In some xerophytes , such as cacti , most of the leaves are modified into spines , greatly reducing the leaf area for transpiration ; the photosynthetic function of the leaves is taken over by the green stems 在一些旱生植物中，如仙人掌，大部分的叶片都特化为刺，极大的减少了叶片区域的蒸发作用，同时光合作用为绿色的茎所承担。
2.
Many researches show , the environmental adaptable process of the xerophytecan be divided into two different stages . in the first stage , seeds sprout and fini - sh the adaptation xerophytic process ; in the second stage , xerophyte grows in arid condition by using natural water 前人大量研究工作表明，旱生植物对环境的需求，可划分为两个不同阶段，前一阶段始于种子萌发并逐渐形成适旱结构，后一阶段是植物在干旱条件下利用当地自然水源而生长。
3.
Weather or not the vegetation restoration and rebuilt can be achieved will largely depend on weather or not sprout can build up the mechanism to resist dry stress . this point of view has been pro - ved by plants living on the natural water . usually the xerophyte has particular ability to endure drought for long term 植被恢复与重建能否取得进展，在很大程度取决于幼苗期能否完成适旱过渡，这种现象，在依赖自然水源生繁的地区特别明显。荒漠中自然生长的植被，通常具有耐受长期干旱的特殊能力。
4.
The fact that the xerop - hyte grows naturally in desert presents that the sprout of xerophyte has special adaptive ability to endure the first draught season in its life . it is the most essential factor for the sprout of the xerophyte going through the first hot summer to build up the xeromorphic structure and physiological function 在水分条件渐减乃至干旱、炎热的立地条件中，幼苗能否及时适应? ?旱生结构的迅速形成与生理功能的迅速完善，是决定旱生植物能否在荒漠气候条件下继续生长的至关重要的因素。
5.
4 the optimal water niche of m . h and m c are wetter than middle soil water content , belongs to mesophytes ; the optimal water niche of mosla scabra , on photosynthesis is more wetter than that of m . h and me , the optimal water niche between mesophytes and hygrophytes , and leaning to hygrophytes ; the photosynthetic water condition of m . d is arid environments , and its ecotype exits between mesophytes and xerophytes , and leaning to xerophytes . 5 m . h and m . s are locating between shade plants and sun plants , while m . c and m . d obviously belong to sun plants 4 、杭州石荠?与华荠?光合的最适水分条件是中等偏湿，其水分生态类型应属于中生植物；石荠?光合的最适水分条件比杭州石荠?与华荠?光合的最适水分条件要求更湿，其水分生态类型介于中生和湿生植物之间，更偏向湿生；小鱼仙草光合作用的水分生态条件是干旱条件，其水分生态类型介于中生与旱生植物之间，更偏向旱生。
6.
The paper made an ecological anatomy , a cultivation experiment on the lime - soil habtat and an analysis on the diurnal variation of photosynthetic an transpiration rate from three aspects of morphology , transplantation , physiology . the conclusion is that : ( 1 ) from the viewpoint of morphological anatomy , it has typical xerophyte structure such as strong root system , small leaf area , dense floss under the leaf surface , high stomatal density , the small opening degree , developed vessels and palisade tissues etc 从形态学、栽培学和生理学三方面对迷迭香进行生态解剖、石灰土上的栽培实验以及光合蒸腾速率日进程的分析，得出以下结论： ( 1 )在形态解剖上：迷迭香具有发达的根系，较小的叶面积，叶片下表面密被绒毛，气孔密度大，开度小，厚的角质层和发育良好的木质部和栅栏组织等典型的旱生结构。
7.
The ways of study are followed : insp - ecting and observing their living condition on the open fields ; cultivating sp - rout , examining physiological and biochemical changes in plants ; paraffin sec - tioning . the study results show : due to the species diversity , though the sproutsof xerophyte have several strategies to adapt to environmental drought in the long term evolution process , they have obtained same adapting mechanism to the short of water 研究结果表明：由于物种多样性，在长期的适应演化过程中，旱生殖物幼苗对恶劣生境的适应方式多种多样，但其对水分条件的适应机理却是一致的。与生命周期短暂的短命植物不同，多年生旱生植物的当年生幼苗，当面临水分胁迫时，其结构和生理功能具有迅速改组与完善的特征。
8.
The characteristics of biodiversity of yellow river delta are as follows : the vegetation structure is simplex and coverage is lower , which is characterized with obvious younger nature and abundant wetland ; the flora composition is simple , the plants usually could resist against salt and drought ; the xerophytes and meso - xerophytes are abundant , there are many mutual species with inner mongolia , which incarnated the biology corridor function of yellow river ; there are many animal species belong to national protected species , so the significance for biodiversity protection is great 黄河三角洲地区生物多样性主要表现出如下特点：植被结构简单、覆盖度低、生态系统年轻性特点和湿地生态系统特点明显；植物种类少、常具有抗盐、抗旱特性；旱生、中旱生植物以及与内蒙古共有植物种类多，充分体现了黄河的生物廊道作用；主要保护动物种类多，生物多样性保护意义重大。
