Soil bacterial community responses to revegetation of moving sand dune in semi-arid grassland

Abstract

Grasslands in semi-arid Northern China are widely desertified, thus inducing the formation of a large area of moving sand lands. Revegetation of the sandy land is commonly adopted to restore degraded grasslands. The structure of the soil microbial community might dramatically change during degradation and recovery because microorganisms are one of the major drivers of ecological process through their interactions with plants and soil. Assuming that soil properties are the key determinants of the structure of soil bacterial community within the same soil type, whether the vegetation type causes the significant difference in the structure of soil bacterial community during revegetation and restoration of the degraded grasslands remains poorly understood. Our study aimed to (1) investigate the response of soil bacterial communities to the changes during vegetation degradation and recovery and (2) evaluate whether the soil bacterial communities under plantations return to their native state. We detected the shifts in diversities and compositions of the soil bacterial communities and the relative abundance of dominant bacterial taxa by using the high-throughput Illumina MiSeq sequencing technique in an area covered by 32-year-old Caragana microphylla, Artemisia halodendron, Hedysarum fruticosum, Pinus sylvestris var. mongolica, Populus simonii, and Salix gordejevii sand-fixing plantations and in the native community (NC) dominated by elm, and moving sandy dune (MS). We found that the obtained operational taxonomic units by 16S rRNA gene sequencing and diversity index in MS were all significantly lower than those in NC, and the number and composition of dominant genera were significantly different between NC and MS. Interestingly, the compositions of bacterial communities and the dominant genera in different sand-fixation plantations (C. microphylla, A. halodendron, H. fruticosum, P. sylvestris var. mongolica, P. simonii, and S. gordejevii) were all similar to those of the native soil of NC, suggesting that the plantation type and soil properties exhibit a minimal effect on the compositions of soil microbial communities within a continuous landscape. These results revealed that the structure of the soil bacterial community of degraded sandy grassland (even degenerated into a mobile sand dunes) in semi-arid region can be reversibly restored by planting indigenous shrub or semi-shrub plantation on human time scales.

Prokaryotic community shifts during soil formation on sands in the tundra zone

“…However, prokaryotic α-diversity increased from the unfixed sands to the mature soil on Site I, while prokaryotic communities of all samples on Site II did not follow the same pattern, and their α-diversities did not change with the successional stage. The obtained results partly contradict previously discovered trends of incremental growth of prokaryotic α-diversity during revegetation on moving dunes [10]. However, some studies reported the highest prokaryotic diversity at the early stages of soil formation [59,60].…”

“…Currently, chronosequences of soil formation can be observed in areas with variable climatic conditions and on omnigenous parent material, such as glacial retreats [1–4], sand dunes [5–7], volcanic rocks [8], or anthropogenic landscapes [9]. Changes in microbial community structure during the process of sand dune fixation have mostly been studied for arid and semi-arid regions [6,10,11] and for coastal environments [5]. Currently, successional traits during sand fixation in the cold climate of the tundra have received increasing attention.…”

“…While the succession of plant communities is relatively well studied, information on the prokaryotic community assemblage during soil formation is still lacking [10,13]. It is known that the first organisms to colonize parent rock are phototrophs, diazotrophs, chemolithotrophs and heterotrophs, whose taxonomic composition depends on the substrate properties [4,8,14].…”

Prokaryotic community shifts during soil formation on sands in the tundra zone

“…However, prokaryotic α-diversity increased from the unfixed sands to the mature soil on Site I, while prokaryotic communities of all samples on Site II did not follow the same pattern, and their α-diversities did not change with the successional stage. The obtained results somewhat contradict previously discovered trends of incremental growth of prokaryotic α-diversity during revegetation on moving dunes [10]. However, some studies reported the highest prokaryotic diversity at the early stages of soil formation [57,58].…”

Effect of aridity and dune type on rhizosphere soil bacterial communities of Caragana microphylla in desert regions of northern China

“…In degraded sandy grasslands in semi-arid regions (even degraded to moving dunes), the community structure of soil bacteria can be reversibly restored by planting shrubs or semi-shrubs (including C . microphylla ) [29]. However, in-depth investigations of rhizosphere bacterial communities of C .…”