---

作 者 ：李晓靖1，周本智1*，洪奕丰1,2，唐轶琳1，曹永慧1，王小明1，李 谦1

期 刊 ：西北植物学报 2012年 9期 页码：1858~1865

关键词：冰灾；萌枝；部位；光合作用；叶绿素荧光参数；

Keywords:ice and snow storm, resprouts, segments, photosynthesis, chlorophyll fluorescence parameters,

摘 要 ：以2008年南方冰雪灾害中受到严重损害的木荷为对象，在浙江江郎山设置5个400 m²样地，通过Li-6400光合仪人工控制光强和CO₂浓度测定相关光合参数，采用指数方程对不同受害类型木荷(倒木和断木)的光合生理响应曲线进行拟合，并结合叶绿素荧光参数分析了不同部位萌枝叶片的光合能力。结果表明：（1）光响应曲线中，木荷断木不同部位萌枝叶片在初始阶段(光照强度0～200 μmol·mol^-1)较陡，随着光强的增大，断木相对于倒木较早达到光饱和点，但其最大净光合速率较倒木低；CO₂响应曲线中，倒木和断木在起始阶段(CO₂浓度在0～200 μmol·mol^-1)的斜率较接近，随着CO₂浓度增加，各条拟合曲线趋势相似。（2）不同受害类型木荷之间比较，倒木的光饱和最大净光合速率(P_Lmax)、CO₂饱和最大净光合速率(P_Cmax)、光补偿点(LCP)、光饱和点(LSP)、有效光化学效率(F_v′/F_m′)分别比断木高22.03%、5.22%、13.73%、52.48%、22.53%，且二者间的P_Lmax、LSP、F_v′/F_m′均差异显著。（3）相同受害类型木荷的不同部位之间比较，倒木不同部位的P_Lmax、P_Cmax、PSⅡ最大光化学效率(F_v/F_m)、F_v′/F_m′、PSⅡ潜在活性(F_v/F₀)、电子传递速率(ETR)均表现为底部>中部>顶部，而断木不同部位则表现为顶部和中部大于底部，但未达到显著水平。研究发现，遭受冰雪灾害的木荷倒木的光合作用能力高于断木，且倒木底部和断木顶部的光合作用能力高于其它部位。

Abstract:Schima superba,one of the typical components of subtropical evergreen broad-leaf forest community,suffered from 2008 ice and snow storm.With five 400 m² established plots in Jianglangshan Mountain,located in Zhejiang Province,the response of photosynthesis rate to light intensity and CO₂ concentration in different patterns of S.superba (uprooted and decapitated trees) were measured and fitted through exponential equation method by using Li-6400 portable photosynthesis system.Meanwhile,the chlorophyll fluorescence parameters of different segments of damaged trees were studied.The results are showed as follows:(1)The slope of initial phase light response curve of decapitated trees was higher than that of uprooted trees.With the increase light,the decapitated trees achieve the light saturation point earlier and lower than that of uprooted trees.The slopes of initial phase of the CO₂ response curve of uprooted and decapitated trees were similar.With the increase of CO₂ concentration,each curve has a similar trend.(2)The maximum net photosynthetic rate of saturated light (P_Lmax),the maximum net photosynthetic rate of saturated CO₂ (P_Cmax),light compensation point (LCP),light saturation point (LSP) and effective photochemical efficiency of PSⅡ (F_v′/F_m′) of uprooted trees were 22.03% (P<0.05),5.22% (P>0.05) 13.73% (P>0.05),52.48% (P<0.05) and 22.53% (P<0.05) higher than that of decapitated trees.(3)P_Lmax,P_Cmax,the maximal photochemical efficiency of PSⅡ (F_v/F_m),effective photochemical efficiency of PSⅡ (F_v′/F_m′),potential activity of PSⅡ (F_v/F₀) and electron transport rate (ETR) of uprooted trees were the highest in basal segment,followed by those in middle segment,and those in top were the lowest.F_v/F_m,F_v′/F_m′,F_v/F₀,ETR,P_Lmax and P_Cmax of decapitated trees were the highest in top and middle segment,and those in basal were the lowest,while there were no significant difference between those segments of decapitated trees (P>0.05).The photosynthetic capacities of uprooted trees was higher than that of decapitated trees.The photosynthetic capacities of basal of uprooted trees and top of decapitated trees were higher than that of other segments.

---