By using materials more than once, we conserve natural resources. In the case of paper, recycling saves trees and water. Making a ton of paper from recycled stock saves up to 17 trees and uses 50 percent less water.
  

Cork wine stoppers are simply discarded without regard by the millions each day in the USA.

The wine cork is one of the most natural products in use in modern consumer society. Made entirely from the bark of the cork oak and coated only with a thin film of wax or resin, the cork is devoid of synthetic additives and completely biodegradable.

Cork is a renewable resource and its harvesting is a truly sustainable example of agroforestry. After use as a stopper, the cork biodegrades without producing toxic residues or may be recycled into other products such as floor tiles, gaskets and sports equipment.

Cork has been used for thousands of years but the most widespread application in its history is as a wine closure-a use that began in the 1600s and grew in association with the spread of mass - produced glass bottles.  The world's first cork stopper factory opened in around 1750, in Anguine (Spain) marking the beginning of the industrial application of cork.

By this time Portugal is the world's leading cork producer.

The secret is its unique cell structure, which technology cannot replicate. Cork consists of a honeycomb of tiny impermeable cells made from suberin, a complex fatty acid, and filled with an air-like gas. There are on average about 40 million cells per cubic centimetre of cork or around 800 million cells in a single wine cork.

Cork's cell-like structure makes it easy to compress and so less liable to damage from corking machines. Amazingly, the cork is capable of being compressed to about half its width without losing any flexibility and it is the only solid that can be compressed in one dimension without increasing in another dimension.

The cushion-like cork cells also display what is known as elastic memory. When compressed they constantly try to return to their original size, thus maintaining a tight seal. This means the cork exerts a very even pressure against the surface of the bottle neck and can compensate for imperfections in the bottle.

Being elastic, cork is also more tolerant than other materials of changes to temperature and pressure.

Portuguese cork forests are one of the most successful examples of sustainable agroforestry anywhere in the world, supplying more than half the world's corks  Portugal's cork forests are a protected resource, subject to a code of good practice to ensure sustainability of production. Almost nothing is wasted - each part of the cork tree serves an ecological or economic purpose.

Not only is cork itself recyclable, biodegradable and renewable, the cork forests provide valuable habitat for birds and other animals and contribute to a mixed agrarian economy that has sustained farmers for many centuries.

The cork oak is well suited to the hot, arid conditions of southern Portugal, helping to protect the soil from desertification and the oaks are home to many species, including the wild boar and rare birds such as the black stork and the Egyptian mongoose.

Portugal's cork forests are a carefully protected resource. The paramount importance of the cork industry to the Portuguese economy had led to strict regulation of the growth and management of cork trees.

The mature tree may only be harvested for its bark once every nine years and only when the tree is healthy.

With the help of reforestation programs funded by the European Union and the Portuguese Government, the area of cork forest under cultivation in Portugal is growing by about four per cent a year.  Today, new trees are being planted at twice the rate at which old trees are dying.

In addition to its ecological value, the cork oak is remarkable in that every part of the tree serves some useful economic purpose.  Here are a few examples:  The acorn of the cork tree, as well as being used for propagation, is used as animal fodder and as a source of cooking oils;

The leaves of the tree are used as fodder and a natural fertilizer

Tree prunings and decrepit trees provide firewood and charcoal. Various chemical products are made from the tannins and natural acids contained within the wood. Of course, the most valuable part of the tree is the bark, used for making myriad cork products.

More than 50 per cent of the cork bark goes into stoppers, including natural wine corks, champagne corks, Twin Top corks, bar-top corks for fortified wines and spirits, and small corks for other uses.

All of the cork bark is used in production - nothing is wasted. As cork waste is generated in the production process, it is granulated and returned into the process. Even the fine particles of cork dust are collected and used as fuel to heat the factory boilers. Bark from the tree's first two harvests (known as virgin and secondary bark) is used to make corkboard insulation and cork tiles.

Cork from the third and subsequent harvests (known as reproduction cork) is used for whole cork products, principally stoppers, and a range of granulated cork products, including noticeboards, gaskets, golf balls,  and floor tiles.     Cork is also combined with rubber for gaskets, valves and insulation in buildings and railways. It is even found in the nose cone of the space shuttle.

The oldest and largest productive cork tree in the world is the "Whistler Tree", so called because of the numerous songbirds that occupy it.

It was planted in 1783 near the town of Åguas de Moura in the Alentejo region of Portugal. It was five years old when the first English settlers arrived in Australia and six years old when the French Revolution began in 1789.

Bottles of wine sealed with cork in that same year, 1789, were discovered 40 years ago in a French cellar, with both the wines and corks in good condition - proof of the long life and superb sealing abilities of  natural cork.

Stripping the bark from the Whistler Tree in June 2000 took a team of five men almost four hours.

The Whistler Tree is more than 14 metres (45 feet) high and 4.15 metres (nearly 15 feet) in circumference. It was first harvested in 1820, and since then it has been harvested another 20 times.

The 1991 harvest produced 1200 kilograms of bark - more than most trees yield in a lifetime. This single harvest was enough for more than 100,000 wine corks. The latest harvest, in June 2000, was less productive but it still produced an impressive 650 kilograms, 10 times the yield of an average cork tree.

Real corks are preferable to plastic corks for many reasons. The main one being that cork forests in Portugal and Spain supports an incredible diversity of wildlife.

Cork trees are now protected by the Portuguese government as  renewable resource and the average life span of a cork tree is more than 200 years.

The combined output of Spain and Portugal should yield approximately 250,000 tons of cork bark (170,000 tons from Portugal and 80,000 tons from Spain), an increase over 1999.