不同树种生长适应性及其对土壤微生物数量的影响

通过调查不同树种新造林树高生长量、保存率及其土壤细菌、真菌、放线菌数量等，研究其生长、适应性及对土壤微生物数量的影响。结果表明：光皮桦、桤木、楸树、栾树、湿地松5年生树高分别为7．4、6．5、6．3、4．8、4．2m，保存率分别为92％、65％、82％、78％、90％；不同树种造林后对土壤微生物数量的提高有明显差异，5个树种造林后林分土壤微生物数量提高的效果排序为桤木〉光皮桦〉栾木〉楸树〉湿地松；新造林均表现为造林当年土壤微生物数量明显下降，一般下降35％～40％，第2年底回升并超过造林前水平，第3-5年逐年增加。

The growth adaptability of different tree species and their effects on soil microbial quantity

Through the investigation of different tree species in new forest height growth, survival rate and soil bacteria, fungi and actinomyees quantity, the growth and adaptation of different tree species and their effects on soil microbial quantity were studied. The resuits showed that, the height of Betula luminifera, alder, Catalpa bungei, Koelreuteria paniculata and Pinus elliottii with 5-year-old were 7.4 m, 6. 5 m, 6. 3 m, 4. 8 m, 4. 2m respectively, and the save rate were 92% , 65% , 82% , 78% , 90% respectively. There were significant differences on soil microbial quantity among different tree species of afforestation, the effect on soil microbial quantity increase was in order of alder 〉 Betula luminifera 〉 Koelreateria paniculata 〉 Catalpa bungei 〉 Pinus eUiottii. The new forest showed soil microbial quantity decreased obviously at the first year of afforestation, generally decreased by 35% ~ 40% , picked up even exceeded the level of before afforestation at the end of the second year, and increased year by year from the third year to the fifth