冷蒿种群在不同放牧干扰下叶绿素、可溶性糖的对比研究

Changes of Chlorophyll and Soluble Sugar Content of Atemisia frigida Population under the Disturbance of Grazing

对放牧干扰下冷蒿种群叶绿素、可溶性糖的含量变化进行了研究.结果表明:在生长初期和盛期,随着放牧强度的增加,冷蒿体内叶绿素a、叶绿素b及总叶绿素含量变化不大.在生长末期,叶绿素含量随放牧强度的增加而增加,但是增加的幅度较小.在不同的放牧梯度上生长初期和盛期,可溶性糖含量随着放牧强度的增加变化不显著.在生长末期,可溶性糖含量随着放牧强度的增加显著降低.从光合色素、光合产物的变化趋势看,放牧干扰并未影响冷蒿的光合作用,相反放牧延长了光合时间.这是冷蒿种群耐牧,再生能力强,并随着放牧强度的增加,逐渐取代羊草、大针茅等植物优势地位的原因之一.

The contents of chlorophyll and soluble sugar of Atemisia frigida populations under different grazing intensities were studied.The results showed:with the grazing intensities increased,the contents of chlorophyll a,b and total chlorophyll changed little in early and middle growth periods,but increased a little in a late growth period. With the grazing intensities increased, the contents of soluble sugar changed little in early and middle growth periods,but decreased significantly in a late growth period.The trend of the change of chlorophyll and photosynthesis products showed that the disturbance of grazing did not influence photosynthesis.It was an important reason why Atemisia frigida population could endure grazing disturbance and regenerate strongly,and with the grazing intensities increased,it could replace Stipa grandis and Leymus Chinensis to become the dominant specie. 