamp, Plains Freshwater Sedge Wetland, Cane Grass-lignum Halophyllic Herbland and Calcarenite Dune Woodland. Land use is mainly restricted to grazing owing to the waterlogged state of soils in most years. Soils include the grey cracking clays and sandy soils that reflect Recent

alluvium

deposits. While waterlogging is the major limitation, salinity is also expressed at the surface in many of these swamps as spiny rush.

Located west of Barwon Heads, this swamp forms part of the Moolap Sunklands. The vegetation most prominent here is the Reed Swamp class
	Reed swamp vegetation class of the Moolap Sunklands

Component	1	2	3	4
Proportion of soil-landform unit	2%	38%	40%	20%
CLIMATE Rainfall (mm)	Annual: 640
Temperature (^oC)	Minimum 9, Maximum 19
Precipitation less than potential evapotranspiration	October–March
GEOLOGY Age and lithology	Quaternary clay, sand and gravel, coastal sand dunes and minor basalt
Geomorphology	6.2.5 Alluvium, alluvial terraces, floodplains and coastal plains of the Sedimentary Western Plains
LANDUSE	Uncleared: Nature conservation; water supply Cleared: Cropping (cereal); sheep and beef cattle grazing
TOPOGRAPHY Landscape	Swamps and depressions associated with sedimentary plains
Elevation range (m)	4–148
Local relief (m)	1–2
Drainage pattern	Deranged
Drainage density (km/km²)	2.7
Landform	Alluvial plains
Landform element	Dune	Depressions	Swamp	Undulating plain
Slope and range (%)	2 (0–5)	1 (0–2)	1 (0–2)	2 (1–4)
Slope shape	Convex	Straight	Straight	Convex
NATIVE VEGETATION Ecological Vegetation Class	Coastal Saltmarsh (20.5), Reed Swamp (8.3%), Plains Freshwater Sedge Wetland (1.3%), Cane Grass-Lignum Halophyllic Herbland (1.2%), Calcarenite Dune Woodland (1.1%)
SOIL Parent material	Aeolian sediments; clay silt and sand	Sedimentary derived alluvium; clay silt and sand	Sedimentary derived alluvium; clay silt and sand	Sedimentary derived alluvium; clay silt and sand
Description (Corangamite Soil Group)	Grey and black clays (31)	Grey and black clays (31)	Grey and black clays (31)	Grey and black clays (31)
Soil type sites	SW37, CLRA15, CLRA35	SW37, CLRA5, SW39	SW37, CLRA15, CLRA35	SW37, CLRA15, CLRA35
Surface texture	Light clay	Light clay	Light clay	Light clay
Permeability	High	Low	Low	Low
Depth (m)	>2	>2	>2	>2
LAND CHARACTERISTICS, POTENTIAL AND LIMITATIONS	Uniform expansive clays, high to very high water holding capacity and nutrient holding capacity depending on depth. Sodic subsoils, surface soils may be self-mulching. Low site drainage. Susceptibility to waterlogging.	Uniform expansive clays, high to very high water holding capacity and nutrient holding capacity depending on depth. Sodic subsoils, surface soils may be self-mulching. Low site drainage. Susceptibility to waterlogging.	Uniform expansive clays, high to very high water holding capacity and nutrient holding capacity depending on depth. Sodic subsoils, surface soils may be self-mulching. Very low site drainage. Susceptibility to waterlogging.	Uniform expansive clays, high to very high water holding capacity and nutrient holding capacity depending on depth. Sodic subsoils, surface soils may be self-mulching. Low site drainage. Susceptibility to waterlogging.

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