With the increase of age of Hedysarum species,ratio of edible tender branches decreased in August,ratio of lignified branches of 2-year Hedysarum species accounted for 53.82% of the total biomass and that of 3-year species accounted for 78.77% .

• 岩黄芪属植物随着年龄的增长；可供家畜采食的幼嫩枝条所占比例逐渐下降；生长2年的岩黄芪属植物8月份木质化枝条占总生物量干重的53.；82%25；生长3年的木质化枝条占总生物量的78