不同林地清理方式对杉木人工林生态系统的影响

在杉木中心产区福建尤溪建立径流场，进行不同林地清理方式对杉木人工生态系统影响的６ａ定位研究结果表明：炼山清理迹地导致林地严重的水土流失，炼山后的６ａ中要地的水、土、肥人分别达８７６７．３２ｍ＾３／ｈｍ＾２、３８．００ｔ／ｈｍ＾２、５２３．１６ｋｇ／ｈｍ＾２，分别是不炼山林地的３．１０、１９．７０、６．１０倍。两种清理方式林地流失量差异随时间推移逐年缩小，于第６年趋于一致，炼山具有短期激效效应，经雨

EFFECT OF DIFFERENT GROUND CLEARANCE ON CHINESE FIR PLANTATION ECOSYSTEMS

Through the long term runoff observation in Youxi county, Fujian Province, the effect of different ground clearance on chinese fir plantation ecosystems has been studied for six years. The results are as follows: Serious soil erosion from chinese fir plantation is caused by control burning. The loss of water , soil and nutrient in control burning site during six years are 8767.32 m 3/hm 2, 38.00 t/hm 2 and 523.16 kg/hm 2, respectively, which are 3.1, 9.7 and 6.1 times of that of non burning sites, but the difference of soil erosion between control burning and non burning sites is getting smaller in after years; Control burning might have a short term benefit for soil fertility. But after rainy period, if would be disappeared and then the soil fertility decreased rapidly until the stand closed; The nutrients of surface layer in non burning sites would be enriched, due to the decomposition of the slash, its soil fertility has been improved; Moreover control burning can enhance the survival rate of chinese fir seedlings and their growth and development of undergrowth during a short period.