Effect of simulated nitrogen sedimentation on soil chemometric characteristics of the Gahai wetland
[Objective]In the context of increasing global nitrogen deposition,a simulation study of the effect of nitrogen deposition on the soil chemometric properties will help to identify the soil element cycling process and the balance feedback mechanism of the wetland ecosystem.[Method]The Gahai wetland in the east of the Qing-hai Tibet Plateau was considered as the experimental site.Four different nitrogen(N)treatments were organized including blank control CK(0 g/m2),N5(5 g/m2),N10(10 g/m2)and N15(15 g/m2).[Result]The contents of soil organic carbon(SOC),total nitrogen(TN)and total phosphorus(TP)among the different N application treatments were the highest in the N10 treatment,while the lowest values were observed in the N15 treatment.Along the vertical soil profile,soil SOC and TN contents gradually decreased with the depth of the soil layer,while the soil TP first increased and then decreased.The SOC and TN contents first increased and then de-creased with increasing N deposition concentration,while the TP content first decreased and then increased.The soil stoichiometric ratio was the highest in the 0～10 cm layer,and was significantly higher than that in other soil layers(P<0.05).In 0～40 cm layer,soil C∶N ratio was the highest in N10 treatment,and was significantly higher than that in N5(21.18%)and N15(6.84%)treatments.In addition,soil C∶P and N∶P ratios were highest in N5 treatment and were significantly higher than those in N5(14.85%and 33.38%)and N10(32.27%and 42.64%).[Conclusion]The increase in nitrogen deposition significantly affected the carbon,nitrogen and phosphorus con-tents and ratios in the wetland soils.Overall,the results indicate that phosphorus is a major limiting factor for plant growth in the study area and that N is in a relatively balanced state.
nitrogen depositionGahai wetlandsoil carbonnitrogen and phosphorussoil stoichiometry
万方数据
维普
