毛乌素沙地中国沙棘克隆生长对土壤水分含量的响应

通过生物量测定和跟踪挖掘法,研究了毛乌素沙地中国沙棘克隆种群生长特征和形态特征对土壤水分条件的可塑性反应 。结果表明:低水分条件下,植株个体和种群都较小,子株数量、萌蘖根条数和分枝级数较少,而隔离区较长,种群趋向于游击型 ; 高水分条件下,植株个体和种群都较大,子株数量、萌蘖根条数和分枝级数较多,而隔离区较短,种群趋向于集团型。在生物 量分配方面,低水分条件下,枝条、叶片、根系和地上生物量分配比例较大; 高水分条件下,树干、萌蘖根和地下生物量分配比 例较大。土壤水分条件差异引起中国沙棘个体大小和种群大小的分化,进而导致了种群适合度的差异。

The response of clonal growth of Hippophae rhamniodes L.subsp sinensis to the availability of soil moisture in Mu Us sand land

Based on the biomass determination and track mining techniques,plasticity strategy of Hippophae rhamniodes L.subsp sinensis population at different soil moisture conditions was studied in the Mu Us sand land.The results showed: under low level of soil moisture supply,plant individuals and population were smaller,the daughter ramets density and branching intensity were smaller while spacer was longer,which caused population tend to guerrilla type;under high level of soil moisture supply,plant individuals and population were bigger,the daughter ramets density and branching intensity were bigger while spacer was shorter,which caused population tend to phalanx type.In addition,the biomass allocation of branch,leave,root and aboveground were more under low level of soil moisture supply;the biomass allocation of trunk,spacer and underground biomass were more under high level of soil moisture supply.Differences of soil moisture conditions caused the plant individuals and population differentiates and led to the differentiation in population fitness.