以科尔沁沙地引进树种银中杨(Populus alba × P。berolinensis)与乡土树种白榆(Ulmus pumila)为研究对象，分析2树种不同器官(叶片、枝条和根系)中非结构性碳水化合物(NSC)的季节动态及凋落叶中NSC含量，比较不同树种的碳分配与储存策略。结果表明:随着季节变化，银中杨叶片可溶性糖和NSC含量先下降后增加，淀粉含量逐渐下降;枝条和根系可溶性糖含量及可溶性糖/淀粉先上升后下降，而淀粉含量先下降后上升;从春季到秋季，白榆枝条NSC含量变化不显著，根系可溶性糖、淀粉及NSC含量先下降后上升;银中杨春季和夏季叶片可溶性糖含量高于白榆，除秋季枝条外，白榆各器官淀粉含量高于银中杨，可溶性糖/淀粉低于银中杨，白榆凋落叶可溶性糖、淀粉和NSC含量高于银中杨;银中杨NSC主要用于生长消耗，群落中的竞争性更强;白榆NSC更多以淀粉形式储存，抗逆性更强，有利于植物-土壤间的碳循环。
Seasonal variations in non-structural carbohydrates of Populus alba×P.berolinensis and Ulmus pumila in Horqin Sandy Land
We analyzed seasonal changes of non-structural carbohydrate(NSC)contents in different organs(leaf,branch and root)and leaf litter of an introduced species Populus alba × P.berolinensis and a native species Ulmus pumila in Horqin Sandy Land.Carbon allocation and storage strategies of those two species were compared.Results showed that for P.alba × P.berolinensis,contents of soluble sugar and NSC decreased and then increased while starch content gradually decreased in leaves over season;soluble sugar content and ratio of soluble sugar to starch increased and then dropped,starch content decreased and subsequently rose in branches and roots over season.In contrast,for U.pumila,NSC content in branches remained unchanged while contents of soluble sugar,starch and NSC in roots firstly decreased and then increased from spring to autumn.Soluble sugar contents in leaves of P.alba × P.berolinensis were higher than those of U.pumila in spring and summer.Except for branches in autumn,starch contents in all organs of U.pumila were higher than that of P.alba × P.berolinensis,and the ratio of soluble sugar to starch was lower than that in P.alba × P.berolinensis.Contents of soluble sugar,starch,and NSC in leaf litters of U.pumila were higher than those of P.alba × P.berolinensis.Therefore,NSC is mainly used for growth and con-sumption,implying stronger competition for P.alba × P.berolinensis in the community.NSC is more stored as starch,which may contribute to the stronger stress resistance of U.pumila and facilitate the carbon cycle between plant and soil.
shelterbelt declinecarbon allocationintroduced tree speciesnative tree speciesadaptive strategymatching site with tree species
万方数据
维普
