Arid and semi-arid environments fact sheet | Field of Mars EEC

What are arid and semi-arid environments?

Arid and semi-arid environments are dry surroundings where water is limited for much of the year. An arid environment usually receives very little average rainfall, while a semi-arid environment receives a little more but is still dry. Rain may be irregular, so plants and animals often depend on short wet periods after storms.

These environments can include different habitats and ecosystems, such as dry lake beds, sand dunes, saltbush plains, acacia shrublands, grasslands and woodlands. A habitat is the place where an organism lives. An ecosystem is the living things and non-living features interacting together. An environment is the wider set of surroundings and conditions.

In NSW, arid and semi-arid environments are mostly found in the west of the state. They are very different from the wetter forests and creeks near Field of Mars Reserve, but both places show how climate, soil, water, plants, animals and people shape environments.

An arid and semi-arid environment.

The Walls of China in Mungo National Park show landforms shaped by wind, water and time.

Where are arid and semi-arid environments found?

Arid and semi-arid environments cover much of inland Australia. They occur in places with low rainfall, high evaporation and long dry periods. In NSW, they are mostly found west of the Great Dividing Range, where the climate becomes drier than coastal and tableland areas.

Western NSW includes dry environments with saltbush and bluebush plains, acacia shrublands, grasslands, dry lake beds, sand plains and rocky areas. Protected areas such as Mungo National Park, Mutawintji National Park, Gundabooka National Park, Sturt National Park and Paroo-Darling National Park help conserve some of these environments.

Dry inland environments can include open woodland, shrubs, grasses, tracks and sandy soils.

What living and non-living features make up arid and semi-arid environments?

The living features include hardy plants, animals, fungi, bacteria and other small organisms. Plants such as saltbushes, bluebushes, acacias, grasses and shrubs are producers because they use sunlight to make food. Animals are consumers because they feed on plants, seeds, nectar, insects or other animals. Decomposers recycle dead material and return nutrients to the soil.

The non-living features include sunlight, heat, wind, rocks, sand, clay, soil moisture, salt, dry lake beds and occasional water after rain. These features affect where plants can grow, where animals can shelter and how food webs work. When rain falls, short bursts of plant growth, flowering and insect activity can quickly support other animals.

Saltbush plains can grow in dry inland NSW where soils, rainfall and salinity shape plant communities.

What plants and animals live in arid and semi-arid environments?

Plants in arid and semi-arid environments need to survive heat, dryness and irregular rainfall. Some have small leaves, tough stems, deep roots or spreading roots that help them reduce water loss or collect water quickly after rain. Saltbushes, bluebushes, copperburrs, acacias, wattles, grasses, grevilleas and some mallee eucalypts can be part of these environments.

Animals also need adaptations for dry conditions. Kangaroos, wallabies, lizards, birds, bats, insects and other animals may avoid the hottest parts of the day, shelter in shade or burrows, move across large areas to find food, or use water carefully. Some animals become more active after rain when plants grow, flowers open and invertebrates become easier to find.

Red kangaroos can live in dry inland environments such as Sturt National Park in NSW.

Lizard burrows can provide cool, sheltered places for animals in sandy arid environments.

How do living things depend on arid and semi-arid environments?

Living things in arid and semi-arid environments are connected through food chains and food webs. Plants are producers because they make food using sunlight. Herbivores such as kangaroos, wallabies and insects feed on plants. Other animals, including some birds, reptiles and mammals, feed on invertebrates or other animals. Decomposers break down dead material and recycle nutrients back into the soil.

Water is one of the most important parts of these connections. After rain, plants may grow quickly, flowers may produce nectar and seeds, and invertebrates may become more common. These changes can provide food for birds, reptiles and mammals. When dry conditions return, many living things slow down, shelter, move away or rely on stored energy and hardy food sources.

Apostle birds feed on seeds and invertebrates in dry environments, linking plants and animals in food webs.

How are arid and semi-arid environments connected to Aboriginal Peoples and Country?

Arid and semi-arid environments are Country. They are connected to Aboriginal Peoples through living cultural responsibilities, knowledge, stories, language, travel routes, food resources, water places and care for land. This knowledge belongs to the Traditional Custodians of each place and should not be treated as the same across Australia.

In far south-western NSW, the Willandra Lakes Region includes Mungo National Park and other dry lake landscapes. The region is part of the traditional Country of the Ngyiampaa, Mutthi Mutthi and Southern Paakantyi peoples. Public sources record that First Nations people have lived around the ancient lake shores for at least 50,000 years, and Mungo National Park is jointly managed with Traditional Custodian representatives.

Mungo National Park protects dry lake and dune landscapes in the Willandra Lakes Region.

Why are arid and semi-arid environments important?

Arid and semi-arid environments are important because they support plants, animals and ecosystems that are adapted to dry conditions. Many species found in these environments can survive with little rainfall, high temperatures and long dry periods. These environments also help people learn how living things depend on water, soil, shelter and each other.

Arid and semi-arid environments also have cultural, historical and heritage importance. Aboriginal Peoples have cared for and lived with these landscapes for thousands of years. In many places, old buildings, homesteads, woolsheds, fences, wells and tracks show how European settlement, farming and transport changed dry inland areas over time. These features help students understand that arid and semi-arid environments are important natural, cultural and historical landscapes.

Mungo Woolshed shows part of the pastoral history of Mungo National Park.

What threatens arid and semi-arid environments?

Threats vary between places. Some arid and semi-arid environments can be damaged by invasive animals, weeds, heavy grazing pressure, soil erosion, changed fire patterns, inappropriate visitor access and disturbance to fragile landforms. Rabbits can reduce vegetation and stop seedlings from growing, while feral cats and foxes can prey on native animals.

Climate change is also a threat because rising temperatures, more extreme heat and longer or more severe droughts can place extra stress on plants, animals, soils and water sources. In dry environments, small changes in rainfall, ground cover or soil condition can affect many living things in the food web.

Feral goats can damage arid and semi-arid environments by eating native plants, reducing ground cover and increasing erosion.

How can you help protect arid and semi-arid environments?

Visitors can help by staying on marked tracks, respecting signs and closures, avoiding fragile dunes and dry lake beds, taking rubbish home and never removing plants, rocks, fossils or cultural material. Cleaning shoes, tyres and camping gear can also help reduce the spread of weed seeds and soil diseases.

Students can help by learning from reliable sources, listening to Aboriginal-led information where it is publicly shared, conserving water, supporting protected areas and explaining why dry inland environments are important. Even if you live near the coast, your choices can still affect water, climate, waste and biodiversity across Australia.

Walking on marked tracks helps protect fragile soils, plants, landforms and cultural places.

Related fact sheets

Environments and ecosystems

• Ecosystem and environment fact sheets⁠ – Explore Field of Mars EEC fact sheets about local, Sydney and wider NSW environments.
• Ecosystems and environments fact sheet⁠ – Compare habitats, ecosystems and environments across NSW.
• Field of Mars Reserve fact sheet⁠ – Compare dry inland environments with local Sydney bushland, creeks and wetlands.
• Eucalypt forest fact sheet⁠ – Compare dry inland shrublands with a Sydney eucalypt forest ecosystem.

Habitats

• Habitat fact sheets⁠ – Explore how different habitats provide food, shelter, breeding places and protection for living things.
• Tree habitats fact sheet⁠ – Learn how trees provide shade, food, shelter and movement pathways.
• Shrub habitats fact sheet⁠ – Explore plant layers that provide flowers, seeds, shelter and habitat structure.
• Ground cover habitats fact sheet⁠ – Learn how low plants and grasses shelter small animals and protect soil.
• Rock and log habitat fact sheet⁠ – Explore how rocks, logs and crevices provide shelter, warmth and feeding places.

Animals and food webs

• Mammal fact sheets⁠ – Explore mammals, adaptations, habitats, threats and food webs across Sydney and NSW.
• Reptile fact sheets⁠ – Learn about reptiles, including lizards, snakes, turtles and geckos in Australian environments.
• Bird fact sheets⁠ – Explore how birds feed, move, reproduce and survive in different habitats and ecosystems.
• Invertebrate fact sheets⁠ – Learn about insects, spiders and other small animals that support food webs and decomposition.
• Red fox fact sheet⁠ – Learn about an introduced predator that can affect native animals in many Australian environments.

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