The ecology of Melbourne, Victoria, is a complex and dynamic system influenced by the city's geographical location, climate, and human activities. Melbourne's natural environment includes diverse ecosystems ranging from coastal heathlands to grassy woodlands, riparian forests, and wetlands. These ecosystems support a rich array of flora and fauna, many of which are unique to the region. However, urbanisation, habitat fragmentation, and the introduction of invasive species have significantly altered the city's ecological balance, leading to various conservation and restoration initiatives.[1][2]

Climate and geography

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Climate

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Melbourne experiences a temperate oceanic climate (Köppen climate classification Cfb), characterised by warm summers, mild autumns, cool winters, and variable springs.[1] The city's weather is notably changeable, often attributed to its location at the intersection of hot inland areas and the cool Southern Ocean. Annual rainfall averages around 600 to 650 mm, with most of it falling during the cooler months.[2] The city's climate significantly influences its ecological processes, affecting vegetation patterns, water availability, and wildlife behaviour.[1]

Temperature variability

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Melbourne's average summer temperatures range from 14 °C to 26 °C, with occasional heatwaves pushing temperatures above 40 °C. Winters are cooler, with temperatures ranging from 6 °C to 14 °C. This temperature variability influences plant phenology, wildlife activity, and the prevalence of bushfires, particularly in dry years.[1]

Rainfall patterns

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Melbourne's rainfall is unevenly distributed, with the wettest months typically occurring in winter and spring. However, the city also experiences periods of drought, which can have profound effects on water resources, vegetation health, and agricultural productivity.[2]

Geography and topography

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Melbourne is located on the northernmost point of Port Phillip Bay, extending inland towards the Dandenong Ranges and the Great Dividing Range. The city is built on a mixture of volcanic plains, sedimentary formations, and coastal dunes, contributing to its diverse soil types and landforms.[3]

Volcanic plains

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The western suburbs of Melbourne are part of the Victorian Volcanic Plain, one of the world's largest basalt plains. This region features fertile but shallow soils, supporting a variety of grassland species. The plains are home to rare ecosystems such as the Western Basalt Plains Grassland, which is critically endangered due to urban development and agricultural use.[3][4]

Coastal dunes and wetlands

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Melbourne's coastline along Port Phillip Bay includes sandy beaches, coastal dunes, and significant wetland areas. These environments support diverse plant communities, such as salt-tolerant grasses and shrubs, and provide crucial habitats for migratory birds and marine life.[5]

Rivers and waterways

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The Yarra River is the most significant waterway in Melbourne, flowing from the Yarra Ranges through the city to Port Phillip Bay. Alongside other rivers like the Maribyrnong and Werribee, the Yarra supports riparian vegetation and provides vital water resources for the city's ecosystems.

Flora

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Melbourne's native flora is a product of its diverse climates, soils, and landforms. The region supports a range of ecosystems, from grasslands and woodlands to coastal heathlands and wetland environments. Despite urbanisation, the city still retains areas of native vegetation that are crucial for maintaining biodiversity.[6]

Woodlands

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In areas such as the Yarra Ranges and Dandenong Ranges, native eucalypt woodlands are predominant. Species such as Eucalyptus regnans (Mountain Ash) and Eucalyptus obliqua (Messmate) are common. These woodlands provide habitat for a wide variety of wildlife, including marsupials, birds, and insects.[6]

Grasslands

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The native grasslands of Melbourne, particularly those on the Western Basalt Plains, are among the most endangered ecosystems in Australia. Dominated by species such as Themeda triandra (Kangaroo Grass), these grasslands are home to several threatened species, including the Striped Legless Lizard (Delma impar).[6]

Wetlands and riparian vegetation

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Melbourne's wetlands, such as those found in the Western Port and Port Phillip regions, support a variety of aquatic plants and are important breeding grounds for waterbirds. Riparian zones along rivers like the Yarra feature species such as Melaleuca ericifolia (Swamp Paperbark) and Acacia dealbata (Silver Wattle).[6]

Fauna

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Melbourne’s fauna is diverse, with species adapted to its varied habitats, from urban parks to coastal wetlands. The region hosts a mix of native and introduced species, some of which have adapted remarkably well to human-dominated landscapes.

Mammals

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Native mammals such as the common brushtail possum (Trichosurus vulpecula), eastern grey kangaroo (Macropus giganteus), and sugar glider (Petaurus breviceps) are frequently seen in Melbourne's suburban areas, parks, and reserves. These mammals play an important ecological role: possums, for instance, help disperse seeds, while kangaroos help maintain grassland habitats. The grey-headed flying fox (Pteropus poliocephalus), a large fruit bat, is also common in Melbourne’s parks, where it aids in pollination and seed dispersal. Despite urban pressures, possums are especially adaptable, often finding shelter in roofs and gardens.[7]

Birds

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Melbourne is home to a rich variety of bird species, including the widely recognized Australian magpie (Gymnorhina tibicen), which has adapted to urban environments and even engages in complex social behaviours with humans. In contrast, species like the superb fairywren (Malurus cyaneus) are more specialised, thriving in bushland and parklands. Birds of prey, such as the wedge-tailed eagle (Aquila audax) and peregrine falcon (Falco peregrinus), are also found in Melbourne’s outskirts, especially in open or mountainous areas. Wetlands across Melbourne attract waterbirds such as the black swan (Cygnus atratus) and royal spoonbill (Platalea regia), both of which play a role in maintaining healthy aquatic ecosystems.[8]

Reptiles and amphibians

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Melbourne’s reptile species include the eastern blue-tongued lizard (Tiliqua scincoides), often seen basking in suburban gardens, and the eastern long-necked turtle (Chelodina longicollis), which relies on the city’s wetland habitats. Amphibians like the common eastern froglet (Crinia signifera) and southern brown tree frog (Litoria ewingii) are key indicators of wetland health, with their presence often reflecting the quality of local water sources. These frogs are common in suburban gardens as well, where they benefit from backyard ponds and natural water sources.[9]

Marine Life

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Melbourne’s coastal areas support marine species such as the Australian fur seal (Arctocephalus pusillus doriferus) and bottlenose dolphin (Tursiops aduncus), which are frequently sighted along the shoreline and attract significant interest from locals and tourists. These marine mammals contribute to the biodiversity of the Port Phillip Bay area and play a role in maintaining marine ecosystem health.[10]

Fish

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The rivers and streams around Melbourne are home to native freshwater fish like the Australian grayling (Prototroctes maraena) and river blackfish (Gadopsis marmoratus), both of which are important for the region's aquatic ecosystems. These species help sustain predator populations and contribute to nutrient cycles in freshwater habitats.

Invertebrates

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Melbourne’s invertebrate fauna includes species like the spiny leaf insect (Extatosoma tiaratum), various butterflies, and a range of spiders, all of which contribute to local biodiversity. Invertebrates play critical roles in pollination, soil health, and as food sources for other species, underscoring their importance to Melbourne's ecosystems.

Invasive species

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Several invasive species pose significant threats to the native ecosystems of Greater Melbourne:

  • Foxes: Introduced in the 19th century, foxes (Vulpes vulpes) are major predators of native wildlife, affecting populations of birds, small mammals, and reptiles. Their presence leads to a decline in these vulnerable populations, reducing biodiversity and disrupting the natural food chain.
  • European rabbits: These rabbits (Oryctolagus cuniculus) compete with native herbivores for food and cause extensive damage to vegetation through overgrazing, leading to soil erosion and habitat degradation. Such habitat loss can have lasting effects on other native species reliant on the same ecosystem.
  • Weeds: Invasive plant species such as gorse (Ulex europaeus) and blackberry (Rubus fruticosus) threaten native flora by outcompeting indigenous plants. This disrupts the ecological balance, altering nutrient cycles, water availability, and the overall structure of plant communities, which affects the animals that depend on native vegetation.[11]

See also

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References

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  1. ^ a b c d "Climate statistics for Australian locations". Australian Bureau of Meteorology. 2023.
  2. ^ a b c "Water and environment | Melbourne Water". www.melbournewater.com.au. Retrieved 18 August 2024.
  3. ^ a b Environment (8 August 2022). "Environment". Environment. Retrieved 18 August 2024.
  4. ^ Gullan, P (2017). The Victorian Volcanic Plains: An Ecological History. CSIRO Publishing.
  5. ^ "Home". Ecology Australia. Retrieved 18 August 2024.
  6. ^ a b c d Flora of Melbourne: A Guide to the Indigenous Plants of the Greater Melbourne Area. Hyland House Publishing. 2011.
  7. ^ Jackson, Stephen (2003). Australian mammals: biology and captive management. Collingwood, Vic: CSIRO Pub. ISBN 978-0-643-06635-9. OCLC 51738642.
  8. ^ Pizzey, Graham; Knight, Frank; Pizzey, Sarah (2012). The field guide to the birds of Australia (9. ed., revised and updated ed.). Sydney: Harper Collins Publishers. ISBN 978-0-7322-9193-8.
  9. ^ Robertson, Peter; Coventry, A. John (2019). Reptiles of Victoria: a guide to identification and ecology. Clayton, VIC: CSIRO Publishing. ISBN 978-0-643-09393-5.
  10. ^ Edgar, Graham J. (2000). Australian marine life: the plants and animals of temperate waters (Revised ed.). Frenchs Forest, N.S.W. London: Reed New Holland. ISBN 978-1-876334-38-3.
  11. ^ Environment (13 February 2024). "Invasive species on public land". Environment. Retrieved 2 November 2024.
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