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. swamp (SW)

swamp meadow (SM) and meadow (ME) in the Zoige Wetland Nature Reserve

were studied by means of field investigation

laboratory analysis

and mathematical statistics. Compared with SW soil

total organic C and N concentrations in the whole soil profile decreased by 29.55% and 6.52% in SM soil

and by 67.53% and 40.04% in ME soil; storages of C and N decreased by 67.49% and 60.10% in SM soil

and by 85.14% and 54.47% in ME soil

respectively. Total P concentration in the soil followed the order of SM＞ME＞SW

and P storage in the soil followed the order of ME＞SW＞SM. Both total organic C and N concentrations in the soil of SW increased obviously with increasing soil depth

while the concentrations of total organic C

N and P in the SM 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 SW

SM 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.