Australian ecosystems Flashcards
Deserts
True deserts are areas with rainfall less than 100mm a year on average. 18% of mainland Australia is desert. Many desert plants are ephemerals, short-lived species that appear following good rain. Deserts also feature xerophytes, plants that have physical adaptations suited to the dry environment.
Grasslands
In arid regions, ground cover is typically hummocks and tussocks with a very low cover of <30%. The dominant species are grasses, which vary in height from 2cm to 2m. Many species are adapted to fire and drought.
Scrublands
Foliage cover of 30-70%.Scrublands can also be called shrublands and healthlands, and they contain many different vegetation types. The typical vegetation is shrubs with a variable overstorey of small trees. Scrublands are adapted to drought, fire and low (but highly variable) rainfall.
Woodlands
Widely spaced canopy cover of 10-30%; well-developed shrubs and grasses. The widely spaced trees are fewer and more scattered than in forests. Woodlands are mainly dominated by eucalypts and found mostly in southern, temperature Australia.
Alpine
Low, fairly continuous ground cover. Alpine ecosystems are found in cold mountain regions, including above the tree line (where altitude makes even summer temperatures too low for much tree growth). This ecosystem has rocky landscapes, and may contain glacial lakes and have seasonal snow coverage.
Open (sclerophyll) forests
Fairly open canopy cover of 30-70%; good understorey and ground cover. These forests are 25-35m high, with fairly even height and moderately dense canopies that often join up. The forest floor can range from dry to damp and is covered with grasses and shrubs. These forests are dominated by eucalypts and are the most common forest type in Australia.
Closed (rainforest) forests
Dense canopy cover of 70-100%; distinct layers or storeys within forest. Rainforests are filled with mostly evergreen trees and typically receive high amounts of rainfall. Tropical rainforests are found near the equator, with high average temperatures and humidity, while temperate rainforests lie mostly in coastal mountainous areas within the mid-latitudes.
Reefs and marshes
Dense growth. A reef is a ridge of material at or near the surface of the ocean. Reefs can occur naturally. Natural reefs are made of rocks or coral, which is the remains of skeletons of small animals. A marsh is a wetland, an area of land where water covers ground for long periods of time.
