松嫩平原草甸三种植物叶片N、P化学计量特征及其与土壤N、P浓度的关系

Characteristics of plant leaf nitrogen and phosphorus stoichiometry in relation to soil nitrogen and phosphorus concentrations in Songnen Plain meadow

测定了松嫩平原草甸3种主要植物羊草(Leymus chinensis)、芦苇(Phragmites com-munis)和尖叶胡枝子(Lespedeza hedysaroides)叶片全氮、全磷浓度,并分析了它们与土壤全氮、全磷浓度的关系。结果表明:3种植物叶片全氮浓度种间差异显著(P<0.05),而全磷浓度种间差异不显著(P>0.05);3种植物叶片全氮浓度与土壤全氮浓度相关性不显著(P>0.05),而叶片氮磷比与土壤全磷浓度均呈显著负相关(P<0.05);表明同一地区,不同植物叶片全氮浓度差异较大,而全磷浓度差异较小;与叶片全氮、全磷浓度相比,叶片氮磷比受土壤养分的影响更显著;另外,该地区羊草和尖叶胡枝子生长受到磷限制,可考虑适当施用磷肥。

We measured total nitrogen （N） and total phosphorus （P） concentrations in leaves of Leymus chinensis, Phragmites communis and Lespedeza hedysaroides in Songnen Plain meadow, and analyzed their relationship with soil total N and total P concentrations. The results showed that foliar total N concentration differed significantly among three species （P〈0. 05 ）, while foliar total P concentrations did not show significant difference （P〉0. 05 ）. The leaf N concentration of the three species had no significant correlation with soil total N concentrations （P〉0. 05）, while the leaf N：P ratio was significantly negatively correlated with soil total P concentrations （P 〈 0. 05 ）, suggesting that in our study area, different plant species had great difference in their leaf N concentration, but less difference in their leaf P concentration. Compared with leaf N and P concentrations, leaf N ：P ratio was more related to soil N and P concentrations. In addition, the growth of Leymus chinensis and hedysaroides in study area was P-limited, and thereby, appropriate application of P fertilizer could be considered.