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作 者 ：胡春香,刘永定

期 刊 ：生态学报 2003年 23卷 1期 页码：38~44

关键词：荒漠土壤；藻类；群落结构；垂直分布；沙坡头；

Keywords:semi-desert, soil, algae, species composition, biomass, vertical distribution, seasonal variance, Shapotou,

摘 要 ：对沙坡头地区半荒漠土壤中藻类植物的垂直分布进行了为期一年多的采样、分析 ,结果发现结皮层有藻类植物 2 4种 ,蓝藻及其丝状种类的比例最大 ;结皮下 0～ 5 0 mm和 5 0～ 1 0 0 mm层次分别有 1 5种、1 0种 ,且都以硅藻及单细胞种类最丰富 ;深层次出现的种类在浅层次都出现 ;1 0 0 mm以下层次没有任何藻种发现。生物量从表及里随深度的增加而锐减 ,99%的分布在结皮层 ;就结皮层中 78%的在 0～ 0 .1 mm层次 ,96%在 0～ 1 .0 mm深度。种类数变化在结皮层和结皮下 0～ 5 0 mm层次都与降水量相关 ,而结皮下 5 0～ 1 0 0 mm层次基本不变。

Abstract:Shapotou (37°27′N, 104°57′E) is located in the southeast of Tegger Desert, Zhongwei County, Ningxia Hui Autonomous Region of China. The average annual precipitation is ca.186 mm (mainly in summer), evaporation more than 2900 mm. The windy days (>5 m/s) are more than 200 days each year. Forty five years ago there was only shifting sand dunes. Since 1956 drought-resistant trees are batch planted each several years under irrigation and non-irrigation conditions. Now the stable algal crusts had formed on the to...

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