Influence of slope aspect on the microbial properties of rhizospheric and non-rhizospheric soils on the Loess Plateau, China

Abstract

Abstract. Slope aspect is an important topographic factor in the micro-ecosystem environment, but its effect on the microbial properties of grassland rhizospheric soil (RS) and non-rhizospheric soil (NRS) remain unclear. A field experiment was conducted at the Ansai Research Station on the Loess Plateau in China to test the influence of slope aspects (south-facing, north-facing, and northwest-facing slopes, all with Artemisia sacrorum as the dominant species) on RS and NRS microbial biomass carbon (MBC) contents, phospholipid fatty acid (PLFA) contents, and the rhizospheric effect (RE) of various microbial indices. Soil samples were collected from the three slope aspects, including rhizospheric and non-rhizospheric region, and analyzed to determine the various related microbial indices. The results showed that MBC content differed significantly among the slope aspects in RS but not in NRS, and the RE for MBC content in the south-facing slope was larger than that in the north-facing slope. RS total, bacterial, and Gram-positive bacterial PLFA contents in the south-facing slope were significantly lower than those in the north- and northwest-facing slopes, and RS Gram-negative bacterial (G−) and actinomycete PLFA contents in the south-facing slope were significantly lower than those in the north-facing slope. In contrast, NRS total, bacterial, and G− PLFA contents in the north-facing slope were significantly higher than those in the south- and northwest-facing slopes, and NRS fungal and actinomycete PLFA contents in the north- and south-facing slopes were significantly higher than those in the northwest-facing slope. RE for all PLFA contents except fungal in the northwest-facing slope were higher than those in the south-facing slope. Slope aspect significantly but differentially affected the microbial properties in RS and NRS, and the variable influence was due to an evident RE for most microbial properties.

Slope aspect affects the soil microbial communities in karst tiankeng negative landforms

“…Microbial communities are sensitive indicators of vegetation and soil properties changes, and their interaction is considered to be the main driving factor of ecosystem functions [ 40 ]. Many studies have indicated that the difference in soil microbial community structure is mainly affected by the vegetation characteristics and soil properties [ 22 , 41 ]. The type of vegetation community determines the initial composition of the microbial community, and vegetation affects the structure of the microbial community by affecting the soil environment [ 42 , 43 ].…”

“…Some studies have found that north slopes have higher microbial biomass carbon (MBC) and relative abundance of Gram-negative bacterial than south slope [ 20 ]. However, other studies have shown that the total phospholipid fatty acid, diversity of bacterial and fungal in the south slope were higher than that in north slope [ 22 ]. These results reflect the obvious influence of slope aspect on microbial community characteristics.…”

Slope Aspect Affects The Soil Microbial Communities In Karst Tiankeng Negative Landforms

“…Microbial communities are sensitive indicators of vegetation and soil properties changes, and their interaction is considered to be the main driving factor of ecosystem functions [33]. Many studies have indicated that the difference in soil microbial community structure is mainly affected by the vegetation characteristics and soil properties [19,34]. The PCoA and AMOSIM analysis showed the microbial community of the shady and sunny slope were differed.…”

“…Some studies have found that north slopes have higher microbial biomass carbon (MBC) and relative abundance of Gram-negative bacterial than south slope [17]. However, other studies have shown that the total phospholipid fatty acid, diversity of bacterial and fungal in the south slope were higher than north slope [19]. These results re ect the obvious in uence of slope aspect on microbial community characteristics.…”

Response of bacterial community characteristics in the rhizosphere soil of Stellera chamaejasme L. to its expansion on the Qinghai‐Tibet Plateau

“…Soil microorganisms release mineral elements that contribute to plant growth by driving organic matter and nutrient cycling in the soil, while plants transfer carbon and nitrogen to the soil through debris and root secretion (Kardol et al, 2006; Kuramae et al, 2011). Plant species have a decisive effect on soil microorganisms in their area (Ai et al, 2018). As a result, plant expansion affects soil microbial community structure (Stefanowicz et al, 2019; Yang et al, 2016), composition (Batten et al, 2006), and functions (Souza‐Alonso et al, 2014; Zhao et al, 2019).…”