Biodiversity in Saline and Non-Saline Soils Along the Bohai Sea Coast, China

A plethora of information is available on the effects of salinity on plant growth and soil physico-chemical properties, but the effects on soil organisms are often neglected. Thus, a systematic investigation of how soil biodiversity, including bacteria, nematodes, mites, and earthworms, changes along saline gradients was conducted along the Bohai Sea coast at Laizhou City, Shandong Province, China, with 30 soil samples randomly selected and classified by salinity into two categories: saline and non-saline. Testing revealed a significantly higher abundance of the surveyed organisms in non-saline soils. The redundancy analysis showed that a negative correlation was observed between electrical conductivity and soil organism abundance in saline soil, but not in non-saline soil. Soil organic matter, available nitrogen, and total nitrogen all positively affected organism abundance in both saline and non-saline soils. The richness and Shannon diversity of nematodes were significantly higher in non-saline soils, but were not significantly different between soil types for other organisms. None of the environmental factors surveyed was obviously related to soil organism diversity. Consequently, our results suggested that soil electrical conductivity only negatively affected soil organisms in saline soil, while soil fertility positively affected soil organisms in both saline and non-saline soils.