科尔沁沙丘-草甸相间地区黄柳和小叶锦鸡儿光合速率对光照强度和CO_2浓度的响应  

Response of photosynthetic rate of Salix gordejevii and Caragana microphylla to light intensity and CO_2 concentration in the dune-meadow transitional area of Horqin sandy land

作　　者：吕扬[1] 刘廷玺[1] 闫雪[1] 段利民[1] 张圣微[1] 韩春雪[1] 

机构地区：[1]内蒙古农业大学水利与土木建筑工程学院,呼和浩特010018

出　　处：《生态学杂志》2016年第12期3157-3164,共8页Chinese Journal of Ecology

基　　金：国家自然科学基金重点与面上项目(51139002;51479086;51369016);内蒙古水利科技项目;教育部科技创新团队发展计划(IRT13069);内蒙古自治区草原英才产业创新创业人才团队;内蒙古农业大学寒旱区水资源利用创新团队(NDTD2010-6)资助

摘　　要：本文采用Li-6400光合作用仪对科尔沁沙丘-草甸相间地区固定沙丘低洼部位的小叶锦鸡儿(Caragana microphylla Lam.)群落和半流动沙丘阴坡上部的黄柳(Salix gordejevii Chang et Skv.)群落进行光响应曲线和CO_2响应曲线的测定,然后通过直角双曲线模型、非直角双曲线模型、直角双曲线修正模型3种拟合模型对两种植物光合-光/CO_2响应曲线进行拟合分析。结果表明:直角双曲线修正模型能更好地拟合植物光合速率随光强和CO_2浓度变化的真实情况,并且计算出的最大净光合速率、光饱和点、CO_2饱和点等光合参数都与实测值最接近;受不同生境的影响,两种植物的光合特性参数存在差异,小叶锦鸡儿存在较高的光饱和点(LSP)和较低的光补偿点(LCP),表现出对环境较强的适应能力,而黄柳的表观量子效率大于小叶锦鸡儿,所以对光能的转化效率高,低的暗呼吸速率使小叶锦鸡儿消耗更少的光合产物;在CO_2饱和情况下,小叶锦鸡儿和黄柳的最大净光合速率(Pn max)分别达到了44.5、29.7μmol·m-2·s-1,为光饱和下的3.98和1.87倍。CO_2浓度高的生境更能促进黄柳生长,而小叶锦鸡儿在较低的CO_2浓度下能进行光合作用形成有机物的积累,同时小叶锦鸡儿有较高的羧化效率,表现出较强的CO_2同化能力。The light response curves and CO2 response curves of Caragana microphylla and Salix gordejevii in the dune-meadow transitional area of Horqin sandy land were measured using a Li-6400XT portable photosynthesis system. The measured data were fitted using a rectangular hy- perbola model, a non-rectangular hyperbola model, and a modified rectangular hyperbola model of the photosynthetic response to light and intercellular CO2 concentration, respectively. The re- sults showed that the modified rectangular hyperbola model could better fit the light response and CO2 response curves. However, there were significant differences in photosynthetic characteristic parameters between the two plants, due to the effects of the desert environment. C. microphylla showed a lower light compensation point and CO2 compensation point, but a higher light satura- tion point than S. gordejevii. This suggested that C. microphyUa had a stronger ability to adapt to the environment. The apparent quantum yield of S. gordejevii was greater than that of C. micro- phyUa, which indicated that S. gordejevii had a high conversion efficiency of light energy. In addition, C. microphylla presented a lower rate of dark respiration than that of S. gordejevii. When the C02concentration reached saturation, the maximum net photosynthetic rates of C. microphyllaand S. gordejevii were 44.5 and 29.7 μmol·m^-2·s^-1 respectively, which were 3.98 and 1.87 times of those under saturation light. A habitat with high CO2 concentration promoted the growth of S. gordejevii, while C. microphylla formed the accumulation of organic matter at a lower CO2 coneentration. At the same time, C. microphylla had high efficiency of carboxylation and a strong ability of CO2 assimilation.

关 键 词：小叶锦鸡儿 黄柳 光响应曲线 CO2响应曲线 拟合模型 

分 类 号：Q945.11[生物学—植物学]