土壤水分状况对长白山阔叶红松林主要树种叶片生理生态特性的影响

Potted seadlings of Pinus koraiensis , Fraxinus mandshurica,Juglans mandshurica,Tilia amurensis, and Quercus mongolica ,which are five dominant species in the Korean pine broadleaf forest at Changbai mountain,were grown in different soil moistures.We designed three soil moisture scenarios:85%～100%(high water,CK),65%～85% (medium water,MW) and 45%～65% (low water,LW) of field water holding capacity.The results show that characteristics of typical drought resistance on the leaves are significantly developed.The net photosynthetic rate and water use efficiency of F. mandshurica were higher compared with CK at MW.The net photosynthetic rate and water use efficiency of other 4 tree species at CK were lower than those at MW and LW.The transpiration rate of 5 tree species responses differently to various soil water status.

不同土壤水分条件下珍珠油杏的光合光响应特征

用CIRAS-2便携式光合仪测定了不同土壤水分条件下(土壤相对含水量为84.7%～22.8%)2年生珍珠油杏叶片净光合速率、蒸腾速率、水分利用效率、胞间CO2浓度等光合生理参数的光响应过程,探讨其光合生理特性对土壤水分和光照强度的响应规律。结果表明:(1)随着土壤水分含量的降低,珍珠油杏叶片净光合速率、蒸腾速率、暗呼吸速率、光饱和点均呈降低趋势,表观量子效率先升高后降低,光补偿点先降低后升高。(2)利于珍珠油杏进行高光合作用并维持高水分利用效率的土壤相对含水量为43.6%～84.7%,适宜的光照强度为800～2 000μmol.m-2.s-1,即珍珠油杏对土壤水分和光照强度适应范围较广。(3)在土壤相对含水量43.6%～73.5%范围内,气孔限制是导致珍珠油杏光合速率下降的主要原因,在低于43.6%范围内,非气孔限制是导致光合速率下降的主要原因。研究认为,珍珠油杏是一种抗旱性比较强的植物,适合在华北干旱瘠薄山地引种栽培。