Author:
Yonghong Wu
Affiliation:
The Geography Science Department of MinJiang University and Fuzhou, China
Keyword(s):
Minjiang River estuary, intertidal wetland, vegetation rhizosphere sediments, heavy metals
Abstract:
In order to investigate the characteristics of heavy metal elements enrichment in the rhizosphere sediments of different vegetation types, several cores of the rhizosphere sediments (0~20 cm) were collected from different vegetation types zone in intertidal wetland of Langqi Island, the Minjiang estuary. The results demonstrate that heavy metals have obvious enrichment at the depth of 2 cm in the sediment surface in the rhizosphere of Spartina alterniflora, Scirpus mariqueter and Phragmites australis. Heavy metals also showed obvious accumulation at the depth of 10~12 cm in the rhizosphere sediments of Scirpus mariqueter and Phragmites australis, while Spartina alterniflora did not show this feature. The content of heavy metals in the rhizosphere sediments of Scirpus mariqueter reached its lowest value at the depth of 16 cm, then increased with depth. It is speculated that the adsorption of heavy metals by the roots of Scirpus mariqueter mainly concentrates at the depth of 16 cm. Pea
rson correlation analysis was conducted on the changes of heavy metal in sediments under different vegetation, shows that obvious positive correlation is observed between Cu, Fe, Mn, Pb and Zn, indicating that they have similar sources and may have a certain relationship with human activities. However, Cr, Sr is more likely to come from natural sources. The enrichment of Rb, Zr may be influenced by the selective adsorption of different plant roots or other environmental factors.
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