Dot Point 1: Ecosystems at Risk - HSC Geography Course

1. YEAR 12 HSC GEOGRAPHY
UNIT 1:Ecosystems at Risk
1: Biophysical interactions which lead to diverse ecosystems and their functioning
Mr Shipp

2. MAIN SYLLABUS

3. • Ecology is the science that examines the interactions between living
(biotic) and non-living (abiotic) environment
• Ecosystems are dynamic and adaptive systems through solar energy is
captured and channelled through a variety of lifeforms
Ecosystems and their Functioning

5. • Vary naturally or through
human intervention
• Ecosystems have changed
due to global climate and
sea level (10,000 years
ago)
• Ecosystems can be
classified due to their
dominant feature, physical
features or vegetation
• Ecosystems can be
categorised by terrestrial or
aquatic
Variations in Ecosystems

7. Hint: The Biosphere is the aggregate of all ecosystems on the
planet

8. INTERDEPENCE
LEVEL 2: DEFINITIONS
TERRESTRIAL

9. Hint: For the HSC paper, you will need to know two different types of ecosystems.
It is important to know different types away from your excursion
• Ecosystem productivity can involve:
• The amount of biomass produced in an area (per metres
squared)
• Energy flows of nutrients and matter through the ecosystem
Productivity of Ecosystems

11. • Producers, consumers and decomposers form a
chain that facilitates the energy from the sun
through plants to animals in the ecosystem
• Through the food chain nutrients are cycled through
the different tropic levels
Energy Flows

14. • The sun is the primary source
of energy which plants use
to photosynthesise
• Nutrient cycles pass from the
non-living (Atmo, Litho and
Hydro) to living (Bio)
environment
• Nutrients and energy is lost
which results in fewer tertiary
consumers than primary

15. • Energy enters the biological
system as light energy, then
transformed into chemical
energy in organic molecules by
cellular processes including
photosynthesis and respiration
• This energy is dissipated,
meaning it is lost to the system
as heat; once it is lost it cannot
be recycled.
• Thus the earth is an open
system with respect to energy.

17. • Most of the available food or nutrients for any ecosystem are found in the
top layer of soil and leaf litter.
• The biomass (total dry weight of all organisms at each level) of food
available is in the lowest trophic levels.
• Nutrients can be passed through oxygen, carbon, water, phosphorus and
nitrogen cycles
Nutrient Cycling

18. • The consequence of the loss of energy between trophic
levels that contaminants collect in animal tissues
• This occurs when an organism absorbs a toxic substance
at a rate greater than that at which the substance is lost.
Bioaccumulation

20. AUTOTROPHIC
LEVEL 2: DEFINITIONS
HETEROTROPHIC

22. HSC EAR ESSAYS
2018
2019?
2017
2016
2015

23. DESCRIBING AFFECTS OF NUTRIENT CYCLING
LEVEL 4: PAST PAPER QUESTION