| To understand the physical and chemical properties of soil in 0-100 cm layer in different forest
types，this paper studied five typical forest types in the coastal platform of Hainan Island. The results showed that
soil bulk density of secondary forest was the highest, while Acacia auriculaeformis forest was the lowest. The variation
coefficient of soil layer showed that the coconut forest was the largest, and Casuarina equisetifolia forest was the
lowest. The total soil porosity and non-capillary porosity of five different forest types (0-10 cm, 10-20 cm) increased
with the depth of soil, but in other layers, they were irregularity. The soil water content increased with the depth of soil,
and the differences were significant in different forest types. The pH value in five different forest types was acidic or
slightly acidic, the differences between Casuarina equisetifolia forest and secondary forest, Eucalyptus forest, Acacia
auriculaeformis forest were significant. Soil total N content in soil profile had a clear vertical distribution, which
decreased with the depth of soil. The differences of total N and K contents were significant，while the P content was
not in different forest types. There was significant difference in soil total nitrogen between 0-10 cm and other layers in
the same forest type, which indicated that the surface layer of seashore sand soil was more beneficial for N cycle. |
