Abstract:

Expansion or contraction of forest ecosystems on the earth has been driven by the changes in relative scarcity of the products and services from the lands．For a long history worldwide，food has been relatively scarcer than wood，so forests have been largely changed into agricultural uses．However，due to the dramatic decrease of forests in the world during the last century，wood products as well as forest ecological services are becoming relatively scarcer than food and therefore many agricultural lands have been converted back into forestlands．Meanwhile．Plantations have replaced natural forests as a major timber supply in most countries．This paper first briefly explains the evolution of forest land use/cover from economics perspective，then uses land use changes in the US，New Zealand and the Hainan Island of China as examples to support our argument．Finally a perspective of the future forestland change is presented based on the principles of economics．

Key words: forest ecosystem, forest transition, relative scarcity, land use, the United States, New Zealand, Hainan Island