Terrestrial landscape health
Terrestrial landscape health is one of three conceptual models that broadly focus on the biophysical systems in our region. They describe the ‘health’ of the systems and should be considered in association with the socially based conceptual models and subregional information to get a full picture of what we know about our region.
This conceptual model is based around our understanding of increasing loss and modification of native habitat. It includes two critical thresholds for ecosystems:
- below 60% habitat cover can result in a loss of ecological connectivity
- below 10% habitat cover can result in a loss of physical landscape function.
It is a generic description of landscape change, outlining broad impact types and implications.
About terrestrial landscapes
The terrestrial landscapes of the region support environmental health, economic productivity and social wellbeing.
The value of services provided by the soils, plants and animals are incalculable – they generate oxygen, remove carbon dioxide from the atmosphere, filter water for drinking, recycle nutrients, maintain habitat, provide recreational spaces and support tourism.
This region is unique with woodland and forest landscapes flanking the Mount Lofty Ranges, ocean to the south and west, and more arid habitats to the north and east.
The Mount Lofty Ranges are also a nationally recognised biodiversity ’hotspot’ and support a high diversity of native species and vegetation communities.
This region has a diverse bird fauna and supports over half of all bird species in South Australia. It also has a significant number of declining bird species with the Mount Lofty Ranges recognised as hotspot for declining woodland birds.
The native vegetation cover remaining in this region, since European settlement, is approximately 13% of which only 22% is protected under dedicated conservation tenures.
The coastal ecosystems range from samphire flats and mangrove forests in the north through broad sandy beaches and dunes in the metropolitan area to cliffs and sandy beach communities in the south.
These diverse ecosystems give enormous value to our society. The mangrove/samphire flat system is economically important because it is a breeding habitat for a number of commercial fish and crustacean species. These system are also the final destination for a number of migratory birds which travel annually from Siberia to escape the northern winter. And the sandy beaches not only make a popular recreational area, they are also a valuable protection barrier from coastal inundation and damage to homes and infrastructure.
Biodiversity in the region continues to decline, and faces continual pressures as metropolitan Adelaide grows. Key issues include fragmentation and degradation of native vegetation and landscapes, inappropriate fire regimes, unsustainable land management and resource use. The control and management of invasive species is also critical to protect biodiversity and primary production in the region.
A case study: Community action conserving biodiversity in the South Para
One of the largest areas of intact vegetation in the region occurs in the South Para catchment. In some areas the condition of habitat has been reversed and restored by changes in practice. The case study shows how following the conceptual model can lead to management and maintenance responses being implemented, which contributes to achieving desired outcomes for terrestrial landscape health.