W

e are constantly being encouraged to grow more trees, but apart from carbon capture and the natural beauty of a tree, what are the real benefits?

When we look at the countryside today we are not seeing it as it used to be, because almost all the big specimen trees have been logged or burnt off and are only slowly recovering. We know that 97 per cent of kauri trees have been felled, but the same is true of most big trees with good timber.

To understand a forest, we need to start with a single tree, and from there we can quickly get a picture of a mass of trees.

A decent-sized tree would be more than 200 years old with a height of 20-plus metres, a trunk about 750mm in diameter, and weigh about 15 tonnes, so it’s quite an investment by nature to get it this far. And it might last for 500 to 1000 years.

A single tree has quite an area of shade, so the temperature below will be lower, and in a city this would be a benefit to offset the heat from tarmac and concrete, as well as softening the look of a concrete city jungle. The biggest benefit of trees is controlling the temperature, humidity and rainfall flow, which collectively make the climate of New Zealand. In a light rain shower the raindrops would land on the