The content characteristics on Fe, Mn and Cu in the grassland vegetation of Xilin River Basin
Fe、Mn、Cu在锡林河流域温带草原植被中的含量特征

Fe, Mn and Cu, as elements of the fourth period in the periodic table of elements, are all essential elements for plants and animals in grassland ecosystems. The contents of Fe, Mn and Cu in parts of the grassland vegetation , such as shoots, standing dead, litters and roots, were measured in the initial stage of plant growth and the later stage of plant growth, respectively. The results showed that the contents of Fe, Mn and Cu in shoots were suitable for plant and livestock, and the nutritive value of the Stipa baicalensis grassland community, which belongs to meadow steppe, is higher than those of the Leymus chinensis and Stipa grandis grassland communities, which belong to typical steppe, in point of essential elements Fe, Mn and Cu.Regularities of Fe, Mn and Cu content distribution in shoots, standing dead, litters and roots are as follows: From litters and roots, standing dead, to shoots, their contents gradually decreased; along the precipitation, air temperature and altitude gradient, the contents of Fe and Mn in shoots and litters gradually decreased from Stipa baicalensis grassland community, Leymus chinensis grassland community to Stipa grandis grassland community, and Cu gradually increased in the initial stage of plant growth and decreased in the later stage of plant growth as the same order. The contents of Fe and Mn in standing dead gradually increased in the initial stage and decreased in the later stage, and the contents of Cu gradually increased in the initial stage and the later stage. The contents of the three elements in every part of plant ecosystems were higher in the initial stage of plant growth than the later stage. The more intensely the dead plants aboveground were decomposed, the higher the contents of Fe, Mn and Cu were. Cu is very abundant in roots.