Abstract: In order to provide a scientific basis for evaluating the management measure of Castanea mollissima inter-planting with Rubus chingii, the impact of soil bacterial structure and biodiversity was studied. Soil samples from Castanea mollissima inter-planting with different density of Rubus chingii (0, 100 and 400 plants/Mu）were collected. Soil bacteria were sequenced by Illumina High Throughput Sequencing technique. And, the soil physical and chemical indexes were also analyzed. The results showed that soil bacterial structure of Castanea mollissima forest was similar among different modes, Proteobacteria (31.20%) and Acidobacteria (29.70%) were the most common bacteria. After inter-planting with Rubus chingii, Chao1 and Simpson index indicated dominance of soil bacteria were increased significantly, but diversity was decreased. The influences of inter-planting and density were mainly affected by soil bacterial community on the Phylum level and Order level, respectively. Castanea mollissima forest soil organic matter, total nitrogen, hydrolyzable nitrogen, available phosphorus and total phosphorus content were increased significantly by inter-planting with Rubus chingii. The soil potassium content was decreased with the increase of inter-planting density. The changes of soil physical and chemical property caused by inter-planting may explain the influence of bacterial community structure. The changes of Acidobacteria and Acidobacteriales were correlated with nitrogen content. The change of Chloroflexi was correlated with organic matter. 

Key words: Castanea mollissima, Rubus chingii, inter-plant, soil bacteria