Tropical Rainforests

• Climate-

  • The same all year round
  • Hot (temperature is generally between 20-28 C and only varies by a few degrees all year)
  • Rainfall is high, around 2000mm per year
• Plants-

  • Most trees are evergreen
  • Many trees are tall (typically 30-45 m in height) and the vegetation cover is dense, little light reaches the forest floor
  • Lots of epiphytes (plants that grow on other plants and take nutrients and moisture from the air) e.g. orchids and ferns
• Soil-

  • Not very fertile as heavy rain washes nutrients away
  • There are surface nutrients due to decayed leaf fall, but this layer is thin as decay is fast in warm, moist conditions
• Animals-

  • Rainforests are believed to contain more animal species than any other ecosystem
• People-

  • Many indigenous people have adapted to life in the rainforest
• Rainforests have very high biodiversity (variety if organisms living in a particular area)

  • Contain around 50% of the worlds plant, animal and insect species, and may contain half of life on earth
  • Productive environments because the conditions are stable
  • Many organisms have evolved to depend on just a few other species to survive, specific to their habitat and food source
  • Deforestation will likely lead to the extinction of many species and loss in biodiversity
• All the parts of the rainforest are dependent on one another- if any one changes everything is affected
• Interdependence-

  The warm and wet climate helps fungi and bacteria decompose dead plant material quickly. This makes the surface soil high in nutrients, meaning plants can grow easily

  Plants pass on their nutrients when eaten by animals. Animal populations are high because of dense vegetation. When animals die, their nutrients are transferred back to the soil, encouraging more vegetation. Many plant and animal species have formed symbiotic relationships
• Plants are adapted to high rainfall, high temperatures and competition for light
• How are trees adapted?

  Trees compete for sunlight by growing tall

  Many trees have smooth, thin bark as there's no need to protect the trunk from cold temperatures. The smooth surface also helps water to run off easily

  Large, stable buttress roots support the tall trees trunks
• How are plants adapted?

  Plants have thick waxy leaves with pointed drip tips. This encourages rainwater runoff so the weight so water doesn't damage the plant. This also means there's no standing water for fungi or bacteria to grow in.

  Climbing plants, such as lianas use tree trunks to reach sunlight

  Plants drop their leaves gradually throughout the year, meaning they can go on growing all year round
• How have plants adapted to poor soil?

  • A rapid cycling of nutrients through the ecosystem, a sort of fast-food delivery
  • The absorption of sunlight, leading to photosynthesis n the warm, humid climate, which is ideal for plant growth throughout the year
  • The ability of plants to adapt as they compete for sunlight and nutrients.

  A) Biomass

  B) Soil

  C) Litter

  
• How have plants adapted to heat and humidity?


  Vegetation copes with both heat and heavy rainfall by:

  • Using the circulating water as a sort of cooling system
  • Passing water to the soil or returning it to the atmosphere
  • Having leaves that can cope with the large amounts of water falling on them- waxy leaves and drip tips, flexible stems to allow leaves to move with the sun to maximise photosynthesis