A2 Biology Field Studies
Specification points covered today:
(h) explain how human activities can manipulate the flow
of energy through ecosystems (HSW6b);
*continuation from earlier
(i) describe one example of primary succession resulting
in a climax community;
(j) describe how the distribution and abundance of
organisms can be measured, using line transects, belt
transects, quadrats and point quadrats (HSW3);
Key words that you will need
to be able to define......
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Moraine
Pioneer plants
Succession (primary & secondary)
Seral stages
Climax community
Continuous/interrupted transect
Line transect
Belt transect
Intensive farming is a way
of manipulating energy
flow in food chains
How might farmers go about minimising the
loss of energy from their crops and
livestock to ensure MAXIMUM yield? (using
named examples may help)
1. __________________________________________
2. __________________________________________
3. __________________________________________
4. __________________________________________
5. __________________________________________
Monocultures
A single species of plant grown
in one area – what would be the
ADVANTAGES of this?
Minimising energy loss from
movement
Youtube link
Does high productivity outweigh the ethical
concerns?
Exam question (3 marks)
Suggest which animals would be the most efficient
to farm; Endotherms (like birds & mammals) or
Ectotherms (like worms, fish & reptiles)
Explain your answer
Changes in Ecosystems:
Ecological Succession
DESCRIBE WHAT YOU SEE
Succession definition:
• Natural, gradual changes in the types of
species that live in an area; can be
primary or secondary
• The gradual replacement of one plant
community by another through natural
processes over time
Glaciers retreat to leave
MORAINE
Moraine – debris that a melting glacier
leaves behind. Contains rocks of
various sizes
LABEL what is happening at each stage a-d
Primary Succession
• Begins in a place without any soil
– Sides of volcanoes
– Landslides
– Flooding
– Glacier retreat
• Starts with the arrival of living things such
as lichens that do not need soil to survive
• Called PIONEER SPECIES
Primary Succession
• Soil starts to form as lichens and the forces of
weather and erosion help break down rocks into
smaller pieces
• When lichens die, they decompose, adding
small amounts of organic matter to the rock to
make soil
QUESTION: a) Decomposers would breakdown lichens into
what nitrogen containing compound? (1)
b) What is the process called that converts this compound into
USABLE nitrogen-based chemicals for plant growth? (1)
c) Name the micro-organisms involved & any intermediate
products (3)
http://www.life.uiuc.edu
Primary Succession
• Simple plants like mosses and ferns can
grow in the new soil
http://www.uncw.edu
http://uisstc.georgetow
n.edu
Primary Succession
• The simple plants die, adding more
organic material
• The soil layer thickens, and grasses,
wildflowers, and other plants begin to take
over
http://www.cwrl.utexas.edu
Primary Succession
• These plants die, and they add more
nutrients to the soil
• Shrubs and tress can survive now
http://www.rowan.edu
Primary Succession
• Insects, small birds, and mammals have
begun to move in
• What was once bare rock now supports a
variety of life
http://p2-raw.greenpeace.org
Secondary Succession
• Begins in a place that already has soil and
was once the home of living organisms
• Occurs faster and has different pioneer
species than primary succession
• Example: after forest fires
SERAL stages
http://www.geo.arizona.edu
http://www.ux1.eiu.edu
http://www.agen.ufl.edu
Climax Community
• A stable group of plants and animals that
is the end result of the succession process
• Does not always mean big trees
– Grasses in prairies
– Cacti in deserts
W
What conditions would plants be
exposed to and how would they be
adapted to this?
Transects: LINE, BELT, CONTINUOUS, INTERRUPTED
Procedures & equipment to consider when studying
succession
Distinguish between a line transect and a belt transect.
Outline the advantages and limitations of using a frame
quadrat.
Outline the advantages and limitations of using a point
quadrat.
Studying succession – normally involves
use of transects
Describe how you would investigate plant diversity along a sand dune.
For each scenario use pages 190 & 191
Scenario 1: Using a gridded quadrat along a line transect (8 marks)
Scenario 2: Using a point quadrat along a belt transect (8 marks)