Ecological Stoichiometry Characteristics and Storage of Soil Carbon, Nitrogen and Phosphorus During the Wetland Degradation Process
The aims of this study were to investigate the ecological stoichiometry characteristics during the process of wetland degradation,and clarify the relationship between the changes in C and N sink function of the soil and the balance in soil C,N and P.Soil C,N and P concentrations,storages and ecological stoichiometry in three kinds of wetland landscape with different degrees of degradation,i.e.marsh (MA),marsh meadow (MM) and meadow (ME) in the Zoige Wetland Nature Reserve,were studied by means of field investigation,laboratory analysis,and mathematical statistics.Compared with MA soil,total organic C and N concentrations in the whole soil profiles decreased by 29.55％ and 6.52％ in MM soil,and by 67.53％ and 40.04％ in ME soil;storages of C and N decreased by 67.49％ and 60.10％ in MM soil,and by 85.14％ and 54.47％ in ME soil,respectively.Total P concentration in the soil followed the order of MM＞ME＞MA,and P storage in the soil followed the order of ME＞MA＞MM.Both total organic C and N concentrations in the soil of MA increased obviously with increasing soil depth,while the concentrations of total organic C,N and P in the MM and ME soil decreased with increasing soil depth.For all three types of soil,C,N and P storages in the 40-100 cm layers were generally higher than those in the 0-40 cm layers.For the soil in the MA,MM and ME,C/N was 40.38,31.70 and 23.26,while C/P was 409.52,247.46 and 113.07,and N/P was 10.43,7.90 and 5.02,respectively,with C/N,C/P and N/P declining as the wetland degradation became intensified.When C/P is high and N/P is ＜14,both N and P are limiting factors for plant growth,and N is more limiting than P.In conclusion,degradation of the Zoige Wetland has led to decreased concentrations and storages of C and N in the soil,and the C and N sink function of the soil,in particular the C sink function,has been weakened during the wetland degradation process.
degraded wetlandC, N, Pecological stoichiometryZoige
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NSTL
万方数据
维普
