Plant Adaptations
1. Bark
In drier, temperate deciduous forests a thick bark helps
to limit moisture evaporation from the tree's trunk. Since this is not
a concern in the high humidity of tropical rainforests, most trees have
a thin, smooth bark. The smoothness of the bark may also make it difficult
for other plants to grow on their surface.
2. Lianas
Lianas are climbing woody vines that drape rainforest
trees. They have adapted to life in the rainforest by having their roots
in the ground and climbing high into the tree canopy to reach available
sunlight. Many lianas start life in the rainforest canopy and send
roots down to the ground.
3. Drip Tips
 The
leaves of forest trees have adapted to cope with exceptionally high rainfall.
Many tropical rainforest leaves have a drip tip. It is thought that these
drip tips enable rain drops to run off quickly. Plants need to shed water
to avoid growth of fungus and bacteria in the warm, wet tropical rainforest.
4. Buttresses
Many large trees have massive ridges near the base that
can rise 30 feet high before blending into the trunk. Why do they form?
Buttress roots provide extra stability, especially since roots of tropical
rainforest trees are not typically as deep as those of trees in temperate
zones.
5. Prop and Stilt Roots
Prop and stilt roots help give support and are characteristic
of tropical palms growing in shallow, wet soils. Although the tree grows
fairly slowly, these above-ground roots can grow 28 inches a month.
6. Epiphytes
 Epiphytes
are plants that live on the surface of other plants, especially the trunk
and branches. They grow on trees to take advantage of the sunlight in the
canopy. Most are orchids, bromeliads, ferns, and
Philodendron relatives.
Tiny plants called epiphylls, mostly mosses, liverworts and lichens, live
on the surface of leaves.
7. Bromeliads
 Bromeliads
are found almost exclusively in the Americas. Some grow in the ground,
like pineapple, but most species grow on the branches of trees. Their leaves
form a vase or tank that holds water. Small roots anchor plants to supporting
branches, and their broad leaf bases form a water-holding tank or cup.
The tank's capacity ranges from half a pint to 12 gallons or more. The
tanks support a thriving eco-system of bacteria, protozoa, tiny crustaceans,
mosquito and dragonfly larvae, tadpoles, birds, salamanders and frogs.
Mangroves
 On
tropical deltas and along ocean edges and river estuaries, trees have adapted
to living in wet, marshy conditions. These trees, called mangroves, have
wide-spreading stilt roots that support the trees in the tidal mud and
trap nutritious organic matter.
Nepenthes
 Pitcher
plant vines in the family Nepenthaceae have leaves that form a pitcher,
complete with a lid. Sweet or foul-smelling nectar in the pitcher attracts
insects, especially ants and flies, that lose their grip on the slick sides
and fall into the liquid. Downward-pointing hairs inside the pitcher prevent
the insects' escape. The insects are digested by the plants and provide
nutrients. Pitcher plants are not epiphytes but climbers rooted in the
soil.
  
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