Ecophysiological Evidence for the Competition Strategy of Two Psammophytes Artemisia halodendron and A. frigida in Horqin Sandy Land, Nei Mongol  

作　　者：ZHOUHai-Yan LISheng-Gong LIXin-Rong ZHAOAi-Fen ZHAOHa-Lin FANHeng-Wen WANGGang 

机构地区：[1]StateKeyLaboratoryofAridAgro-EcologyofLanzhouUniversity,Lanzhou730000,China [2]DepartmentofBiology,UniversityofUtah,SaltLakeCity,UT84112,USA [3]ShapotouStationofDesertExperimentalResearch,ColdandAridRegionsEnvironmentalandEngineering [4]DepartmentofBiologicalScienceandBiotechnology,YantaiNormalUniversity,Yantai264025,China

出　　处：《Acta Botanica Sinica》2004年第3期284-293,共10页Acta Botanica Sinica（植物学报：英文版）

摘　　要：Gas exchange, water relations and leaf chemical characteristics were examined of twodominant psammophytes: Artemisia frigida Willd and A halodendron Turcz. ex Bess in Horqin sandy land, NeiMongol, China under different water regimes. The measurements were conducted by submitting the plantsto five different irrigation levels. A. fTigida was characterized by lower photosynthetic rate (Pn), lowertranspiration rate ( TR and lower shoot water potential (ψuw) relative to A. halodendron. Foliage of A frigdahad higher values of relative water deficit (RWD), bound water content (BWC), ratio of bound water contentto free water content (BWC/FWC) and integrated drought-resistant index (DI than that of A. halodendron.Water relations differed significantly between two species in response to soil water availability. ψw, BWCand BWC/FWC ratio of A halodendron exhibited large variation with gradual decrease of soil moisture.However, in terms of these parameters, A. fRIGIDA was characterized by higher capacity of water holding anddrought tolerance relative to A halodendron. Proline and total soluble sugar contents of A frigida and Ahalodendron tended to increase with decrease of soil moisture and the former had a larger increaseamplitude than the latter. This shows that A frigida has a higher osmotic regulation ability than A halodendron.Under the extreme drought conditions, ψw, RWD, BWC and BWC/FWC of two species were approximate,but soluble proteins degraded largely. A large amount of accumulation of organic matter, proline and totalsoluble sugars were observed in both A halodendron and A frigida. The increase in proline and total solublesugar contents and soluble protein degradation of A frigida far exceeded those of A. halodendron. Webelieve that the accumulated materials at this moment are mostly of nutrient substances available for therecovery of plants after the drought. This is one of the reasons why A halodendron plants died while Afrigida plants survived under extremely drought condition. Our results suggest that these

关 键 词：内蒙古 科尔沁沙地 沙生植物 冷蒿 差不嘎蒿 竞争策略 生理 生态学 水分胁迫 气体交换 

分 类 号：Q948.122.1[生物学—植物学]