Based on the 141 surface sediments collected from the Yazhou Bay, Hainan Island, the distribution characteristics of grain size components, grain size parameters and sediment types were analyzed. The results indicate that the samples can be classified into 6 types as argillaceous arenaceous gravel, gravelly argillaceous sand, sand, silty sand, arenaceous silt and silt in the study area. In particular, the arenaceous silt is most widely distributed. The grain size diameters increase and then decrease, showing a banding distribution from north to south. The separation coefficient is generally high, which indicates the complex sediment sources and hydrodynamic conditions in this area. Base on Flemming ternary diagram, combined with sediment sources, hydrodynamic conditions and topographic features, the study area is divided into three sedimentary districts from north to south: the nearshore zone which showing the characteristics of wave-controlled deposition is mostly impacted by wave winnowing and transport, and the grain size is relatively small; the central Yazhou Bay zone is a high-energy coarse grained sand area, mainly controlled by the combined action of runoff, wave and tidal current; relatively, the southern zone is mainly affected by tidal current load, where the wave action is weakened, the sediment is the finest and deposited in a lower energy environment. In addition, the analysis of sediment transport trend shows that the midwest part of the study area is a depositional center, the silt of coastal erosion, Ningyuan River and offshore tidal current transport are carried to this area.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |