The distribution of SOC concentration at varying soil depths in the 0–60 cm layer.

Bars indicate a significant difference (n = 4, p<0.05) at the same soil depths between different plant communities, as determined by ANOVA; AG: alfalfa grassland, CT: Chinese tamarisk, LF: locust forest and CF: cotton field.</p

The distribution of soil TN concentration at varying soil depths in the 0–60 cm layer.

Bars indicate a significant difference (n = 4, p<0.05) at the same soil depth between different plant communities, as determined by ANOVA; AG: alfalfa grassland, CT: Chinese tamarisk, LF: locust forest and CF: cotton field.</p

Results of two-way ANOVA for the effects of plant community, soil depth and seasonal dynamics on SOC and TN distribution (n = 216).

Results of two-way ANOVA for the effects of plant community, soil depth and seasonal dynamics on SOC and TN distribution (n = 216).</p

The distribution of soil AP concentration at varying soil depths in the 0–60 cm layer.

Bars indicate a significant difference (n = 4, p<0.05) at the same soil depth between different plant communities, as determined by ANOVA; AG: alfalfa grassland, CT: Chinese tamarisk, LF: locust forest and CF: cotton field.</p

The ratio of soil carbon to nitrogen (C:N) among plant communities.

Bars indicate a significant difference (n = 4, p<0.05) between plant communities at the same soil depth, as determined by ANOVA; AG: alfalfa grassland, CT: Chinese tamarisk, LF: locust forest and CF: cotton field.</p

Correlation relationships between C, N and P among plant communities in the YRD.

Correlation relationships between C, N and P among plant communities in the YRD.</p

Seasonal dynamics of C:N ratio among plant communities and average C:N ratio.

Bars indicate a significant difference (n = 4, p<0.05) between different seasons, and average concentration is between plant communities, as determined by ANOVA; AG: alfalfa grassland, CT: Chinese tamarisk, LF: locust forest and CF: cotton field.</p

The study location and plant communities of the northeast estuarine area in the YRD, China.

The study location and plant communities of the northeast estuarine area in the YRD, China.</p

Correlation coefficients of soil properties (n = 24).

Correlation coefficients of soil properties (n = 24).</p

Seasonal dynamics and average concentrations of SOC, TN and AP.

Bars indicate a significant difference (n = 4, p<0.05) between different seasons and between plant communities, as determined by ANOVA; AG: alfalfa grassland, CT: Chinese tamarisk, LF: locust forest and CF: cotton field.</p