The Shire of Kalamunda has a rich diversity of natural environments made up of streams, wetlands, forests and woodlands, with a unique display of endemic flora and fauna, all on the City’s doorstep. Nearly three quarters of the Shire still remains as natural bushland, which the Shire is committed to preserving and enhancing.
The natural environment is comprised of three distinctive landform types or geomorphic provinces, namely the Swan Coastal Plain, the Darling Scarp and Darling Plateau.
The Swan Coastal Plain extends westwards from the lower edge of the Darling Scarp is generally low relief terrain made up of alluvial, aeolian deposits, including the Guildford, Forrestfield and Southern river soil associations. In general, the soils become more fertile on the east of the Swan Coastal Plain in the zone of transition between the Swan Coastal Plain and the Darling Scarp, locally identified as the ‘foothills’. Wetlands can be found in low lying areas upon the Swan Coastal Plain and their water levels are often interlinked to underlying groundwater levels.
Swan Coastal Plain
The Swan Coastal Plain section of the Shire contains soil and vegetation associations as follows:
The Guildford classification unit is restricted to the south western coastal plain section of the Shire and consists of a flat alluvial plain containing gravelly yellow and brown duplex soils with sand and loam topsoils. The Guildford complex is described as a mixture of open forest to tall open forest of Marri - Corymbia calophylla, Wandoo - Eucalyptus wandoo, Jarrah - Eucalyptus marginata and woodland of Wandoo and rare occurrences of common name - Eucalyptus lane-poolei. Minor components include Flooded Gum - Eucalyptus rudis and Swamp Paperbark - Melaleuca rhaphiophylla.
The Southern River classification unit is characterised by sandplain with low dunes and many intervening swamps, iron and humus podzols, peats and clays and is found throughout High Wycombe, western parts of Forrestfield and Wattle Grove. This vegetation is described
as open woodland of Marri - Corymbia calophylla, Jarrah - Eucalyptus marginata and Banksia species with fringing woodland of Flooded Gum - Eucalyptus rudis and Swamp Paperbark - Melaleuca rhaphiophylla along creek beds.
View plants of the Guildford and Southern River complex
The Forrestfield classification unit comprises the laterised foothills of the Darling Scarp and is dominated by gravelly and sandy soils. The occurrence of imperfectly drained and duplex soil is common throughout this association, particularly in association with alluvial fans and drainage channels. This soil association occurs throughout Maida Vale and the central parts of Forrestfield and Wattle Grove. The Forrestfield complex vegetation ranges from open forest of Marri - Corymbia calophylla, Wandoo - Eucalyptus wandoo, Jarrah - Eucalyptus marginata to open forest of Marri, Jarrah, Sheoke - Allocasuarina fraseriana - Banksia species. Fringing woodland
of Flooded Gum appear in the gullies that dissect this landform.
View plants of the Forrestfield complex
The Swan classification unit is restricted to the northern tip of Gooseberry Hill and occurs as alluvial terraces with red earths and duplex soils. The unit is closely associated with the Helena River and is contained within the Kalamunda National Park.
View plants of the Swan complex
The Darling Scarp classification unit is characterised by moderately steep to very steep scarp hill slopes with shallow yellow-brownish earths and yellow duplex soils. Granite outcropping is common throughout this unit which occurs on the western portions of Gooseberry Hill, Kalamunda and Lesmurdie.
View plants of the Darling Scarp complex
The Darling Plateau covers the majority of the Shire and is dominated by lateritic uplands and duritic gravels and sands which form a gently undulating surface. The topography ranges from 50m AHD (Australian Height Datum) on the westerly fringe of the deeply dissected Darling Scarp to 360m AHD on elevated ridges. From west to east, the soils include the Darling Scarp, Swan, Dwellingup, Yarragil, Helena, Murray and Cook associations.
The Darling Plateau is the dominant landform type, covering the majority of the total area of the Shire and contains the following soil associations:
The Dwellingup classification unit comprises almost half the total area of the Shire and encapsulates the lateritic uplands of the Darling Plateau. The crests and upper slopes are a common landform feature dominated by lateritic duricrust and shallow gravelly sands.
The Yarragil classification unit occurs on the minor upland valleys in the western part of the Darling Plateau and encompass the valley side slopes, headwaters and floor. The soils range from yellow duplex soils to sands over mottled clay on side slopes and headwaters to poorly drained uniform clays on valley floors. The Yarragil association is commonly adjacent to the Dwellingup unit associated with the major valleys.
View plants of the Dwellingup and Yarragil association
The Murray classification unit is a common feature of the deeply incised valleys with soils consisting of yellow, red and brown gradational earths and yellow mottled duplex soils. The narrow alluvial terraces occur throughout the Upper Helena Catchment and in large pockets within the suburbs of Bickley, Carmel and Canning Mills.
View plants of the Murray complex
The Helena classification unit is characterised by deeply incised major valley systems associated with the Middle Helena and Bickley Brook Catchments. The steep valley side slopes give way to gently inclined valley floors lower in the landscape. Yellow duplex soils, gradational earths and granite rock outcropping are common features.
The Cook classification unit comprises of hills that rise above the general plateau of the lateritic uplands. The mantled laterite surface may also contain granite rock outcrops and shallow duplex soils.
View plants of the Helena and Cook complex
Click here to view the Soil Zonings within localities of the Shire.
Soil zones and respective vegetation complexes can be used to determine plants localities of a given area. For example Ledger Road Reserve in Gooseberry Hill has Dwellingup soils associated with lateritic uplands of the Darling Plateau; view plant list here.