Responses of bacterial communities to spatial distribution and biogeochemical migration in Panzhihua mining tailing

<p>Heteropogon contortus were the domiant plants in Panzhihua mining tailing due to the characteristic of drought-enduring and toxicity resistance. The aim of this work was to determine the effects of the successive planting of Heteropogon contortus on soil characteristics, including heavy metals contents and biogeochemical migration. Spatial distribution of heavy metal and enzyme activity in surface soils and rhizosphere soil as well as responses of bacterial community were systematically researched. In the meanwhile, High-throughput 16s RNA sequencing results indicated that the abundance and diversity of bacterial communities from different altitude locations were quite diverse in soil samples. The contents of some heavy metals and enzyme activity markedly affected on the structures of bacterial communities surface soils and rhizosphere soil. The most abundant bacterial communities were Actinobacteria (29.74 %), Proteobacteria (28.06 %), Chloroflexi (13.73%) in phylum level in the original soil samples. The abundance of Proteobacteria (19.87 %, 27.57 %, 29.35 %) and Patescibacteria (1.56 %, 1.83 %, 2.66 %) of non-rhizosphere soil was gradually increased along with the increasing latitude, which is just the opposite rule to the abundance of Acidobacteria (17.19 %, 14.58 %, 11.77 %) and Gemmatimonadetes (4.61 %, 3.17 %, 2.86 %). Results in this study emphasized the heavy metal contaminations in soils and rhizosphere soil, providing valuable information on how heavy metal contamination influences soil bacterial communities across a chronosequence spanning 50 years.</p>