The tropical rainforest
is hot and it rains a lot, about 80 to 180 inches per year. This
abundance of water can cause problems such as promoting the growth of bacteria
and fungi which could be harmful to plants. Heavy rainfall also increases
the risk of flooding, soil erosion, and rapid leaching of nutrients from
the soil (leaching occurs when the minerals and organic nutrients of the
soil are "washed" out of the soil by rainfall as the water soaks into the
ground). Plants grow rapidly and quickly use up any organic material
left from decomposing plants and animals. This results is a soil
that is poor. The tropical rainforest is very thick, and not much
sunlight is able to penetrate to the forest floor. However, the plants
at the top of the rainforest in the canopy, must be able to survive 12
hours of intense sunlight every day of the year. There is a great
amount of diversity in plant species in the tropical rainforest.
- drip tips and waxy surfaces
allow water to run off, to discourage growth of bacteria and fungi
- buttresses and prop and
stilt roots help hold up plants in the shallow soil
- some plants climb on others
to reach the sunlight
- some plants grow on other
plants to reach the sunlight
- flowers on the forest floor
are designed to lure animal pollinators since there is relatively no wind
on the forest floor to aid in pollination
- smooth bark and smooth or
waxy flowers speed the run off of water
- plants have shallow roots
to help capture nutrients from the top level of soil.
- many bromeliads are epiphytes
(plants that live on other plants); instead of collecting water with roots
they collect rainwater into a central reservoir from which they absorb
the water through hairs on their leaves
- epiphytic orchids have aerial
roots that cling to the host plant, absorb minerals, and absorb water from
on leaves help shed excess water.
help support plants in the shallow soil.
collect rainwater into a central reservoir.