World Biomes

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World Biomes

• Tropical Rain forest

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Distribution of biome

• The tropical rainforest is found between 10 N
  and 10 S latitude at elevations below 1,000 m.
  There are three major, disjunct formations
• Neotropical (Amazonia into Central America)
• African (Zaire Basin with an outlier in West
  Africa also eastern Madagascar)
• Indo- Malaysian (west coast of India, Assam,
  southeast Asia, New Guinea and Queensland,
  Australia.

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Distribution
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Climate

• The tropical rainforest is a forest of tall trees
  in a region of year-round warmth. An average of
  1250 to 6600 mm of rain falls yearly.
• The temperature in a rainforest rarely gets
  higher than 34 C or drops below 20 C average
  humidity is between 77 and 88. There is usually
  a brief season of less rain. In monsoonal areas,
  there is a real dry season. Almost all
  rainforests lie near the equator.

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Soil

• The soil is infertile, deeply weathered and
  severely leached. Rapid bacterial decay prevents
  the accumulation of humus. The concentration of
  iron and aluminium oxides gives the soil a bright
  red colour and sometimes produces minable
  deposits (e.g., bauxite). On younger substrates,
  especially of volcanic origin, tropical soils may
  be quite fertile.

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Plants I

• A tropical rainforest has more kinds of trees
  than any other area in the world. Scientists have
  counted about 100 to 300 species in one 1-hectare
  area in South America. Seventy percent of the
  plants in the rainforest are trees.

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Plants II

• All tropical rainforests resemble one another in
  some ways. Many of the trees have straight trunks
  that don't branch out for 100 feet or more. There
  is no sense in growing branches below the canopy
  where there is little light. The majority of the
  trees have smooth, thin bark because there is no
  need to protect them from water loss and freezing
  temperatures. It also makes it difficult for
  epiphytes and plant parasites to get a hold on
  the trunks. The bark of different species is so
  similar that it is difficult to identify a tree
  by its bark. Many trees can only be identified by
  their flowers.

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Kapok tree
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Brazil nut
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Rubber tree
Ruffled Fan palm
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Orchids
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Bromeliad
Fern tree
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Carnivorous plants
Venus Fly Trap
Pitcher plant or Monkey Cup
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Plants III (growth forms)

• Epiphytes the so-called air plants grow on
  branches high in the trees, using the limbs
  merely for support and extracting moisture from
  the air and trapping the constant leaf-fall and
  wind-blown dust.

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Plants IV (growth forms)

• Lianas woody vines grow rapidly up the tree
  trunks when there is a temporary gap in the
  canopy and flower and fruit in the tree tops.

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Plants V (growth forms)

• Climbers green-stemmed plants that remain in the
  understory. Many climbers, including the
  ancestors of the domesticated yams (Africa) and
  sweet potatoes (South America), store nutrients
  in roots and tubers.

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Plants VI (growth forms)

• Stranglers these plants begin life as epiphytes
  in the canopy and send their roots downward to
  the forest floor.

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Fungi

• Fungi can live on the forest floor because they
  do not need sunlight for growth.

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Plants VIII

• Rainforests now cover less than 6 of Earth's
  land surface. Scientists estimate that more than
  half of all the world's plant and animal species
  live in tropical rainforests. Tropical
  rainforests produce 40 of Earth's oxygen.
• About 1/4 of all the medicines we use come from
  rainforest plants. More than 1,400 varieties of
  tropical plants are thought to be potential cures
  for cancer.

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Animals

• Animal life is highly diverse. Common
  characteristics found among mammals and birds
  (and reptiles and amphibians, too) include
  adaptations to an arboreal life (for example, the
  long tails of New World monkeys), bright colours
  and sharp patterns, loud vocalizations, and diets
  heavy on fruits.

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Insects
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Amphibians and reptiles
Constrictor Python
Tree frogs
Chameleon
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Birds
Paradise bird
Harpy Eagle
Macaw
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Mammals
Sloth
Tapir
Howler Monkey
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People I
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People II

• Farming huge tracts of rainforest are cleared
  for large-scale commercial plantations or
  livestock ranching. Ironically, rainforest soil
  is useless to humans. Rainforest soils are
  notoriously poor and cannot support human
  agriculture for more than a few years. Crops may
  grow well at first, mostly subsisting on the
  minerals released when the forest is burnt. But
  these minerals wash away quickly without the
  protection of the thick forest canopy and the
  soil soon becomes useless.
• Humans destroy by collecting and killing wild
  animals and plants.

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People III

• Rainforest is also cleared to make way for homes
  for people, and infrastructure like dams, roads,
  electrical and communications installations.
• Rainforests are dug up as we mine for oil, gold
  and other minerals. Small scale gold prospectors
  use mercury which is toxic to extract gold.

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People IV

• Logging of trees for building materials,
  firewood, paper products. Rainforests contain 50
  of global standing timber. Unlike the
  faster-growing temperate timber trees, rainforest
  trees take decades to reach economic size so it
  is not easy to harvest them in a sustainable
  manner. Logging roads usually allow other
  commercial exploitation to follow.

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People V

• Humans kill by breaking up a rainforest into
  smaller clumps. It destabilises the forest
  interior temperature and humidity are no longer
  constant. Such fluctuations kill plants and
  animals adapted only for stable conditions. If
  the fragment is too small, it can't withstand
  natural seasonal changes. It also prevents
  natural movement of plants and animals from one
  part of the forest to another.