Types of Rainforests
There
are two types of rainforests -- tropical
and temperate. Tropical and
temperate rainforests share certain characteristics. For example, most
trees flare at the base. Vegetation is dense, tall and very
green. Both types of rainforests are rich in plant and animal species,
although the diversity is greater in the tropical rainforest.
Montane forests are
found in mountainous areas and may contain plants such as oaks, rhododendrons,
and pines, which are characteristic of temperate deciduous forests. At
higher altitudes, temperatures are cooler. Even close to the equator, frost
and snow can occur.
Precipitation and Climate
Both tropical and temperate rainforests are very lush
and wet. Rainfall falls regularly throughout the year. The tropical rainforest receives 80-400 inches of rainfall per year. It rains a lot in
the temperate rainforest, too -- about 100 inches per year. And even more
moisture comes from the coastal fog that hovers among the trees.
Tropical rainforests are warm and moist; while temperate
rainforests are cool.
|
Tropical |
Temperate |
Temperatures |
warm |
cool |
Number of tree species |
many (hundreds) |
few (10-20) |
Types of leaves |
broadleaf |
needles |
Age of trees |
50-100 years |
500-1000 years |
Epiphytes |
lots of different kinds including orchids
and bromeliads |
mostly mosses and ferns |
Decomposition rate |
rapid |
slow |
Are all Tropical Forests, Rainforests?
Only a small percentage of the tropical forests are rainforests.
To be a tropical rainforest, forested areas must:
-
Lie between the Tropic of Cancer and the Tropic of Capricorn.
-
Receive rainfall regularly throughout the year (80-400 inches
per year).
-
Remain warm and frost free all year long (mean temperatures
are between 70° and 85°F) with very little daily fluctuation.
Consequently, many forested areas in the tropics are not
rainforests. Forests that receive irregular rainfall (monsoons followed
by a dry season) are moist deciduous forests.
Trees in these forests may drop their leaves in the dry season.
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