FORESTS AND FLOODS

New Zealand Herald, Volume LXXIII, Issue 22512, 1 September 1936, Page 15

FORESTS AND FLOODS

Sir, —The community is under a distinct obligation to the New Zealand Herald for periodically drawing notice to the grave menace to the future of New Zealand duo to floods caused by forest destruction and the urgent need of afforestation on a large scale, as in Germany, Japan, India and many other countries. When the afforested area of a country sinks below 25 per cent (as in New Zealand) the climate is bound to be affected adversely to an ever-in-creasing extent, both as regards the evenness of the changes as well as of their intensity. Unless we plant forests on a very extensive scale New Zealand is destined to bo subject to periodical droughts, electrical storms, cloudbursts and floods, soil erosion and tho silting up of rivers and harbours to an everincreasing extent. Forests act as static condensers of atmospheric electricity and as lighting conductors and thus not only attract clouds an'd rain, but cause a gentle and continuous precipitation of the rain, breaking the force of its impact on the soil, controlling the runoff, thus retaining moisture in the soil —ensuring an even distribution of rain throughout the year, breaking the force of the wind and tempering both the heat of summer and the cold of winter. It takes Nature 400 years to renew the humus and top soil, once these have been washed away by floods, and a single violent flood has been found to wash away 39 tons to the acre of top soil. Valleys subject to periodic floods are notoriously unhealthy, particularly as regards the incidence of goitre and cancer. Forests are also scavengers of the soil and purifiers of the atmosphere, for they consume tho carbonic acid gas exhaled by human beings and animals, which helps to form wood, and they return back to the atmosphere tho life-giving oxygen. In the foliage, flowers and fibres of forests are stored up vast quantities of minerals extrapted from the soil, as well as vast quantities of nitrogen and vitamins extracted from the air, by the agency of sunlight. Owing to tho purity of the air, health sanatoria are preferably situated in forests. Forests give sanctuary to birds, animals, reptiles, insects and bacteria —all necessary for the health, wealth and happiness of humanity. Forests provide the sun with the main outlet for its enormous energy, equal to over three million horse-power per square mile of soil. Where forests are destroyed, this vast energy, with its legitimate occupation gone, is free to do the destructive work of causing droughts, electrical storms, cloudbursts and floods and soil erosion, etc., which slowly and surely converts what was once a fair land into a desert. Thos. A. F. Stone.