Spatial Variation Of Mycorrhizal Fungi And Its Relationship With Soil Factors In The Rhizosphere Of Male And Female Populus Cathayana Rehd. At Chaka Saline Lake

Arbuscular mycorrhizal fungi(AMF), ectomycorrhizal fungi(ECMF), dark septate endophytes(DSE) colonization rates, AMF spore density, glomalin content and their relationships with soil factors at different soil depths of Populus cathayana Rehd. males and females were studied in different degrees of salinization about Chaka Saline Lake. The main results included as follows:1. AMF and ECMF colonization rates and AMF spore density in the saline lake area were higher than un-saline lake area. AMF and ECMF colonization rates at the rhizosphere of males were lower than females in the unsaline lake area, which was opposed to the saline lake area. In the both sites, AMF spore density at the rhizosphere of males was higher than females.DSE colonization rates in the saline lake area were higher than unsaline lake area.2. The reduction of root colonization by mycorrhizal fungi at the rhizosphere of males and females were observed with the increasing of soil depth in the saline lake area. AMF colonization rates at the rhizosphere of males were significantly higher than females. The colonization rate of ECMF also decreased along with the increase of soil EC accordingly. In contrary, the root colonization by DSE increased. A different pattern of root colonization by mycorrhizal fungi in males and females was observed. Along with the increasing of soil EC,the differences aggravated between males and females in the same site and soil layers.3. Glomain contents in the saline lake area were lower than un-saline lake area. The contribution of glomain for soil C storage in saline lake area was lower than un-saline lake area. Glomain contribution at the rhizosphere of males was higher than females in both sites.4. The contribution of glomain for soil C storage increased with increasing of the soil depths in the same site. Differences in levels of glomain across gradients in EC couldtherefore reflect similar process. In saline lake area, it showed that the content of TG, EEG,and its contribution for soil C storage decreased along with the soil depth lake. Furthermore,the content of glomain at the rhizosphere of females was slightly higher than males, while the contribution of glomain for soil C storage at the rhizosphere of males was higher than females.5. Soil enzyme activities in the saline lake area were lower than unsaline lake area. In the saline lake area, soil nutrient contents at the rhizosphere of females were higher than males,while in the unsaline lake area soil enzyme activities was the same with soil nutrient contents.6. The reduction of soil enzyme activities at the rhizosphere of males and females were observed with the increasing of soil depth in the saline lake area. And the increase of soil EC at different sites induced to the decline of soil enzyme activities. In the same site, the value of soil EC1:5 decreased with the increasing of soil depth. The degree of soil salinization from light to heavy was followed by un-saline lake area, saline lake, saline factory and saline mountaion. The value of soil p H ranged from 7.08 to 9.42, and it suggested that most soil among sites belonged to the alkaline soil. The content of nitrate nitrogen(NO3-N) and ammonium nitrogen(NH4-N) had a significant difference among sites, soil layers, and sexes.The variation tendency among sites and soil layers were the same with soil enzyme activities.The content of NO3-N and NH4-N in the surface soil(5~15cm) of females were higher than males. Meanwhile, the content of NH4-N was higher than NO3-N. The content of available P was also decreased along with the increasing of soil depths, and soil EC. And a significant difference was existed between males and females. The content of available P in the rhizosphere of females was higher than males.