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xerophyte n.【植物;植物學】旱生植物。 xerophytic a...

xeroradiography

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 黃河三角洲地區生物多樣性主要表現出如下特點:植被結構簡單、覆蓋度低、生態系統年輕性特點和濕地生態系統特點明顯;植物種類少、常具有抗鹽、抗旱特性;旱生、中旱生植物以及與內蒙古共有植物種類多,充分體現了黃河的生物廊道作用;主要保護動物種類多,生物多樣性保護意義重大。

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 研究結果表明:由于物種多樣性,在長期的適應演化過程中,旱生殖物幼苗對惡劣生境的適應方式多種多樣,但其對水分條件的適應機理卻是一致的。與生命周期短暫的短命植物不同,多年生旱生植物的當年生幼苗,當面臨水分脅迫時,其結構和生理功能具有迅速改組與完善的特征。

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 從形態學、栽培學和生理學三方面對迷迭香進行生態解剖、石灰土上的栽培實驗以及光合蒸騰速率日進程的分析,得出以下結論: ( 1 )在形態解剖上:迷迭香具有發達的根系,較小的葉面積,葉片下表面密被絨毛,氣孔密度大,開度小,厚的角質層和發育良好的木質部和柵欄組織等典型的旱生結構。

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 、杭州石薺?與華薺?光合的最適水分條件是中等偏濕,其水分生態類型應屬于中生植物;石薺?光合的最適水分條件比杭州石薺?與華薺?光合的最適水分條件要求更濕,其水分生態類型介于中生和濕生植物之間,更偏向濕生;小魚仙草光合作用的水分生態條件是干旱條件,其水分生態類型介于中生與旱生植物之間,更偏向旱生。

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 在水分條件漸減乃至干旱、炎熱的立地條件中,幼苗能否及時適應? ?旱生結構的迅速形成與生理功能的迅速完善,是決定旱生植物能否在荒漠氣候條件下繼續生長的至關重要的因素。

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 植被恢復與重建能否取得進展,在很大程度取決于幼苗期能否完成適旱過渡,這種現象,在依賴自然水源生繁的地區特別明顯。荒漠中自然生長的植被,通常具有耐受長期干旱的特殊能力。

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,旱生植物對環境的需求,可劃分為兩個不同階段,前一階段始于種子萌發并逐漸形成適旱結構,后一階段是植物在干旱條件下利用當地自然水源而生長。

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,大部分的葉片都特化為刺,極大的減少了葉片區域的蒸發作用,同時光合作用為綠色的莖所承擔。