376 
cork at $97.13 per ton, this is ‘equiva- 
lent to an annual income of $5.44 per 
acre, which is about one-half that of an 
estimated acre in the United States. 
From the investment point of view, 
it appears that the cork oak in this 
country will compare very favorably 
with that in the Mediterranean region. 
The cork forest produces income in 
addition to that derived from the 
cork. For the first 20 years, while 
the trees are young, the land provides 
forage for sheep, goats, and other 
cattle. When the acorns mature in 
the twentieth year, the land may be 
converted to hog pasture, and used as 
such throughout the life of the forest, 
so that cork and pork will be produced 
at the same time. After the fortieth 
year, thinning provides wood from 
which additional income may be 
derived. These augmentative com- 
modities will probably more than offset 
the cost of rent, labor, and overhead, 
so that the return on the cork will be 
all profit. 
Cork production will remain profit- 
able only as long as an economic 
balance is maintained between supply 
and demand. Any tendency to over- 
produce will invariably prove to be 
detrimental to the undertaking. There- 
fore, if the proposed cork-forest in- 
dustry is to be within economic 
ANNUAL REPORT SMITHSONIAN INSTITUTION, 1948 
bounds, the total number of trees 
should not exceed the 28,000,000 
prescribed in the 22-year forest of 
table 10. 
It would be purely conjectural to 
attempt a statement as to how long 
and at what rate the 22-year forest 
will continue to produce. These are 
essential points which must be de- 
termined by observation and study 
of growth and production trends 
during the earlier stages of develop- 
ment, in order that reliable data 
might be obtained concerning the 
cycles in which subsequent forests 
should be planted so that they arrive 
at maturity when the preceding one 
reaches exhaustion, and, thereby, per- 
petuate cork production at a rate that 
will satisfy the Nation’s need. 
REFERENCES 
1. Witiiams, Simon, Bull. Torrey Club, 
vol. 66, pp. 353-365, 1939; ibid., vol. 69, 
pp. 1-10, 115-129, 1942. 
2. Mirov, N. T., and Cummine, W. C., 
Journal of Forestry, vol. 43, pp. 
589-591, 1945. 
3. Ryan, Victor A., Some geographic and 
economic aspects of the cork oak. 
Crown Cork and Seal Co., Inc., 
Baltimore, Md., 1948. 
4, BurEAU oF ForeIGN and Domestic Com- 
MERCE, Specialties Division, World 
Production and Trade in Cork. U. S. 
Department of Commerce, Washington, 
DD C393 7% 
