Comparisons of plant calcium fraction between two different vegetation zones in semi-arid region

To explore the characteristics of plant calcium(Ca) fraction, we analyzed 91 plant species in the Ningxia Habahu National Nature Reserve in Yanchi County of Ningxia and 84 plant species in Zhenglan Banner of Inner Mongolia. Results show that, for the two regions, there is no significant difference between Ca fraction for the same growth type, and between water soluble Ca content or between hydrochloric acid soluble Ca content for plants of the same ecosystem and between hydrochloric acid soluble Ca content for plants of the same family. In similar vegetation zones, there is a significant difference among hydrochloric acid soluble Ca content for different growth types in Yanchi County and Zhenglan Banner,which was the highest for annual herbs and the lowest for perennial herbs. There is a significant difference between acetic acid soluble Ca content and between hydrochloric acid soluble Ca content for sandy land and grassland ecosystems in Yanchi County. There is a significant difference among the same Ca fraction of different families in the same region. Thus, the characteristics of plant Ca fraction are results of long-term adaptation to the environment.