Fragile Ecosystems Flashcards
(18 cards)
Fragile ecosystem
- Ecosystems that are extremely vulnerable to disturbances especially as a result of human activities
- It is more difficult for these systems to readjust
- Permanent changes may occur
Resilient ecosystetems
Changed for a period of time but return to normal
What makes an ecosystem fragile
- Unusually dry or wet weather
- Disease that effects plants or animals
- Alien species of plant or animal
- Deforestation
Deforestation
Large scale cutting down of rainforests
- land for farming
- logging
- mining
- transport
Where are tropical rainforests?
Between the tropics
Characteristics of rainforest climate
Hot and wet through the year
Heavy rainfall during most afternoons
No winters or summers
Predictable weather
Emergents
Tallest trees
Over 50m tsll
Eg Kapok tree
Canopy
Block out the sun from the lower layers
80% of rainforest wildlife
Eg birds, snakes, monkeys
Lianas climb to the canopy to reach sunlight
Under canopy
bare tree trunks and lianas
Shrub layer
Densest plant growth
Shrubs, ferns and other plants needing less light
Saplings of emergents and trees are found here
Buttress roots
Developed by tall trees to stop them toppling over
Plant roots
Soil is poor
Grow close to surface to grab nutrients
Lianas
Loop around tree trunks to reach sunlight
Air plants / epiphytes
Perch up high on branches
Sharp edges on leaves
Keep hungry things away from
Thick waxy coat on leaves
Protects against rain and insects
Drop tip on leaves
Lets rain drip off
Rainforest nutrient cycle
- Dead leaves and animal waste fall all year round
- Decomposers release nutrients from them
- Soil is poor because nutrients don’t get a chance to sink in
- Roots quickly take up the nutrients again
- The nutrients help vegetation geow
