Comparison on the numbers of soil microorganisms in invaded and non-invaded areas of Eupatorium adenophorum.
The numbers of soil microorganisms (bacteria, actinomycetes, fungi, free-living dizotrophs, cellulolytic bacteria, silicate bacteria and organic phosphate bacteria) in invaded and non-invaded areas of Eupatorium adenophorum in 4 seasons were determined and compared. The correlation analyses were calculated between the numbers of different microbe groups. The results showed that: (1) The variations of the numbers of soil microorganisms in invaded and non-invaded areas in 4 seasons were similar, the number of soil actinomycetes in autumn was maximum but relatively low in spring; the numbers of other microorganisms were relative high in spring and summer but low in autumn. (2) Invasion influenced the numbers of soil microorganisms which caused to the higher number of soil bacteria in invaded area than that in non-invaded area, the numbers of soil actinomycetes, nitrogen-fixing bacteria, cellulose decomposing bacteria, potassium bacteria and phosphorus bacteria in non-invaded area were more than that in invaded area; in spring the number of soil fungi in invaded area was extremely significantly higher than that in non-invaded area, the number of fungi in the summer and winter was significant or extremely significant lower than that in non-invaded area. (3) Invasion affected the correlation between the numbers of soil bacteria and other microorganisms, there was a significant positive correlation between soil bacteria and fungi, silicate bacteria and organic phosphate bacteria (P<0.01) in invaded area, but in non-invaded area only soil bacteria had highly significant positive correlation (P<0.01) with free-living dizotrophs.