Tropical and subtropical moist broadleaf forests

From Wikipedia, the free encyclopedia

TSMFs of the World

Tropical and subtropical moist forests within the Holdridge Life Zone classification scheme.

Tropical and subtropical moist broadleaf forests (TSMF), also known as tropical moist forests, are a tropical and subtropical forest biome.

Tropical and subtropical moist broadleaf forests are found in a belt around the equator and in the humid subtropics, and are characterized by warm, humid climates with year-round rainfall. Tropical and subtropical forest regions with lower rainfall are home to Tropical and subtropical dry broadleaf forests and Tropical and subtropical coniferous forests. Temperate rain forests also occur in certain humid temperate coastal regions.

The biome includes several types of forests:

Lowland equatorial evergreen rain forests, commonly known as tropical rainforests, are forests which receive high rainfall (more than 2000 mm, or 80 inches, annually) throughout the year. These forests occur in a belt around the equator, with the largest areas in the Amazon basin of South America, the Congo basin of central Africa, Indonesia, and New Guinea.
Moist deciduous and semi-evergreen forests, receive high overall rainfall with a warm summer wet season and a cooler winter dry season. Some trees in these forests drop some or all of their leaves during the winter dry season. These forests are found in parts of South America, in Central America and around the Caribbean, in coastal West Africa, parts of the Indian subcontinent, and across much of Indochina.
Montane rain forests, some of which are known as cloud forests, are found in cooler-climate mountainous areas.
Flooded forests, including freshwater swamp forests and peat swamp forests.

Tropical and subtropical moist broadleaf forests are common in several terrestrial ecozones, including parts of the Afrotropic (equatorial Africa), Indomalaya (parts of the Indian subcontinent and Southeast Asia), the Neotropic (northern South America and Central America), Australasia (eastern Indonesia, New Guinea, northern and eastern Australia), and Oceania (the tropical islands of the Pacific Ocean). About half of the world's tropical rainforests are in the South American countries of Brazil and Peru. Rain forests 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 rain forests.

1 Rainforest layers
2 Threats
3 See also
4 External links

[edit] Rainforest layers

The rainforest is divided into four different parts, each with different plants and animals, adapted for life in that particular area.

[edit] Emergent layer

This layer contains the emergents—trees which tower above the canopy. The trees are usually evergreens, which are able to withstand the harsh temperatures and high winds. Eagles, butterflies, monkeys, and bats inhabit this layer.

[edit] Canopy layer

Away from river banks, swamps and clearings where dense undergrowth is found, the forest floor is relatively clear of vegetation, as little sunlight penetrates to ground level. The densest areas of biodiversity are found in the forest canopy, a more or less continuous cover of foliage formed by adjacent treetops.

The canopy, by some estimates, is home to 40% of all plant species, suggesting that perhaps half of all life on Earth could be found there. A quarter of all insect species are believed to exist in the rainforest canopy.

Scientists have long suspected the richness of the canopy as a habitat, but have only recently developed practical methods of exploring it. As long ago as 1917, U.S. naturalist William Beebe declared that "another continent of life remains to be discovered, not upon the Earth, but one to two hundred feet above it, extending over thousands of square miles".

True exploration of this habitat only began in the 1980s, when scientists developed methods to reach the canopy, such as firing ropes into the trees using crossbows. Exploration of the canopy is still in its infancy, but other methods include the use of balloons and airships to float above the highest branches and the building of cranes and walkways planted on the forest floor.

The leaves on the canopy level have bent tips to allow rain water to drip down into the understory and ground.

[edit] Understory layer

There is a space between the canopy and the forest floor, which is known as the understorey (or understory). This is home to a number of birds, monkeys, snakes, and lizards. The leaves are much larger at this level. Insect life is also abundant.

[edit] Forest floor

This region receives only 2% of the rainforest's sunlight. Thus, only specially adapted plants can grow in this region. It also contains decomposing plant and animal matter, which disappears quickly due to the high humidity and temperature found in this region.

[edit] Threats

The most severe threat to the tropical and subtropical moist broadleaf forests is human intervention. Clearing and degradation of tropical moist forests for timber, grazing land and agriculture, continues to lead towards severe soil erosion of already nutrient-poor soils. The rapid rate of clearing is destroying the homes and biodiversity in one of the most prolific animal and plant biomes on earth. Due to all of this, tropical rainforests now only cover 6% of the earth’s surface.