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Google圖書搜尋
Forest Resources of the Douglas-fir Region
Horace Justin Andrews
Robert William Cowlin
出版
U.S. Department of Agriculture
, 1940
URL
http://books.google.com.hk/books?id=CD3S7mLniR4C&hl=&source=gbs_api
EBook
FULL_PUBLIC_DOMAIN
註釋
The highest service that forests of the Douglas-fir region can render is in support and stabilization of communities dependent on them. Forests support in one way or another about half the population of the region. To redeem this enormous responsibility for service, forests must furnish a permanent annual harvest of material equal at least to present production. This will required sustained-yield forest practice, including acceptance of the responsibilities of permanent ownership.
