Sand-fixation plantation type affects soil phosphorus transformation microbial community in a revegetation area of Horqin Sandy Land, Northeast China

Abstract

Revegetation is an effective approach for comprehensive control of sandy desertification. Different sand-fixation plantations may vary in protection function, the improvement of soil properties, and the re-formation of soil microbial community because of the differences in the biological and ecological attributes of plant species. However, few studies have focused on the response of soil P-cycle-related microbial community to sand-fixation plantation type. This study aimed to (1) compare the effects of different sand-fixation plantations on soil properties, (2) investigate the compositions and structures of P-transformation-involved microbial communities under different plantations, and (3) analyze the relationship between soil properties and P-transformation microbial communities. Soil samples of six 36-year-old plantations, i.e., Hedysarum fruticosum, Salix gordejevii, Caragana microphylla, Artemisia halodendron, Populus simonii, and Pinus sylvestris var. mongolica, were taken in Horqin Sandy Land, Northeast China. The compositions of soil phoD- and gcd-harboring microbial communities were detected using high-throughput Illumina MiSeq sequencing. Plantation type had significant effects on soil pH, nutrients, P fractions, and biological activities, thereby affecting the structures of phoD and gcd communities. The abundance of phoD gene was hundreds of times more than that of gcd, and it significantly varied with plantation type. The dominant phoD taxa included Cyanobacteria, Proteobacteria, Planctomycetes, and Actinobacteria phyla or Scytonemataceae, Nostocaceae, and Isosphaeraceae families, while Proteobacteria and Rhizobiaceae were the absolutely dominant gcd taxa. Many N fixers (belonging to Rhizobium, Mesorhizobium, and Bradyrhizobium) may have the abilities for P transformation depending on phoD or/and gcd. Plantation and soil properties significantly affected the quantities of dominant taxa and slightly affected the basic compositions of phoD and gcd communities. Soil pH and available P were the main factors affecting the structure of phoD community, while that of the gcd community was mainly affected by soil pH and NH4-N. The mixture of shrub and semi-shrub plantations is recommended to restore vegetation on moving sand dune in the Horqin Sandy Land.