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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CO2浓度的响应

吕扬,刘廷玺*,闫雪,段利民,张圣微,韩春雪   

  1. (1内蒙古农业大学水利与土木建筑工程学院, 呼和浩特 010018)
  • 出版日期:2016-12-10 发布日期:2016-12-10

Response of photosynthetic rate of Salix gordejevii and Caragana microphylla to light intensity and CO2 concentration in the dune-meadow transitional area of Horqin sandy land.

LU Yang, LIU Ting-xi*, YAN Xue, DUAN Li-min, ZHANG Sheng-wei, HAN Chun-xue   

  1. (Water Conservancy and Civil Engineering College, Inner Mongolia Agricultural University, Hohhot 010018, China).
  • Online:2016-12-10 Published:2016-12-10

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CO2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/CO2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CO2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、CO2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CO2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、29.7 μmol·m-2·s-1,为光饱和下的3.98和1.87倍。CO2浓度高的生境更能促进黄柳生长,而小叶锦鸡儿在较低的CO2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CO2同化能力。

关键词: 干沉降通量, 干沉降速率, 臭氧干沉降, 沉降阻力

Abstract: 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 hyperbola model, a nonrectangular hyperbola model, and a modified rectangular hyperbola model of the photosynthetic response to light and intercellular CO2 concentration, respectively. The results 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 saturation point than S. gordejevii. This suggested that C. microphylla had a stronger ability to adapt to the environment. The apparent quantum yield of S. gordejevii was greater than that of C. microphylla, 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 CO2 concentration reached saturation, the maximum net photosynthetic rates of C. microphylla and 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 highCO2 concentration promoted the growth of S. gordejevii, while C. microphylla formed the accumulation of organic matter at a lower CO2 concentration. At the same time, C. microphylla had high efficiency of carboxylation and a strong ability of CO2 assimilation.

Key words: ozone dry deposition flux, ozone deposition resistance., ozone deposition, ozone dry deposition rate