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NSWGeographyQuick questions
Focus Area: Ecosystems and global biodiversity (2022 syllabus)
Quick questions on Ecosystem structure and function: HSC Geography 2022 Focus Area
10short Q&A pairs drawn directly from our worked dot-point answer. For full context and worked exam questions, read the parent dot-point page.
What is defining an ecosystem?Show answer
An ecosystem is a community of living organisms (the biotic component) interacting with the non-living environment (the abiotic component) within a defined area. The boundary is set by the question being asked: a rotting log, a coral bommie, a catchment, or an entire biome can all be analysed as ecosystems.
What are biogeochemical cycles?Show answer
Unlike energy, matter is recycled. The major cycles to know:
What are biotic components?Show answer
Producers (autotrophs such as plants, algae, phytoplankton); consumers (herbivores, carnivores, omnivores); decomposers (fungi, bacteria, detritivores).
What are abiotic components?Show answer
Climate (temperature, precipitation, sunlight, wind); substrate (soil, rock, sediment); water chemistry; topography; disturbance regimes (fire, flood, tropical cyclone).
What is carbon cycle?Show answer
CO2 is fixed by photosynthesis, transferred through food webs, returned by respiration and decomposition. Long-term storage occurs in vegetation, soils, ocean dissolved inorganic carbon, sediments and fossil fuels. Human combustion of fossil fuels is shifting carbon from long-term storage into the atmosphere on geological-scale timeframes.
What is nitrogen cycle?Show answer
Atmospheric N2 is fixed by lightning and by nitrogen-fixing bacteria (some free-living, some in legume root nodules). Nitrogen moves through nitrification, assimilation by plants, consumption, decomposition, and denitrification back to N2. Industrial Haber-Bosch fertiliser production has roughly doubled the rate of nitrogen fixation globally, contributing to eutrophication of waterways.
What is water cycle?Show answer
Evaporation, transpiration, condensation, precipitation, runoff, infiltration, groundwater flow. Ecosystems both depend on and shape water cycling: forests transpire water that supports downwind rainfall; wetlands moderate flood flows; mangroves trap sediment.
What is q1?Show answer
Define an ecosystem and identify two biotic and two abiotic components, with reference to a named ecosystem. [4 marks]
What is q2?Show answer
Explain energy flow and one biogeochemical cycle in an ecosystem of your choice. [6 marks]
What is q3?Show answer
Analyse the spatial distribution of two major ecosystem types, explaining the abiotic factors that shape their location. [8 marks]