7. What part of the plant is involved in
reproduction?
8.
9. Carbon dioxide is generally available
to most plants from the air surrounding
them.
Sunshine is also generally available but in
some cases plants have to actively seek it.
Plants that live in dense forests do
have to compete for light.
Noting that most plants grow towards
the light, consider the these cases:
10. Many trees in
the forests
grow very tall
to get to the
sunlight.
12. Plants that live on the forest floor are
adapted to live in the shade and require
less sunlight.
13. To protect themselves, plants cannot run away from
animals that want to eat them, such as deer, goats,
bears, insects, and rabbits. But many plants do have
ways to protect themselves.
Some plants taste bitter.
Some plants have
thorns on their leaves or
stems.
14. Some plants are poisonous and cause
a rash on an animal’s skin. You may be
familiar with the rash caused by poison
ivy.
15. A plant gets water through its roots
and loses water through its leaves .
Many of a plant’s adaptations have
to do with getting and retaining
water.
16. Most plant adaptations seem to have
come about because of the plant’s water
supply.
We will study plant adaptations in:
1) Deserts
2) Grasslands: savannas, prairie &
steppe grasslands
3) Forests: rain, deciduous & coniferous
4) Tundra.
17. First, some plant adaptations found in
Desert plants.
The desert regions shown in brown are dry
and generally hot, and often have poor soil that
holds little water.
18. Plants in deserts
either have:
1) long roots that
spread out wide
and absorb a lot of
water when it does
rain or
2) roots that grow
deep into the
ground.
19. Desert plants
often store
water in their
stems or
leaves.
Cactuses have
stems but no
leaves.
Waxy
coating on
the leaves
or stems
reduce loss
of water.
21. Next, some plant adaptations found in
Grassland plants.
The grassland regions can be divided into
Savannas (tropical grassland) shown here in
yellow which generally have a warm climate
and always have definite wet and dry seasons.
22. ...and the prairie and steppes regions of the
Earth. These regions, shown here in yellow,
have mainly dry weather, deep fertile soil, and
are usually hot in the summer and cold in the
winter.
25. The Baobab tree in African grassland has a huge trunk
to store water during the dry season.
26. Next, some plant adaptations found in
the forests of the world.
There are three forest regions. The Tropical
Rain Forests, shown here in dark green, seldom
get below 68 degrees. They also get about 100
inches of rain each year and have less than one
inch of top soil.
27. Tropical rainforest trees have
shallow roots because the soil is so
thin. Buttresses and stilt roots help
prop up plants in the shallow soil.
28. Many rainforest leaves have “drip tips”—
a pointed shape which helps drain
excess water from the leaf.
29. Epiphytic orchids
have aerial roots that
cling to the host
plant. They absorb
minerals, and water
from the atmosphere.
30. The Deciduous Forests shown here in dark
green, have four seasons with rain in the
summer and rain or snow in the winter.
The temperature
varies from hot in the
summer to below
freezing in the winter.
Rain is plentiful, about
30 to 50 inches per
year but the trees
become dormant in
the winter when there
is less water
available.
31. In both the tropical rain forest and
deciduous forest the trees have
BIG
to absorb as much sunlight as possible.
LEAVES
Water loss through these big leaves is not a problem because
these regions normally get adequate water.
32. The thin, broad, light-weight leaves of the
deciduous trees can capture a lot of sunlight
to make a lot of food for the tree in warm
weather.
34. When the weather gets cooler, the broad
leaves cause too much water loss and can
be weighed down by snow, so the tree
drops its leaves. New ones will grow in the
spring.
35. Continuing with adaptations found in the forests of the world
we consider the coniferous forest shown here in dark
green.
These regions have short summers and long cold winters.
Temperature not hot in the summer but very cold in the
winter. Moisture is generally good in the spring and
summer, but freezes and is not available for the plants in
the winter.
37. They do not drop leaves
Needle-like leaves (needles) all at once in
with waxy covering fall. They are kept
help reduce water loss throughout the year to
during freezing make food whenever
weather. sunshine and water are
available (short
summers).
38. The triangular shape of many conifer
trees helps shed heavy snow to save
branches from breaking.
39. Finally, we look at plant adaptations found in
the Tundra shown below in brown.
This is a vast, flat, treeless Arctic region of Europe, Asia, and
North America in which the subsoil is permanently frozen.
40. This plant
grows in a
clump to help
conserve heat.
These tundra
plants are low-
growing to avoid
the harsh winds.
42. We have touched on just a tiny sample of
the remarkable adaptations plants around
the world have made in order to survive.
The thing to remember is that plants, as
well as animals, must satisfy their needs in
order to survive, they have to
adapt
to conditions in their environment.