Beating around the bush

For this post, I wanted to introduce the biodiversity of Australia and look at how this is changing. Biodiversity is the variability of life and genetic health within an ecosystem, biodiversity is highest in areas of high primary productivity, such as tropical rain-forests and coral reef systems. Globally the genetic biodiversity of the world is classed as beyond the zone of uncertainty, meaning we are in venturing in unknown waters, possibly creeping into a 6th a mass extinction. 

Continental isolation has led to very high levels of endemism across the Australia continent and the surrounding ocean. Across the vast country, it's estimated still 75% of the flora and fauna remains to be formally described. There are 150,000 species of flora and fauna identified across Australia,  endemism is 93% through flowering plants, 46% of birds, 69% of mammals, 94% of amphibians, 93% of reptiles. Figure 1 shows an example of an endemic Australian reptile, Tiliqua rugosa.

 Figure 1. A Shingleback (Tiliqua rugosa) lizard in the Plumridge lakes region of Western Australian. As an example of Australian biodiversity. Photo credit J Chapman

Australian biodiversity is in decline, pressures from multiple fronts have had a cumulative strain upon the environment, which even given the increasing amount of area, which is under protection (currently 17% of land and 36% Australian marine area) has led to deterioration of the Australian environment.

Figure 2. Terrestrial protected areas and Indigenous Protected Areas for 2016
From State of the Environment 2016 

Some of the most significant threats to biodiversity across Australia are clearing and land use, climate change, invasive species and related pathogens, governance, changing fire regimes and pollution. Not surprisingly, the areas surrounding regions of high human habitation are feeling a disproportionate level of impact (Fig. 3).

Figure 3. Showing the distribution of threatened ecological communities in Australia, listed under the Environmental Protection and Biodiversity Conservation Act 1999.
Source: Environmental Resources Information Network, Australian Government Department of the Environment and Energy, 2015. via Australia, State of The Environment 2016. 

Since Europe colonizers arrived on Australian shores, the amount of native forests has decreased by ~38%, what makes this more remarkable, than the already staggering figure, is that the bulk of this deforestation was during the 20th century, post world war two. The Southwest corner of Western Australia was classified as a 'biodiversity hotspot' with exceptional concentrations of endemic species, however by the year 2000, ~90% of the primary ecosystem had been cleared largely for farming, through the wheatbelt.

Figure 4. Total native forest coverage by state expressed as a percentage of total land area (data from Australian Bureau of Rural Sciences 2010). Altered from Corey and Bradshaw (2012) 

The most critically important factor leading to ecosystem decline and species extinction, is habitat loss, through land clearing, with the cattle industry being the primary driver. Even though levels of habitat loss have stabilised through most of Australia, the overall level of land clearance is astonishingly high for a developed nation, with no immediate sign of decline.

The level of biodiversity across Australia is magnificent, with many species still awaiting formal classification, but without further protection from government in the most sensitive and critical areas and lifestyle changes among it's population, then there will be lesser country for future generations.