Study On Soil Organic Carbon And Nitrogen In Wetland Of Xiao Bo Lake In Qinghai Lake

Wetland is an ecosystem that arises when inundation by water produces soils dominatedby anaerobic processes, which, in turn, forces the biota, particularly rooted plants, to adapt toflooding. Soil organic carbon (SOC) and nitrogen play an important role in wetland ecologysystem and global climate change. Numerous researches had been done to understand thebehaviors of SOC and nitrogen in wetlands.In this work, a high latitude cold wetland, named Xiaobohu Lake wetland in QinghaiLake was studied. Horizon samplers of soil profile under five typical vegetation covers(Achnatherum splendens, Achnatherum splendens and Irisensata Thunb mixing,IrisensataThunb, Blysmus sinocompressus, Carex tristachya) were taken for SOC andnitrogen analyzing. The differences of the SOC and nitrogen content in soil among differentvegetation types were compared by one-way ANOVA methods. And the vertical distributionof SOC and nitrogen in soil were also investigated. The main results of this work weresummarized as follows:The SOC content in Xiaobo lake wetland soils ranged from4.56to136.67g/kg. Thedifference of SOC was significant among different vegetation types covered soils, due to thedifference of soil moisture. The variations of SOC in soils under the same vegetation werelarge, with the highest coefficient of variation (CV) value of65.46％. The verticals variationsof SOC in soil profile were not significant, and the highest SOC content was appeared in20-40cm depth soils.The nitrogen content in Xiaobo lake wetland soils ranged from0.03to0.86g/kg. Thereis no difference of nitrogen content in soils among different vegetation covers, and thenitrogen content was highest in soils under Carex tritachya vegetation. The verticaldistribution of soil nitrogen also showed no significantly variations, however it acted asdecrease from soil top layers to bottom layers. The highest nitrogen content was appeared in0-20cm depth soil.The difference of the ratio of C/N among different soil layers was significant, thebottom soil layer had the highest ratio of C/N. The ratio of C/N in different vegetation coversoils increased in the order Blysmus sinocompressus Tanget Wang，Carex tristachya.>Achnatherum,splendens >Achnatherum,splendens+Irisensata>Thunb>Irisensata Thunb.The surfer content of soils in Xiaobo lake wetland ranged from2.47to7.20g/kg, withthe mean of4.09g/kg. The difference of surfer among different vegetation cover soils wassignificant and the difference among different soil layers was not significant. No significantcorrelations between surfer and SOC, nitrogen was found in this work.