Recovery of Soil-Denitrifying Community along a Chronosequence of Sand-Fixation Forest in a Semi-Arid Desertified Grassland

Revegetation on moving sand dunes is a widely used approach for restoring the degraded sandy land in northeastern China. The development of sand-fixation forest might improve structures soil microbial communities and affect N cycle. In present study, diversities nitrite (nirS nirK) nitrous oxide (nosZ) reductase genes were investigated under chronosequence Caragana microphylla shrub (9- 19-year), adjacent non-vegetated shifting sand-dune, natural dominated by C. microphylla. dominant compositions gene abundance analyzed clone library technique quantitative polymerase chain reaction, respectively. taxa nirK, nirS, nosZ all similar to those sand-dune. However, three abundances linearly increased across age. Clones associated with known denitrifiers carrying nosZ, or nirS genes, such as members Pseudomonas, Mesorhizobium, Rhizobium, Rhodopseudomonas, Azospirillum, Cupriavidus, detected. These found be abundant denitrification. Soil pH, total N, available affected denitrifying altering relative taxa. Overall, although attributes age had no significant effects constituents communities, revegetation sand-dunes facilitated restoration due increase nutrients.