Characteristics of tropical rainforests

Evergreen (high temperature, high rainfall)

• Nvr a need for plants in a tropical rainforest to lose their leaves due to lower temp or lower rainfall
• Retain their leaves all yr round and photosynthesize all yr round
• Thus its evergreen

Diversity of plant and animal species

• Hot and wet environment gives rise to rich biodiversity
• In Amazon rainforest: 300 different plant species within 0.01km2
• In forests in UK: 40 plant species within 27000km2

Structure of tropical rainforest

•  (above 30m)

Emergent layer: Consists of the tallest trees (up to 80m)

: Uppermost layer where some trees rise and tower above other trees

: Trees in this layer have tall, straight and smooth trunks with few branches

Canopy layer (20 to 30m)

: Trees grow closely and densely together

: Trees between 20-30m tall

: Crowns interlock to form an almost continuous cover

: Blocks almost ALL sunlight from passing through 

: Lianas, thick and woody. Has vines that wrap ard and climb other trees

: Epiphytes, Plants which grow on trees (Ferns, orchids, mosses, lichen)

Undergrowth layer (below 20m)

: Vegetation is sparse and poorly developed

: Has plants such as moss, ferns, some lianas and epiphytes and other small plants that are thin and widely spaced

: Have much larger leaves compared to those in other layers

: Thin layer of leaf litter