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林业科学 ›› 2002, Vol. 38 ›› Issue (3): 27-33.doi: 10.11707/j.1001-7488.20020305

• 论文及研究报告 • 上一篇    下一篇

温度对杉木中龄林针叶光合生理生态的影响

张小全 徐德应   

  1. 中国林业科学研究院森林生态环境与保护研究所,北京100091
  • 收稿日期:1999-04-21 修回日期:1900-01-01 出版日期:2002-05-25 发布日期:2002-05-25

EFFECTS OF TEMPERATURE ON THE PHOTOSYNTHETIC PHYSIO-ECOLOGY OF 18-YEAR-OLD CHINESE FIR(CUNNINGHAMIA LANCEOLATA(LAMB.)HOOK.)

Zhang Xiaoquan,Xu Deying   

  1. Research Institute of Forest Ecology, Environment and Protection, CAF Beijing100091
  • Received:1999-04-21 Revised:1900-01-01 Online:2002-05-25 Published:2002-05-25

摘要:

采用活体测定方法,在大气CO2 浓度(350±10)μL·L-1、70%±5%相对湿度和一定光合有效辐射通量密度条件下,测定了18a生杉木(Cunninghamia lanceolata (Lamb.)Hook.)中龄林针叶净光合速率(Pn)、气孔导度(gs)、蒸腾速率(E)和暗呼吸(Rd)等光合生理生态指标对温度的响应。结果表明,杉木中龄林针叶光合生理生态指标对温度的变化非常敏感。Pn对温度的响应呈抛物线型,不同季节Pn的最适温度不同,在生长盛期(5月下旬)和后期(10月中旬)为25℃左右,在生长中期30℃左右,但生长盛期当年生针叶例外,其Pn最适温度仅22℃~23℃。Pn的最适温度与测定前5d平均最高气温更接近。gsE对温度的响应与Pn相似,但gs 达最大值的温度比Pn低。在试验条件下温度对Pn的影响可能主要由于非气孔因素引起。温度对gs的影响可能源于叶面-大气水汽压差(VPD)的变化和光合作用引起的胞间CO2 浓度的改变。温度对E的影响与gsVPD的变化密不可分。暗呼吸随温度增加呈指数增加,但由于生理活性和所处光环境的差异,当年生针叶Rd明显高于1a生和2a生老叶。杉木针叶光合生理生态对温度变化的长期响应与适应,还有待于进一步的研究。

关键词: 净光合速率, 气孔导度, 蒸腾速率, 暗呼吸, 温度, 杉木中龄林

Abstract:

Under the ambient atmospheric CO2(350±10)μL·L-1,70%±5% relative humidity and PPFD of 400、800 and 1200μmol·m-2s-1,the temperature dependence of net photosynthetic rate (Pn),stomatal conductance (gs),transpiration rate (E) and dark respiration (Rd) of 3 age classes of 18-year-old Chinese fir shoots were measured in 3 growing seasons of 1998 in Fenyi County of Jiangxi Province, one of the central distribution area of Chinese fir. With the increase of temperature the Pn, gs and E showed sharp parabolic responses while R d responded exponentially. However the maximum gs reached at much lower temperature than Pn and E. The optimum temperature of Pn was around 25℃ in fast-growing season (late May) and late season (middle October) while it was around 30℃ in middle season (late July) except for the current shoot in the late May with the optimum temperature between 22℃ and 23℃ because it was not fully developed then.The optimum temperature of Pn for mature shoots was more relevant to the average highest temperature of 5 days before measuring date. The impact of temperature on gs may result from the changes of saturated vapour pressure deficiency (VPD) and the intercellular CO2 concentration (Ci). The response of E to temperature may be related to the changes of gs and VPD. The Rd of old shoot was lower than current shoot due to the lower physiological activity and poor light environment. However the responses of Pn,E and gs to temperature discussed in this paper are instantaneous and the long-term responses and acclimation need to be studied further.

Key words: Net photosynthetic rate, Stomatal conductance, Transpiration rate, Dark respiration, Temperature, 18-year-old Chinese fir