<正>以山地杨树人工林为对象，研究了不同覆盖量和覆盖材料对杨树根际土壤磷动态的影响。结果表明：覆盖后杨树根际全磷含量随着覆盖量的增加而增加，2.5、5.0、7.5kg/m2覆盖处理的杨树根际土壤全磷量分别比cK高10.77%、13.85%和52.31%；4种覆盖材料间差异不大，但均大于对照。覆盖能有效提高杨树根际土壤有效磷含量，覆盖量越大，效果越明显；不同覆盖材料对根际土壤有效磷的影响有较明显的差异，对杨树根际土壤磷动态变化的影响与不同覆盖厚度处理结果相似，覆盖以后杨树根际土壤全磷含量及有效磷含量有先下降后上升的趋势。

Different pulp concentration as carbon source for cellulase proc’tuction by Trichoderma reesei was investigated. The best pulp concentration was 12 g/L. After 3 days of cultivation, the filter paper activity, CMCase activity and [3-glucosidase activity were 1.68,0.96 and 0.28 U/mL respectively. Fed-batch manner could significant increase cellulase production by Trichoderma reesei. The fed-batch manner was that initial pulp concentration was 9 g/L and 2 g/L pulp was added to the culture at second, third and fourth day. After 3 days of cultivation, the filter paper activity, CMCase activity and β-glucosidase activity became 2.41,0. 72 and 0.27 U/mL respectively. Compared with batch culture used 15 g/L pulp, the filter paper activity increased 1.8 times.