杉木泡桐混交林生产力及其土壤肥力特性研究

杉木泡桐混交之后，林地肥力得到明显改善。杉木泡桐混交林与相同立地条件下杉木纯林相比，杉木坡下部和坡上部，平均树高分别高1.7m和1.6m，平均胸径分别大2.1cm和2.2cm，单株材积分别大0.0196和0.020m^3，杉木蓄积量分别大45.5675和53.2455m^3/hm^2，加上泡桐的蓄积量，坡下部长坡上部混交林林分的蓄积量分别大60.5475和60.7850m^3/hm^2。这说明杉木泡桐混交是一种良好的混交组合，形成了有利于杉木生长的环境条件，充分利用生态空间和林地资源，对土壤理化特性具有较好的改良效果。

Studies on Productivity and Soil Fertility Characters of Mixed Stand of Chinese Fir and Paulownia

Fertility characters of soil gained obvious melioration since Chinese fir was mixed with paulownia (Pauloconia australis). Compared to contradistinctive Chinese fir pure plantation beneath the same soil qualification, Chinese fir in the mixed stand of Chinese fir and paulownia is 1.65m higher at average height, 2.15cm larger at average diameter, 0.0199m 3 larger at single-plant volume, 49.4050m 3/hm 2 larger at fir stand volume, 60.6662m 3/hm 2 larger at total stand volume. The results indicate that Chinese fir mixed with paulownia is a kind of fine mixed combination. It offers advantageous environment condition for the growth of Chinese fir, utilizes ecosystem space and land resources sufficiently, and largely improves physical and chemical characteristics and fertility of soil.