Rubber

It has just been announced that the small Brazilian state of Espirito Santo, part of the Mata Atlantica region, is the 4th largest rubber producing state in Brazil, with 14,000 hectares of “seringueiras”, or rubber trees. Most of the rubber latex produced is bought up by two cooperatives and sent to Michelin, who process it and turn it into tyres. There is a state plan to expand to 75,000 hectares by 2025.

What does this mean for the countryside? Well the rubber tree, Hevea brasiliensis, is native, sort of. Actually it comes from the Amazon rain forest, but grows well further south, as long as it is below 800m and with less than 1,000 mm of rain per year. It is very vulnerable to frost so needs north facing slopes (this is the southern hemisphere remember) and tends to be susceptible to fungi, though there are resistant varieties.

It is a tall tree, up to 144ft if given it's head, but normally kept to 80ft to encourage latex production. This means that it doesn't start producing rubber until about 5-6 years old – only 8,000 hectares of the 14,000 in Espirito santo are actually producing. Because of this young plantations are usually combined with cash crops such as pineapple or papaya, or animals such as goats. Even perennial crops such as coffee or pepper.

When the tree has reached the end of it's useful life you can of course use the wood. But, frankly, it's main advantage is that it is very cheap. It warps easily, and is very liable to rot, so cannot be used out doors. If you see something made from “parawood” or “Malaysian oak”, beware!

Rubber

Look in the corner of your living room, or maybe in the pub you visit this evening, and somewhere you will see the rubber plant. Long lived, almost indestructible, they make excellent house plants, and they are healthy too. It´s been shown that they filter tobacco smoke and other pollutants from the air.

A Ficus elastica in Vitoria, Brazil

The Rubber plant is not the same as the Rubber tree. Well, actually, you can make rubber from the latex, but commercial rubber is made from the tree Hevea brasiliensis, a Brazilian native that is now grown all over the world. The Rubber plant, Ficus elastica, is a type of fig from India and requires a special wasp to set seed. And, left to it´s own devices it is BIG. Up to 60m in rare cases, although 40m is more normal. The trunk can be up to 2m in diameter.

To help support all this weight the rubber plant produces lots of buttress roots down the side of it's trunk which both help support heavy branches and also anchor the tree. It's also hung like a christmas tree with ariel roots.

These roots can be trained, guided, to grow where you want, and in parts of India have been used to make living bridges across canyons. They will root on the other side and can make narrow bridges up to 100ft long. Not only are they free, but self sustaining and will actually get stronger over time as the roots thicken.

Painting by Helio Mello (1926-2001)

So, how does one make rubber? Well, actually I wouldn't, as the latex is nasty stuff and causes all sorts of skin problems, but if you must, this is how to do it. Make a cut in the trunk and collect the latex that runs out. Coat a thin layer over a wooden paddle and hold high over a wood fire until the solution has set and the smoke has turned it grey. Gradually add more latex, waiting each time for it to set, until you have a big black lump of rubber. Cut for use.