Liang W.,Wetland Ecosystem Research Station of Hangzhou Bay |
Shao X.,Wetland Ecosystem Research Station of Hangzhou Bay |
Wu M.,Wetland Ecosystem Research Station of Hangzhou Bay |
Li W.,Wetland Ecosystem Research Station of Hangzhou Bay |
And 2 more authors.
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2012
The effects of saltmarsh vegetation on phosphorus fractions in the sediments were studied in this paper. Phosphorus fractions in the two layer (0-5cm,10-20cm) sediments from four saltmarsh vegetation types(Bare flat, Scirpus mariqueter, Phragmites australis, Spartina alterniflora) were analyzed. The results indicated the impacts of vegetation succession on P fractions. The content of total phosphorus (TP) in the sediments from S. alterniflora (MC) habitats was higher than from the other vegetaion. The content of soluble and loosely bound P(SL-Pi) in was the lowest in bare flat(CK) and highest in sediments from MC haibitats. Similarly, the content of reductant soluble P(RS-Pi) in the sediments from P. australis(LW) and MC habitats were obviously higher than CK and S. mariqueter(BC). Adversely, the content of Ca-Pi in CK and BC habitatas sediments were significantly higher than LW and MC. The content of different organic P fractions was significantly different. In all vegetation types, the content of labile P(L-Po) was the lowest; the content of moderately labile P(ML-Po) was the highest; the content of nonlabile P(NL-Po) was at an intermediate level. Inorganic P covered up about 74% -89% of TP Ca-Pi,which was the main form of inorganic P, was retained by adsorbing and precipitating in the time of sediment deposition. The results suggested that biomass production and nutrient cycling processes with vegetation succession led to the difference of phosphorus forms. In early stage of succession, BC changed the P fractions of surface sediments significantly; but it imposed no obvious impact on subsurface sediments. In the later period, LW and MC promoted rapid accumulation of organic P in surface sediments but a litter less increase in subsurface sediments. At the same time, vegetation succession promoted Ca-Pi transforming to soluble and active P.