不同生态区域沙地建群种油蒿的钙组分特征

为探索同一物种在不同生态区域钙组分特征的差异,选择我国北方沙地重要建群种油蒿(Artemisia ordosica)为研究对象,采集了内蒙古杭锦旗、乌审旗、阿拉善左旗以及宁夏盐池县和陕西榆林市榆阳区不同沙地类型、不同生长阶段的油蒿样品,利用连续组分法测定分析了油蒿的钙组分特征.结果表明,在油蒿的不同器官中,叶水溶性钙和醋酸溶性钙均显著高于枝和根,叶与根盐酸溶性钙均显著高于枝.在不同生态区域,降水量较多的地区油蒿体内水溶性钙含量较多,降水量较少的地区油蒿体内盐酸溶性钙含量较高.分析得知,降水条件较好的地区较高的水溶性钙主要体现在油蒿的叶中,而降水条件较差的地区较高的盐酸溶性钙主要体现在油蒿的叶和根中.油蒿在不同生长阶段钙组分没有显著差异,但不同类型沙地上油蒿的钙组分却有显著差异.可见,不同生态区域的油蒿,生境条件越好体内水溶性钙含量越高,生境条件越差体内盐酸溶性钙含量越高.

An analysis of calcium components of Artemisia ordosica plant on sandy lands in different ecological regions

To study the differences in calcium content in the same plant species among different ecological regions, we determined the plant calcium content in Artemisia ordosica, an abundant, widespread species on sandy soils in northwest China. To determine the different plant calcium components, water soluble Ca, acetic acid soluble Ca and hydrochloric acid soluble Ca, we used a sequential fractionation procedure method. Water soluble Ca and acetic acid soluble Ca are physiological active, water soluble Ca contains a Ca ion and part of water soluble Ca salts, and hydrochloric acid soluble Ca is Ca oxalate. In general, the more stressful an environment, the more Ca oxalate the plant contains. In the present study, we collected different life stages and different plant organs of A. ordosica from different sandy soil types, and different ecological regions. As growth stages, we used young plants, adult plants and old plants. The types of sandy soil include shifting sandy soil, semi-fixed sandy soiland fixed sandy soil. The ecological regions we selected were located in Hangjin county (Kubuqi Desert), Wushen county (Mu Us Sand Land) and Alashan Zuoqi county (Tengger Desert) in Inner Mongoilia autonomous region, Yanchi county (Mu Us Sand Land) in Ningxia Hui autonomous region and Yuyang district of Yulin city (Mu Us Sand Land) in Shaanxi province. Our results showed that at organ level, water soluble Ca and acetic acid soluble Ca were significantly higher in leafs than in branches or roots, while hydrochloric acid soluble Ca was significantly higher in leafs and roots than in branches. In relatively wet ecological regions, the plant contained higher water soluble Ca, while in drier ecological regions, plants contained higher levels of hydrochloric acid soluble Ca. Moreover, these higher levels of soluble Ca in areas with higher rainfall mainly existed in the leaves, while the high levels of hydrochloric acid soluble Ca in dry ecological regions was found mainly in the leafs and roots. There was no difference between the different growth stages of the plant, but we found significant differences between different sandy soil types. Comprehensive analysis of the environmental and vegetation conditions suggests that the different calcium components in A. ordosica species were not only influenced by rainfall but also by evaporation, and we find no indication that the calcium content differs between the different growth stages of the plant. To conclude, we find higher water soluble Ca content in plants in less stressful habitats, while we find higher hydrochloric acid Ca levels in more stressful habitats.