【摘要】 为了揭示天然臭柏群落在不同演替阶段对沙地环境的生理反应和适应性,对毛乌素沙地图克境内不同演替阶段臭柏的叶片含水量和叶绿素含量变化进行研究.结果表明,臭柏群落演替早期,叶片含水量较高,随着演替的进行逐渐降低,演替第Ⅲ阶段到演替第Ⅳ阶段,叶片含水量呈现较迟缓的下降趋势.在演替的进行过程中,臭柏的CHLa、CHLb和CHLa+b含量均呈现先上升后下降的趋势,演替第Ⅳ阶段达到最低水平,CHLa/b的含量在各阶段间变化不显著.演替第Ⅳ阶段,由于古老的固定沙地上形成较厚的结皮层,土壤变得相对紧密结实,不利于降水的渗入,导致土壤沙化,随着干旱胁迫的增加,叶绿素受到损伤.更多还原

【Abstract】 In order to explain physiological the reaction and adaptation of Sabina vulgaris community to sandy environment at different succession stages,we study the change of leaf water content and the chlorophyll contents of Sabina vulgaris in Tu Ke of Mu Us Sandland.The result show that leaf water content of Sabina vulgaris has the declining trend with the process of the succession.The leaf water content is decreased at the former period of the succession the decreasing becomes slow from the third succession stage to the fourth succession stage.With the process of the succession,contents of CHLa,CHLb and CHLa+b increase first and then decrease,and reach the minimum level at the third succession stage.The change of contents of CHLa/b is not significant in each stage of the process.At the fourth succession stage,the soil becomes relatively tightly solid due to the crust formed on the ancient stable sandland and it is disadvantage to water penetrating.This results in the soil desertification and the damage of the chlorophyll in the process of increasing of drought stress.更多还原