Tropical Wet Evergreen Forests or Rainforests

 

Climatic Conditions

  • Annual rainfall exceeds 250 cm
  • The annual temperature is about 25°-27°C
  • The average annual humidity exceeds 77 percent and
  • The dry season is distinctly short.

Characteristics

  • Evergreen: Due to high heat and high humidity, the trees of these forests do not shed their leaves together.
  • Mesophytic: Plants adapted to neither too dry nor too wet type climate..
What are mesophytes?

●     Unlike hydrophytic plants, such as water lily or pondweed, that grow in saturated soil or water, or xerophytic plants, such as cactus, that grow in extremely dry soil, mesophytes are ordinary plants that exist between the two extremes.

●     Mesophytic environments are marked by average to hot temperatures and soil that is neither too dry nor too wet.

  • Lofty: The trees often reach 45 – 60 metres in height.
  • Thick Canopy: From the air, the tropical rain forest appears like a thick canopy of foliage, broken only where it is crossed by large rivers or cleared for cultivation.
  • All plants struggle upwards (most epiphytes) for sunlight resulting in a peculiar layer arrangement. The entire morphology looks like a green carpet when viewed from above.
  • Less undergrowth: The sunlight cannot reach the ground due to thick canopy. The undergrowth is formed mainly of bamboos, ferns, climbers, orchids, etc.

 

Distribution

  • Western side of the Western Ghats (500 to 1370 metres above sea level).
  • Some regions in the Purvanchal hills.
  • In the Andaman and Nicobar Islands.

Timber

  • Hardwood: The timber of these forests is fine-grained, hard, and durable.
  • It has high commercial value but it is highly challenging to exploit due to dense undergrowth, absence of pure stands, and lack of transport facilities [Read previous posts on Climatic regions to understand how lumbering industry works in Equatorial Rainforests (hardwood) and Taiga Climatic (softwood) conditions].
  • The important species of these forests are mahogany, mesua, white cedar, jamun, canes, bamboo, etc.