草地早熟禾及沿阶草对古油松和古侧柏土壤微生物数量特征的影响

Influence of Poa pratensis and Ophiopogon japonecus on the Soil Microbial Community of Ancient Pinus tabulaeformis and Ancient Platycladus orientalis

草地早熟禾与沿阶草作为古油松和古侧柏下垫面后,会对古树土壤微生物的种类及数量产生影响。结果表明,古树下建植草坪后,土壤三大微生物数量均为细菌〉放线菌〉真菌,且0~20cm土层微生物数量高于20~40cm;草地早熟禾与沿阶草的建植可增加古树0~40cm土层土壤三大微生物的数量,草地早熟禾的增加效果好于沿阶草。2种草坪草均增加了古树0~40cm土层反硝化细菌的数量,降低了古树0~40cm土层自生固氮菌的数量,同时可促进0~40cm土层纤维素分解菌数量的增加,但这种影响不显著。

This research selects two common ancient trees（ancient Pinus tabulaeformis and ancient Platycladus orientalis）,and two common turfgrasses（Poa pratensis and Ophiopogon japonecus）in Beijing,ino rder to find the influence of the grass to the ancient trees underlaying surface,the author measured microbial numbers of the soil in depth 0-40 cm.The number of the bacteria,fungi and actinomycete in 0-20 cm layer was higher than 20-40 cm,the number of the bacteria was higher than fungi and actinomycete.The two grasses increase the number of soil microorganisms of the old trees in depth 0-40 cm,and the Poa pratensis was better than the Ophiopogon japonecus.The two grasses can all increase denitrifying bacteria in 0-40 cm and reduce the number of nitrogen-fixing bacteria in the layer of 0-40 cm and the two of this trend was not significant.Thet wo grasses can all increase cellulose-decomposing bacterium＇s number in 0-40 cm layer.