ENVIRONMENTAL STUDIES
GRADE 10
At the beginning of the year your Life Sciences teacher has grouped the learners in your class. Each group needed to identify a
terrestrial ecosystem (of known size e.g. 10m by 10 m) in their local environment.
Your group was approached by people from the local newspaper who indicated that they are interested in your ecosystem and that
they wanted to publish an article on your planned investigations within your ecosystem. They will need information on the biotic and
abiotic factors in your ecosystem. They also will need information on the positive and/or negative impact(s) of humans on your
ecosystem, a list of strategies that the school or your group could implement to reduce or prevent the negative human impact on your
ecosystem /school environment as well as ways to evaluate your implementation strategies.
The due date for your group’s findings is
……………………..2012.
For the purpose of investigating both biotic and abiotic factors as well as human impact on your ecosystem your group decided to
conduct the following experiment/s. You also decided to record your results/findings and to write up your experiment/s (see suggested
format below):
(a)
To use a sample method (e.g. quadrat method ) to get an estimate of the types and numbers of the plants in the selected
ecosystem.(Additional: A field guide or key to identify plants)
(b)
To use collecting nets/traps/branch shaking to collect and count a sample of insects in the selected ecosystem. (Additional:
A field guide e.g. SASOL guides or key to identify insects)
(c)
To use a thermometer to record the temperature at different points in the selected ecosystem and to comment on the
relationship between temperature and plant /animal life.
Investigation: Environmental studies Grade 10
2
(d)
To study the soil texture and compare the water – retaining ability (water capacity) of the different soil types in the
ecosystem in order to comment on plant/animal life living in the soil.
(e)
To collect and count (if possible) the evidence of human impact on the ecosystem.
PLEASE NOTE:
Investigations (experiments) MUST BE conducted in the usual scientific format. The following components must be included when
you COMMUNICATE/WRITE UP your experiments:
(a)
(b)
(c)
(d)
(e)
(f)
hypothesis
method/s used,
variables (controlled, dependant and independent),
recording of results/findings (graphs, tables etc.) analyzing results
Conclusions (identify trends, similarities and differences), communicate errors and modifications and make suggestions
how you would improve results.
You may include photographs as additional records.
Developed by Jean Goliath
2012
Investigation: Environmental studies Grade 10
3
SUGGESTED FORMAT FOR WRITING UP OF EXPERIMENTS
1. Hypothesis
2. Methods –
describe what you did and/or how you set up the experiments.
3. Results –
record what happened in the investigations, your results and any other observations. Tables and graphs
are included to enable you to make sense of your data.
4. Discussion and conclusion –
Analysis of your results. Report on shortcomings and make suggestions on how you would improve
your investigation. Also include strategies to reduce/prevent human impact on ecosystem/environment
and ways to evaluate these strategies over time.
Developed by Jean Goliath
2012
Investigation: Environmental studies Grade 10
4
DRAFT MEMORANDUM/TEACHER NOTES ON INVESTIGATIONS
Investigation(a)
Scientists usually use a sampling method e.g. quadrat method to get an estimate of the types and numbers of living things in an
ecosystem.
QUADRAT METHOD TO STUDY PLANTS:
Make a quadrat of known size by using material like pieces of wood, sticks or strong wire. The quadrat could be square and the
sides should be of similar length e.g. 1m each. Learners randomly throw the quadrat in the ecosystem. They need to take more than
one sample. At the end of each throw they observe the plants inside the quadrat and record their observations in tables and graphs
e.g. name/description of plant species, number of plants of a particular species in quadrat 1, 2, 3 etc., calculate the total number of
each plant species in the quadrats.
Learners can estimate the total number of each plant species in their ecosystem by using the following formula:
Total number of a specific plant species in quadrat 1 =
number of the plant species in sample area x habitat area
sample area
They than use the same formula to calculate the number of a specific plant species in the other sample areas. After this they get the
sum of the answers for each quadrat and divide their answer by the number of times that they have made a sample selection to get
the average total number of that plant species in their ecosystem.
Developed by Jean Goliath
2012
Investigation: Environmental studies Grade 10
5
Investigation (b)
USE OF NETS/TRAPS/BRANCH SHAKING TO COLLECT AND STUDY ANIMAL LIFE.
Nets:
Learners use nets to collect as many insects as they can from the air, bushes, grass and ground. They then need to count and
identify the types and record their results in tables and graphs.
Traps:
Traps can be made from household material e.g. use jars/pots etc. The traps are dug in the ground so that they are level with the
ground and touch it all around. Please note that surrounded vegetation should be disturbed as little as possible. Pour catching fluid
e.g. anti freeze mixed with water or tissue moistened with a few drops of ethyl acetate (pharmacies) in each trap. Put traps at equal
distance from each other. Mark the traps with a flag.
Branch shaking:
Learners use a white sheet/fabric and lay the sheet at the bottom of the branch that they will shake. The firmly shake the branch
and when finished they collect the insects by bringing the corners of the sheet together. They then need to funnel the collected
insects into a jar. After this they add ethanol to the jar. They then take the jars into the classroom and examine what they have
collected. In the classroom they separate the insects into groups that look different by using tweezers/toothpicks. They may need a
magnifying glass for this. They then record the different groups (see attached example of a field guide - SASOL) on a data sheet
and count the number of different groups. They can now calculate the average number per bush and this will give them an idea of
the biodiversity of insects in their ecosystem. They can record their results on a data sheet and graph.
Developed by Jean Goliath
2012
Investigation: Environmental studies Grade 10
6
EXEMPLAR OF A RUBRIC TO ASSESS PRACICAL INVESTIGATION
Assessment criteria
Formulate a hypothesis
Identify variables
Designing/planning
and conducting of
experiments
Presenting results in an
appropriate format e.g.
graphs, tables,
drawings etc.
0
No attempt was
made
Cannot identify
any correct
variables
Not be able to
design or
conduct any of
the experiments
No attempt was
made
Critically analyze
No attempt was
information/data/results made
Developed by Jean Goliath
Marks
2
3
Hypothesis is
clearly
formulated and
expressed
Can identify two Can identify all
variables
three variables
correctly
correctly
Able to design
Creative
and conduct
practical
suitable
experiments
experiments
have been
with less
planned and
support of the
conducted
educator
without support
Results correctly
Results correctly Accurately
presented in
presented in
presents results
appropriate format appropriate
in appropriate
but with a lot of
format but with formats
errors/omissions
some
errors/omissions
1
Hypothesis is
incorrect cannot
be tested/Provides
a statement
Can identify one
of three variables
correctly
Able to design and
conduct simple
experiments with
the support of the
educator
Analyze
Analyze
information but do information but
not consider any
only considers
Analyze
information
based on all
4
Total
Critically analyze
information based on
all gathered
2012
Investigation: Environmental studies Grade 10
7
of the gathered
information
some of the
gathered
information
gathered
information.
Methods
evaluated
without
appropriate
suggestions for
improvement
Draws
acceptable
conclusions
Methods
critically
evaluated with
appropriate
suggestions for
improvement
Draws
acceptable and
accurate
conclusions with
clear and logical
arguments.
Critically evaluates
investigation and data
collecting methods
No attempt was
made
Methods
evaluated without
suggestions for
improvement
Drawing conclusions
No conclusions
made
Draws incorrect
conclusions
information and
explain
trends/patterns in
data
NB: Separate rubrics can be developed to assess graphs and tables.
Developed by Jean Goliath
2012
Investigation: Environmental studies Grade 10
8
REFERENCE/RESOURCE:
Weaving Alan , 1999. SASOL, Insects of Southern Africa, A first field guide. (Struik
Publishers)
Developed by Jean Goliath