Habitat loss is one of the most significant drivers of biodiversity decline and extinctions worldwide. Humans are the major cause of habitat loss, as more and more habitat is cleared for urban development, agriculture and industry to support our growing population. Habitat can also be lost through environmental factors like fire or drought.
Habitat fragmentation is a related process that is often associated with habitat loss. It occurs when remaining vegetation is broken up into small, isolated patches by clearing or construction of barriers such as roads. This can result in populations of a species becoming isolated in small fragments of habitat, where they are more susceptible to inbreeding and the impacts of catastrophic natural events.
Fragmented habitat remnants are also more susceptible to degradation by influences from the surrounding areas, including invasion by weeds and feral animals and the impacts of uncontrolled grazing. This can lead to the loss of species from an area and interruption of important ecosystem functions, such as pollination and food webs.
In Australia, habitat loss has a major impact on native species and ecosystems and land clearing has been listed at both Federal and State levels as a Key Threatening Process. Within NSW alone, there are approximately 360 threatened species and 25 threatened ecological communities for which habitat loss, or fragmentation, is a known threat. In NSW it is estimated that 2000 individual birds alone are lost for every 100 ha of woodland cleared.
Habitat loss in the GER corridor
The GER corridor contains a significant amount of uncleared vegetation, however habitat loss, fragmentation and degradation are still major threats to its species and ecosystems. At least 17% of the total GER corridor area has been cleared or disturbed.
Clearing has been particularly focused on certain types of habitats throughout the GER. For example, significant areas of rich volcanic or alluvial soils have been heavily cleared for agricultural purposes, leading to their degradation. These areas need significant restoration, as well as protection and maintenance of remaining vegetated areas, such as remnants of fertile woodland vegetation contained within the Travelling Stock Routes (TSR) networks in NSW and Queensland.
Preventing and reversing habitat loss
GER has an important role to play in preventing and reversing the impacts of habitat loss, fragmentation and degradation. It is vital that the existing uncleared vegetation in the region is protected and managed in a way that maintains its environmental values and biodiversity. GER works closely with landholders to support them in managing habitat on their properties, though a variety of informal and formal commitments. GER and its partners also work to protect habitat on a range of public land types.
In areas of the corridor where habitat has been fragmented and degraded, GER is rebuilding linkages between habitat patches, revegetating cleared areas, and improving management of vegetation remnants and the lands around them to maintain and restore their environmental values.