Rainforest are forests characterized by high rainfall, with definitions setting minimum normal annual rainfall between 1750–2000 mm (68-78 inches). The monsoon trough, alternately known as the intertropical convergence zone, plays a significant role in creating Earth's tropical rain forests. There are two types of rainforest, tropical rainforest and temperate rainforest. Malaysia located near equator are blessed with tropical rainforest.
40 to 75% of all species on the world's habitats are indigenous to the rainforests. It has been estimated that many millions of species of plants, insects, and microorganisms are still undiscovered. Tropical rainforests have been called the "jewels of the Earth", and the "world's largest pharmacy", because over one quarter of natural medicines have been discovered there. Tropical rainforest are well known for its medicinal plants and herbs. Rainforests are also responsible for 28% of the world's oxygen turn over, often misunderstood as oxygen production, processing it through photosynthesis from carbon dioxide and storing it as carbon through biosequestration.
There is misconception that to walk through rainforest is easy in believing that the undergrowth in a rainforest which is restricted in many areas by the lack of sunlight at ground level makes it possible to walk through, not like walking in the park though. Characther of forest floor or shrub layer not only determine by level of sunlight going through the canopy but also the type of soil. Granite soil would make it possible for a clear forest floor. That is why vegetation of quartz ridge forest, peat land forest, lowland Dipterocarp Forest, and Hill forest would differ from each other. Eventhough with a minimun amount of sunlight there would be vines plants tangle from forest floor struggle to rise to the highest canopy. Forest floor composition of dense, tangled growth of vines, shrubs, and small trees called a jungle is determine by level of sunlight passing through the rainforestcanopy . 
Tropical Rainforest
A tropical rainforest is a biome found within (roughly) 10 degrees north or south of the equator. They are common in Asia,Australia, Africa, South America, Central America, Mexico and on many of the Pacific Islands. Within the World Wildlife Fund'sbiome classification, tropical rainforests are considered a type of tropical wet forest (or tropical moist broadleaf forest) and may also be referred to as lowland equatorial evergreen rainforest. Minimum normal annual rainfall between 1,750 millimetres (69 in) and 2,000 millimetres (79 in) occurs in this climate region. Mean monthly temperatures exceed 18 °C (64 °F) during all months of the year.
Other than temperate zoning (latitude) that give distinct character of tropical rainforest, other climatic factors that determining tropical rainforest biome, especially plant and organisms are humidity and elevation.
Tropical rainforest found in Malaysia also known as tropical moist broadleaf forest (also share some character of tropical dry forest on dry season depends on regional climatic change) can be further calssified into:
i) Flooded forests, including freshwater swamp forests, mangrove forest and peat swamp forests. These forest are part of Wetlands. Wetlands are permanent and temporary wet places such as lakes, rivers, ponds, marshes, swamps, peatlands, mangrove forests, salt pans, sandy beaches and coral reef. The ecosystems provide us with a myriad of ecological services.
ii) Lowland tropical rainforests, are forests which receive high rainfall (more than 2000 mm, or 80 inches, annually) throughout the year. Tropical Rainforest Malaysia are mostly dominated by trees from the Dipterocarpaceae family. The dipterocarp forest occurs on dry land just above sea level to an altitude of about 900 metres.The term ‘dipterocarp’ specifically refers to the fact that most of the largest trees in this Rainforest Malaysia belong to one plant family known as Dipterocarpaceae. It was so called because their fruits have seeds with two wings (di = two; ptero = wing; carp = seed). Thus, Lowland Rainforest Malaysia are commonly referred to as Lowland Dipterocarp Forest. Lowland Rainforest Malaysia is up to elevation 300m above sea level.
iii) Hill Forest / Hill Dipterocarp Forest - from elevation 300m-750m above sea level
iv) Upper Hill Forest - from elevation 750m-1200m above sea level.
v) Montane Rainforest Malaysia, normally above 1000m at some mountains the vegetation already can be classified as Montane forest, this can be extinguished with plants exist are small bonsai tree, coniferous plant, fern and eafy bryophytes. The type of forest exist on higher elevation can also be determined by temperature and soil. Biome of tropical highland mountains range which are known as cloud forests , mossy forest or mountain forest, are found in cooler-climate mountainous areas. Titiwangsa Mountains Ranges from Mount Chamah and Ulu Sepat till Mountains in Perak such as Mount Irau, Cameron Highland are well known for its mossy forest beauty.
- Tropical coniferous forest - pine tree trail in Fraser Hill once have distinct character or tropical pine forest, however regional warming which correlated with deforestation and clearance of forest area for farming and plantation in nearby areas has reduce the size coniferous forest area.
To experience Rainforest Malaysia by yourself, if reading this article would be harder to comprehend than your exam paper then head for Taman Negara Malaysia Pahang or known as Pahang National Parks. Take the trail up to Mount Tahan would surely present you with all kind of Rainforest Malaysia from big tree at lowland rainforest up to bonsai montane forest at Mount Tahan Peak. Taking that route would take around 1 week for return trip from Kuala Tahan if you have the time and got the fitness. Otherwise go to Cameron Highland or Fraser Hill (Bukit Fraser) to see and feel breezy Hill dipterocarp forest and Montane forest air. To see mossy forest you have to go deeper into the trail. Deeper into the forest with lower temperature more mossy the forest will be. If you dare enough, hike up to Mount Irau Cameron Highland. You will see what, most normal tourist do not have chance to see of Rainforest Malaysia, but be prepare for a wet wet wet and muddy trail and prepare accordingly. For a more "easy trail" hike up Mount Kinabalu! do not mislead by word "easy trail", what it meant is that the trail are very well maintained. You do not have to crawl below fallen log, walking through muddy pool, instead just pace yourself on beautiful trail and stairs.. you still need a good fitness though,, otherwise you will just simply torturing yourself. At Mount Kinabalu trail you will see beautiful Rainforest Type from Hill dipterocarp rainforest, montane rainforest and end up to barren granite of Mount Kinabalu's peak.
Temperate Rainforest
For temperate rain forests of North America, Alaback's definition is widely recognized:
- Annual precipitation over 1400 mm
- Mean annual temperature between 4 and 12 degrees Celsius. (39 and 54 degrees Fahrenheit)
However, required annual precipitation depends on factors such as distribution of rainfall over the year, temperatures over the year and fog presence, and definitions in other countries differ considerably. For example, Australian definitions are ecological-structural rather than climatic:
Plant in temperate rainforest are all predominantly coniferous, sometimes with an understory of broadleaved trees and shrubs. The conifer dominance is a consequence of two climatic factors: Although the region has high total precipitation, most occurs during the winter, and summers are relatively dry. During summer, moisture stress reduces the amount of photosynthesis possible especially for broadleaved trees. However, winters are very mild, and coniferous species are capable to carry on substantial amounts of their yearly photosynthesis during fall, winter and spring.
Layer of tropical rainforest
A tropical rainforest is typically divided into four main layers, each with different plants and animals adapted for life in that particular area: forest floor / shrub layers , understory, canopy, and the emergent. Only the emergent layer is unique to tropical rainforests, while the others are also found in temperate rainforests. While plant in temperate rainforest are all predominantly coniferous, tropical rainforest are blessed with diverse plant species.
The emergent layer contains a small number of very large trees which grow above the canopy layer, reaching heights of 45-55 m, although on occasion a few species will grow up to 70 m or 80 m tall. Such species of emergent layer is Tualang tree.
The canopy is the primary layer of the forest and forms a roof over the two remaining layers. Most canopy trees have smooth, oval leaves that come to a point. It's a maze of leaves and branches. Many animals live in this area since food is abundant.
Little sunshine reaches the understory layer, so the plants have to grow larger leaves to obtain sufficient sunlight. The plants in this area seldom grow to 12 feet. There is a large concentration of insects here.
The shrub layer and forest floor will be dimmer than other layer. Few plants grow in this area, as a result. Since hardly any sun reaches the forest floor things begin to decay quickly.
All this layers can only be found on lowland rainforest, as the contour change with increasing height the type canopy and layering also differ transform into montane forest.
