BACTERIAL COMMUNITY SUCCESSION AND INFLUENCING FACTORS OF IMPERATA
CYLINDRICA LITTER DECOMPOSITION IN A DEGRADED COPPER TAILINGS DAM OF
CHINA
Abstract
Litter decomposition is a critical component of the ecological
nutritional transformation process. It is particularly important to
investigate characteristics and interactions of bacterial communities in
litter decomposition in heavy metal polluted degrade areas, which will
help clarify driving mechanisms of organic matter and nutrient cycling
in mining areas that harbor contaminated soil. Imperata cylindrical was
the dominant plant species in the degrade area investigated; thus, we
selected this species as research object. Here we explore bacterial
community characteristics and key microbial groups as well as driving
factors of litter decomposition using in-situ litter decomposition
experiments. The nutrient content of I. cylindrica decreased, while the
litter pH status increased as decomposition progressed in one of the
three sub-dams investigated (i.e., S516). Proteobacteria and
Actinobacteriota were the dominant bacterial phyla during the different
litter decomposition stages. Moreover, the role of Friedmanniella was
critical in sustaining both structure and function of the bacterial
community during the early decomposition stage. Quadrisphaera became the
dominant species as litter decomposition progressed. Litter properties
and enzyme activities both had significant effects on litter bacterial
community characteristics, whose driving factors varied during different
restoration stages. The bacterial community dynamics of litter were
affected primarily by litter properties during the decomposition
process. Furthermore, the most crucial factors that impacted bacterial
litter structure were pH and copper content. Findings will help to
deepen our understanding of litter decomposition mechanisms in degraded
ecosystems, while also providing a scientific basis for improving
effectiveness of material circulation and nutrient transformation in
degrade ecosystems.