206 SECTIONAL ADDRESSES 
As a form of vegetation which rises high above the surface of the ground, 
the value of the forest in breaking and tempering the effects of the cold 
winds has long been recognised and appreciated by the agriculturist. 
An adjacent sheltering strip or even clump of trees exercises a marked 
influence on farm crops and pasture lands ; stock also thrive better in the 
shelter afforded. The trees afford shelter and at the same time exercise 
a very marked influence on the rate of evaporation of moisture from the 
surrounding area ; this influence, in lessening the surface velocity of the 
wind and rendering it more moist, may be noted up to between 300 and 
400 ft. from the trees, but the distance varies with the height of the 
trees. In spring the pasture is earlier and more abundant, while in the 
autumn it remains longer green. ‘The question of a reasonable balance 
between forest and grazing land is one of considerable biological and 
economic importance. 
In the time available it is obviously only possible to refer to a few 
aspects of forest biology. I would have liked to say more about the 
importance of plant geography, but probably enough has been said to 
indicate how important this branch of botany is to forestry. Plant 
physiology and ecology are also of the highest service in the applied 
science of forestry. Plant anatomy is likewise of great value in wood 
technology, timber identification, seasoning, testing and preservation, 
which are all very materially helped by a knowledge of wood anatomy. 
It is needless to say that without the help of the botanical systematist 
the forester would frequently find himself in serious difficulties, while 
the mycologist is equally indispensable. 
Many biological problems of first-class importance in silviculture 
have still to be tackled, and it is to botany that the forester must look for 
their ultimate successful solution. 
