Threatened plant and animal species are those which may be vulnerable to extinction in the wild due to low populations, highly restricted distributions and habitats or continued threatening processes. The Wet Tropics is has a high proportion of threatened species, many of which are also rare or endemic. They include some iconic species such as the southern cassowary and the mahogany glider, but most of them are little known, particularly the plants, frogs and invertebrates. The high level of threatened species is related to the unique evolution of the flora and fauna in the Wet Tropics, as well as loss of habitat due to forest clearing and changes to water and fire regimes.
You can read all about the value of threatened species and communities and the Australian and Queensland legislation on the threatened species and communities page.
Maintaining and restoring healthy ecosystems as habitat for threatened species is the best way to prevent further declines. This includes creating habitat connectivity across the Wet Tropics landscape for plants and animals to move around and interbreed. Much of the tree planting for wildlife corridors has focused on particular endangered species such as the cassowary and the mahogany glider as key representatives of habitat types. Habitat restoration and connectivity is also a primary response to the potential impacts of climate change.
Fragmentation from roads, powerlines and other linear infrastructure can be a barrier to animal movement. For example, many species will not cross cleared or weed infested areas. Fish often need specially designed culverts to enable them to move across road and small levees and dam walls. Roadkills by cars is a significant threat for many species such as the cassowary and arboreal mammals.
As landscapes become fragmented through clearing, infrastructure development or cyclone damage, there are more opportunities for weeds, feral animals and diseases to overwhelm natural habitat. Wild and domestic dogs are a particularly direct threat to many threatened species such as the cassowary. Other invasive species may compete for food resources or out-compete native species. Diseases can be a very specific threat to certain species - for instance, the impacts of chytrid fungus on frogs or phytophthora and myrtle rust on plants.
Ecosystems such as the wet sclerophyll forests along the western edge of the World Heritage Area require regular fire management to ensure they remain as long term habitat for a range of threatened species (see altered fire regimes).
Drainage of wetlands and swamps and changes to water flows for dams and agriculture may also have a significant impact on wetland vegetation communities and animals (see altered water flows and quality).
Most management efforts for threatened species have focused on animals rather than plants, probably due to people’s natural affinity with animals. However, vegetation communities such as Mabi forest and littoral rainforests have been listed as endangered and there have been major community efforts to replenish and connect these vegetation types.
Some land acquisitions at Little Cooper Creek under the Daintree Rescue Program were specifically targeted at protecting rare and threatened plants and some threatened animal habitat may include endangered plants. There are numerous rare or endangered terrestrial orchids and ant plants in melaleuca woodlands between Tully and Cardwell which have been identified as a management priority.
Conservation management may also focus on some animal species that, although not officially listed as a threatened species (vulnerable or endangered), are considered potentially vulnerable due to their rarity or susceptibility to threatening processes. For example: