The equator is a line that circles the centre of our global world and is situated halfway between the north and south poles. Temperatures at the equator are high. These high temperatures cause accelerated evaporation of water, which results in frequent rain in rainforests in the tropics.
An important characteristic of rainforests is apparent in their name. Rainforests lie in the intertropical convergence zone where intense solar energy produces a convection zone of rising air that loses its moisture through frequent rainstorms. Rainforests are subject to heavy rainfall, at least 80 inches (2,000 mm), and in some areas over 430 inches (10,920 mm) of rain each year. In equatorial regions, rainfall may be year round without apparent "wet" or "dry" seasons, although many forests do have seasonal rains. Even in seasonal forests, the period between rains is usually not long enough for the leaf litter to dry out completely. During the parts of the year when less rain falls, the constant cloud cover is enough to keep the air moist and prevent plants from drying out. Some neotropical rainforests rarely go a month during the year without at least 6" of rain. The stable climate, with evenly spread rainfall and warmth, allows most rainforest trees to be evergreen—keeping their leaves all year and never dropping all their leaves in any one season. Forests further from the equator, like those of India, Thailand, Sri Lanka, and Central America, where rainy seasons are more pronounced, can only be considered "semi-evergreen" since some species of trees may shed all of their leaves at the beginning of the dry season. Annual rainfall is spread evenly enough to allow heavy growth of broad-leafed evergreen trees, or at least semi-evergreen trees. The moisture of the rainforest from rainfall, constant cloud cover, and transpiration (water loss through leaves), creates intense local humidity. Each canopy tree transpires some 200 gallons (760 liters) of water annually, translating to roughly 20,000 gallons (76,000 L) of water transpired into the atmosphere for every acre of canopy trees. Large rainforests (and their humidity) contribute to the formation of rain clouds, and generate as much as 75 percent of their own rain.
There is an umbilical connection between healthy forests and water regimes. Forests are nurseries and cisterns for our life giving rivers. Forest areas give birth to all the major and minor rivers. Most of the rivers spring from some unknown forests. Because of the slope the rain water cannot stay to soak into the earth, it flows downhill rapidly taking some of the earth with it This run-off on the hillsides will only be halted, and water will percolate into the earth where there is a good tree cover. In fact a forest “traps” rainwater and channels it into underground streams.
Rainforests around the world still continue to fall. Does it really make a difference? Why should anyone care if some plants, animals, mushrooms, and microorganisms perish? Rainforests are often hot and humid, difficult to reach, insect-ridden, and have elusive wildlife.
Bamboo brakes, Muthodi, Karnataka
The northern portion of the range is generally drier than the southern portion, and at lower elevations makes up the North Western Ghats moist deciduous forests ecoregion, with mostly deciduous forests made up predominantly of teak. Above 1,000 meters elevation are the cooler and wetter North Western Ghats montane rain forests, whose evergreen forests are characterized by trees of family Lauraceae.The evergreen Wayanad forests of Kerala mark the transition zone between the northern and southern ecoregions of the Western Ghats. The southern ecoregions are generally wetter and more species-rich. At lower elevations are the South Western Ghats moist deciduous forests, with Cullenia the characteristic tree genus, accompanied by teak, dipterocarps, and other trees. The moist forests transition to the drier South Deccan Plateau dry deciduous forests, which lie in its rain shadow to the east.
The Nilgiris, an offshoot of the Western Ghats, rise precipitously to form extensive grassy downs and tablelands seamed with densely forested gorges or Sholas. They are composed of evergreen trees with dense undergrowth.
1. Malabar Giant Squirrel 2. Lion tailed Macaque
One hundred and twenty species of mammals are known from the Western Ghats of which fourteen species are endemic (found only in that area).
Aerial view -Andamans & Nicobar Islands
Andaman & Nicobar Islands are blessed with a unique tropical rainforest canopy, made of a mixed flora with elements from Indian, Myanmarese, Malaysian and endemic floral strains. So far, about 2,200 varieties of plants have been recorded, out of which 200 are endemic and 1,300 do not occur in mainland India.The South Andaman forests have a profuse growth of epiphytic vegetation, mostly ferns and orchids. The Middle Andamans harbours mostly moist deciduous forests. North Andamans is characterised by the wet evergreen type, with plenty of woody climbers. The north Nicobar Islands (including Car Nicobar and Battimalv) are marked by the complete absence of evergreen forests, while such forests form the dominant vegetation in the central and southern islands of the Nicobar group. Grasslands occur only in the Nicobars, and while deciduous forests are common in the Andamans, they are almost absent in the Nicobars. The present forest coverage is claimed to be 86.2% of the total land area.