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作 者 ：马剑英^1,2,3;陈发虎²;夏敦胜¹;孙惠玲²;段争虎¹;王刚³

期 刊 ：应用生态学报 2008年 19卷 05期 页码：1166-1171

关键词：红砂；

摘 要 ：红砂是我国西北干旱区荒漠植被的主要优势种，对荒漠生态系统的稳定性具有重要作用.通过测定我国境内红砂主要分布区21个自然种群407个植株叶片稳定碳同位素（δ¹³C）值、叶片氮磷钾含量、叶片含水量、脯氨酸和叶绿素含量等生理指标，分析了不同自然种群红砂叶片δ¹³C值与相关生理指标之间的关系.结果表明：红砂叶片钾含量、叶片含水量和脯氨酸含量均对δ¹³C值有显著影响（P<0.001），其中叶片钾含量的影响最大（r=0.793），叶片含水量次之（r=-0.786）.说明叶片的δ¹³C值可以反映植物的水分亏缺程度；不同种群间植物δ¹³C的丰度差异能从另一个侧面反映植物营养元素含量的变化状况；在干旱条件下，红砂叶片气孔导度的
变化是影响其δ¹³C值随环境变化的主要原因.

Abstract:Reaumuria soongorica is a dominant species in the desert shrubbery veg
etation in arid regions of northwestern China, playing an important role in the
maintenance of the stability and continuity of desert ecosystem. In this paper,
a total of 407 individuals in 21 natural populations ofR. soongorica were s
elected from its main distribution areas to measure the leaf stable carbon isoto
pe composition (δ¹³C) and nitrogen, phosphorus, potassium, water, proline
and chlorophyll contents, with the correlations between the δ¹³C value a
nd the test physiological parameters analyzed. The results showed that leaf δ¹³C value was significantly correlated with the contents of leaf potassium,
water, and proline (P<0.001), and the correlation with leaf potassium conte
nt was most profound (r=0.793), followed by that with leaf water content (
r=-0.786), indicating that the variation of leaf δ¹³C value could reflect the nutritional status of the plants, and also, their water-deficient degree. The different distribution trends in leaf δ¹³C value of R. soongoricawere likely caused by stomatal conductance, rather than by nutrient-related changes in photosynthetic efficiency under extremely low available water conditions.

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