Chapter 3, Natural vegetation
Tropical Rainforests
Distribution
Between 10N and S of the equator
Eg. Amazon Basin in South America and Congo Basin in Africa
Climate(temperature and rainfall)
About 27degree
Over 1500mm in rainfall
Structure
5 vertical layers(Emergent layer, Canopy layer, Understorey layer, Shrub layer, Undergrowth layer)
Diversity of plants
High biodiversity
Density
Dense emergent and canopy layers
Sparse undergrowth
Leaves
Evergreen
Broad, waxy and drip tips
Flowers and fruits
Flowering and fruiting all year round
Colourful flowers
Bark and branches
Branches are high up on the trunk
Smooth and thin bark
Roots
Shallow buttress roots
Mangrove Forests
Distribution
Between 23.5N and S of the equator
Can be found in especially along sheltered coastal regions and places where rivers constantly deposit clay and silt.
Climate (temperature and rainfall)
20 to 30degree
1000mm to 2000mm in rainfall
Structure
3 horizontal zones (coastal zone, middle zone, inland zone)
Diversity of plants
4 main species: Avicennia, Sonneratia, Rhizophora, Bruguiera
Density
Dense canopy
Sparse undergrowth
Leaves
Evergreen
Broad, leathery with drip tips
Flowers and fruits
Buoyant fruits with sharp tips
Colourful flowers
Bark and Branches
No adaptation to climate or environment
Roots
Aerial, Prop and Kneed roots
Tropical Monsoon Forests
Distribution
Between 10 and 25 N and S of the equator
Southeast Asia, Southern China and Northern Australia
Climate(temperature and rainfall)
About 26degree
Over 1500mm, with wet and dry seasons
Structure
3 vertical layers (Canopy layer, Understorey layer, Undergrowth)
Diversity of plants
High biodiversity but fewer than tropical rainforests
Density
Dense during wet season, sparse during dry season
Dense undergrowth
Leaves
Decidous
Waxy with drip tips
Flowers and fruits
Flowering and fruiting during the dry season
Bark and Branches
Thick and coarse bark
Branches are around the middle
Roots
Deep tap roots
Coniferous Forests
Distribution
Between 60N and 70N of the equator
Mainly located in Alaska, Northern Canada. Areas of high altitudes where the climate is cold
Climate (temperature and rainfall)
As low as -40degree in winter, about 21degree in the summer
300mm to 635mm in rainfall
Structure
Uniform in height
Diversity of plants
Pure stands of single species such as pine and spruce
Density
Not dense
Sparse undergrowth
Leaves
Evergreen
Needle-like
Flowers and fruits
Female cones produce seeds
Male cones produce pollens
Bark and Branches
Thick bark
Branches slope downwards
Roots
Shallow spreading roots
