再论现代林学、森林与林业——对北京林业发展之初议

本文论述了林学、森林和林业近两个多世纪以来的发展变化。林学经历了由传统林学向现代林学的转变。现代林学是以森林生态系统的营建、恢复、改造、经营管理和合理利用为研究对象和内容，以全面发挥森林生态系统的多功能和多种效益为目的，并做到森林可持续发展、永续利用的学科。对森林的认识也经历了由单株树木到树木群体再到森林生态系统的变化，森林对环境的影响由局部影响转向深入研究森林对大范围包括国家、洲及全球的影响。特别是热带森林有地球的“心脏”、“肺”之称，影响全球。人们对林业的认识也从长期以木材利用为中心，转变到全面发挥森林多功能、多效益的复合产业和公益事业，以实现森林的永续利用和可持续发展。本文还对北京林业未来发展的定位、布局、质量及多功能经营问题，提出了一些新见解。

New Recognitions on Modern Forest Science, Forests and Forestry: Discussions on Fortstry Development in Beijing

This paper discusses the development and variations of forest science, forests and forestry in the past two centuries.The forest science has experienced a transformation from the traditional forest science to modern forest science.Modern forest science,taking the establishment,restoration,reform,management and rationally utilization of forest ecosystem as its research objects and content,is now a discipline with the purpose of bringing the multiple functions and multiple effects of forest ecosystem into full play in the fields of economy,ecology,society,culture,medical and health care,tourism and recreation,sports,entertainment and scientific researches.The recognitions on forests also have been changed from individual trees to tree community and now to the forest ecosystem.The studies on the influences of forests on the environment have been re-orientated from the influences on local areas to those on the large scale including a country,a continent and even the globe.In the past decades,the idea that regarding the tropical forests as the earth's heart or lung has influenced the whole world.As for the industry of forestry,an evident change is that the timber centered forestry has been replaced by the multi-purposed industry and public service forestry.The main tasks of today's forestry are to fully play the multiple functions and multiple effects of forests and to realize the forever utilization of forests and sustainable development of forestry.At last the paper puts forward some new suggestions for the positioning,arrangement,quality enhancement and multi-function management of forestry in Beijing.