Influences of land reclamation on soil bacterial communities of
abandoned salt pans in the Yellow River Delta
Abstract
Reclamation has been widely accepted to restore abandoned lands. Most
studies focused on the improvement of land reclamation in soil nutrients
and microbial activities. However, the effects of reclamation time on
bacterial communities of abandoned salt pans are still unclear. The
object of this study is to: i) assess the successional change of soil
physicochemical properties and bacterial communities in reclaimed
abandoned salt pans with different reclamation histories, and ii) figure
out the main limit factors on the improvement of soil quality in
reclaimed abandoned salt pans. The soils in a farmland (RTBL) and six
abandoned salt pans with 1 year (RT1), 2 years (RT2), 3 years (RT3), 4
years (RT4), 8 years (RT8), and 9 years (RT9) of reclamation were
sampled to investigate the temporal variation of soil properties, heavy
metal content, bacterial community composition, and diversity. Results
showed that the soil bulk density (BD), total dissolved salt (SS),
median particle size (MMAD) decreased with the increase of reclamation
time, while soil nutrient (soil organic matter, total nitrogen,
available phosphorus, available potassium) showed an opposite trend. The
bacterial α-diversity increased first, then decrease. Land reclamation
enhanced the relative abundances of Acidobacteria, Chloroflexi, and
Actinobacteria but reduced the relative abundances of Proteobacteria,
Gemmatimonadetes, and Bacteroidetes. Compared with RTBL, the soil
nutrients and bacterial community structure in RT1, RT2, RT3, and RT4
showed a significant difference.Therefore, reclamation time is a vital
driving force for restoring soil physicochemical properties and
bacterial communities in abandoned