Grass dominated understory Occurring on dry, fertile sites, the vegetation structure is usually open with heights of 15 to 41 metres. Soil is usually dolerite and flats are subject to frost and cold air-drainage. The shrub layer is sparse and a dense, species rich ground layer of grasses and herbs is present. Typical species include
tussock grass, kangaroo grass (
Themeda triandra), wallaby grass (
Austrodanthonia sp.) and sagg (
Lomandra longifolia).
Heath dominated understory On dry and infertile sites the shrub layer is dense and species rich. Soil type is often sandstone, quartzite or granite and orchid species may be present. The shrub layer height remains under 2 metres with the tree canopy 15 to 30 metres high. Particularly in recently burnt sites,
bracken fern often dominates the ground cover. Typical species present include
Epacris species, legumes (
Fabaceae), wattles (
Acacia sp.), bull-oak (
Casuarinaceae) and grasstree (
Xanthorrhoea australis). Legumes are an important feature of these environments as they provide nitrogen to the infertile soils (see
nitrogen fixation).
Sedge dominated understory The dense ground cover of sedges and cord rushes increase the fire frequency of these environments. If fire is infrequent the forest understory structure will change as sedge species have high light requirements that are not met when the canopy becomes dense. It follows therefore, that the canopy cover in these communities is sparse, with a tall understory with variable cover. The dominance of sedges in these communities is caused by their rapid vegetative colonisation after fire, occurring by sprouting from their underground root system. Typical species include cutting grass (
Gahnia grandis), sword sedge (
Lepidosperma sp.), buttongrass (
Gymnoschoenus sphaerocephalus), and
rushes. Soil in these environments usually has poor drainage.
Shrub dominated understory This type of forest is found on comparatively fertile and well-drained sites. A high rock surface cover persists and a multi-layered shrubby understory is present, but not tall. The increased drainage in these areas permits the growth of members of the ash group of eucalypts to grow in shaded regions and peppermints to grow in more exposed regions. This forest type often contains similar species to those found in wet sclerophyll sites such as the native cherry (
Exocarpus cupressiformis), wattles (
Acacia sp.), banksia (
Banksia sp.), guitar plant (
Lomatia tincatoria) and hakea (
Hakea sp.). == Flora ==