不同载畜率对短花针茅叶片解剖结构的影响

Changes of leaf anatomy structure of Stipa breviflora under different stocking rates

以内蒙古荒漠草原9年连续定量放牧历史试验基地上的短花针茅为研究对象,镜下观测其叶片结构的变化,分析其形态结构与放牧强度的关系。结果表明:在测定的叶片8项结构指标中,厚度随着载畜率的增加而显著增加(P<0.05);主脉厚度的变化也表现出相近的特征。上、下表皮细胞面积在重度载畜率下显著减少(P<0.05),抗旱性结构加强;在轻度载畜率下显著减少或出现减少的倾向;中度载畜率时保持了与CK相近的水平(P>0.05),这与中度放牧时对氮、磷吸收能力增强有关。上、下表皮角质层厚度和上、下表皮细胞厚度在不同载畜率水平下均无显著性差异(P>0.05),对长期的放牧干扰表现得比较稳定。

The study area is located in desert steppe of Inner Mongolia, and has a 9 - year continuous quantit tive grazing history. The study made the Stipa breviflora leaves as research object, by analyzing its anatomy structure change with grassland stocking rates, to determine the relationship between the changes of main plant morphological structure characteristics and grazing intensity. The results showed that in the measured 8 structure index of the leaves, the leaves thickness increased significantly with the increase of stocking rate （ P 〈 0.05 ） ; the change of the main vein thickness also exhibited similar characteristics. The cell area of upper and lower epidermis decreased significantly under heavy stocking rate （ P 〈 0.05 ）, and drought resistance structure strengthened ; the cell area decreased significantly or appeared the tendency of decrease under light stocking rate; and the cell area maintained the level similar to CK under moderate stocking rate（ P 〉 0.05 ）, which related to enhance the ability of absorption to nitrogen and phosphorus when under the moderate grazing. Both cuticle thickness and cell thickness of upper and lower epidermis, which performed relatively stable to long - term of grazing disturbance, had no significant variance under different stocking rate levels （ P 〉 0.05 ）.