a2 biology field studies

A2 Biology Field StudiesSpecification 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......

• 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.__________________________________________

Spec point (h

)

Monocultures

A single species of plant grown in one area – what would be the

ADVANTAGES of this?

Minimising energy loss from movement

Does high productivity outweigh the ethical concerns?

Youtube link

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://uisstc.georgetown.edu

http://www.uncw.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

http://www.geo.arizona.edu

SERAL stages

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

WWhat 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 & 191Scenario 1: Using a gridded quadrat along a line transect (8 marks)

Scenario 2: Using a point quadrat along a belt transect (8 marks)