Characteristics Of Carbon?nitrogen And Phosphorus In Dominant Plants In Different Wetland Distribution Areas Of Poyang Lake

Carbon(C),nitrogen(N)and phosphorus(P)are the basic nutrient elements in plants,which play an important role in plant growth and physiological regulation functions.At present,the regional pattern of C,N and P stoichiometric and its driving factors are still important research field of ecological stoichiometry,the result will not only help reveal the stoichiometric convergence and differentiation between species,to predict ecosystem function,the process also responding to the global change is of great significance.In this study,four typical wetlands were selected,Xingzi ?Wucheng?Poyang and Nanji,from north to south in Poyang Lake,and then collect plant samples.By measuring the leaf,stem,root and litter of C,N,P content,nitrogen and phosphorus chemical Characteristics of Dominant Plants in Poyang Lake Wetland.provides the foundation for revel the response and adaptation mechanism of plant communities to large dynamic water changes in large-scale rivers and lakes.The main results and conclusions are as follows:(1)The leaves content of carbon,nitrogen and phosphorus of plants in Poyang lake ranges from 146.47 to 512.39mg·g-1,5.07 to 29.26 mg·g-1 and 0.03 to 2.58 mg·g-1separately.The content of N and P in leaves of the four wetland plants is extremely significant difference(P<0.01),and both N?P content of Leaves are in the order of Xingzi > Poyang > Nanji > Wucheng.However,there is no significant difference in content of C,and it in the order of Poyang > Wucheng > Nanji > Xingzi.The average values of C:N,C:P and N:P in leaves of Poyang Lake wetland are 17.99,327.47 and18.76,respectively,also C:N and C:P are extremely significant difference(P<0.01)in the four wetland,both are showed Wucheng > Nanji > Poyang > Xingzi.Yet N:P is showed Poyang > Wucheng > Nanji >Xingzi and no significant difference.(2)The stem C,N,P content range respectively is 318.24 ~ 532.31 mg·g-1,4.89 ~36.90 mg·g-1,0.10 ~ 5.33 mg·g-1 in Poyang lake.The content of N in stem of the four wetland plants is remarkable difference,and C,P content of stem are extremely significant difference(P<0.01).The order of stem C content among the four wetland is showed Wucheng > Nanji > Xingzi > Poyang,content of N in stem is showed Poyang > Xingzi > Nanji > Wucheng and P is showed Xingzi > Poyang >Nanji >Wucheng.The average values of C:N,C:P and N:P in stems of Poyang Lake wetland are 45.18,659.36 and 15.34,respectively.Only C:N of stems has remarkabledifference in the four wetlands,But no significant difference in C:P and N:P.(3)The roots content of C,Nand P of plants in Poyang lake ranges from 77.55to577.48mg·g-1,5.31 to 413.37 mg·g-1 and 0.05 to 3.74 mg·g-1 separately,and C content of fine roots is lower than thick roots,but higher than thick roots in the content of N and P.The content of N and P in roots of the four wetland plants is extremely significant difference(P<0.01),but no significant difference in C content.The average values of C:N,C:P and N:P in roots of Poyang Lake wetland are 34.98,454.01and13.54,respectively.The C:N,C:P and N:P values of thick roots are significantly higher than those of fine roots.The C:N in roots of the four wetland plants is remarkable difference,and C:P?N:P are extremely significant difference(P<0.01).(4)The litter content of C,Nand P of plants in Poyang lake ranges from 146.47to512.39mg·g-1,5.07 to 29.26 mg·g-1 and 0.03 to 2.58 mg·g-1 separately,The content of C and P in litter of the four wetland plants is extremely significant difference(P<0.01)but no significant difference in N content.(5)The distribution of C,N and P in the dominant plants of Poyang Lake wetland was significantly different in different organs and litter.The variation range of C is from 77.55 to 577.48 mg·g-1,and the order is showed stem > leaf > root >litter.The variation range of N is from 4.89 to 52.29 mg·g-1,and the order is showed leaf >litter > root > stem.The variation range of P is from 0.03 to 5.33 mg·g-1,and the order is showed leaf > root > stem >litter.Meanwhile,there was a significant positive correlation between leaf P content and litter P content,but the content of N and P in stems was negatively correlated with N and P in litter.The C:N,C:P are both showed stem > root > leaf in different organs,and N:P is showed leaf > stem > root.In different organs,just have a significant negative correlation between leaf N and root N content(P<0.05).(6)The difference of C,N and P content and the stoichiometric relationship in plants of the four typical wetlands in Poyang Lake is mainly affected by the differences of exposed time,soil moisture,N,P nutrient content and so on.