科尔沁草原主要牧草冷蒿和差不嘎蒿的生理生态学特性与竞争机制  

Ecophysiological Characteristics and Their Competition Mechanism of the Two Dominant Grasses in Horqin Sandy Land: Artemisia halodendron and Artemisia frigida

作　　者：周海燕[1] 赵爱芬[2] 

机构地区：[1]兰州大学干旱农业生态国家重点实验室,兰州730000 [2]中国科学院寒区旱区环境与工程研究所沙坡头开放试验站,兰州730000

出　　处：《生态学报》2002年第6期894-900,共7页Acta Ecologica Sinica

基　　金：国家重点基础研究发展规划资助项目 ( G2 0 0 0 0 4 870 4 );中国科学院寒区旱区环境与工程研究所知识创新工程资助项目 ( CACX2 1 0 0 31 )

摘　　要：一日内冷蒿和差不嘎蒿的光合速率 ( Pn)、蒸腾速率 ( E)和水分利用效率 ( WUE)在早或晚出现了最高值 ,而其余时间则变化低缓 ,原因归结于沙地环境因子和植物内部因子的共同作用。冷蒿的 Pn和 WUE日均值高于差不嘎蒿 ,E的日均值却低于差不嘎蒿 ,说明冷蒿在干旱环境下具有较高的物质生产量和节约用水的能力。自然状态下冷蒿各生长季的水势 ( ψw)和充分膨胀时的渗透势 ( ψ10 0π )远低于差不嘎蒿 ,水分相对亏缺 ( RWD)、束缚水含量 ( BWC)、束缚水与自由水的比值 ( BWC/F WC)远高于差不嘎蒿 ,表明其具有更强的抗旱性 ;干旱和旱后复水条件下差不嘎蒿的 RWD、BWC和 BWC/FWC产生大幅度波动 ;长期极端干旱条件下两者 RWD、BWC和 ψw终极值相近 ;长期淹水对冷蒿生理过程的影响更大些。干旱使两种牧草蛋白质发生分解 ,脯氨酸和可溶性糖大量累积 ,其中冷蒿的累积量远远超过差不嘎蒿 。It is revealed that the maximum Pn, E and WUE of the two concerned grasses appears at both dawn and dusk time, comparing to a slow variation at other time due to the co-action of sandy environment factors and the inter-factors of the grass. %A. halodendron% has a higher daily average Pn and WUE but lower daily average E than %A. frigida.% It suggests that %A. halodendron% has a relatively higher primary productivity and water saving capability in aridity situation. At natural conditions, %A. frigida% has much lower %Ψ-w% and %Ψ+{100}-π% than %A. halodendron,% while %A. halodendron% has much lower RWD, BWC, BWC/FWC than %A. frigida,% implying %A. frigida% more drought-resistant than %A. halodendron.% Drought and post-drought watering produces very variable RWD, BWC and BWC/FWC in %A. halodendron.% Long-term drought stress makes the two grasses have similar RWD, BWC and %Ψ-w% while long-term waterlogging has a greater impact on %A. frigida.% Drought stress could stimulate decomposition of protein, considerable accumulation of proline and soluble sugar, which are far higher in %A. frigida% than %A. halodendron.% Accumulation of proline and soluble sugar might be the key to their competition mechanism.

关 键 词：科尔沁草原 牧草 冷蒿 差不嘎蒿 生理生态特性 竞争机制 

分 类 号：S812[农业科学—草业科学]