There were two stages with the obvious change velocity of plant species : the period of 15 - 25 years and the period of 40 - 50 years . the biological spectrum of vegetation in shapotu region was not complete 该研究区植物生活型谱不完整,以高位芽植物和一年生植物为主,辅以少量的地面芽植物,没有地上芽和隐芽植物。