【作者】 张毅；

【导师】 黄培祐；

【作者基本信息】 新疆大学 ， 植物学， 2004， 硕士

【摘要】 荒漠中自然生存的植被，往往具有耐受长期干旱的特殊能力。但在其生长过程中能否获得必要的水分供给，能否随环境水分变化而相应变化，对旱生植物的存续无疑是极其重要。本项研究选取在荒漠中受当地气候波动影响较小、年际的植被数量变化相对较轻微的三种荒漠植物：角果藜(Ceratocarpus arenarius L.)、土大戟(Euphorbia turczaninowii Kar.et Kir.)和密枝猪毛菜(Salsola implicata Botsch.)为研究对象。以研究其在极其苛刻的生存条件下，幼苗能否免遭厄运的一些适应性状。通过野外固定区域的样地定期观测及测定立地含水变化，就近盆栽试验进行比较；并通过生理生态测定和石蜡切片观测等方法进行系列研究。 研究结果表明：在当地不同层次沙土含水变化的过程中，三种植物的分布和生长状况与0-20cm沙土层的含水状况显著相关。由于对干旱生境的适应方式各不相同，其生理生态反应和结构的变化因种而异，但对沙土水条件的适应机理却是近似的，从而在年际气候波动较大的生境中，这几种植物较早春期萌发的大部分植物幼苗有较多的存在机会。角果藜是试验植物中生活周期最短的植物，通过最早出现最高的根茎比值来加强其对水分的吸收和在体内的运输；以其叶片色浅且密生绒毛，有助于减少日光的照射，降低叶片温度，以此降低蒸腾，改善机体水分状况，从而获得较多生存机会。土大戟依赖其直立且粗壮的幼茎，有效保障体内的水分运输；维持着机体较高的水势。密枝猪毛菜在三种植物中开花结实最晚，但在沙层含水降低的过程中，体内贮水稳定且高似与叶片发达的角质层有关，这有助于降低蒸腾耗水；且具发达的贮水组织，利用自身所含的水量，在环境严重缺水时得以维持个体的生存。更多还原

【Abstract】 Normally many xerophytes have particular ability to endure drought for a long time. Whether these plants receiving enough soil water in the process of growing and reproducing and bringing interrelated responses along with the changes of sandy soil water is the most essential key to exist under arid weather condition.The study select three desert plants, Ceratocarpus arenarius L. and Euphorbia turczaninowii Kar.et Kir and Salsola implicata Botsch which the wave of climate have less effect on them and the annual changes of the amount of vegetation is comparatively less as the research objects. Study on some adaptable properties when they are under rigor survival condition, whether the seedling can avoid death. The ways of the study are followed: inspecting and observing their living condition on the sand dune; continuously mensurate the changes of sandy soil water; cultivating sprout; examining ecological and physiological changes in three plants and paraffin sectioning.The study results show: in the course of the changes of sandy soil water, the status of the three plants’ distributing and growth and the status of 0-20cm’s sandy layer containing water are notable correlation. Due to their modes to adapt to arid condition, ecological and physiological responses and the changes of structure are all different, but their mechanism to adapt to the sandy soil water changing is consistent, consequently they have more chances to exist in the entironment what has biggish annual wave of climate comparing to mostly plants that bourgeon in early spring. Ceratocarpus arenarius L. has the shortest living cycle in the three plants. It enhances absorbing and transporting water by earliest forming topmost the ratio of root and stem. It’s light-colored leaf and dense floss conduce to decrease <WP=6>irradiation of the sunlight and recede the leaf temperature, so as to reducing transpiration and improving status of inside water and gaining more chances to exist. Euphorbia turczaninowii Kar.et Kir effectively guarantee the transport of inside water and maintain upper water potential depending on it’s erect and sturdy stem. In the three plants, Salsola implicata Botsch is the lattermost efflorescing and seeding. But along with water content of sandy soil reducing, the steady amount of inside containing water seem to be concerned with developed keratose layer. This help to reduce transpiration consuming water and keep living in entironment being serious short of water.更多还原