【摘要】 采用撒茎法对构成古尔班通古特沙漠苔藓结皮的优势种刺叶墙藓(Tortula desertorumBroth.)进行室内沙培实验,探讨不同沙埋深度对刺叶墙藓无性繁殖的影响。结果表明:(1)在不添加任何营养元素或激素的原沙基质培养条件下,刺叶墙藓的植株碎片仍然能够生长并发育成完整的植物体。(2)在所设置的不同沙埋厚度条件下,刺叶墙藓的植株碎片在2 mm沙埋厚度时生长较好,生长趋势表现为:前12 d内生长较快,之后生长缓慢。第22 d以后,未见新生植株,苔藓植株数趋于稳定。大于2 mm的沙埋厚度则抑制其生长。同时指出,沙埋也是影响古尔班通古特沙漠苔藓植物生长和分布的因素之一。更多还原

【Abstract】 The Gurbantonggut Desert(44°11′～46°20′N,84°31′～90°00′E),the largest fixed and semi-fixed sand desert in China,is located in the central area of the Junggar Basin in north Xinjiang,its area is 4.88×10~4 km~2,and some odd pieces of sand deserts and sandlands are distributed in its peripheral regions.The annual precipitation in the desert is generally about 150 mm and varies in a range of 70～100 mm in the hinterland,and the precipitation occurs mainly in spring.The annual evaporation is over 2 000 mm,the annual and extremely maximum temperatures are 6～l0 ℃ and over 40 ℃ respectively.The annual accumulated temperature ≥10 ℃ varies in a range of 3 000～3 500 ℃,and the relative humidity varies in a range of 50%～60% and below 45% during the period from May to August.Haloxylon persicum,H.ammodendron,Ephedra distachya and some short arbors dominated by annual plants are extensively distributed in the desert,the vegetation coverage is 40%～50% on the fixed dunes and 15%～25% on the semi-fixed dunes,and microbiotic crust is distributed under the vegetation.In this paper,an experimental study on the effect of sand burial depths on the growth of Tortula desertorum,a dominant species in moss crust in the Gurbantonggut Desert,is carried out.The results show that the fragments of Tortula desertorum can grow on sand surface without fertilizing any nutrition elements or hormones.Under different sand burial depths ranged from 2 mm to 20 mm,the fragments of Tortula desertorum can grow well under 2 mm-thick sand,they can growth rapidly in first 12 days and reach their maximum values after 22 days.The growth of the fragments of Tortula desertorum is restricted with increasing sand thickness,and sand burying is one of the factors affecting the growth and distribution of mosses in the Gurbantonggut Desert.更多还原