Geoscience Reference
In-Depth Information
animals and their adaptations to their regional locations are discussed in Chapters
3 and 5 under each section on Regional Expressions of the Biome.
The Tropical Forest Biomes are the most ancient, diverse, and ecologically
complex biomes on the planet and support more than half of the Earth's species.
At least 3 million species are known to inhabit the tropical forests of the world.
This number could be 10 or more times greater, because not all tropical species
have been scientifically described. New species within these forests continue to be
discovered.
Table 1.1 Comparison of Tropical Rainforest and Seasonal Forest Biomes
T
ROPICAL
R
AINFOREST
T
ROPICAL
S
EASONAL
F
OREST
Location
Along the Equator, between
10
North and south of the tropical
rainforest (10
N and S latitude
-23
N and S
latitudes)
Temperature
controls
Tropical latitudes, constant
solar insolation
Tropical latitudes, shifting so-
lar insolation
Temperature
patterns
Little to no variation
Minimal seasonal variation
Precipitation
controls
ITCZ, convective showers
Shifting ITCZ and Trade
Winds
Precipitation totals High
Seasonal drought
Seasonality
No
Yes
Climate type
Tropical wet
Tropical wet and dry
Tropical seasonal wet
Dominant growth
forms
Broadleaf evergreen trees,
vines, epiphytes
Broadleaf deciduous trees,
vines, epiphytes
Major soil orders
Oxisols, ultisols, inceptisols,
and entisols
Oxisols, ultisols, inceptisols,
and entisols
Soil characteristics
Low fertility, low nutrients,
highly weathered, acidic,
red to yellow in color
Higher fertility, some
nutrients, weathered, red to
brown in color
Biodiversity
Highest in world
Very high
Age
Ancient: Tertiary to Mid-
Cretaceous origin
Ancient: Tertiary to Mid-
Cretaceous origin
Current status
Highly threatened with total
extinction due to severe
deforestation, mining,
changes in land use that
affect climate patterns
within the forest, high
development and popula-
tion pressures, and climate
change
Highly threatened/endangered
due to severe deforestation,
mining, changes in land use
affecting climate patterns
within the forest, high devel-
opment and population pres-
sures, and climate change
Note:
ITCZ
ΒΌ
Intertropical Convergence Zone.
