Abstract: Studies on photosynthesis characteristic,soil respiration and biomass(aboveground/belowground)of Leymus chinensis in two soil types had been made in 1999.The results show that(1)Leaf width,net photosynthesis ratio (An)and stomatal conductance(gs)of Leymus chinensis in meadow alkali soil are less than those in wind sand soil,and plants are higher than those in wind sand soil,but leaf length,transpiration rate and water use efficiency have no significant difference in two soil types.(2)Aboveground biomass,density and shoot/root of Leymus chinensis in meadow alkali soil are larger than those in wind sand soil,but belowground biomass has no significant difference in two soil types.(3)CO₂ releasing from soil respiration and litter of Leymus chinensis community in meadow alkali soil is more than that in wind sand soil.

Key words: Leymus chinensis community, Meadow alkali soil, Wind sand soil, Photosynthesis, Soil respiration, Biomass

摘要： 研究两种土壤类型对羊草个体和群落生物学特征的影响。结果表明,在碱化草甸土,羊草的叶宽、净光合速率和气孔导度均低于风沙土型,而单株重则高于后者,而叶长、蒸腾速率和水分利用效率差异不显著。碱化草甸土型羊草的群落密度、地上生物量均高于后者,而根冠比则低于后者。株高、凋落物量及地下生物量在两者间差异不明显,碱化草甸土型羊草群落土壤呼吸及凋落物分解排放的CO₂量均高于风沙土型。

关键词: 羊草, 碱化草甸土, 风沙土, 光合作用, 土壤呼吸, 群落生物量