Since European settlement, the region's natural assets have been increasingly exposed to vegetation clearing activities, introduced weeds and feral animals, plant diseases and pathogens such as Phytophthora or dieback, altered fire regimes and overgrazing.
In addition, a greater understanding of new and emerging threats, such as climate change and water scarcity, have also highlighted their significance as key threats to biodiversity.
The ongoing management of threats across the region is increasingly necessary to maintain robust ecosystems that are more resilient in the face of intensifying global warming, and bolster their ability to self-sustain and support native species.
One of the most significant threats to the biodiversity of the Adelaide Hills is weed invasion. Most of Australia's native vegetation has been invaded at some point since European settlement, or is highly vulnerable to invasion by exotic species. Nationally, invasive plants account for approximately 15% of all flora, and about one-quarter of these are either serious environmental weeds or have the potential to be serious weeds1.
Weeds are essentially species which do not belong in an area. Many plants were intentionally introduced from foreign countries as suitable fodder plants for domestic stock or for soil stabilisation purposes, but most were imported as ornamental garden plants. Even some Australian species have become problematic outside of their natural distribution, including the Sydney Golden Wattle (Acacia longifolia ssp. longifolia), the eastern states Rosemary Grevillea (Grevillea rosmarinifolia) and the Western Australian Bluebell Creeper (Billardiera heterophylla).
Some weeds are prolific invaders of pastures whilst others thrive in bushland communities, out-competing and smothering native plants, and threatening the survival of local native plants and animals. Major infestations have the potential to physically alter the natural state of the bush, by impacting on a number of ecological features including the community structure, natural diversity (species richness), species composition and abundance. There are many examples throughout the Adelaide Hills where bushland has become severely modified by weeds and habitat values are now compromised.
The most common and problematic weeds within the region range from trees, such as Sweet Pittosporum (Pittosporum undulatum), Desert Ash (Fraxinus angustifolius), Olive (Olea europaea), Pine (Pinus radiata), and shrubby, woody weeds including Gorse (Ulex europaeus), Montpellier Broom (Genista monspessulana), Erica (Erica sp.), Boneseed (Chrysanthemoides monilifera) and Blackberry (Rubus fruticosus), to grassy, herbaceous and creeping exotics such as Blue Periwinkle (Vinca minor), Rice Millet (Piptatherum miliaceum), Phalaris (Phalaris aquatica) and Bulbil Watonia (Watsonia meriana ssp. bulbifera).
Weeds have been categorised to reflect factors such as invasiveness, potential to spread, 'perceived' and 'actual' impacts and their environmental, economic and social impact. Some of the more common and emerging plants known from the Adelaide Hills Council district fall into one or more of the listed categories.
Contacts and useful links
If you suspect that you have a declared or alert weed on your land or adjoining roadside, please contact Landscapes Hills & Fleurieu Board or Council for identification and management advice.
For information to help manage invasive weeds, visit the Weeds Australia website via the link below.
For alternative common and scientific names for all plants prohibited from sale in South Australia, and a free Weed Control app, which provides information about the control of weeds declared in South Australia, please visit Primary Industries and Regional SA (PIRSA) Biosecurity SA Division website via the link below.
Phytophthora cinnamomi is a water-borne soil pathogen that infects the roots and stems of certain susceptible native plants and also introduced plants including ornamentals (lilies, camellias, hibiscuses and rhododendrons), vines (grapes), fruit (avocados pears, apples, citrus, raspberries, cherries, apricots, peaches, olives), nuts (macadamias, chestnuts and walnuts) and vegetables (potatoes)1. It reduces their ability to transport water and nutrients, ultimately leading to plant death.
Phytophthora is native to South East Asia and was probably introduced into Australia shortly after European settlement. It is now present in all states of Australia2, but mainly across southern Australia where rainfall zones are within the 400–600mm annually.
The pathogen has the potential to significantly impact upon plant communities by modifying floristics and community structure, often leading to local extinctions of populations of susceptible species. There is currently no cure for Phytophthora, so areas that become infested, remain infested. Dieback caused by the root-rot fungus is listed as a key threatening process under the Commonwealth Environment Protection and Biodiversity Conservation (EPBC) Act 1999.
Phytophthora is known to be a threat to many plant species listed under the EPBC Act, and other species listed as threatened under state or territory legislation are also at risk. See Appendix in Phytophthora Management Guidelines for specific native plant species susceptible to P. cinnamomi in South Australia.
- Death or deterioration of health of susceptible plant species (eg. Eucalyptus obliqua (Messmate Stringybark), Eucalyptus baxteri (Brown Stringybark), Xanthorrhoea sp. (Yacca), Banksia sp. (Banksia), Isopogon ceratophyllus (Conebush), Leptospermum sp. (Tea Tree), Acacia myrtifolia (Myrtle Wattle), Pultenaea involucrata (Mount Lofty Bush-pea), Acrotriche fasciculiflora (Pink Ground-berry) and species from Fabaceaea (Pea family).
- Diseased plants with general discolouration of foliage, usually red or yellow foliage.
- Phytophthora resistant species remain unaffected.
- Progression of deaths over time, particularly down slope and an obvious boundary may be apparent between diseased and healthy areas.
- Avoid areas of known Phytophthora infestations.
- Stay on designated roads and tracks.
- Obey road signs indicating restricted areas associated with Phytophthora infestation.
- After entering or working in areas of infestation, clean soils from footwear (and/or horses hooves) with a stiff brush and spray with undiluted methylated spirits (see Hygiene procedures table below).
- Using hygiene stations on tracks/trails where provided.
- Clean machinery and equipment and other tools appropriately before using in other areas.
- Undertake works in Phytophthora infested areas when conditions are driest (avoid winter months).
- If infestation areas are known, use machinery in areas that are un-infested first, moving to infested areas last, following up with appropriate hygiene measures.
- Avoid excavating in infested areas.
|Items for Management||Hygiene procedure||Disinfectant / rate||Comments|
|Vehicles, machinery, large equipment|
Pay particular attention to wheels, mudflaps, undercarriage and other areas difficult to access
Remember to disinfect brush or tool used in dry brushing
|Small equipment, hand tools, footwear|
Disinfection with spray bottle
1 part household bleach
All soil should be removed before disinfecting
Avoid recontaminating Footwear
Remember to disinfect brush or tool used in dry brushing
Disinfection with footbath
1 part household bleach
All soil should be removed before disinfection
Useful for large groups of people
(source: Phytophthora Technical Group (2006) Phytophthora Management Guidelines)
The Department of Environment, Water & Natural Resources can provide further information on Phytophthora and how to control it.
Download a brochure on Phytophthora below.
1 Department for Environment and Heritage (2009) Phytophthora is killing our plants! Fact sheet.
2 Phytophthora Technical Group (2006) Phytophthora Management Guidelines — Second Ed. Unpublished report prepared for the Government of South Australia.
There are a number of introduced animals that pose significant threats to biodiversity across the Adelaide Hills region. Some of these 'feral' animals are also responsible for costing millions of dollars in damage, control efforts and loss of production within the agricultural industry1.
The following pest animals are either already well entrenched, are emerging as a serious pest or not currently established, but are at risk of establishing in the Mount Lofty Ranges.
Photo thanks to the Friends of Black Hill and Morialta
Since their introduction in the mid-1800s, foxes have become one of the main predators which have had a devastating effect on the smaller native species of mammals, birds and reptiles across the region, and in particular have been implicated in the extinction of almost 30 native mammals from mainland South Australia. In conjunction with widespread loss of habitat across the region, foxes have placed further pressure on remaining populations of native species, including threatened species such as the Southern Brown Bandicoot, Yellow-footed Antechinus, Cunningham's Skink and the Common Brushtail Possum. They are also known to kill lambs and poultry.
Landholders are responsible for the satisfactory control of foxes on their properties under the Natural Resources Management Act 2004. Given this legislative requirement, many landholders are actively managing foxes on their individual properties, whist others have undertaken a coordinated approach with volunteer groups and organisations such as the Hills and Fleurieu Landscape Board. Overall the management across council lands is somewhat 'ad hoc', with sporadic management undertaken by the Hills and Fleurieu Landscape Board in consultation with Council. In many cases, the risk of off–target poisoning to domestic dogs, is too great and therefore the AHC do not endorse the use of baits and fumigation within their reserves.
Contacts and useful links
Fox reporting website and smartphone app
FoxScan is a community website that allows you to record and map sightings of foxes, fox damage, and control activities in your local area. Use FoxScan data recorded in your region to help decide where to undertake control, and coordinate with your neighbours. Find link below.
Rabbits were an early introduction to all states of Australia following European settlement. Their numbers rapidly exploded causing huge impacts to biodiversity and agriculture alike. They actively compete with native animals for food resources and damage sown crops and native plants by ringbarking trees and shrubs, inhibiting regeneration by eating seed and seedlings. Their warrens are also responsible for soil erosion and destabilisation. Competition and land degradation by rabbits is listed as a key threatening process under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999.
There are growing reports of feral rabbit populations across the Adelaide Hills region over 2023 following wetter conditions combined with a milder summer. The most appropriate contact for advice regarding management of declared pests on your property and the wider region is the Hills and Fleurieu Landscape Board - Mt Barker. Method, timing, placement and exclusions may all need to be considered for rabbit control in your specific situation to maximise effect and prevent off target damage or to ensure the baits are actually taken by rabbits rather than off-target species.
In February 2023, the Board held 12 distribution days for private landowners to collect Pindone treated carrots at six pickup locations, and followed up with the option of residents purchasing more Pindone carrots or K5 calicivirus treated carrots in March. Now that there have been some autumn rains and green feed abundant, the best time to lay baits has ended, as rabbits will not uptake enough bait when there is abundant natural food supply. Baits will become available again in this summer (the exact date will depend on weather conditions, but it’s likely to be early-mid December.)
Since the release of the biological controls Myxoma Virus and Rabbit Calicivirus Disease (RCD) or rabbit haemorrhagic disease (RHD) (1937 and 1995 respectively), rabbit numbers overall have been significantly reduced. However, eventually rabbits developed resistance to Myxomatosis and are also predicted to become resistant to RCD. Currently their numbers still fluctuate in response to seasonal conditions and other management tools being utilised by landholders to control populations, including poisoning, shooting and warren destruction. These are suitable methods in rural settings, however controlling rabbits in urban and bushland areas can be problematic. Modifying the environment to reduce the suitability for rabbits is the best overall approach, such as removing available refuge (rubbish, woodpiles etc) and destroying warrens.
A national release of a Korean strain of Rabbit Haemorrhagic Disease Virus, known as RHDV1 or K5, was undertaken in 2017. The release took place at 45 sites across South Australia and data from 16 sites showed rabbit numbers decreasing by approximately 50%. In September 2019, PIRSA Biosecurity again released K5 at strategic South Australian locations including 4 in the Mt Lofty Ranges including the Central Hills in the Adelaide Hills region.
While rabbits are amongst the most susceptible species to the effects of the poison Pindone, it also toxic to a range of native species. Granivorous birds (e.g. Crested Pigeon, Bronzewing Pigeon), bandicoots (e.g. Southern Brown Bandicoot), native rodents (Bush Rats) and macropods (e.g. Western Grey Kangaroo) are vulnerable to primary poisoning from ingesting baits. Rabbits can bio-accumulate Pindone, and poisoned rabbits can be lethargic and easier to catch, increasing the risk of secondary poisoning. Dasyurids (e.g. antechinus) and raptors may be susceptible to secondary poisoning from ingesting poisoned rabbits, particularly raptors with high sensitivity and for which rabbits are a significant dietary component (e.g. Wedge-tailed Eagles, Brown Goshawks). Raptors vary in sensitivity to Pindone (e.g. Nankeen Kestrels are less susceptible). . Possums are relatively resistant to Pindone but it is used to control them in New Zealand. Avoiding baiting where there is a high risk of poisoning to non-target native fauna (e.g. in or next to bushland or refuge areas for vulnerable species) is a recommended strategy for avoiding off-target damage.
Dogs, cats, cattle, goats and chickens are also susceptible to Pindone. Sheep and horses are relatively resistant but sheep may still be affected, including bleeding and death at shearing, an increase in stillborn and non-viable lambs, and reduced sperm motility. For these reasons, Council does not participate in a rabbit baiting program, but instead participates in the annual warren fumigation and ripping program with the Landscape Board, and promotes their annual bait distribution program for private landowners.
Domestic and commercially kept rabbits will be at risk from the virus so the official warning is that unless your rabbits are kept inside and in an insect-safe place, they need to be vaccinated.
Please report any rabbit sightings or activity (warrens, damage, and control activities) via RabbitScan to assist the development of regional rabbit control programs.
Deer were first introduced into Australia in the 1800s as game animals. Within Mount Lofty Ranges region, some Fallow and Red Deer have escaped from commercial properties and are becoming widespread as 'feral' pest species. There are six species of feral deer across Australia, however the main pest species in South Australia is the Fallow deer and the Red Deer. The current population estimates are approximately 40,00 in the State, 8,000 in Hills and Fleurieu region, 1,500 in Green Adelaide and a further 2,000 in peri-urban settings.
The impacts caused by deer include damage to native vegetation and commercial crops and pastures, and more recently residential gardens in peri-urban settings. More specifically the impacts are causing overgrazing, browsing, trampling, ring-barking, dispersal of weeds and spreading disease such Phytophthora, damage to fences, creation of trails through bushland and acceleration of erosion.
Currently Landscapes Hills and Fleurieu is undertaking a range of investigations and compliance measures to identify the distribution, impacts and potential options for controlling Fallow Deer which have escaped from commercial properties. The State and region are working towards eradication of the species in a 10 year timeframe under the recently developed strategic management strategies.
Under the Landscapes Act 2019, 'feral' deer are a Declared species and it is the landholder's responsibility to satisfactory control feral deer on their properties. It is also a deer keeper's responsibility to notify neighbouring landowners and the Landscapes Hills and Fleurieu Board of escaped farmed deer.
Any sightings of feral deer should be reported to Landscapes Hills and Fleurieu where landowners can also obtain advice about control measures.
Contacts and useful links
Deer reporting website and smartphone app
FeralDeerScan is a free community resource for landholders, community groups and pest controllers. DeerScan can be used to map sightings, report problems or damage caused by deer, and document control actions. It can be used to inform your neighbours and local biosecurity authorities about current deer problems. You can use DeerScan to record new (and historical) observations of deer in your local area, as this will help to build a detailed picture of deer populations.
Goats arrived in Australia with the settlement of the colonies by the first Europeans. Descending from those that escaped, the feral population has spread across Australia, where they cause significant economic and environmental damage through overgrazing and competition with livestock and native herbivores. More specifically, goats are known to trample, heavily browse and ring-bark native and planted vegetation, cause erosion, spread weeds and leave strong odours around their camps, driving away some native species.
Currently goats are actively monitored and removed in some National Parks and Wildlife reserves with methods such as satellite tracking, trapping and shooting, with collaboration between numerous stakeholders.
Council does not currently manage goats on Council land due to the high risk posed to public safety associated with some of these methods.
Under South Australia’s Landscapes Act, 2019, feral’ goats are a declared animal and it is the landholder’s responsibility to satisfactory control them on their properties. It is also the responsibility of landowners who keep goats to notify neighbouring landowners of any escaped animals.
Any sightings of feral goats should be reported to Landscapes Hills & Fleurieu, where landowners can also obtain advice about control measures.
Contacts and useful links
Hills and Fleurieu Landscape Board Mount Barker — 8391 7500 Deer control advice Upper level, corner Mann and Walker streets, Mount Barker SA 5251
PIRSA Biosecurity SA — (08) 8303 9620
Goat reporting website and smartphone app
FeralGoatScan is a community website that allows you to record and map sightings of feral goats, damage, and control activities in your local area. Use data to identify priority areas for feral goat control, and work with your local land managers to implement control in a coordinated approach.
Feral cats are defined as those that live independent of humans and survive by hunting or scavenging. Introduced early during European settlement, feral cat colonies become established in the wild by the 1850s. Mostly feral cats have spread from domestic populations, either as abandoned animals or intentionally released to help manage rats and mice populations.
Feral cats impact significantly on Australia's biodiversity, predating on a range of native species, particularly birds, reptiles, amphibians and small mammals. Between the foxes and feral cats, their combined impacts have led to the extinction of almost 30 native mammals from mainland South Australia and continue to threaten many more2.
In 2015 a Threat Abatement Plan for predation by feral cats set out a national framework to guide and coordinate Australia's response to the impacts of feral cats on biodiversity. It identified the research, management and other actions needed to ensure the long-term survival of native species and ecological communities affected by predation by feral cats.
The Council Cats By-law 2018 (By-law No. 6), was created to control and manage cats in the Council area. The objects of the By-law is to manage and limit the number of cats within domestic premises of two individuals, with certain exemptions allowed. Council has also resolved through the by law to adopt a registration scheme for cats, and impose full confinement of domestic cats by 1 January 2020. During 2018 Council developed a revised Animal Management Plan.
Feral cat reporting website and smartphone App
FeralCatScan is a new project by the Invasive Animals CRC and Australian Government Department of the Environment, and is supported by communities Australia-wide to improve knowledge about feral cats to help protect Australia's threatened wildlife.
1 Copyright, Department of Environment, Water and Natural Resources (2015) Deer pest management guide — Fallow Deer (Dama dama)
2 Natural Resources Management (NRM) board — Animal Pests of South Australia Factsheet
- Deer pest management guide - Fallow Deer (Dama dama) — Copyright, Department of Environment, Water and Natural Resources (2015)
- Controlling Rabbits in Urban Areas Factsheet — Copyright Department of Environment, Water and Natural Resources
- Management of foxes in rural areas factsheet — Copyright Department of Environment, Water and Natural Resources
Loss of habitat
Loss of habitat is one of the most serious threats to Australia’s terrestrial biodiversity. According to a statement released at the Society for Conservation Biology Oceania conference in Brisbane in 2016, land clearance in recent years has tripled, mainly to facilitate the expansion of pasture, agriculture and urbanisation. Woodland and forest loss is at nearly 300,000 hectares per year (according to the government’s latest figures) putting Australia amongst the world’s worst deforestation countries in the developed world1.
Historically vegetation clearance has been extensive in the Mount Lofty Ranges with only 13% of the original native vegetation remaining. In the Adelaide Hills Council region, remaining native vegetation cover is estimated at approximately 17,265 hectares, which is 21.7% of the total council area. These statistics reflects total ‘vegetation coverage’ and is misleading because it does not consider the condition of the vegetation community, so the actual area of viable habitat could be much lower.
As native vegetation continues to be cleared from the landscape or is further compromised by weed invasion and other destructive impacts, the lack of cover and subsequent loss of habitat begins to disadvantage local native species. It is considered that regional habitat retention targets must be at least 30% remnancy to avoid substantial loss of regional wildlife species, in particular birds2 and catastrophic loss of species can be expected when vegetation cover drops below 10%3.
It is vital to the region’s wildlife that ongoing land management focuses on retention and restoration of remaining native vegetation, as well as re-establishment of wildlife habitat through revegetation with local provenance species. Creation of wildlife corridors, or ‘biodiversity corridors’, is also necessary to improve connectivity of fragmented patches and better enable the movement of wildlife across the landscape.
Of the 17,265 hectares of native vegetation remaining, it is estimated that 31.5%, or 5,447 hectares is protected or managed for conservation in either the National Parks and Wildlife Reserves System, Heritage Agreements, Bush for Life sites and some Council parks and reserves.
1 Society for Conservation Biology/UNSW (2016)
2 Possingham, H. P. and Field, S. A., (2001). Regional bird extinctions and their implications for vegetation clearing policy. Lifeline 7:15–16.
3 DEH (2009) Informing Biodiversity Conservation for the Adelaide and Mount Lofty Ranges Region, South Australia. Priorities, Strategies and Targets.
The predicted changes to our environment driven by global warming present a number of key challenges for our natural environment. The increase to local temperatures by an average of one degree, reductions in winter rainfalls, increases in number of days over 35°C and increases in intensity of storm events, are some of the factors that are likely to directly impact on local biodiversity though the following mechanisms:
- Alteration of the timing of flowering and breeding cycles in native plants and animals,
- Interruption to winter growing season for plants,
- Increase in frequency and severity of bushfires,
- Increase in frequency and severity of flood events,
- Higher potential for erosion events,
- Changes in the impacts of introduced plants (weeds) and feral animals,
- Reductions in groundwater recharge, and
- Reductions in average stream flows.
A key management strategy identified under the Climate Change and Biodiversity Landscape Scenario Assessment for the Resilient Hills and Coasts Region document for terrestrial 'Upland Landscapes', is to 'Increase Resilience'. These landscapes would be expected to retain significant biodiversity values under all scenarios, but this would be contingent on removing existing threats, repairing past impacts, and re-instating impaired ecological processes1.
Conversely, wetland and riparian ecosystems are considered likely to experience significant variability in water regimes and the key management strategy is 'Active Adaptation to Transformation' to avoid the likely loss of these ecosystems and help maintain stability and ecological function.
A number of potential broad opportunities with regard to biodiversity management are worthy of consideration to help respond to climate change uncertainty. These could include:
- Strategic creation of new habitat areas through revegetation, including wildlife corridors and buffer zones across the region,
- Restoration and protection of existing habitat areas,
- Adjustment to species mixes for revegetation programs to accommodate changing conditions,
- Improving water storage capacity for use during dry periods, whilst ensuring environmental flows for local catchments,
- Improving fire-fighting capacities, and
- Developing adaptive integrated pest management programs.
1 West, A. (2016) Climate Change and Biodiversity Landscape Scenario Assessment for the Resilient Hills and Coasts Region. Natural Resources Adelaide and Mount Lofty Ranges, Department of Environment, Water and Natural Resources, Adelaide.
Inappropriate fire regimes
The Australian bush has adapted to fire over millions of years. Prior to the arrival of indigenous people to the continent, bushfires often started from lightning strikes.
Once aboriginal people started to arrive approximately 50,000 years ago, they used fire (fire-stick farming or mosaic burning) to help manage the vegetation by changing the structure and composition, and also as a hunting aid by flushing out animals. This changed many ecosystems, with the result of plants and animal species becoming adapted to fire or even disappearing from the landscape altogether.
Many of those that have become adapted to fire have developed physical characteristics to assist them in survival during and after a fire event. In some cases plant species have become reliant on fire to regenerate or to release their seeds. Other plants benefit from the increase in light, reduction in direct competition and influx of nutrients in the soils.
As with plants, some animal species benefit from their habitat burning, whilst others are disadvantaged. Some are either killed, whist others have the ability to escape. Overall fire can have both positive and negative effects on an ecosystem.
Fire ‘regimes’ have changed substantially since pre-European settlement and are now limited to either ‘uncontrolled’ bushfires, or ‘controlled’ or ‘prescribed’ burning . This has resulted in many plant and animal species being adversely impacted due to fire being either too often, too infrequent or too severe. The potential impacts of these scenarios are outlined below.
- Catastrophic loss of biodiversity (Loss of habitat and significant populations of plants and animals).
- Changes in plant species composition and structure due to loss of fire-sensitive plant species.
- Too severe fires can lead to elimination of plant populations, even those that possess some adaptations to fire.
- Increased weed invasion following fire.
- Loss of hollows in large trees (however fire also can also enhance hollow development in some instances).
- Reduction in invertebrate numbers and diversity.
- Disruption of life cycles of plants and animals, and has the potential to prevent plants and animals from recolonising the area.
- Changes in plant species composition and structure due to loss of fire-sensitive plant species.
- Increase in nutrient levels which aid weed growth.
- Increase in weed invasion.
- Reduction in the capacity for native plants to germinate through increased competition with weeds, thereby increasing the fire risk.
- Prevention and reduction of native seed set in soils.
- Loss of woody debris and leaf litter which provides habitat and enhances soil health and protection from erosion.
- Can threaten plant populations by damaging those flowering/seeding or sensitive juvenile plants.
- Can threaten fauna population during optimal breeding times.
- Changes in plant species composition and structure due to loss of those plant species that may rely on a fire event to regenerate.
- Reduction in optimal habitat for some species.
South Australia is no stranger to 'natural disasters'. Bushfires, severe storms, droughts and flooding are the main offenders, with the potential to cause significant hardship for individuals and communities, and can even result in loss of life.
In most natural systems, floods and fire in particular, can play an important role in maintaining key ecosystem functions and promoting biodiversity. From triggering native plant species recruitment and fauna breeding events, dispersal and migrations, to refilling wetlands and recharging groundwater systems, our ecosystems display some level of resilience to these natural events. However environmental damage can also be considerable in response to the more serious events and following impacts to biodiversity are well recognised.
- Loss of hollows and habitat trees.
- Injury and death of wildlife falling from trees (birds, bats, possums, koalas etc).
- Damage and loss of habitat (nests and hives etc).
- Drowning of wildlife caught in flood waters or inundated in dens and burrows.
- Wind/water erosion to creeks and river banks, exposed sites, hill-slopes, and floodplains.
- Excessive deposition of sediment, smothering vegetation and potential habitat.
- Loss of plant species on creek banks.
- Influx of nutrients in creeks, rivers and reservoirs.
- Dispersal of weed species.
- Dispersal of exotic fish species.
- Loss or reduction of wetland function.
- Release of pollutants from flooded sewers etc.
- Erosion of soils and potential loss of already very low levels of nutrients.
- Wildlife death and injury.
- Large-scale loss of habitat.
- Local extinctions of entire populations of plants and animals.
- Displacement of wildlife.
- Increased vulnerability to wildlife from predators, traffic and interaction with humans.
- Increased weed recruitment and promotion of invasive species.
- Exposed soils vulnerable to erosion and potential loss of already very low levels of nutrients.
- Wildlife death.
- Increased vulnerability to stressed wildlife (eg koalas and possums seeking water on the ground).
- Death and loss of plant species.
- Reduction in plant recruitment.
- Interference/interruptions to wildlife breeding cycles.
Inappropriate recreational activities
The inappropriate use of areas for recreational purposes (such as for off-road vehicles/bikes, horses), poses a significant threat to biodiversity across the region. Whether it is off-road vehicles in parks and reserves or bike riding and horse riding on designated walking trails, the use of areas unsuitable for these activities can lead to a number of issues, not limited to:
- Spread of weeds and soil pathogens (eg. Phytophthora).
- Erosion of trails.
- Damage and destruction of native vegetation, including threatened plant populations.
- Disturbance of wildlife.
- Destruction of habitat.
There are designated public areas across our region where some of these activities can legally take place.
The State Government is working to establish Adelaide and the Mount Lofty Ranges as an international mountain biking destination, building on the already extensive network of trails across national parks, forest reserves and other public land.
Find more information on the Visit Adelaide Hills website.
Pollution of waterways
As well as providing a significant component of the total water supply needs of Adelaide, the catchments across the Mount Lofty Ranges contain important aquatic environments that support a number of key communities as well as numerous threatened species. These catchments are also important agricultural areas and increasing urbanisation and rural living has facilitated a number of challenges associated with water quality issues. This includes contamination of through blooms of toxic algae, pesticides, water-borne parasites, sediment from erosion of degraded river banks, animal and human faecal contamination and localised heavy metal contamination.
Some of the direct causes of ongoing contamination of waterways include:
- Faulty or leaking septic tank systems;
- Direct access to waterways by livestock, which exacerbates erosion of banks, stirs up sediment and contaminates water with faecal matter;
- Runoff from overgrazed and cropping areas delivers excessive sediment and nutrients in to the waterways1;
- Stormwater runoff can carry pesticides, fertilizers, rubbish, oil, heavy metals from human activities (eg. Cultivation, livestock management (dairies, piggeries), industry (wineries, abattoirs), landfills, waste and recycling depots and rubbish dumping, wastewater treatment plants).
- Deciduous trees leaf drop in autumn containing high nitrogen content;
- Rubbish dumping.
Once certain contaminants reach waterways, the pollutants can impact directly on the health of native fish, animals, insects and plants that rely on those riparian ecosystems. Other contaminants such as nutrients can cause the excessive influx of unwanted plants and algae that impact natural waterways.
1 EPA (2000) The State of Health of the Mount Lofty Ranges Catchments from a water quality perspective. Environmental Protection Agency, Adelaide, SA.
Outcomes in recent years show South Australia is leading the nation in achieving significant recycling rates and waste diversion. KESAB (Keep South Australia Beautiful), who has played an important role for many years, has effectively engaged with schools, councils and community in delivering litter campaigns, recycling and resource recovery education.
However illegal dumping is still a huge problem across the state, threatening the health of humans and wildlife and damaging the environment. Local offences range from dumping of domestic and commercial waste on roadsides and in bushland, often to avoid disposal fees, to non-licenced activities (eg. asbestos dumping), to general littering.
KESAB has listed a ‘dirty dozen’ of general litter which include cigarette butts, paper and plastic items including food containers and utensils, confectionary wrappers, plastic sheeting, beverage containers (2% in SA compared to 14% in other States), cigarette packets and bottle tops and straws are the key offenders.
In recognition of improving services to the community around litter regulation and local environmental nuisance, the South Australian Parliament passed legislation to support councils to deal with and penalise illegal dumping and littering with the Local Nuisance and Litter Control Bill 2015 coming into effect on 1 February 2017.
Previously, local councils and the EPA managed these issues, as it was not clearly outlined who was the best placed to investigate them. The EPA SA will retain responsibility for assisting councils to manage local nuisance complaints and for leading significant illegal dumping investigations, however councils continue to manage smaller-scale unauthorised dumping cases.
The Act introduces higher penalties for the illegal dumping of asbestos, including a maximum $250,000 fine or two year’s imprisonment, whilst other changes include improving surveillance technology to gather evidence and allowing for public reporting of littering and illegal dumping by associating alleged offence to a vehicle’s registered owner. This effectively gives councils better tools for policing and enforcement.
From 1 May 2017, fines are also imposed to those caught littering from their vehicles following a three-month grace period where warning letters were issued in lieu of fines. Fines range from $210 for general litter, $500 for Class B hazardous litter which includes lit cigarettes or butts, used syringes and glass, and $1,000 for quantities of litter over 50 litres such as illegal dumping.
Unauthorised firewood collection
The collection of timber for firewood from roadsides and woodlands within the district contributes to biodiversity losses through direct loss and damage to existing habitat, and exposure of soils and leaf litter layers, and can lead to reduction in soil nutrients to the forest floor.
Often people fail to appreciate that by removing dead and fallen trees for their firewood, they are impacting on the habitat of native animals. In addition to collection of firewood, it is often mistakenly viewed as 'cleaning up' and reducing fuel loads. However, many native species of birds and mammals rely on fallen branches and dead trees (particularly those with hollows), as valuable habitat.
Species of reptile, such as the Eastern Bluetongue, Sleepy Lizard, geckoes and skinks would utilise fallen sticks and branches, whist mammal species such as Echidnas, Southern Brown Bandicoots, Bush Rats and the Yellow-footed Antechinus all rely on dense woody shrub layers with lots of fallen logs and branches for harbour and protection from predators. A vast variety of invertebrates are also reliant on these habitats, including spiders, ants, termites and borers, with some contributing to the decomposition of woody debris and providing food for native animals.
Dead standing trees are used by many species of birds, bats and possums, particularly those with hollows which provide nesting and den sites to species such as the Yellow-tailed Black Cockatoo, Rainbow Lorikeets and Adelaide Rosellas, the Australian Wood Duck, Brush-tailed and Ring-tailed possums and numerous micro-bat species.
Fallen timber also contributes significantly to soil health. It provides nutrients to the soil as the gradually break down process occurs due to weathering, termites and the growth of fungi. It also acts as mulch, and protects ‘microclimates’ of damp soil, where soil invertebrates thrive and even assists plants to germinate and grow. Fallen logs and branches trap seeds and also assist with soil retention, intercepting and slowing runoff and assisting the accumulation of leaf litter.
The Adelaide Hills Council does not permit any collection of timber along any Council roadsides or reserves and penalties can apply. The best sources of firewood are from registered suppliers within the Adelaide Hills region, however ensure that the wood is ‘sustainably sourced’ so that you can be confident that habitat was not destroyed in the process of obtaining it.