林地前茬对土壤肥力和杉木幼林生长的影响

不同林地前茬的土壤分析和杉木幼林生长调查结果表明：天然次生常绿针阔叶林地上营造杉木幼林生长各指标均明显大于柿子经济林地，杉木造林后第二年，两种林地前茬的杉木幼林生长差异尤为明显，杉木树高和地径比林地前茬为经济林增加66.83cm和1.64cm；天然次生常绿针阔叶林地土壤水分、孔隙状况和土壤结构体均优于柿子经济林地；土壤有机质、全氮、全磷和速效性养分含量也明显高于柿子经济林地．经济林地土壤结构恶化和养分含量下降是杉木造林生长不良的一个主要原因，杉木造林地的合理选择是保证杉木持续速生丰产的一个关键技术环节．

The Effect of Pre-planted Forest Types on Soil Fertility and Growth of Young Chinese Fir Plantation

Through the soil analysis and growth survey of young Chinese fir plantation in different perplanted forest land,the results show that all growth factors of young Chines fir plantation planted in the natural secondary conifer and broad-leaf evergreen mixed forest land are obviously larger than that planted in thepersimmon economical forest land, the second year after planting, the differences of growth of Chinese firplantation in two different pre-planted forest lands are particularly obvious, its height and diameter at breastheight are increased by 88. 15cm and 2. 011cm respctively than that planted in the persimmon forest land ; thesoil water condition, pore space and soil structure in the secondary conifer and broad-leaf evergreen mixedforest land are better than that in the persimmon forest land; the content of soil organic material, total nitrogen, total phosphorus and available nutrient is also larger that in the persimmon forest land. In short,the mainreasons of poor growth of Chinese fir plantation planted in the persimmon forest land are deterioration of soilstructure and decline of nutrient content. So the raional selection of forest lands for Chinese fir is one vitaltechniqe for ensuring sustainable fast-growth and high-yield of Chinese fir.