60 EXPLOITATION OF PLANTS 
the 120 years. So that there would be a net loss at the 
end of the period of about £400. If the trees planted 
had been beech, the loss would be even higher, about 
£620. On the same basis of computation, ash on a 
70 years’ rotation would, however, yield a profit, 
after paying compound interest at 4 per cent., of about 
£170. This discounted into annual payments is 
equivalent to a rental of 9s. 2d. per annum per acre for 
the land. 
On the chalk downs of the Chilterns we can find 
extensive stretches covered with high forest consisting 
of beech. In many parts, wherever clearings occur, we 
almost invariably find ash appearing from self-sown 
seed. These ash thickets are cut down and planted 
with beech and sometimes larch. Were they retained 
and properly maintained, they would show a handsome 
profit in place of the present considerable loss. 
It cannot be asserted that any other of our native 
trees will show a profit if the debt be calculated at 
4 per cent. interest. Larch, however, will yield a rental 
value of about 5s. to Ios. per annum, and Douglas fir, 
the most paying of all our trees, whether native or 
introduced, will yield a rental value of as much as £2 
per acre. 
Even then, looked at as a purely financial investment, 
afforestation on proper lines is not so unprofitable as 
some have led us to believe. But if we compute the 
return in terms not only of money but of employment, 
decentralisation of population, establishment of rural 
industries, and independence of sea-borne supplies, 
then surely the undertaking is not merely justified, 
but becomes a duty of national importance. 
aes 
