The benefit of trees to our landscape and climate

canopy of leaves and very little water would land on the ground.

The wet leaves would hold the water so it could evaporate into the atmosphere. This would cool the temperature and raise humidity. In a heavier rain storm a big tree can hold 500 litres of water on the leaves and bark, which has the benefit of storing water for a while before it starts its journey to the river.

What is happening to us now is that, having cleared the land of many trees, rainwater gets to the river within minutes of hitting the ground. This surge of water speeds down the river, washing soil from the bank and carrying it to the estuary. The lack of tree roots to bind the bank together leaves the soil vulnerable to erosion, so not only is New Zealand losing topsoil at an average rate of six tonnes per hectare, but the mud swamps our estuary fish grounds and diminishes the ability of fish to breed.

The oceans also have a big influence on our climate, but that is another story.

There is a big initiative in New Zealand to plant trees, but as most of the land is owned by farmers, and they have a relatively low workforce, in my view farmers need government help to plant the unproductive land on their farms to restore the landscape to its original function and repair the damage done by previous generations.

To understand a forest, start with a single tree