中文摘要：

研究了不同覆盖材料和不同覆盖量对杨树人工林根际微生物和酶活性动态变化及杨树生长的影响．结果表明：采用4种材料对杨树林地表进行覆盖后，其根际细菌和真菌数量均高于对照，其中白茅和白栎的效果最佳，分别为对照的3．56和2．43倍．随覆盖量的增加，细菌、真菌数量增多，7．5kg·m^-2处理的细菌平均数量分别比对照高49．58％，真菌数量是对照的6．14倍．生物覆盖后，细菌和真菌数量的年变化趋势相似，均与土壤温度的变化同步，且7月最大，12月最小．脲酶和磷酸酶的活性也随着覆盖量的增加而增强．不同覆盖材料间，脲酶、磷酸酶活性变化均为马桑〉蕨类〉白茅〉白栎〉CK．根际土壤脲酶和磷酸酶活性的年动态变化与细菌与真菌的年变化相似，且7月最高，12月最低．生物覆盖对杨树的树高、胸径和生物量具有显著的促进作用．

英文摘要：

Coriaria nepalensis, Pteridium aquilinum var. latiuscukum, Imperata cylindrical var. major, and Quercus fabric were used as mulching materials to study their effects on the rhizosphere soil microbial population and enzyme activity and the tree growth in poplar plantation. The results showed that after mulching with test materials, the populations of both bacteria and fungi in rhizosphere soil were more than those of the control. Of the mulching materials, I. cylindrical and Q. fabric had the best effect, with the numbers of bacteria and fungi being 23.56 and 1.43 times higher than the control, respectively. The bacterial and fungal populations in rhizosphere soil increased with increasing mulching amount. When the mulching amount was 7.5 kg m-2, the numbers of bacteria and fungi in rhizosphere soil were 0. 5 and 5.14 times higher than the control, respectively. Under bio-ulching, the bacterial and fungal populations in rhizosphere soil had a similar annual variation trend, which was accorded with the annual fluctuation of soil temperature and got to the maximum in July and the minimum in December. The urease and phosphatase activities in rhizosphere soil also increased with increasing mulching amount. As for the effects of different mulching materials on the enzyme activities, they were in the order of C. nepalensis 〉 P. aquilinum 〉 I. cylindrical 〉 Q. fabric. The annual variation of urease and phosphatase activities in rhizosphere soil was similar to that of bacterial and fungal populations, being the highest in July and the lowest in December. Bio-mulching promoted the tree height, DBH, and biomass of poplar trees significantly.