Research On The Ecological Distribution Of Microbes And Its Main Effecting Factors In Liaohe Estuary Wetland

Microbes are one of the important parts of the ecological system, which always coexist with plants and animals in the process of biological evolution. Being the decomposers and delivers of material flowing in the ecosystem, it plays a key role in the flowing of material, energy and information. The number of heterotrophic bacteria (HB) is an important index of wetland, which is also the comprehensive reaction to the ecological conditions. Based on the database observed in the wetland, the distribution of the HB and its main influencing factors were analyzed by field survey and field culture experiments in Liaohe estuary wetland. The microbial community structure of the soil was also studied by using the degeneration gradient gel electrophoresis (DGGE) technology. As a result, it can provide basis for the further exploitation.The result of field investigation is given below. The number of HB increased to the largest in June, and reduced to the minimum in August, and increased gradually in September. The field culture experiments showed that the number of the HB was affected by salinity, C/N ratio, petroleum oil and vegetation. As for the Shannon-Wiener, it is bigger in the soil with vegetations and increases as the season varies, while it reduces in the barren soil, after studying the result of DGGE. The number of HB vary vast in different stations and seasons, which only have a better relevance with pH (p<0.05),compared with other affected factors.The result of culture investigation is as follows. The number of HB was inhibited by salinity and their numbers reduced rapidly. The increase of C/N ratio significantly stimulated the growth of the heterotrophic bacteria, and the number of HB in the group of C/N ratio was 10:1 increased by 2 times compared with the control group. Petroleum oil pollution significantly inhibited the growth of HB. The number of HB reduced with increasing of petroleum oil pollutants. The number of HB in the reeds group was larger than the group without reed. The trend of HB in the soil with Suaeda heteroptera Kitagawa is similar to the HB in the soil with reed. But the result is reverse as the salinity is higher.