Issue: Land condition - Condition of terrestrial species and ecological communities
This is an issue under the Land theme of the Data Reporting System.
The condition of the land is almost synonymous with the condition of the land’s biodiversity. Generally, the pressures affecting the condition of the land do so by affecting the condition of the things that live in it, and the pressures affecting the condition of terrestrial biodiversity do so by affecting the condition of the land on which life depends for habitat and survival.
Species, habitats and ecological communities are crucial aspects of terrestrial biodiversity. The health of species, their habitats and ecological communities, determines the overall capacity of the land’s biodiversity to maintain the health of the land.
- LD-01 The proportion and area of native vegetation and changes over time
To fully understand what is happening to species, habitats and ecological communities, we would need indicators that show long term changes in number of species present within each habitat and habitat type, changes in numbers and distribution within each species, both within each habitat and between different habitats, an understanding of how each different species interacts with each other species and of seasonal, climatic and anthropogenic changes in habitats. To understand these processes at a continental scale, we would need to have this information across all habitats comprising the continent’s ecosystems.
Even if these interactions were understood, we would need sufficient historical data or understanding of ecological processes to know whether a major fluctuation between species is indicative of a natural, ecologically beneficial process or is a symptom of anthropogenic degradation.
No indicators, which either individually or collectively have the capacity to do this, have been identified. In the absence of any way of assessing the overall condition of all aspects of Australia’s terrestrial biodiversity, and the ecosystem as a whole, considering the condition of a selection of key species, communities and habitats is probably the best we can do. Known declines in species, communities or habitats may be indicative of broader declines in species communities and habitats. In particular, the extent of native vegetation which provides habitat for species may serve as a surrogate indicator for the general condition of the species and ecological communities which maintain the overall condition of the land.
Vegetation provides habitat for life forms from all the kingdoms (other plants, animals, fungi, bacteria and viruses). While the mere presence (extent) of vegetation is not necessarily indicative of the condition of either the vegetation itself or of the other things that live there, the ecological communities which maintain the overall condition of the land are more likely to still be present where native vegetation is still present. Therefore, the extent of native vegetation may serve as a surrogate indicator for the general condition of the species, habitats and ecological communities which maintain the overall condition of the land.
- LD-03 Change in extent and proportion of woody vegetation, clearing and regrowth
Extent of woody vegetation is a key indicator of the condition of the land, and therefore of terrestrial species and ecosystems. Woody vegetation is predominantly perennial and generally contributes to deeper and more stable surface soil, deeper root systems and groundwater, better protection for surface water, a more life-friendly microclimate and a more secure habitat for other plants and animals. Extent and change in extent, clearing and regrowth of woody vegetative cover is a surrogate indicator of the condition of species, habitats and ecological communities.
- LD-17 Fragmentation of remnant vegetation
While the gross area of vegetated land remaining is one indicator of the condition of the land and its biodiversity, the health and resilience of that remaining vegetation is also largely dependent on the size of the fragments and their proximity to each other.
Fragmented patches of vegetation may be the only remaining examples of particular vegetation groups or ecosystems in a region. They may also provide a source for any revegetation or restoration activities. The smaller and more isolated the remnants, the less viable and more vulnerable are the plants, animals and other biodiversity inhabiting them to external pressures as their boundaries (representing a significant proportion of their total area) are exposed to disturbances.
- BD-02 Conservation status of nationally significant species and ecological communities, compared with previous years
Changes to the landscape and native habitat as a result of human activity has put many of Australia’s unique species at risk. Although conservation status does not provide a measure of condition of species or ecological communities, it could, with other parameters, be used to indicate condition.
- Land - Land condition- Condition of terrestrial genetic diversity
- Land - Land condition- Soil stability and quality
- Land - Land condition- Hydrology
- Land - Land condition- Land cover
- Coasts and Oceans - Condition of the ocean and coastal waters- Condition of species, habitats and ecosystems
- Biodiversity - Species, habitats and ecological communities- Species diversity
- Biodiversity - Species, habitats and ecological communities- Conservation status of species and ecological communities