对三北防护林体系工程的思考与展望.pdf

11 1 . 11 . 1 Vo l N o 2004 3 Resear ch o f Soil and Water Con serv ation M ar. , 2004 朱金兆, 周心澄, 胡建忠 ( , 100083) , , 197 8 , 2 3 2 203 . 7 2 hm2 , 5. 05% 9 % , , , , , ( ) ( ) ( ) , 21 50 , , , , ; ; ; ; 727. 2 3 1005-34 09 ( 2004) 0 1-0189 -04 S A Thoughts and Vi ews of the Three North Shel terbel t Program Z HU Jin -z hao , ZHO U X in -cheng, HU Jian-zhong ( B e ij ing For estry Univ er sity , B eij ing 1000 83, China ) Abstract N oted as a g reat splendid pro gr am , the three no rt h shelter belt pro gr am is no t o nly a pioneering w o rk in Chinas eco - , - . 197 8, con stru ction but al so the impor tant p ar t of na tio nal eco con str u ct ion Star ted in the sur vival ar ea of the pr og ram is ac- cumulated to be 22. 037 2 m illio n hm2 in 23 y ears, a nd the f o rest cov erag e ha s been incr eased fro m 5. 05 % in the beginning t o 9 % up to now . T he pro tectio n f or est sy st em in som e key a reas h av e been set up so st ably th at it s eco log ical , eco no m ic and so - cial benef it s h av e been impr ov ed g reatly . T he pro gr am h as a br eakthro ugh fro m t he tr aditio nal model into a multiple o ne, th at , , , , - is t he co mbinatio n of belt p atch and net the combination of a rtif icial aff or estation aer ial so w ing aff o restat ion and clo sing hill and sand dune to f acilitat e aff