Area of Study 1 - Why is maintaining biodiversity worth a sustained effort?
Key Knowledge - How can biodiversity and development be sustained?
- the definition and categories of biodiversity: genetic, species and ecosystem
- the importance of genetic diversity within a species or population experiencing environmental change
- ecosystems as a source of renewable services that impact on human health and well-being:
- provisioning services: potable water; food; fuel; fibre; and pharmaceuticals
- regulating services: control of climate and disease; pollination; and water purification
- supporting services that maintain conditions for life on Earth: cycling of nutrients; soil formation; and photosynthesis
- cultural services: aesthetic values; recreational benefits; and sense of place
Key Knowledge - Biodiversity changes over time
- evidence of variation in rate and extent of change in biodiversity over time: significant mass extinctions and periods of rapid species diversification that can be inferred from the fossil record
- natural changes occurring over different time scales that influence ecosystem diversity, species endemism, the formation of diversity hotspots, and rate of extinction: volcanic eruptions; fire; El Niño; tectonic plate movement; and evolution
Key Knowledge - Assessing changes in species diversity
- practical techniques used for assessing species diversity: sampling with grids, transects and different shaped quadrats, including consideration of edge effects and mark-recapture
- measurement of species diversity, including species richness, endemism and the application
of Simpson’s Index of Diversity (SID):
SID =
- conservation categories for ranking species according to their risk of extinction: extinct in the wild; critically endangered; endangered; vulnerable; near threatened; and least concern
- qualitative assessment of conservation status to identify the species most in need of conservation action: changes in availability of suitable habitat, geographic distribution, and population size
Key Knowledge - Threats to biodiversity
- human and non-human threats to biodiversity: creation and isolation of small populations through habitat loss and over-exploitation; inbreeding due to small population size; loss of pollinators, dispersal agents, host species or symbionts that affect reproduction and persistence of species; bioaccumulation that concentrates some persistent pollutants within organisms and biomagnification along a food chain; climate change; disease; and introduced species that compete for shelter, food and water