Climate change, population pressures and urbanisation are among the major challenges to the future health of environments in the Macedon Ranges, Hume, Mitchell & Whittlesea area. 

Climate change

The Climate Change in the Port Phillip & Western Port Region report identifies risks and responses to warmer, drier conditions and rising sea levels across the region.

The most climate-sensitive and affected environmental assets in the Macedon Ranges. Hume. Mitchell & Whittlesea area are predicted to be:

• large areas of native vegetation in Macedon, along the Great Divide north of Cobaw, Lancefield and Whittlesea
• native vegetation in the valleys of the upper Deep Creek and Merri Creek and in conservation reserves at Woodlands and Jacksons Creek
• riparian and in-stream habitats in the upper reaches of Deep Creek and Moonee Ponds Creek
• numerous freshwater wetlands, particularly at Kalkallo, Wallan and Beveridge
• soils on steeper slopes along the Great Divide around Macedon and south through Gisborne to Toolern Vale
• soils in the Deep Creek catchment and on the hills north and east of Whittlesea where erosion risk is increased by climate-induced vegetation loss and more frequent intense fire.

The urban heat island effect will be an issue for Melbourne. Current development of growth areas to support Melbourne’s future population will see more people exposed to extreme urban heat levels and significantly increase the number of heat-vulnerable communities.

Climate Risk Assessments developed by the three Local Government-based Alliances for Greenhouse Action, the Eastern Alliance, the Northern Alliance and the Western Alliance find:

• Vulnerability to climate change is compounded for newly arrived migrants, the aged and young children and people living in relative poverty, in sub-standard housing or with poor English
• Lack of understanding of local flora and fauna species responses to climate change is hampering timely and effective investment and action for biodiversity conservation
• Social and policy pressures for larger fire breaks and more fuel-reduction burning is impacting biodiversity and air quality
• Changing wildfire frequency and intensity in warmer, drier conditions is damaging biodiversity and increasing demands for fire-management effort
• Fire agency management planning often conflicts with the environmental protection goals and targets of local, regional and state environment strategies.

Urbanisation and population growth

Population forecasts for the Macedon Ranges Hume Mitchell Whittlesea area predict growth of 56% over the next 20 years – from 543,000 in 2021 to 970,000 in 2041*.  (* Population forecast data for Macedon Ranges Shire is limited to the 2021-2036 period)

The urbanisation effect of population growth on land, waterways and biodiversity is suggested in forecasts for the construction of new dwellings.  These are predicted to double in number across the Macedon Ranges Hume Mitchell and Whittlesea area from 155,600 in 2016 to 322,100 by 2041.

Significant urban development and population growth is forecast for this area and is likely to bring:

• demands for space, facilities, transport infrastructure and access to recreation areas 
• damage from illegal clearing, vehicle tracks, vandalism, feral animals, firewood collection and rubbish dumping
• altered stream flows and water pollution from increased hard-surface run-off
• waterways habitats damaged by flood protection works and sediment inputs
• barriers to animal movement created by roads and infrastructure
• continuing habitat damage from recreation, vandalism, informal vehicle tracks and rubbish
• continued clearing for buildings, fences, access, views etc.
• feral domestic animals
• pest plants and plant diseases such as Phytophthora cinnamoni spread by humans, birds and animals and from dumped garden waste.

Green Wedge protection

Preserving Melbourne’s Green Wedges, rural and semi-rural land outside the Urban Growth Boundary, is likely to cause ongoing social, economic and political tension. Urban and rural land uses and priorities, residential amenity and farm business activities often conflict at Green Wedge boundaries. 

Farming becomes more difficult and economically challenging as new suburbs butt up against farm fences. Selling and subdividing peri-urban farmland is an attractive economic choice for ageing and/or cash-poor farmers.  Many see few better options than this ‘last harvest’. Land just outside the Urban Growth Boundary is often left vacant or poorly managed in ‘land banks’ as owners await and/or lobby for rezoning and subdivision.  

Victorian Government policy is to protect Green Wedges from urban development and inappropriate uses. Persistent commitment to this policy will be needed from local councils, State Government and its agencies to protect it from gradual erosion through piecemeal exemptions.

Pest plants and environmental weeds

Pest plants and environmental weeds are a major threat to the area’s natural environment and to its agricultural enterprises. Once established, they grow vigorously because they have few natural predators or diseases to control them. They change and destroy habitats and ecosystems, outcompeting indigenous plants for light, nutrients and water. This leaves our wildlife without food and habitat, leading to the decline of our native animals. In addition to various listed weed species that remain priorities for control, Texas needlegrass and lobed needlegrass are examples of unlisted weeds that pose growing threats.

Many pest plants are spread from domestic gardens. Seeds are spread by birds and animals or by people dumping garden cuttings into our bush and waterways.

Pest animals and predators

The introduction of exotic plants and animals has had significant consequences for the area’s native animal and plant species.

Pest animals impact on native plants, animals and their habitats.  Increasing populations of feral deer pose significant biodiversity and biosecurity threats while fox and feral cat predators are primary causes of native animal declines and extinctions.

Other pest animals including rabbits directly compete with native wildlife for food and shelter, damage native vegetation and degrade the land, while introduced fish species compete for food and prey on native fish, tadpoles and frogs.

Changing fire regimes, frequency and intensity

Traditional Owners have used fire as an ecological management tool for more than 40,000 years, understanding that Australian plant and animal communities rely on ‘regimes’ of fire intensity, frequency, season, extent and type to regenerate and maintain health and diversity. Fire regimes create food, shelter and breeding sites for native animals.

Changing fire regimes caused by climate change and human intervention through the 20th Century means some native plant and animal communities have been unnaturally insulated from fire, while others have been exposed to more frequent burning.

A drier future climate will increase the likelihood more frequent and severe wildfire, like those experienced across south east Australia in the summer of 2019-20 where an estimated 1 billion native animals were killed.

Incremental damage and clearing of native vegetation

Incremental damage to the area’s native vegetation has been caused by illegal clearing, vandalism, informal vehicle tracks, firewood collection and rubbish dumping. Incremental clearing at the edges of remnant patches and of individual trees is expected to continue. Some losses will prompted by wildfire control, others for future residential development.

Native vegetation loss across the Macedon Ranges Hume Mitchell Whittlesea area is likely to continue species decline.  The 2004 biodiversity study, How much habitat is enough? showed that landscapes with less than 15% vegetation cover may support diverse but low populations of native plant and animal species, but their future is not assured.  The study recommends that increasing vegetation cover above 15% could be an intermediate revegetation goal while 35% cover should be a goal where practicable. 

Barriers to nature conservation policy and strategy on the urban edge are discussed in the City of Hume’s Land and Biodiversity Plan 2015-2019 and other council and authority plans.  It lists and explores:

• development pressure
• habitat loss and fragmentation
• climate change
• waterway and wetland degradation
• erosion
• weeds
• pest animals
• inappropriate land management
• lack of knowledge of cultural heritage values
• lack of knowledge of local fauna populations
• lack of community connectedness to nature.

Supporting Wurundjeri Woi-wurrung connection with Country

There is a challenge to strengthen the role and influence of traditional ecological knowledge and practices in today’s natural resource management programs, where that is allowed and offered by Traditional Owners.

There are currently relatively few Aboriginal people who have jobs taking care of Country in this region, with the exception of some outstanding examples such as the Wurundjeri Narrap Team. There is a challenge in providing timely, tailored support for Registered Aboriginal Parties and other Aboriginal organisations so they can determine their aspirations and build their workforce to suit their aims with the appropriate range of skills.

Traditional Owners’ rights to water have largely been excluded from water planning and management policies and programs. Without water rights, Traditional Owners are unable to decide where or how water can be used to support cultural, spiritual, environmental or economic outcomes. There is an opportunity to address this in water planning and securing water allocations for Registered Aboriginal Parties to enable cultural watering.