Imagine a place with no seasons. Where every day seems like the last.
A place where it rains almost every day. A place of constant heat, and humidity.
Some might call such a place a hell, while for others, it might be paradise.
It is a place on earth with more species of plants and animals than anywhere else.
Because of the oxygen generated by its millions of trees, it has been dubbed the lungs of the world.
You have arrived at the band encircling the centre of the Earth. Welcome to the Tropical Rainforest.
We begin our journey through Earth’s climate zones here, because here is
the very centre of the Earth, the equator. And it is no accident that such a hot and wet
climate exists on the equator, because it is here that the sun is strongest,
striking the earth directly at 90 degrees. And as it does so, it causes the hot air to rise,
pulling in moisture from the surrounding seas. As this humid air rises up into the high
atmosphere, it cools. But cool air cannot hold onto moisture like warm air can,
and so that moisture precipitates out into vast, towering thunder clouds,
which then finally release as torrential rain. And it is because of its central position,
on the equator, that little to no change in temperature is experienced throughout the year.
While more northerly and southerly latitude experience the colder and hotter seasons,
life on the equator is about watching the sun drift slightly north and slightly south
of being directly overhead. In any position, it is still beating down, producing that heat,
and the thermals that produce all that rain. There is more complexity to this of course…
some areas on the equator experience wet and dry seasons, but we’ll cover and explain this more in
the following video, which concerns the Tropical Monsoon and Tropical Savannah.
So, what kind of vegetation do we find here? Well… tropical rainforest, funnily enough. But what
is it? Rainforests occur in other parts of the world – forests that grow in areas of very high
rainfall. But the tropical rainforest has a unique combination of high rainfall and high temperature,
which results in the most vigorous plant growth to be found anywhere on the planet.
In terms of sheer biomass, this growth most notably occurs in the form of evergreen hardwood trees, meaning dense,
hard wood, like mahogany, teak, sandalwood and rosewood. But unlike the hardwoods of
more temperate latitudes, these trees retain their leaves, and grow, all year round. A
diverse array of plants grow in the shade below the thick tree canopy, and this further leads
to a huge number of animal species in all classes - insects, arachnids, amphibians, reptiles, birds
and mammals. Spend a night in a tent here and… well you’ll soon get to know some of these guys.
So where in the world can we find these forests? Well, naturally, they’re all within the tropical
zone. The most famous of these is of, course, the Amazon river basin of South America which
stretches across many countries most notably Brazil, Peru, Colombia, Ecuador, Venezuela and
the Guyanas. The Pacific Coast of Colombia on the other side of the Andes mountains is also home to
this climate. And then there’s the Congo basin of Africa mostly within the country of the Congo
Zaire, but also including parts of Uganda. The last of the three main rainforest zones is in
South-East Asia, with almost all of Indonesia and Malaysia falling within this climate type,
along New Guinea and the southern and eastern stretches of the Philippines. Many islands of
the Pacific experience the same climate, including the Solomon Islands, Fiji and French Polynesia.
And what about major world cities? Are any found in the tropical rainforest? Well only
two feature, and these are just hours apart from each other on the southern tip of Malaysia. Kuala
Lumpur, the capital of Malaysia and famous for the Petronas Towers… and Singapore, a highly developed
global financial, shipping and aviation hub. So enough chatter – I know you’re all dying
to see some temperature and rainfall graphs, right? Well here they are,
across three continents and oceans, all remarkably the same. High and almost unchanging temperature
throughout the year, and high rainfall throughout the year with no dry seasons.
We should mention something about the graph of Hilo in Hawaii. At almost 20 degrees north of
the equator, it’s pretty far from it, and yet still possesses a very wet and warm climate.
A different mechanism is in play here
The year-round rainfall is due to it being on the windward side of the large volcanoes on
the Big Island of Hawaii. North-easterly winds, known as trade winds, blow moist warm air off
the Pacific all year round, and when this moist air hits the mountainous slopes, it rises, cools
and dumps huge amounts of rain upon the city. There are some other parts of the tropics where
this pattern is found, including the Caribbean coasts of Central America and some Caribbean
islands, including the Dominican Republic and Puerto Rico as well as some eastern
coastal areas of Brazil and Madagascar. So, that’s it for this climate zone. I
hope you enjoyed it and I would love to hear your comments, especially if
you live or have experienced personally life in the Tropical Rainforest climate.
As usual, I encourage you all to hit the like button, and Subscribe if you haven’t already done
so, and tell all your friends by Sharing. I’ll see you all in the next
video, as we penetrate the secrets of the Tropical Monsoons and Savannahs. Until then, stay dry!