不同土壤水分条件下焕镛木幼苗的生理生态特性  

Physioecological characteristics of Woonyoungia septentrionalis seedlings under various soil water conditions

作　　者：曾小平[1] 赵平[1] 蔡锡安[1] 孙谷畴[1] 彭少麟[1] 

机构地区：[1]中国科学院华南植物研究所,广州510650

出　　处：《生态学杂志》2004年第2期26-31,共6页Chinese Journal of Ecology

基　　金：广东省自然科学基金团队项目 ( 0 0 3 0 3 1);中国科学院鹤山丘陵综合开放试验站基金资助项目

摘　　要：在不同的土壤水分条件下 (土壤含水量分别为 2 0 1%、14 3%和 13 2 % ) ,比较研究濒危物种焕镛木幼苗的生理生态特性 ;测定了焕镛木叶片的净光合速率 (A)、气孔导度 (gs)、内在水分利用率效率 (WUE)、比叶面积 (SLA)及叶片的光合作用 光响应曲线。结果表明 :随着土壤含水量的增加叶片的净光合速率和气孔导度相应增高 ,生长在最高土壤含水量下的植株 ,日平均光合速率、气孔导度分别为 8 5 5± 4 32 μmol·m-2 ·s-1和 81 5 7± 8 4 1μmol·m-2 ·s-1,分别比生长在最低土壤含水量下的植株高 2 5 6 1%和 17 6 8% ;另一方面 ,水分利用效率、比叶面积随土壤含水量的降低而趋于增加 ,土壤含水量最低时 ,植株的日平均水分利用率、比别增加0 2 8%和 15 87% ,其中 ,水分利用效率的变幅较小 ;光饱和点随着土壤含水量的增加而增高。较高的土壤湿度有利于焕镛木的生长。In this study, the physioecological characteristics of transplanted seedlings of Woonyoungia septentrionalis, an endangered plant were compared under three defferent soil water conditions in Guangdong Province. The soil water contents (Sw) for plants growth were 20.1%, 14.3% and 13.2%, respectively.The net photosynthetic rate (Pn), stomatal conductance (g s), intrinsic water use efficiency (WUE=Pn/g s), specific leaf area (SLA) and photosynthesis-light response curves of leaves were measured. Results showed that both Pn and g s of plants increased with raising Sw. The daily average values of Pn and g s were 8.55±4.32 and 81.57±8.41μmol·m -2 ·s -1 under the highest Sw condition, wich were 25.61% and 17.68% higher than that under the lowest Sw condition respectively. On the orther hand, WUE and SLA of plants tended to increase with reduction of Sw condition. The daily average values of WUE and SLA under the lowest Sw condition were 108·94±16.37μmol·mol -1 and 96.61±23.82cm 2·g -1 ,which were 0.28% and 15.87% higher than that under the highest Sw condition, respectively. The variation ranges of WUE were smaller among different Sw. According to the photosynthesis-light response curves, there was an increase in the saturation point of the photosynthesis of W. septentrionalis with raising Sw. The results suggest that higher soil moisture was beneficial to growth of W. septentrionalis.

关 键 词：焕镛木 土壤水分 净光合速率 比叶面积 

分 类 号：S718.4[农业科学—林学]