[Accumulation and cycle of heavy metal in Sonneratia apetala and S. caseolaris Mangrove Community at Futian of Shenzhen, China].

The absorption, accumulation, distribution and cycle of Cu, Pb, Zn, Cr and Ni in S. apetala and S. caseolaris Mangrove Community at Futian Mangrove Nature Reserve of Shenzhen were studied. The results showed that the Cu, Pb, Zn, Cr and Ni contents in forest soil were increased from bottom to surface layer, and the storage of the five heavy metals in the surface layer(depth 0-30 cm) was Zn > Pb > Ni > Cr > Cu. The concentration ability was S. caseolaris > S. apetala > K. candel. The existing accumulation of Cu, Pb, Zn, Cr and Ni in the community were respectively 23,019.61 micrograms/m2, 23,429.65 micrograms/m2, 117,870.41 micrograms/m2, 6835.79 micrograms/m2, 12,995.08 micrograms/m2. The annual absorption were 6592.20 micrograms/m2, 2664.77 micrograms/m2, 24,123.56 micrograms/m2, 853.25 micrograms/m2, 1990.86 micrograms/m2, respectively. The annual return were 3179.50 micrograms/m2, 1300.64 micrograms/m2, 8401.31 micrograms/m2, 398.99 micrograms/m2, 646.20 micrograms/m2, respectively. The annual net retention accumulation of Cu, Pb, Zn, Cr and Ni in the community were 3413.07 micrograms/m2, 1364.13 micrograms/m2, 15,722.25 micrograms/m2, 454.25 micrograms/m2, 1344.66 micrograms/m2. The turn over period of Cu, Pb, Zn, Cr and Ni were 8, 19, 15, 18 and 21 years.