WHEN TO CUT DOWN TIMBER

Temuka Leader, Issue 10359, 31 August 1922, Page 4

WHEN TO CUT DOWN TIMBER

Timber cut in spring and in summer is not so durable as that cut in winter, when the life processes of trees are less active. Scientific investigations sustain this btaten-eiit. The durability depends not only , upon the greater or less density, but also upon the presence ! of certain chemical constituents in tb3 wood. Thus a large proportion of resinous matter increases the durability, v.hUe the presence of easily-soluble carbohydrates diminishes it considerably. During the growing season the wood of trees contains sulphuric acid and potassium, both of Which are solvents of carbohydrates, search lesins, and gums; they are known to soften also ihe ligneous tissue to a considerable degree. During the summer months the wood of living tiers contains eight times as 'ihkli sulpharic acid and five times as mm'h potassium as it does during ihe winter months. The presence of these two chemical substances during le growing season constitutes the chief factor in dissolving the natm al preservatives within the wood and in preparing the wood for the different kinds of wood-destroying fungi, such as Polyporus and Agaricts. The fungi can thus penetrate more quickly and easily into the interior of the wood when these wood gums are already partly dissolved and available for their own immediate use. From this standpoint it seems that the best time to cut down the tree is in the winter, when sulphuric acid and potassium are present to a much smaller degree, and the fungi will not be assisted in dissolving the natural preservatives in the wood. Ibe amount of wood gum is always ltss and more easily soluble in sapwood than in heartwood, and for this n ason the former is usuulry regarded worthless for .induiirial purposes.