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青藏高原高寒草地和内蒙古高原温带草地同属中国地带性的草地类型.然而,主导它们的环境因子有所不同.前者主要受生长季低温的影响,后者主要受干旱的影响.发育在这两类草地上的植物,在解剖特征上有何共性和差异,目前少有报道,但却是理解植物适应环境的关键所在.本文通过对青藏高原高寒草地和内蒙古高原温带草地71个样地65种双子叶植物叶片解剖特征的研究,对比分析了不同科、属及不同生活型植物叶片对干旱环境以及高寒环境的适应特征,探讨了叶片总厚度、上表皮和下表皮厚度、叶肉组织厚度、叶肉细胞密度、叶肉细胞表面积和体积等多个解剖特征之间的关系以及气候因子(生长季温度、降水)对它们的影响.结果表明:(1)总体上看,青藏高原与内蒙古高原草地植物的叶片解剖特征存在显著差异,除叶肉细胞密度外,青藏高原高寒草地植物的叶片各组成部分厚度、叶肉细胞表面积和体积均大于内蒙古高原温带草地植物;(2)同一科属植物的叶片解剖特征在两地存在显著差异,并显示出与所有物种总体分析一致的规律;(3)在调查范围内,两地草本植物除叶肉细胞密度外,叶片各组成部分厚度以及叶肉细胞表面积、体积均显著大于木本植物;(4)叶片的各解剖指标间存在显著的协同变化:叶片总厚度,上、下表皮厚度,叶肉细胞厚度,叶肉细胞表面积和体积之间均呈显著正相关,而叶肉细胞密度与这些指标显著负相关;(5)总体上看,青藏高原和内蒙古高原草地植物叶片的解剖特征与生长季温度的关系比与生长季降水密切.因此,尽管青藏高原高寒草地和内蒙古高原温带草地在外貌上有趋同性,但叶片解剖结构有着显著差异,这可能是由于植物对环境的适应进化及(或)环境的筛选作用共同作用的结果.
The alpine grassland in the Qinghai-Tibet Plateau and the temperate grassland in the Inner Mongolia Plateau belong to the zonal type of grassland in China, however, the environmental factors that dominate them are different, the former are mainly affected by the low temperature in the growing season and the latter mainly by the drought. Grassland plants, anatomical characteristics of what are the commonalities and differences, rarely reported, but it is to understand the key to plant adaptation to the environment.Through the grassland in the plateau of Inner Mongolia and temperate grassland in Inner Mongolia, 71 samples of 65 species of Gemini Leaf anatomical characteristics of leaves, comparative analysis of different families, genus and different life-style plant leaves on the arid environment and alpine environment adaptability characteristics of the total leaf thickness, epidermis and lower epidermis thickness, leaf tissue thickness, mesophyll cells Density, mesophyll cell surface area and volume, as well as the climatic factors (temperature and precipitation) during the growing season.The results showed that: (1) Generally speaking, the relationship between the Tibetan Plateau and the leaf of grassland plant in Inner Mongolia There were significant differences in anatomical characteristics, except leaf cell density, alpine meadow grassland plants in the Qinghai-Tibet Plateau (2) The anatomical characteristics of the leaves of the same genus differed significantly between the two places and showed a consistent law with the overall analysis of all species; (3) In addition to mesophyll cell density, the thickness of leaf components and the surface area and volume of mesophyll cells in herbaceous plants were significantly larger than those in woody plants. (4) There was a significant synergistic change among the anatomical parameters of leaves: Thickness, upper and lower epidermal thickness, mesophyll cell thickness, mesophyll cell surface area and volume showed a significant positive correlation, while mesophyll cell density was negatively correlated with these indexes. (5) Generally speaking, the Tibetan Plateau and Inner Mongolia plateau meadows Compared with the growing season, the anatomical characteristics of leaves are closely related to the precipitation in the growing season, so although the alpine grassland in the Qinghai-Tibet Plateau and the temperate grassland in the Inner Mongolia Plateau are similar in appearance, the anatomical structure of the leaves is significantly different, which may be due to the plant- Environmental adaptation evolution and (or) environmental screening effect.