Enrichment ratio (E) of SOM (soil organic matter), TN (total nitrogen), TP (total phosphorus), TK (total potassium), AN (available nitrogen), AP (available phosphorus) and AK (available potassium) at different dune positions.

Notes: US, under shrubs; BS, between shrubs. The t-test was used to show enrichment effect (the difference between US and BS). Different lowercase letters following values indicate a significant difference in SOM, TN, TP, TK, AN, AP and AK under and between shrubs, according to t-test (PEnrichment ratio (E) of SOM (soil organic matter), TN (total nitrogen), TP (total phosphorus), TK (total potassium), AN (available nitrogen), AP (available phosphorus) and AK (available potassium) at different dune positions.