How much oxygen do plants produce, and how can you tell how old trees are?

We explore the curious questions that science can answer

It’s not what you say, but how you say it: talking to your plants could, in fact, help them grow (Getty)

How much oxygen do plants produce?

A mature beech tree produces enough oxygen for 10 people every year, and a lawn 35 sq m (300 sq ft) can produce enough oxygen in a week for one person’s daily demand. The Science Museum in Singapore had a fascinating exhibit to show the importance of green plants in producing oxygen and taking up carbon dioxide. It comprised a large fish tank with aquatic plants and fish in the water. Sealed inside the tank, totally enclosed by water, and linked to an oxygen trapping system, was a cage with healthy, vigorous hamsters in it. Food was provided through a sealed tube system, and the only oxygen they received was directly from the water plants in the surrounding tank.

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