Environmental factors such as sunlight, water, temperature, nutrients, wind, salinity, and wave action shape the evolution of species and determine what types of plant and animal communities can thrive in different ecosystems. Australian ecosystems have adapted to a diversity of environmental conditions including arid climates, variable rainfall, high salinity, fires, and poor soil. Resources in an ecosystem including energy, biomass, and nutrients cycle between biotic and abiotic elements due to the actions of producers, consumers, and decomposers.

1. Environmental Factors
Image credit: http://www.sussexvt.k12.de.us/science/Biochemistry/Population%20Dynamic.htm

2. The type of
community of
organisms that can
flourish in an
ecosystem is directly
influenced by the
environmental
conditions

3. Australian Ecosystems
Diversity of ecosystems where many plant
communities have adapted to
Arid conditions
Variable rainfalls
High salinity
Fire
Poor soil

4. Environmental Factors
Several factors have shaped the evolution of
species
Sunlight
Energy source for photosynthesis
Competition can be quite intense in a rainforest
where plants at ground level receive low
intensity light.
In marine environments plants do not exist
beyond 100 meters due to insufficient light
Majority of producers – phytoplankton found
mainly on surface

5. Other species of algae (brown algae) contain
different pigments which are able to absorb light
enabling them to survive at greater depths
Water
Plant communities have developed adaptations
to suit the water availability of their
environment.
Saltbush, mallee trees etc. can deal with high
temperatures and evaporation keeping water
loss to a minimum

6. Plants have specialized leaves to store water i.e.
cactus
Waxy cuticles -prevent water loss
Some mammals have developed specialized
excretory systems that enable them to excrete
crystalline uric acid to reduce water loss
In rainforests many plants have high water
requirements while moisture at ground level
suits a range of insects and decomposers such as
millipedes, bacteria and fungi.
Lichen, mosses and other climbers grow in an
attempt to access available light

7. Temperature
Many organisms such as humans require a
critical temperature – 370C for cellular
metabolism and other homeostatic processes
Nutrients
Plants require essential nutrients to incorporate
into their tissue and to build organic molecules
such as
Phosphates
Nitrates
Sulfates

8. Many plants need to adapt to nutrient poor
soils, particularly in Australia
Wind
Strong winds force plants to adapt with deeper
or more extensive root systems
Salinity
Plants and animals exposed to high solute
concentrations need special adaptations to
avoid dehydration. Many excrete salts.

9. Wave action
Strong wave action countered by adaptations
such as strong muscular tissue enabling them to
hang on the rock substrate.
There are several typical ecosystems found in
Australia each containing its own biotic and
abiotic factors and a wide range of species

12. Mallee Ecosystem

13. Savanna Woodland Ecosystem

14. Rainforest Ecosystem

15. Intertidal Zone Ecosystem

16. Mangrove Ecosystem

17. Desert / Grassland Ecosystem

18. Resources
Resources are classified as either biotic or abiotic
The productivity of the community is how effective
a particular community is at converting the sun’s
energy.
Of the total amount of energy trapped by producers
only a small % is available at the next trophic level-
primary consumers
The majority is required by the producer for life
processes, growth, cell division, uptake and
synthesis of molecules

19. The term biomass refers to the total weight of
living matter in a community

20. The two main constraints on productivity of a
community are
Energy available
Quality of resources
Humans use fertilizers and irrigation to boost
productivity
Harvest of SA crops depends heavily on amount
and timing of rainfall

21. All organisms require energy and matter to build up
tissue. This energy is neither created or destroyed
but recycled. The main elements include
Carbon
Oxygen
Nitrogen
This recycling is due the actions of decomposers
such as bacteria and fungi which break down
organic material into inorganic material
Eventually returning the elements to the
environment