Microbial functional diversity in rhizosphere and non-rhizosphere soil of different dominant species in a vegetation concrete slope

Abstract

To investigate the effects of different dominant species on the microbial functional diversity of vegetation concrete substrates, the rhizosphere and non-rhizosphere soils of three dominant species (Pennisetum alopecuroides (PA), Arthraxon hispidus (AH) and Pueraria lobata (PL)) of vegetation concrete were studied using the Biolog-Eco method at Xiangjiaba Hydropower Station. The results showed that the microbial activity and microbial functional diversity indices in the rhizosphere soil of the three dominant plants were significantly higher than those in the non-rhizosphere soil and that the microbial activity and functional diversity indices in the rhizosphere and non-rhizosphere soil of AH, as well as in the rhizosphere soil of PL, were at a high level. The carbon sources predominantly used by rhizosphere soil microbes were carbohydrates, amino acids and polymers, while the carbon sources predominantly used by non-rhizosphere soil microbes were carboxylic acids, amino acids and polymers. The governing elements of the carbon source metabolic features of the microbial community were the soil moisture content (WC), organic matter (OM), total nitrogen (TN), potential of hydrogen (pH), microbial carbon (MBC), microbial nitrogen (MBN) and microbial phosphorus (MBP). Based on a thorough examination of these aspects, it was concluded that vegetation had altered the microbial community structure and functional diversity of the vegetation concrete substrate, perhaps improving the overall metabolic activity. A. hispidus with high adaptability should be prioritized in the regeneration of vegetation on concrete slopes.