Ecology of Melbourne

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.

Climate and geography

Main articles: Climate of Melbourne and Geography of Melbourne

Climate

Melbourne experiences a temperate oceanic climate (Köppen climate classification Cfb), characterised by warm summers, mild autumns, cool winters, and variable springs. 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. The city's climate significantly influences its ecological processes, affecting vegetation patterns, water availability, and wildlife behaviour.

Temperature variability

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.

Rainfall patterns

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.

Geography and topography

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.

Volcanic plains

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.

Coastal dunes and wetlands

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.

Rivers and waterways

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

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.

Woodlands

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.

Grasslands

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).

Wetlands and riparian vegetation

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).

Fauna

Melbourne's fauna is diverse, with species adapted to its varied habitats. The region supports a mix of endemic and introduced species, with some native species thriving even in urban areas.

Mammals

Native mammals in Melbourne include species such as the Common Brushtail Possum (Trichosurus vulpecula), Eastern Grey Kangaroo (Macropus giganteus), and the Sugar Glider (Petaurus breviceps). These species are commonly found in suburban areas, parks, and reserves.

Birds

Melbourne is home to a variety of bird species, ranging from the ubiquitous Australian Magpie (Gymnorhina tibicen) to more specialised species like the Superb fairywren (Malurus cyaneus). Wetland areas attract waterbirds such as the Black Swan (Cygnus atratus) and Royal spoonbill (Platalea regia).

Reptiles and amphibians

The region's reptiles include species like the Eastern blue-tongued lizard (Tiliqua scincoides) and the Eastern long-necked turtle (Chelodina longicollis). Frogs, such as the Common eastern froglet (Crinia signifera) and Southern brown tree frog (Litoria ewingii), are also common in wetland areas and suburban gardens.

See also

• Environment of Australia

External links

• City of Melbourne Urban Ecology and Biodiversity Strategy
• Natural Environments - Encyclopedia of Melbourne
• Urban birdwatching guide to Melbourne - Australian Geographic
• Melbourne’s Urban Wildlife - The Nature Conservancy