【作者】 红雨；

【导师】 王林和；

【作者基本信息】 内蒙古农业大学 ， 水土保持与荒漠化防治， 2006， 博士

【摘要】 臭柏(Sabina vulgaris)为柏科圆柏属常绿匍匐针叶灌木,在防治荒漠化方面起着重要的作用。本文运用植物种群生态学、植物生理生态学、种群遗传学的研究方法,探讨了臭柏群落不同演替阶段生理生态学特性,研究结果如下:毛乌素沙地臭柏群落自发演替的基本过程为:半流动沙地沙竹+沙米(有时是白沙蒿)群落→半固定沙地油蒿+臭柏群落→固定沙地臭柏+硬质早熟禾群落→固定沙地臭柏群落→老固定沙地臭柏+苔藓群落,最后可能发展成为地带性的本氏针茅草原。臭柏群落的演替可分为进展演替和逆行演替两个阶段,随着进展演替的发展物种多样性逐步增加,生态环境逐渐变湿。在逆行演替过程中物种多样性开始减少,群落生境向旱生化发展。随着进展演替土壤颗粒组成发生变化,砂粒含量趋于减少、粉粒和粘粒增多、有机质含量逐渐增加、C/N下降,逆行演替阶段与其相反;臭柏群落的演替对有机质积累的影响主要集中在土壤表层0～50㎝土层内;物种丰富度、盖度与土壤粘粒、C、N、K、P呈正相关。随着演替的进行,臭柏叶片含水量呈下降趋势;CHLa、CHLb和CHLa+b含量均呈现先上升后下降的趋势,各阶段间差异显著,CHLa/b在各阶段间差异不显著;PRO、MDA含量呈先上升后下降再上升的变化,各演替阶段间差异极显著。臭柏SOD、POD活性在各演替阶段间差异极显著,而CAT活性差异不显著。演替第Ⅳ阶段臭柏叶片含水量和叶绿素含量的降低,游离PRO含量上升,MDA含量增加,SOD、POD活性增加,表现出环境胁迫下植物受损的生理共性。土壤指标与PRO、MDA、保护酶活性的相关分析显示土壤的多数指标降低会使臭柏叶片内的PRO含量、MDA含量大量积累,保护酶活性大幅度增加。不同演替阶段的生理指标对环境胁迫的响应不同,从各种指标来看,一是在演替第Ⅳ阶段植物体内出现一系列的受损表现;二是多数指标在演替第Ⅲ阶段出现较低水平,因此可以看出在演替第Ⅲ阶段是环境最稳定的关键时期。臭柏种群有着较丰富的遗传多样性,多态位点高达91.05%,用Shannon多样性指数、Nei’s基因多样度对臭柏4个种群的遗传多样性进行评价时,大小顺序为半固定沙地油蒿+臭柏种群>固定沙地臭柏+硬质早熟禾种群>老固定沙地臭柏+苔藓种群>固定沙地臭柏种群;臭柏的种群间遗传分化较小Gst= 0.1761,82.39%的遗传变异存在于种群内;聚类分析显示,演替阶段相近的种群聚到了一起,反映了臭柏种群的遗传分化和演替阶段有着密切的关系; Nm~*=2.7972>1,说明种群间有广泛的基因交流。通过上述研究表明,臭柏群落的演替过程与土壤的发育和基质的变化有着相互联系、彼此制约的规律,不但表明基质条件在臭柏群落演替过程中的作用,更重要更多还原

【Abstract】 Sabina vulgaris plays an important role on preventing desertification. This dissertation discussed ecophysiology of S. vulgaris community through plant community, population, soil, physiological characters and genetic diversity as well at the different successional stages. The results are summarized as follow:The autogenic succession process of vegetation in Mu Us Sandland is from Psammochlou uillosa+Agriophyllum arenarium (Artemisia sphaerocephala) on semi-drift-sand dunes to Artemisia ordosica + S. vulgaris on semi-fixed-sand dunes, then through S. vulgaris+ Poa sphondylodes on fixed-sand dunes, and S. vulgaris on fixed dunes of subclimax stage, to S. vulgaris+moss community on old-fixed-sand dunes which maybe pass to a Stipa bungeana steppe. The S. vulgaris community succession contains progressive and regressive succession. Species diversity increased with the development of the progressive succession, and the ecological environment began getting wet.With the progressive succession, the gravel contents and C/N decrease, silt and clay contents increase, whereas with the regressive succession, things become to opposite. Richness and coverage of species show positive correlation with most index of the soil but negative correlation with C/N. The vegetation succession has effect on accumulation of the organic substances, the relation between number of species, coverage, clays and C/N is close.With the process of the succession, contents of leaf water decrease. Contents of CHLa、CHLb and CHLa+b increase first and then decrease, but the change of contents of CHLa/b is not significant. PRO and MDA contents increase first, and then decrease during the process of the succession. The variance analysis showed that the difference of the PRO contents among stages is more significant.The difference of the SOD and POD activity is more significant among stages, but the CAT activity has no significant change. In the fourth successional stage, the contents of leaf water and chlorophyll decrease, the MDA contents and PRO increase, the activity of SOD and POD increase. All of them show the physiological characters of damaged plant under the environment hardness. It is showed that the decrease of the soil index makes the contents of PRO and MDA accumulated and the protective enzymes activity increased. The responsion of the physiological index to the environment hardness in different successive stage is not similar. First, some damaged characters appeared in the forth stage;更多还原