祁连山高寒草甸4种植物荧光特性的季节变化

摘要

高寒草甸围栏草地上选取矮嵩草（Kobresia humilis）、垂穗披碱草（Elymus nutans）、扁蓿豆（Melissitus rutenica）、黄花棘豆（Oxytropis ochrocephala）4种优势植物,用Mini-IMAGING-PAM测量叶片叶绿素荧光参数的季节变化。结果显示：（1）8月干旱,植物的光合能力受到严重影响,Fv/Fm、qP、ETR值都显著降低,所以8月是当地草地的敏感期;（2）矮嵩草、垂穗披碱草、黄花棘豆在生长后期的光合能力不如生长前期,而扁蓿豆在生长后期要高于前期,而且抗旱能力要高于其他3种植物;（3）垂穗披碱草、黄花棘豆、扁蓿豆在生长后期的光保护能力高于前期,矮嵩草在生长前期高于后期。%Four plants in fenced alpine meadow in Eastern Qilian Moutains were selected to measure their seasonal changes of chlorophyll fluorescence characteristics by Mini-IMAGING-PAM.The results showed that the photosynthetic capacity of these plants was decreased because of the drought in August and their Fv/Fm,qP,ETR values reduced significantly.So,August was a sensitive period of local grassland plants.The photosynthetic capacity of Kobresia humilis,Elymus nutans and Oxytropis ochrocephala in late growth were lower than that in early growth.The photosynthetic capacity of Melissitus rutenica in late growth was higher than that in early growth,and its drought resistance was higher than the other three species.The light protection of Elymus nutans,Oxytropis ochrocephala and Melissitus rutenica in late growth was higher than that in early growth.On the contrary,the light protection of Kobresia humilis in early growth was higher than that in late growth.