Diversity of soil microorganisms in natural Populus euphratica forests in Xinjiang, northwestern China

To better understand the distribution of soil microorganisms in Populus euphratica forests in Xinjiang, northwestern China, we studied and compared the populations and numbers of bacteria, fungi and actinomycetes in the soil at four different age stages of natural P. euphratica forests, i.e., juvenile forests, middle-aged forests, over-mature forests and degraded forests. Results showed that there were clear differences in the amount of microorganism biomass and composition rates across the four forest stages. Dominant and special microorganisms were present in each of the four different soil layers. The vertical distribution showed that the microorganism biomass decreased with increasing soil depth. The population of microorganisms was the lowest at 31–40 cm of soil depth. The microorganisms consisted of bacteria, actinomycetes, as well as fungi. Bacteria were the chief component of microorganisms and were widely distributed, but fungi were scarce in some soil layers. Aspergillus was the dominant genus among the 11 genera of fungi isolated from the soil in different age stages of P. euphratica forests. __________ Translated from Journal of Beijing Forestry University, 2007, 29(5): 127–131 译自: 北京林业大学学报]