Transcript Unit about Fragile environments

Unit about Fragile
environments
Lesson 1
1
What do you think the dark green shaded parts
are? What do you notice about their distribution?
2
The dark green is tropical rainforest
Which
continent
is this part
of?
What is
this
rainforest
called?
Which
countries is
it in?
3
Look at the background colour to each
layer – look at the sun symbol – what do
you think they mean?
4
A bit more about them
Emergents are the tops of the
tallest trees in the rainforest.
These are much higher, and give
the trees an advantage (in terms
of light) than the average trees
that populate the forest canopy.
Canopy is where the upper parts
of most of the trees are found.
The canopy is typically about 65
to 130 feet (20 to 40 metres) tall.
This leafy environment is full of
life such as insects, arachnids,
birds and some mammals.
5
A bit more about them
Under canopy is the second level
up. There is limited sunlight.
Saplings wait here for larger
plants and trees to die, leaving a
gap in the canopy into which they
can grow. Woody climbers called
lianas avoid having to wait for
gaps by rooting in the ground and
climbing up trees to get to the
sunlight.
The shrub layer is at ground level
in a tropical forest. It is dark and
gloomy with very little vegetation
between the trees. During heavier
rainfalls this area can get flooded.
6
How do the plants survive?
Fan palms have large, fanshaped leaves that are good
for catching sunshine and
water. The leaves are
segmented, which allows
excess water to drain away.
7
How do the plants survive?
Rainforests have a shallow layer of
fertile soil, so trees only need
shallow roots to reach the nutrients.
However shallow roots aren't great
for supporting huge rainforest
trees, so many tropical trees have
developed huge buttress roots.
These stretch from the ground to
two meters or more up the trunk,
which help anchor the tree to the
ground.
8
How do the plants survive?
Lianas are woody vines that
start at ground level, and use
trees to climb up the canopy
where they will spread from
tree to tree to get as much
light as possible.
9
How do the plants survive?
Strangler figs : The seed is dropped in a nook at
the top of a tree where it starts to grow, using
the debris collected there. Gradually the fig
sends aerial roots down the trunk of the host,
until they reach the ground and take root.
As it matures, the fig will gradually surround the
host, and start to strangle it.
Meanwhile the figs branches will grow taller,
dominating the sunlight.
Eventually the host will die and decompose
leaving the hollow, but sturdy trunk of the
strangler fig.
10
From what you know
what do you think
the climate is like?
11
Why is it hotter
near the equator?
12
Look at the sun’s rays as they hit the
Earth
same width
ray, more
spread out –
not so hot
same width ray,
not spread out at
all, much hotter
13
Now lets see how the rays pass through
the atmosphere As the rays from
the sun pass
through the
atmosphere,
some of the heat
is reflected back
out into space.
The thicker the
air, the more
heat there is that
never reaches
earth
Look how
much thicker
the air is
14
Why does it rain
every day in the
rainforest?
15
Every
morning
16
Every
Afternoon
17
About 4 o’clock
nearly every day
animated version of this is on http://ysgolrhyngrwyd.wikispaces.com/Unit+2+Environmental+conditions
18
So what have we done today?
We have found where
rainforests are – roughly where are they
The Amazon rainforest is and in which
countries it occurs – can you remember the
continent? The countries?
We found out
The names of the 4 layers where the plants
are – can you name them?
And what are they are like – can you
remember?
Can you think of any plants that are specially
adapted to their environment?
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So what have we done today?
We decided what the climate was like –
what was that?
We found out that there were 2 reasons
why one place might be hotter that
another – can you remember them?
And there was a special sort of rainfall –
what was that called?
20
Here are some mixed up sentences about convection
rainfall – can you sort them out?
1 In cool air the water vapour condenses to form drops of water
2 Sun shines on land and warms the air above it
3 The heavy water drops in cumulonimbus clouds fall as heavy
rain, often with lightening
4 The water droplets get heavier making dark grey
cumulonimbus clouds
5 Warm air cools as it rises
6 Warm air rises taking the water vapour with it
7 Warmth from the sun evaporates the water on the ground
8 Water droplets form into cumulous clouds
21
Homework
Equatorial rainforests cover only 6% of
the Earth's surface but yet they
contain MORE THAN ½ of the world's
plant and animal species!
Today, we looked at some of the special
plants.
Please find a picture of an animal
(mammal, birds, reptile, amphibian, fish
or an invertebrate) that lives in the
Amazon and 3 things about it so the
picture and the information will fit on
one slide only
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