植物生态学报 ›› 2011, Vol. 35 ›› Issue (3): 322-329.DOI: 10.3724/SP.J.1258.2011.00322

• 研究论文 • 上一篇    下一篇

山杏叶片光合生理参数对土壤水分和光照强度的阈值效应

夏江宝1, 张光灿2,*(), 孙景宽1, 刘霞2   

  1. 1山东省黄河三角洲生态环境重点实验室, 滨州学院, 山东滨州 256603
    2山东农业大学林学院, 山东省土壤侵蚀与生态修复重点实验室, 山东泰安 271018
  • 收稿日期:2010-06-23 接受日期:2010-11-26 出版日期:2011-06-23 发布日期:2011-03-02
  • 通讯作者: 张光灿
  • 作者简介:*E-mail: zhgc@sdau.edu.cn

Threshold effects of photosynthetic and physiological parameters in Prunus sibirica to soil moisture and light intensity

XIA Jiang-Bao1, ZHANG Guang-Can2,*(), SUN Jing-Kuan1, LIU Xia2   

  1. 1Shandong Provincial Key Laboratory of Eco-Environmental Science for Yellow River Delta, Binzhou University, Binzhou, Shandong 256603, China
    2College of Forestry, Shandong Agricultural University, Shandong Provincial Key Laboratory of Soil Erosion and Ecological Restoration, Taian, Shandong 271018, China
  • Received:2010-06-23 Accepted:2010-11-26 Online:2011-06-23 Published:2011-03-02
  • Contact: ZHANG Guang-Can

摘要:

以半干旱黄土丘陵区主要灌木树种山杏(Prunus sibirica)为试验材料, 应用CIRAS-2型光合作用仪测定不同土壤质量含水量(Wm)下山杏叶片净光合速率(Pn)、蒸腾速率(Tr)及水分利用效率(WUE)的光响应过程, 探讨山杏光合特性对土壤水分和光照条件的适应性。结果表明: PnTrWUEWm和光照强度的变化有明显的阈值响应。随着Wm (6.5%-18.6%)的递增, 光补偿点降低, 光饱和点、表观量子效率和最大净光合速率均升高; 在Wm为18.6%时, 山杏利用弱光和强光的能力最强, 光照生态幅最宽。随着Wm (9.2%-18.6%)的递增, PnTr有明显升高的趋势, 水分过高或过低, 两者均呈现下降趋势; 山杏对光照环境的适应性较强, 在光合有效辐射为800-1 200 µmol∙m-2∙s-1时, PnWUE都具有较高水平, 饱和光强在983-1 365 µmol∙m -2∙s-1之间。以光合生理参数为指标对山杏土壤水分有效性及生产力进行分级与评价, 确定Wm < 9.2%或Wm > 22.3%时为“低产中效水”; Wm在20.5%-22.3%和9.2%-12.9%时, 分别为“中产低效水”和“中产中效水”; Wm在12.9%-20.5%时为“高产高效水”。其中Wm为18.6%时为“最佳产效水”, 对应光强为1 365 µmol∙m-2∙s-1

关键词: 净光合速率, 山杏, 土壤水分有效性, 阈值效应, 水分利用效率

Abstract:

Aims Our objective was to investigate the threshold effects of photosynthetically active radiation (PAR) and soil mass water content (Wm) on photosynthetic and physiological parameters of Prunus sibirica, and understand the adaptability of P. sibirica to light and soil moisture conditions. We determined optimal Wm and PAR for P. sibirica to maintain higher net photosynthetic rate (Pn) and water use efficiency (WUE).
Methods Using CIRAS-2 portable photosynthesis system, we measured Pn, transpiration rate (Tr), WUE and other photosynthetic and physiological parameters of three-year-old P. sibirica under different soil moisture conditions.
Important findings Pn, Tr and WUE of P. sibirica had the critical response to soil moisture content and PAR. With increases in Wm (6.5%-18.6%), the light compensation point decreased and light saturation point, apparent quantum yield and maximum Pn increased. When Wm was about 18.6%, the low and high light use efficiency of P. sibirica was maximal. The index of Pn, Tr obviously increased with increasing Wm (9.2% to 18.6%), but Pn, Tr decreased when Wm was too high or low. When PAR ranged from 800 to 1 200 µmol∙m-2∙s-1, Pn and WUE were higher and the light saturation points of Pn and WUE were from 983 to 1 365 µmol∙m -2∙s-1. These indicated that P. sibirica possessed higher adaptability to light conditions. Based on photosynthetic and physiological parameters, the soil water availability and productivity of P. sibirica were classified and evaluated. For P. sibirica woodland, < 9.2% or >22.3% were low productivity and middle WUE, 20.5%-22.3% was middle productivity and low WUE, 9.2%-12.9% of Wm was middle productivity and middle WUE and 12.9%-20.5% of Wm was high productivity and high WUE. The optimum high productivity and high WUE of Wm were about 18.6%, and the corresponding optimum PAR was about 1 365 µmol∙m -2∙s-1.

Key words: net photosynthetic rate, Prunus sibirica, soil water availability, threshold effect, water use efficiency