短花针茅种群功能性状对载畜率的响应

Response of Functional Traits of Stipa breviflora Population to Stocking Rates

对不同载畜率下短花针茅种群的表型功能性状(株高、单株重、叶长、叶面积、比叶面积)和元素类功能性状(叶片N含量、叶片C含量、叶片C/N)等性状指标进行了测定,探讨短花针茅种群对放牧的响应机制。结果表明:随着载畜率增加,短花针茅种群表型功能性状指标逐渐降低,重度放牧显著低于对照(P<0.05);载畜率对短花针茅种群叶片C、N含量没有显著影响,中度放牧区C/N显著低于轻度放牧(P<0.05);可塑性指数PI值随着载畜率的增加而变大;叶面积是短花针茅响应放牧干扰最显著的指示性状。

Plant functional traits can be visually reflected in grazing pressure and are also the best grazing response markers.The phenotypic functional traits(Plant height,Plant weight,Leaf length,Leaf area,Specific leaf area)and elemental functional traits(Leaf N content,Leaf C content,Leaf C/N)of Stipa breviflora population under different stocking rate were determined to explore the adaptation mechanism of Stipa breviflora population to grazing.The results showed that:(1)With the increase of stocking rate,the phenotypic functional traits of Stipa breviflor population decreased gradually,and heavy grazing was significantly lower than that of control(P<0.05).(2)There was no significant effect of stocking rate on C and N content in the leaves of Stipa breviflora population,and the C/N ration in moderate grazing area was significantly lower than that in light grazing(P<0.05).(3)The plasticity index(PI)value increased with the increase of stocking rate.(4)Leaf area was the most significant indicator of Stipa breviflora in response to grazing disturbance.