Trees — The Character, Structure, c^r. 39 



the foliage of the trees. The importance of niaiiitaining a dense 

 canopy ahove and a suitable forest floor l)elow cannot be too 

 strongly insisted upon. A constant moisture is kept up by 

 rainfall, the humus, acting like a sponge, a])sorbs the water 

 which gradually percolates to lower levels, to be afterwards 

 drawn upon if required by the loots, while the sur])lus emerges 

 as an even flow into the streams and rivers, freed to a large 

 extent from its fertile suspended mattei'. It is on this ])rinci]ile 

 that many Municipalities afforest ])ortions of the catchment areas 

 of their water supply. 



There is no need to grow timber trees on soils suital)le for 

 agriculture, but there is no reason why vacant land found suitable 

 for timber crops should be lying idle : it should be put to work- 

 Mountain sides, rocky and thin soiled, up to an elevation of 

 1,000 feet should be planted chiefly with softwoods. Perpetual 

 winds, day and night, high up on mountains, i»ut a limit to the 

 growth of trees. In such exposed situations the wind causes 

 the upper shoots to become wind pruned owing to too rapid a 

 transpiration, with the result that the juicy shoots wither and 

 fall off, causing the trees to assume a sttuited appearance. It is 

 partly due to transpiration that many trees shed their leaves in 

 winter, while some actually shed their twigs, provision being 

 made beforehand to heal the wounds : Oaks, Poplars, Willows, 

 Elms, Horsechestnut, are examples. 



There are many problems which would have to be faced in 

 afforesting Ireland. Transport would have to be considered as it 

 is essential that timber should he juit on the market as cheaply 

 as possible. Kail carriage for I'oand timber would be costly 

 owing to the demand for other goods, and this is likely to 

 increase with agricultural development. The demand for the 

 supply of timber for packing cases, crates, etc., is likely to be 

 enormous ; quick transit of food to the consumer is imperative, 

 but timber transport, although it must be at a cheaj) rate, unlike 

 perishable goods, need not as a rule be urgent. Hence, con- 

 sideration should be given to the old canal system which prospered 



