The impact of threats on society and OE by itroduced species Urbanisation

Impact of Invasive Species

Invasive species can significantly impact native species and ecosystems by outcompeting and replacing them, altering food webs, and affecting soil structure and water balance. They can also introduce diseases and parasites to native species and disrupt ecosystem processes like nutrient cycling, seed dispersal, and pollination.

Threats from Invasive Species

Invasive species can pose a threat to human health and economic sectors such as forestry, agriculture, and tourism.

Phytophthora cinnamomi

This soil fungus, also known as cinnamon fungus, was likely introduced to Australia through European settlement and is responsible for dieback in many native plants.

Macquarie Island Case Study

In 2014, Macquarie Island, a UNESCO World Heritage Site, was declared pest-free after a seven-year eradication project that removed feral cats, rats, mice, and rabbits. This has allowed native animals and plants, like burrow-nesting birds, to recover and flourish. The eradication involved shooting, aerial baiting, manual baiting, hunting dogs, and the introduction of calicivirus.

History of Pests on Macquarie Island

Rats, mice, cats, and rabbits were introduced to the island between its discovery in 1810 and the subsequent 60 years. At their peak, it's estimated that feral cats killed 60,000 seabirds a year before they were eradicated in 2000.

Blackberries

The blackberry was introduced to Australia in the mid-1800s as a horticultural plant. It grows vigorously, can quickly infest large areas, reduces native wildlife habitat, limits access to water, displaces native plants, and provides food and shelter for introduced pests like rabbits and foxes.

Socioeconomic Impact of Blackberries

Blackberries reduce the land available for grazing and its productivity by competing for soil moisture and nutrients. They also diminish the aesthetic and conservation value of public lands, parks, and reserves.

Rabbits

Rabbits were first introduced to Australia with the First Fleet in the 18th century for food. They became widespread after a release near Geelong in 1859. Their burrowing, vegetation removal, and soil disturbance contribute to soil erosion. The annual economic damage from feral rabbits in Australia is estimated to be around $600 million in lost production.

Deer

Deer were introduced to Australia from Europe in the 19th century as game animals for hunting. They are a significant emerging pest, causing damage to both the natural environment and agricultural businesses. Their populations are expanding, and they are invading new areas, where they trample plants and foul water holes.

Cats

Cats have a massive and often catastrophic impact on native species and are notoriously difficult to control. There is an urgent need for an effective solution that can be used in diverse landscapes to protect endangered species and prevent others from declining. Felixer traps are a promising option.

Urbanisation

Urbanisation is the growth of towns and cities and the increasing number of people living in them. This growth increases demands for goods and services from the environment and leads to urban sprawl, where suburbs encroach on natural habitats. This creates challenges for developing infrastructure like public transport, roads, schools, and hospitals. Larger cities also consume more energy, resulting in higher greenhouse gas emissions.

Impacts of Urbanisation

These include loss of vegetation, habitat, and biodiversity due to demand for housing land; increased water demand reducing availability for native species; pollution of air, water, and soil; increased need for waste disposal; higher greenhouse gas concentrations; heat retention in urban infrastructure leading to more fossil fuel use for cooling; increased strain on sanitation and health systems; a higher cost of living; and increased land degradation such as salinity and erosion from water loss for irrigation.

Habitat Modification

Altering outdoor environments for human use, like clearing native vegetation for housing and agriculture, has had a dramatic impact on native biodiversity. Most of Victoria has been heavily modified for human use. The removal of any species or feature from an environment affects the entire ecosystem and is a primary cause of native species extinction in Australia. Over 310 native animal species and more than 1180 native plant species are currently at risk of extinction.

Loss of River Flows

Hydro-electricity schemes, irrigation, and town water supply systems, in addition to natural droughts, have drastically altered river flows in Victoria. Rivers and streams have been diverted or dammed, leading to a range of issues from waterways drying up to complete inundation, which has severely affected or destroyed ecosystems. Since 1967, the Snowy Mountains Scheme has diverted 99% of the upper Snowy River's flow for hydro-electricity and irrigation.

Vegetation Loss

Victoria loses approximately 2500 hectares of native vegetation each year. Clearing land for settlements, grazing, mining, logging, and crops has altered environments and, in some instances, completely removed all natural vegetation and habitats for animals, birds, and insects.

Forestry and Sustainability

Around 1% of multiple-use forests are harvested annually, with rotational regeneration efforts aiming for sustainability. It is projected that plantation timber will soon meet all demands for timber and forest products.

Clear Felling

This is one of the most damaging environmental practices, as it removes trees of all ages and slows down regeneration because plants struggle to survive without the protection of older, larger trees. It also results in the loss of animal and bird habitats and nesting sites, which can threaten the survival of species.