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δ13C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.
Reaumuria soongorica is a dominant species in the desert shrubbery vegetation 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 selected from its main distribution areas to measure the leaf stable carbon isotope composition （δ^13C） and nitrogen, phosphorus, potassium, water, proline and chlorophyll contents, with the correlations between the δ^13C value and the test physiological parameters analyzed. The results showed that leaf δ^13C value was significantly correlated with the contents of leaf potassium, water, and proline （P 〈0. 001 ）, and the correlation with leaf potassium content was most profound （ r = 0. 793 ）, followed by that with leaf water content （ r = - 0. 786）, indicating that the variation of leaf δ^13C value could reflect the nutritional status of the plants, and also, their water-deficient degree. The different distribution trends in leaf δ^13C 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.
出处
《应用生态学报》
CAS
CSCD
北大核心
2008年第5期1166-1171,共6页
Chinese Journal of Applied Ecology
基金
国家自然科学基金项目(40671195,4072106,40771004,90502008)
国家科技支撑计划资助项目(2007BAD46B08)
关键词
稳定碳同位素值
生理指标
气孔导度
红砂
δ^13C value
physiological parameters
stomatal conductance
Reaumuria soongorica.
