No abstract

Wang Y F, Shen Y M. Analysis on landscape pattern change and its driving forces of Yancheng National Natural Reserve.

No abstract

摘要:选择 3 个温带沙地 (松嫩沙地、 呼伦贝尔沙地、 科尔沁沙地) 4 个共有种沙生植物 (黄柳 (Salix gordejevii) 、 差巴嘎 蒿 (Artimisia halodendron) 、扁蓿豆(Melissitus ruthenica) ,猪毛菜(Salsola collina) ,通过自然状况下其叶片抗氧化酶活力和渗透调节 物及丙二醛(MDA) 含量日变化分析,探讨抗氧化酶活力和渗透调节物在沙生植物适应沙漠环境强光辐射和温度日变化中的作 用,以及不同科属沙生植物抗逆生理调控机理的差异。 结果表明:(1) 不同沙地的 4 个共有沙生植物种可通过自身快速生理代 谢调解,积累渗透调节物、提高抗氧化酶活力应对沙漠环境强光辐射和温度日变化,但生理调控幅度较小。 (2) 3 个沙地不同科 属的 4 个共有种在渗透调节物含量和抗氧化酶活力及种类上存在差异。 扁蓿豆叶片日均 MDA 含量、 POD(peroxidase) 活力、 CAT(catalase) 活力、脯氨酸含量均最高,分别较其它 3 个种平均高 2、10、2 和 2. 5 倍。 黄柳叶片日均 MDA 含量较高, SOD (superoxide dismutase) 活力和可溶性糖含量最高,分别较其它 3 个种高 1.2 和 3 倍。 差巴嘎蒿和猪毛菜叶内 MDA 含量较低,

Vitex trifolia var. simplicifolia is a good ground cover plant and sand binder for coastal sandy land; it has a high tolerance for salt and drought and, in its natural environment of sand dunes, it is often buried by blowing sand. In these experiments, basis on the stolon length of V. trifolia, the four level of sand burial treatments were set up as no-sand burial, light sand burial (1 / 3 stolon length) , moderate sand burial (2 / 3 stolon length) and severe sand burial (3 / 3 stolon). The different lengths of stolon were buried to two different depth, to half the plant height or to the full plant height, to show how the plant maintained growth under different levels of sand burial. Plant height, lengths of stolon and adventitious roots, the ratio of stolon dry weight (DW) to total DW, and the ratio of shoot and leaf DW to total DW were recorded. Normally, stoloniferous base and middle section of V. trifolia grow slowly, the top of the stolon grew fast. The results showed that during 20d treatments, there was little difference in the growth of stolon from the basal area to the middle section of the