Soil Organic Carbon And Its Fraction Under Different Forest Types In The Laotndingzi Mountain In Liaoning Province

The study estimated soil organic carbon(SOC)storage and its vertical distribution under difference forest types,including Corylus mandshurica Maxim brushwood,Betula ermanii Forest,Picea-Abies and Ribbed Birch mixed forest,deciduous broad-leaved forest in Laotudingzi Mountain of Liaoning Provence.At the same time we studied the vertical distribution of soil Particulate organic carbon(POC),Light fraction organic carbon(LFOC)and Easily oxidizable carbon(EOC)and has been correlation analysis between soil active carbon and soil basic physical and chemical properties.The results were as follows:1?The content of SOC and total nitrogen(TN)decreased with increasing soil depth on all of the four soil profiles,and the content of SOC and TN showed significantly differences among layers.The content of SOC and TN in Picea-Abies and Ribbed Birch mixed forest were the highest among the four forest types(46.98 and 2.91 g/kg,respectively).The content of SOC and TN in four forest soils ranged from 23.45 to 46.98 g/kg and from 1.42 to 2.91 g/kg,respectively,in the order of Picea-Abies and Ribbed Birch mixed forest>Corylus mandshurica Maxin brushwood>Betula ermanii Forest>deciduous broad-leaved forest.2?The mean C/N was in the order of Betula ermanii Forest(18.1)>Picea-Abie.s and Ribbed Birch mixed forest(16.2)>deciduous broad-leaved forest(16.2)>Corylus mandshurica Maxim brushwood(16.1).The order of SOC storage of 0-50 cm soil layer was Picea-Abies and Ribbed Birch mixed forest(96.36 t/hm2)>Corylus mandshurica Maxim brushwood(89.73 t/hm2)>Betula ermanii Forest(8 1.93 t/hm2)>deciduous broad-leaved forest(66.1 6 t/hm2).3?The content of POC FLOC and EOC decreased with increasing soil depth on all of the four soil profiles,and the content of POC FLOC and EOC showed significantly differences among layers.The order f POC cc,ntent of 0-50 cm soil layer was Picea-Abies and Ribbed Birch mixed forest(42.5 1g·kg-1)>Vorylus mandshurica Maxim brushwood(29.41 g·kg-1)>Betula ermanii Forest(28.92g·kg-1)>deciduous broad-leaved forest(21.7g·kg-1),the content of POC at 0-50 cm soil layer is between 2.08 g·kg-11 and 26.38g·kg-1.The order of LFOC content of 0-50 cm soil layer was Picea-Abies and Ribbed Birch mixed forest(44.06 g·kg-1)>Betula ermanii Forest(30.36g·kg-1)>Corylus mandshurica Maxim brushwood(29.11 g·kg-1)>deciduous broad-leaved forest(21.21 g·kg-1).The order of EOC content of 0-50 cm soil layer was Picea-Abies and Ribbed Birch mixed forest(3 1.26g·kg-1)>Betula ermanii Forest(18.11g·kg-1)>Corylus mandshurica Maxim brushwood(17.71 g·kg-1)>deciduous broad-leaved forest(14.8 g·kg-1).The content of POC FLOC and EOC at 0-10 cm soil layer reached 40%,and surface aggregation phenomenon is obvious4?Correlations analysis showed significantly positive correlations between SOC and TN,and highly negative correlation between pH,but no significant correlations between C/N and total phosphorus(TP)and total potassium(TK).The POC,FLOC and EOC content of different forest soil were significantly positive correlated to each other.Correlations analysis showed significantly positive correlations between POC,FLOC,EOC and SOC and TD.Analysis showed significantly correlations between Active carbon and pH,water content(WC)in part forest soil.No significant correlations between soil active carton(POC,FLOC,EOC and SOC)and total phosphorus(TP)and total potassium(TK).