THE ORGANISM IN ITS ENVIRONMENT A case study of Bibra Lake

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THE ORGANISM IN ITS ENVIRONMENT(A case study of
Bibra Lake)

• SOSE/Biology Assignment
• By
• Dr Mark Brian Debowski

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Contents

• The abiotic environment
• Two species of plant (structure)
• Two species of animal (structure)
• Relating plants to the environment (behaviour and
  physiology)
• Relating organisms to the environment
• The web of life.

In this assignment I have chosen to take two
plants of different Class level to contrast. I
have deliberately chosen two animals of the same
Class in order to demonstrate how similar
animals in the same region having different
lifestyles and consequently are structured
differently.
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The Abiotic Environment Air

• Factors which are important include
• Temperature
• Humidity
• Wind velocity
• Bibra lake is situated near Perth in Western
  Australia. The climate is Mediteranian with a
  warm dry summer and a wetter and cooler winter.

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The Abiotic Environment Water

• Factors which are important include
• Salinity (ions)
• Temperature
• Clarity
• Dissolved oxygen
• pH

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In Summer

• As a consequence the micro-climate of the lake is
  very seasonal. In summer the water is still and
  not replenished when it evaporates. As a
  consequence the water levels drop, the
  temperature of the water rises and the clarity
  diminishes in the still water.

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In Winter

• In winter rain runs into the lake, the
  temperature of the water drops, the water level
  rises and the oxygen level in the water increases
  as the water moves. Because the water has flowen
  through limestone it is often crystal clear when
  it enters the lake.

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Aquatic environments vary much less than
terrestial environments in most parameters.
Consequently aquatic organisms cope poorly with
change.
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The Abiotic EnvironmentSoil (around the lake)

• Factors which are important include
• pH
• Soil particle size
• Chemicals present
• Bibra lake is a depression in the limestone
  layers which make up the costal plain. As a
  result the soil tends to be very alkaline, of
  large grains and with very little in the way of
  organic material.

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The soil in the lake

• As a depression where water has collected over a
  long period of time, organic materials have wash
  down and settled in the lake. Over the thousands
  of years organic remains from fuana and flora in
  or near the lake have also settled to the bottom.
• The result is a very rich layer of organic
  material which is found as sediment at the bottom
  of the lake. This is a good source of energy for
  small animals which in turn feed swans
  (interrelationship 1).

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General Principles Structure Relates to Function

• Scientists studying the natural history of
  animals noted in ancient times that the shape and
  form of animals related closely to the lifestyle
  of those organisms.
• Plants which live in wetland environments (for
  instance) often had structures which could easily
  dry out and leaves which could rise to near or
  above the water surface
• Animals living in wet lands had structures which
  made their bodies more water proof.

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Structure Relates to Function(Examples in
Birds-a study in natural history) Reference
R.M. Bain
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General Principles Function Relates to Structure

• Conversely function also relates to structure.
  Reeds live in the water and are supported by it.
  Water is readily available. Consequently only a
  small root system is needed.
• Yet for the Eucalypt, water is in short supply
  and the whole weight of the plant must be
  nourished and supported against gravity. Hence
  the root system of a Eucalypt is extensive and
  woody.

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Plant Species 1 (Structural Adaptations)
Reeds have fleshy erect leaves and shallow roots.
These structures enable them to grow in clumps in
rich soil and shallow water.
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Plant Species 2 (Structural Adaptations)
Eucalyptus are the dominant tree species of the
surrounding land. They have waxy leaves, bark
covered woody stems, deep roots to stand and to
cope with the long periods of dry warm weather.
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Animal Species 1 (Structural Adaptations)
The black swan has water proof feathers, broad
webbed feat for swimming and standing on mud,
wide scoop bills for catching food and a long
neck for reaching deep into the water.
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These two species of water fowl are also found in
Bibra lake. The duck has similar shaped beak and
feet to the Swan but has a shorter neck and legs.
Ducks are generally found in shallower water than
swans. The coot is a reed forager as a result
he has a sharper beak and little webbing to grab
hold of plants as he forages for little animals.
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The Black Swan
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Animal Species 2 (Structural Adaptations)
The pink and grey Gallah is a significantly
different bird. It has a small body, is brightly
coloured, has clawed feet and a curved hard beak.
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Pink and Grey Gallah
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Plant 1 Function and the Environment (Behaviour
and Physiological Adaptations)

• The reeds grow in the shallow waters near the
  edge of the lake where roots reach the bottom.
  They slow the water and provide places to hide
  and breed for little animals which act as food
  for water birds. The reeds also provide shelter
  for breading and hiding of the water birds.

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Plant 2 Function and the Environment (Behaviour
and Physiological Adaptations)

• Eucalyptus trees provide flowers which develop
  seed rich in oils for Pink and Grey Galahs. They
  also provide shelter and nesting sites for
  breeding. Debris rots and flows with the rain to
  the lake providing nutrients for the reeds and
  micro-fauna in the lake.

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Animal 1 Function and the Environment (Behaviour
and Physiological Adaptations)

• There are similarities between swans and the
  other water birds - the most numerous in Bibra
  Lake are the ducks. Features include webbed feet
  and similarly shaped bills. Ducks however are
  more plainly coloured as they nest within the
  reeds and are prone to ground predators. Swans on
  the other hand have nests which are less
  accessible (colour as a function of behaviour).

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Animal 2 Function and the Environment (Behaviour
and Physiological Adaptations)

• Galahs live in the trees near the water. They
  eat seeds hence having clawed feet for grasping
  wood and a curved beak for harvesting grasses and
  seeds (interrelationship 2). This species is very
  communal in nature providing protection in
  numbers

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The Web of Life
All components in an environment both influence
and are influenced by each other. For instance
winter brings new water increasing oxygen and
nutrients in the water of the lake increasing
invertebrate life (food for swans)
(interrelationship 3). Reeds put on new growth,
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• Cooler weather reduces water loss in land plants
  and as a result the Eucalyptus flower producing
  food for the pink and grey population
  (interrelationship 2).
• REFERENCES
• Bain R.M.(1961) Natural History Biologically
  Speaking. Whitcombe and Tombs Pty Ltd. Perth W.A.
• Our Year 11 Biology Texts