Download Seasonal calendar lesson plan - Department of Environment and

Department of Environment and Heritage Protection
Junior Ranger program
Lesson Plan
Seasonal calendar
Purpose
There are patterns in nature that occur around the same time each year, like wattles (Acacia spp) producing masses
of yellow flower in June. Making associations between seemingly unrelated events provides a greater appreciation
of our environment. For example, when the wattle blossoms appear in northern Queensland the weather becomes
cooler, the winds shift to the south-east and the mackerel will be fat and biting closer to the shore. And in the
evenings the constellation Scorpius dominates the evening sky. These events happen every year at roughly the
same time.
Knowledge of these patterns enables Indigenous peoples to predict the occurrence of one event by the appearance
of another. There are widespread Aboriginal belief systems whereby a sequence of seasonal changes—such as
plants flowering, fruits ripening, animals appearing in abundance and seasonal winds arriving—were believed to be
all causally inter-related and inter-dependant, one triggering the next (Memmott, P. 2005).
One way to build on and share this knowledge is to construct a seasonal calendar to record natural events and
make associations between these events.
Links with the Australian curriculum
This activity is suitable for a broad range of year levels and may be used to demonstrate a range of learning
outcomes.
Year 2 Mathematics: Measurement and Geometry/Using units of measurement
Name and order the months and seasons.
Elaboration
Investigating the seasons used by Aboriginal people, comparing these to the seasons used in Western society and
recognising their connections to weather patterns.
Year 4 Science: Science Understanding/Biological sciences
Living things have life cycles.
Elaboration
Making and recording observations of living things as they develop through their life cycles.
30765
Year 5 Science: Science Understanding/Earth and space science
The Earth is part of a system of planets orbiting around a star (the sun).
Elaboration
Recognising the role of the sun as a provider of energy for the Earth.
Year 7 Science: Science Understanding/Earth and space science
Predictable phenomena on Earth, including seasons and eclipses, are caused by the relative positions of the Earth,
sun and moon.
Elaboration
Explaining why different regions of the Earth experience different seasonal conditions.
Year 10 Science: Science Understanding/Earth and space science
Investigating the affects of climate change on sea levels and biodiversity.
Activity:
Based on field observations, develop a seasonal calendar as a visual aid that assists students to make
connections about seasonal changes and events.
Procedure
It is important for junior rangers to continually observe and make note of what is happening around them. Each
time junior rangers conduct field activities they should observe what is happening in the natural environment
and make notes in their junior ranger field journal. These observations and notes will form the basis of a
seasonal calendar.
Students should try to answer questions such as:
• What animals are active today?
• Are there specific birds or animals that are behaving differently at the moment?
• Are the plants flowering at the moment, are new leaves appearing or is the vegetation changing colour?
Be aware also of non-living things—for example, whether it is hot, dry or wet, or whether there are obvious wind
patterns. Students should draw sketches of interesting observations in their field journal.
Whenever junior rangers go into the field ensure they record the following in their field journals:
•
•
•
•
•
•
wind direction
insect activity
temperature
which trees are flowering
appearance of migratory species
lifecycle stages in key species.
When returning to the classroom the entire class should discuss their findings. Include these observations on the
attached seasonal calendar template. It is best to print it in A3 and can easily be printed in black and white.
2
Background information
Measurements of time vary between cultures. Early Europeans noticed a long time ago that the year could be
broken down into four seasons, and many societies and cultures today still use these four seasons.
However, for many Indigenous people time can be measured by the presence or absence of plants and animals
and their associated changes. Knowledge of associations between events in nature lets Indigenous Australians
know that certain food supplies are becoming available. The flowering of a particular plant can be associated
with the availability of other cultural resources. For example, in the Torres Strait when the wind begins to blow
from the north-west, Islanders know that the turtles are mating and will soon lay eggs. In mainland Australia
some Aboriginal clan groups identified seven or more distinct seasons over the year. For more information, visit
http://www.bom.gov.au/iwk/
This knowledge of the seasons is acquired by observing the environment over time and through interpreting the
wisdom accumulated through traditional stories and passed on in customary traditions.
There is more than one explanation to account for the natural changes that occur over the year. A western
scientific explanation is that every year the Earth travels the same path around the sun and, because of the
tilt of the axis, we experience regular seasons. These regular changes in seasons cause a predictable response
in nature.
A traditional Aboriginal belief system still recognises time as being cyclic in nature but also suggests that
events and changes observed are the result of the interaction between living and non-living aspects of nature,
and each affects and predicts the presence of the other. They believe the appearance of Scorpius in the sky
and the mackerel being fat is not coincidence but cause and effect. Talk to Elders in the community about their
understanding of natural cycles and seasons.
Part of a much bigger cycle
Seasonal changes observed in the local environment throughout the year occur as part of a larger cycle of
events that take place on a planetary scale. Nature follows cycles because the Earth undergoes cycles in space.
It spins on its axis—giving us day and night—and rotates around the sun resulting in the seasons of the year.
The axis of the Earth’s rotation is tilted at an angle of 23.5 degrees and it is this tilt that gives us the seasons.
During the Australian summer the southern hemisphere is facing at an angle toward the sun, while during
winter it is pointing slightly away. The seasons change as the sun moves back and forth between these two
positions. If there were no tilt in the axis, every day would be exactly 12 hours long and there would be no
winter or summer; the wattles would not know when to flower and no one would know if the mackerel were fat!
In general, the whole solar system (including the sun, planets and moons) all spin in the same anti-clockwise
direction (looking down from an arbitrary north perspective). The common anti-clockwise spin is the result of
the original direction of spin of the gas and dust cloud from which the solar system formed. The planet Venus
and a couple of moons (which are really just captured asteroids) rotate in the ‘wrong’ clockwise direction.
Venus is thought to have been struck by a planetoid during in the early formation of the solar system causing
the change in rotation.
The Earth is complex. There is always variability in the system despite the precise nature of Newtonian physics.
While the orbit of the planet around the sun can be precisely determined and predicted far into the future,
subsequent seasonal changes in the local environment are subject to variation and are often less precise. For
example, the weather at the beginning of September is different each year even though the Earth is in the same
position relative to the sun.
3
m
be
r
ember
c
e
D
J a n ua
ry
Fe
b
a
ru
g
ay
Au
June
July
Animals present or specific behaviour observed,
for example lorikeets returning, turtles hatching.
Plant response to time of year, for example flowers
present, immature fruit emerging, new growth.
Non-biological observations for example prevailing
wind direction, wet or dry, storm season etc.
4
M
t
us
April
be r
m
e
t
Sep
h
Marc
Octob
er
ry
No
ve
nal Calenda
o
s
a
r
Se
Extension activity (Year 5 Earth and Space)
Understanding how the tilt of the Earth affects the seasons can be difficult to conceptualise. A lamp in the centre
of a room with a terrestrial globe is a great way to show students how the tilt of the Earth affects the length of the
day and seasonal change.
To signify the beginning of the year, make sure the globe’s axis is tilted to 23.5 degrees (think four minutes past
seven on a clock-face) and the southern hemisphere is pointing towards the light source. This represents the
Australian summer position. Next, rotate the globe slowly in a counter-clockwise direction (looking down).
If you don’t have a globe then any spherical object will do to represent the Earth. A basketball
is great as it already has an equator mark. The basketball may also have concentric circles
that can substitute for the Tropic of Capricorn and the Tropic of Cancer. The tropics mark
the most southerly and northerly latitudes on the Earth where the sun can be directly
overhead and are therefore 23.5 degrees south and north of the equator.
The other major circles are the Equator, Antarctic Circle and Arctic Circle. All of the five
major circles of latitude are significant in terms of the length of day experienced on the
ground. Research these lines and describe how they relate to the change of seasons and
key annual events that occur over the course of a year.
During summer the length of a day is longer and the rays of light strike the earth at a steeper
angle, meaning that there is a greater concentration of light energy for a given area. At that same time of year in the
northern hemisphere the days are shorter and the angle of the sun is lower (the same amount of light is spread out
over a larger area). Rotate the globe around the sun (anti-clockwise) to show the orbit of the Earth at various times
of the year. Search the web for a suitable diagram showing the seasons or use http://www.bbc.co.uk/bitesize/ks3/
science/environment_earth_universe/astronomy_space/revision/5/
Keep the axis of the Earth parallel to its starting direction at all times (in reality there is a slight wobble that occurs
over thousands of years like a spinning top moving off-centre when slowing down). On a more human time-scale
the axis points to the same region in space. In the northern hemisphere the Earth’s axis points to a position in
space called the North Celestial Pole. This point is close to a star called Polaris, or the pole star.
There is no easily recognisable star to mark the position of the South Celestial Pole. However, to find this point
simply locate the Southern Cross and extend an imaginary line four and half times the length of the long axis to the
south. The end of this line will mark the position of the South Celestial Pole.
Reference:
Memmott, P. 2005, ‘Tangkic Orders of Time: an anthropological approach to time’ in Scan Journal, vol. 2, no. 2.
29887
5