Sir, – 'It's trees Jim, but not as we know them'. Recent research is claiming that large areas of forest, particularly in warmer latitudes, have much greater effects on rainfall, not just where they are growing, but hundreds (even thousands) of miles down wind than we had thought.

The total amount of rainfall is also increased and the 'culprit' is the transpiration of moisture into the air from trees which goes on after shallower rooting plants (like cereals) are stopped, due to drought.

Researchers even attribute the desert centre of Australia to deforestation of the west coast forests of West Australia by the ancestors of present day aboriginals to hunt the now extinct megafauna using fire. The present day forest clearing in that locale to grow wheat is making the centre and east of Australia drier, it is claimed.

Much nearer to home, it could be argued, that large amounts of forestry in the west and north of Scotland will have the effect of making the east wetter, particularly in the summer months. Perhaps the relatively dry climate enjoyed by our best arable acres, depends on a lot of our hills retaining a significant area forest free?

All is not negative, however, if the trees replaced have commercial annual crops, such as palm oil and rubber in the tropics and sub tropics.

So, if we must grow more trees to satisfy logging requirements and climate change targets, it might need to be done with more care than just short term commercial demands.

Sandy Henderson

Faulds Farm,