Distribution Of Sulfur In Plants And Sediments Of Mangrove In China And Influential Factors

Thirteen important mangrove areas including Hainan,Guangdong,Guangxi, Fujian were studied,Samples of mangrove plants,surficial sediments and vertical profiles and were collected from these places.Accumulation and distribution of sulfur in mangrove plants were discussed by examining the content of sulfur in the leaves, stems and roots of mangrove.Accumulation and distribution of sulfur in mangrove sediments were also analyzed by examining the content of sulfur,pH,organic matter, salinity,the character of soil,iron element.The environmental effect factors were studied to show their relations with the content of sulfur.The results showed:1.Average content of sulfur in surficial sediment was 0.214%in Chinese mangrove wetlands,higher than in the sediments without mangroves,which is only 0.153%.The average content of sulfur in sediments of mangrove wetlands of Hainan,Guangdong, Guangxi,Fujian was 0.34%,0.19%,0.20%,0.18%,respectively.The content of sulfur in the sediments of thirteen areas was Sanya＞Dongzhaigang＞Yunxiao＞Qinzhou＞Ewan＞Yaojiayu＞Gaoqiao＞Shankou＞Daguansha＞Beilunhekou＞Futian＞Luoyangqiao＞Fugong.The content of sulfur was remarkable different among these areas.Even in the same wetland,the sulfur content differed in different types of sediments.2.The character of the mangrove wetland was influenced by environment,organic matter,pH,salinity etc.Sulfur content correlated significantly with organic matter and salinity in sediments,but correlated negatively with pH.The character of sediments and iron concentration were also the factors which influenced distribution of sulfur in the sediments.The ranges of organic matter content,pH and salinity content in the surficial sediments were:was 1.24%～11.1%,3.0～7.5,1.8%～5.5%,respectively.Average content of organic matter,pH and salinity were 2.53%,6.0,2.2%,respectively.3.Sulfur content changed irregularly in the vertical profiles of mangrove wetlands. It included four different types:frist,bottom-enrichment,such as profiles of Futian, Daguansha(soil),Daguansha(sand);second,upper-enrichment,such as profiles of Dongzhaigang A,Dongzhaigang B;third,homogeneous type,such as Fugong;forth, irregularly,such as profile of Gaoqiao.Average content of sulfur was different in vertical profiles.In the profiles of Futian,Dongzhaigang B,Daguansha(soil),Gaoqiao, Daguansha(sand),Dongzhaigang A,Fugong mangrove wetlands,sulfur content was 0.21%(0.16%～0.27%),0.20%(0.14%～0.27%),,0.19%(0.10%～0.30%),0.11%(0.08%～0.1 6%),0.11%(0.05%～0.17%),0.07%(0.014%～0.21%),0.06%(0.016%～0.20%),respectivel. It was because of properities of sediments and deposite rate change greatly in different mangrove wetland.Human activitives also affected distribution of sulfur in the profiles.4.In the vertical profiles of mangrove wetlands,Sulfur content correlated significantly with organic matter in all the vertical profiles;correlated negatively with pH in Fugong and Daguansha(sand) mangrove wetlands.And salinity correlated significantly with sulfur content in Daguansha(soil) and Daguansha(sand) wetlands.The ranges of organic matter and salinity were 0.07%～7.3%and 3‰～45‰; the average content was 4.0‰and 23‰.5.It was a big different of total sulfur concentrations among several major plants in mangrove wetland.Average content of sulfur in mangrove plants was 0.046%,sulfur content differed in the same species of plants in the same mangrove wetlands.The order of sulfur content in plant organs was:leaf＞root＞stem.Sulfur content in the same species of mangrove plant was distinct in different mangrove wetlands.The order of sulfur content in Avicennia marina in mangrove wetlands was:Daguansha＞Sanya＞Shankou＞Futian＞Qinzhou＞Dongzhaigang＞Fugong.The order of sulfur content in Aegiceras corniculatum was:Shankou＞Beilunhekou＞Gaoqiao＞Qinzhou＞Dongzhaigang＞Futian.6.Sulfur content in the leaves of different mangrove plants varied remarkable.The order of sulfur content in different leaves was:Ceriops tagal＞Kandelia obovata＞Rhizophora stylosa＞Avicennia marina＞Lumnitzera racemosa＞Hibiscus tiliaceus＞Aegiceras corniculatum＞Bruguiera sexangula.The order of accumulation ratio of sulfur in different leaves to top-soil in mangrove wetlands was:Ceriops tagal＞Excoecaria agallocha＞Kandelia obovata＞Avicennia marina＞Sonneratia apetala＞Hibiscus tiliaceus＞Rhizophora apiculata＞Bruguiera gymnorrhiza＞Rhizophora stylosa＞Bruguiera sexangula＞Aegiceras corniculatum.7.In profiles of sediments with higher sulfur content,the leaves of plants accumulated more sulfur.