Coaching Centre
Chapter 1: Ecosystems Notes
Ecosystems, biotic and abiotic factors, food chains and food webs, energy flow and the 10% rule, habitat loss, pesticides building up in food chains, introduced species and biological control, microorganisms and what they do for us and against us, managing bushfires and other natural events, and sustainable farming.
Sections
-
1A Ecosystems and the biosphere Mastered
The biosphere and the Earth's four spheres, what an ecosystem is, biotic and abiotic factors, habitats, populations and communities, and the things ecosystems do for people, from clean water to pollination.
-
1B Food chains and food webs Mastered
Where the energy in food comes from, producers and consumers, autotrophs and heterotrophs, herbivores, carnivores and omnivores, decomposers and detritivores, trophic levels, reading and drawing food chains and food webs, and what happens when a species is removed.
-
1C Energy flow in ecosystems Mastered
Why only about 10% of the energy passes from one trophic level to the next, where the rest goes, energy pyramids, why there are fewer predators than prey, why food chains are short, and sustainable ecosystems.
-
1D Habitat loss and pollution Mastered
How people change food webs: urban sprawl and land clearing, species that win and lose, soil erosion and land degradation, overgrazing and overfishing, and how pesticides such as DDT build up in food chains (bioaccumulation and biomagnification).
-
1E Introduced species and biological control Mastered
Why introduced species become pests, rabbits, foxes, cats and the northern Pacific seastar, prickly pear and the cactus moth, cane toads and what went wrong, biological control done well, and why biodiversity makes ecosystems stronger.
-
1F Microorganisms Mastered
What microorganisms are, how small they are, stromatolites and the first life on Earth, bacteria, archaea and extremophiles, protists, microscopic fungi such as yeasts and moulds, why viruses are not counted as living, and making results reliable by repeating trials and averaging.
-
1G Helpful microorganisms Mastered
Microorganisms at every level of a food web: phytoplankton and nitrogen-fixing bacteria as producers, microbes in yoghurt, bread and cows' stomachs as consumers, decomposers and recycling, sewage treatment, cleaning up oil spills, and the microbiome in your gut.
-
1H Harmful microorganisms Mastered
Eutrophication and algal blooms, fish kills, pathogens, disease-causing bacteria, fungi and protists such as tetanus, Salmonella, tinea, chytrid fungus and malaria, viruses and prions, and keeping food safe in the fridge.
-
1I Managing natural events Mastered
Regular and irregular changes in ecosystems, how Australian plants survive fire, cool burns and crown fires, fire regimes, hazard reduction and Aboriginal cultural burning, the Black Summer fires, recovery after fire, and managing floods, droughts, cyclones and earthquakes.
-
1J Conservation and sustainable farming Mastered
Why we conserve biodiversity, Australian ecologists such as Joe Benshemesh and Peter Newman, ecological footprints, green corridors and wedges, dryland salinity, soil organic carbon, no-till farming and organic fertilisers, dung beetles, and selective breeding.
-
1K Ecosystems review Mastered
A summary of the whole Ecosystems chapter, key words, and a mixed test covering food webs, energy flow, human impacts, introduced species, microorganisms, natural events and sustainable farming.