摘要
利用CO2交换测定系统和树干液流测定法分别测定了植物的气孔导度(gs)和冠层平均气孔导度(Gs),估测热带亚热带植物桃金娘(Rhodomyrtus tomentusa)、荷木(Schima superba)、九节(Psychotria ruba)、罗伞(Ardisia quinquegone)和马占相思(Acacia mangium)在水汽压亏缺为1 kPa下gs响应叶表面水汽压亏缺(Ds)或Gs响应叶边界层外水汽压亏缺(D)的敏感度与gs或Gs大小的关系。研究的结果及文献引用的相关数据显示,植物气孔对Ds敏感度(dgs/dlnDs)的种间差异较大,与参比气孔导度(gsref)相关(r2=0.88),冠层平均气孔导度(Gs)的相应关系则为r2=0.86。在Ds或D=1 kPa下具有高gs或Gs的植物,其gs对Ds或Gs对D的敏感度较高。耐旱阳生植物桃金娘和荷木在D=1 kPa时有高的gs或Gs,对水汽压亏缺的敏感度较高,而适于遮荫的树种罗伞则有低的gs,对D的敏感度较低。基于液流密度(Js)计算的马占相思Gs对D表现出密切的关系(r2=0.94),当D=1 kPa时,Gs对D的敏感度-m为72.1 mmol.m-1.s-1.ln(kPa)-1,表明马占相思在低D下有较高的Gs。马占相思的Gs与液流密度关系为r2=0.45,Gs对D的敏感度与荷木相近,是适于华南丘陵坡地生长的耐旱外来树种。
Stomatal conductance at leaf and canopy levels（gs and Gs）Was measured by employing CO2 exchange-measuring system and sap flow measurements to evaluate the stomatal sensitivities（-dgs/dlnDs or-dGs/dlnD） in proportional to magnitude of gs or Gs to water vapor pressure deficit （D） under condition of D=1 kPa.However,the magnitude of the stomatal sensitivity varied considerably among species.The sensitivity was correlated with the reference stomatal conductance（gsref） with a slope of 0.58 at leaf-level（r^2=0.88） and with a slope of 0.65 at canopy-level（r^2=0.86）.The results showed that the species with higher gs or Gs at low Ds or D showed a higher sensitivity to Ds or D.Sun plant such as Rhodomyrtus tomentusa and Schima superba had stomata higher stomatal conductance and exhibited a greater sensitivity to Ds at leaf-level and to D at canopy-level.However,a shade-tolerant species Ardisia quinquegone with lower stomatal conductance was less sensitive to Ds or D.Mean canopy stomatal conductance（Gs） was measured by using sap flow measurement in whole tree of Acacia mangium.The relationship between Gs and D was close（r2=0.94）.When D=1 kPa,the sensitivity of Gs to D（-m） was 72.1mmol·m^-1·s^-1·ln（kPa）^-1 showing Gs〉m.The relationship between mean canopy stomatal conductance and sap flux density was r2=0.45.A higher Gs at low D in A.mangium showed a greater sensitivity to D,which is similar to that of S.superba,implying that it be well capable of regulating leaf water potential if grown in subtropical environment where seasonal dry period occurs.
出处
《中山大学学报（自然科学版）》
CAS
CSCD
北大核心
2007年第4期63-68,共6页
Acta Scientiarum Naturalium Universitatis Sunyatseni
基金
中国科学院知识创新工程重要方向资助项目(KSCX2-SW-133)
国家自然科学基金资助项目(30428022
30270230)
广东省自然科学基金资助项目(031265)
关键词
叶片气孔导度
冠层平均气孔导度
水汽压亏缺
敏感度
stomatal conductance
mean canopy stomatal conductance
vapor pressure deficit
sensitivity to vapor pressure deficit
