The Organic Carbon Distribution Characteristics Of Surface Soil In Southern China's Mangrove Wetlands And Their Influence Factors

Currently,climate change has been one of the most important issue concerned by all over the world.And Carbon dioxide emission is an important factor in global climate change.Carbon sequestration potential of various terrestrial ecosystems,especially wetlands,plays a role in manipulating the excessive increase of CO₂ in the atmosphere.In this study,the distribution characteristics of soil organic carbon in Southern China area and its influencing factors in mangrove swamp were studied.Three divisions?Guangdong,Hainan and Guangxi?of Southern China area were set as survey areas,and nine mangrove species selected to research were as follows,Avicennia marina community;Sonneratia apetala community;?Avicennia marina+Aegiceras corniculatum?community?Rhizophora stylosa+Avicennia marina?community;?Avicennia marina+Aegiceras corniculatum+Rhizophora stylosa?community;Rhizophora stylosa community;Sonneratia caseolaris community;Rhizophora apiculata community;Aegiceras corniculatum community.By cutting ring methodology,three layer?10cm/layer?of 0-30 cm in soil under the forest acquisition of mangrove community were sampled,and in the meantime,p H,salinity,temperature,dissolved oxygen,conductivity and other basic elements of seawater were determined.With the experimental measurement of soil organic carbon content,soil bulk density,soil porosity,moisture content and other Physicochemical index in soil sample,soil organic carbon density and carbon storage were calculated.Using SPSS 17.0 and EXCEL2010 complete the correlation and variance analysis of sample.Comparing the vertical distribution characteristics of soil organic carbon content and density in different mangrove communities,and analyzing the effects of soil physical and chemical properties,latitudinal gradient and Mangrove on soil organic carbon content factors affecting the distribution of soil organic carbon were discussed.The results show that:1.The organic carbon contents of Southern China coastal mangrove swamp soil?0-30cm?ranges from 0.91 to 103.42 g/kg,and the average content is 18.67 g/kg,with a very high coefficient of variation?0.82?;Organic carbon density is 1.68 kg/m²;The estimation of organic carbon storage in surface soil of Southern China mangrove wetland area ?0-30cm?is 50.53 t/hm².2.The contents of organic carbon in surface soil?0-30cm?of mangrove wetlands in different regions were classified as Hainan?25.03 g/kg?> Guangxi?g/kg?>?Guangdong,15.20 g/kg?3.Soil organic carbon content in Southern China shows a vertical distribution,which reveals that the deeper soil layer is sampled,the more organic carbon content is found.?20-30 cm >10-20cm>0-10cm;19.66 g/kg,18.32 g/kg,18.05 g/kg?4.The soil organic carbon content of the surface layer in mangrove wetland of the different plant communities present: Sonneratia apetala?22.27 g/kg?>?Avicennia marina+ Aegiceras corniculatum??22.19 g/kg?> Rhizophora stylosa?21.67 g/kg?> Rhizophora apiculata Blume ?21.38 g/kg?>?Avicennia marina+Rhizophora stylosa+Aegiceras corniculatum??20.51g/kg?>Sonneratia caseolaris?19.24 g/kg?> Avicennia marina?15.63 g/kg?> Aegiceras corniculatum?10.87g/kg?5.Soil organic carbon density distribution of Southern China coastal mangrove: Hainan?2.18kg/m²?> Guangxi?1.55 kg/m²?> Guangdong?1.32 kg/m²?.The vertical distribution of soil organic carbon density increased firstly and then decreased(0-10cm?1.65kg/m²?,10-20cm?1.81 kg/m²?20-30cm?1.59 kg/m²?6.Latitude gradient is an important factor affecting the distribution of organic carbon content of mangrove soil in Southern China area7.The amount of litter in mangrove species is an important factor to the distribution of soil organic carbon content in Southern China8.There is a significant negative correlation between soil bulk density and soil organic carbon content?p<0.01??y=-25.87 x + 45.274,R²=0.357?,and there is a significant positive correlation among soil porosity,soil water content and soil organic carbon?p<0.01?,formula respectively(y=2.1188e^0.0331x,R²=0.421)?y=2.0311 x + 30.273,R²=0.5217?...