| Abstract: | A serious sandstorm occurred in North China from April 5 to April 7, 2000, while the remote smallsand decending took place in even larger area to the far northeast China. In Chanchun city, smallsand descending with snow provides the best samples to conduct a quantitative research on the possible impacts of city - ecology. In the 253km2 urban district area of Changchun city, smallsands accumulated up to more than 3000t on April 7, according to the calculation of four "mud - snow" samples. After naturally melting in room temperature, two samples are taken to do quarantine of "invasion bacteria". As a preliminary result, the individual amount of bacterium in 1 ml sample water is up to 8. 9 x 104 or 1. 05 x 105, and it is estimated that there are 640 million "invasion bacterium" individuals in one square meter. This study proves that other than the obvious environmental effects of sandstorm, the urban micro - ecosystem is very possible under threat by the "invasion bacterium" accompanied by remote descending smallsand. |
