三江源区不同高寒草地植物矿物元素含量特征及分析

本试验对三江源区不同高寒草地植物中6种矿物元素（钾K，钙Ca，钠Na，镁Mg，锌Zn，铁Fe）的含量进行了测定和分析，结果表明：植物中K元素含量为7.314～12.803 g·kg^-1之间，Ca元素含量为2.851～6.823 g·kg^-1之间，Na元素含量为64.404～185.553 mg·kg^-1之间，Mg元素含量为1.272～2.655 g·kg^-1之间，Zn元素含量为14.718～51.387 mg·kg^-1之间，Fe元素含量为161.056～531.677 mg·kg^-1之间；豆科（Leguminosae）植物和杂类草（Forbs）矿物元素含量显著高于禾本科（Gramineae）和莎草科（Cyperaceae）植物；植物中K元素与Mg元素、Ca元素与Na元素、Ca元素与Zn元素、Na元素与Zn元素含量之间呈极显著正相关关系（P<0.01），Ca元素与Fe元素、Mg元素与Fe元素之间呈显著正相关关系（P<0.05）；根据美国国家研究理事会（National research council，NRC）绵羊日粮矿物元素需求标准，三江源区各草地植物中Na，Zn元素相对缺乏，其它4种元素均能满足放牧藏羊的矿物营养需求。

Characteristics and Analysis of Mineral Elements Content in Plants of Different Alpine Grasslands in the Regions of Three-River-Source

The contents of the six mineral elements (K, Ca, Na, Mg, Zn, Fe) in plants of different alpine grasslands in the source region of three Rivers (the Yangtze River, Yellow River, and Lancang River) were determined and analyzed. The results showed that the contents of K element in plants was between 7.314~12.803 g·kg^-1;Ca was between 2.851~6.823 g·kg^-1;Na was between 64.404~185.553 mg·kg^-1;Mg was between 1.272~2.655 g·kg^-1;Zn was between 14.718~51.387 mg·kg^-1, Fe was between 161.056~531.677 mg·kg^-1. The contents of mineral elements in Leguminosae and Forbs were significantly higher than those in Gramineae and Cyperaceae plants. The mineral elements K and Mg, Ca and Na, Ca and Zn, Na and Zn contents in the plants of the alpine grasslands had the significant correlation at the 0.01 level, while Ca and Fe, Mg and Fe had the significant correlation at the 0.05 level. According to the NRC (National research council, NRC) requirements for mineral elements in sheep diets, the mineral elements contents of Na and Zn in plants were relatively deficient in all kinds of alpine grasslands, and the other four mineral elements in plants could meet the mineral nutrition requirements of grazing Tibetan sheep in the source region of three Rivers.