植物生理生态指标对大气CO2浓度倍增响应的整合分析

对 8 4篇文献有关植物对大气CO2 浓度倍增响应进行整合分析(一种对同一主题下多个独立实验进行综合的统计学方法),发现环境因素(土壤水分亏缺、土壤低氮、高温和高浓度O3 )显著地影响植物对高CO2 浓度的响应。无任何环境胁迫时,高CO2 浓度对C3 植物的 12个植物生理生态指标产生负效应,对另 12个则表现正效应,负响应最强的前 5个指标为:气孔导度(gs) >暗呼吸速率(Rd) >单位叶重中的氮含量(Nm) >单位叶重中蛋白质含量(Prm) >单位叶结构重量中氮含量(Ns);正响应最强烈的前 5个指标为:根生物量(Br) >地上部生物量(Bs) >单位叶重中淀粉含量(St) >光饱和时的光合速率(A) >总生物量(Bt)。可见植物的气体交换和生物量受高CO2 浓度影响较大,叶化学成分的变化则以淀粉、单位叶重含氮量和单位叶重蛋白质含量较为明显。无任何胁迫时,C3 植物的总生物量和光饱和时的光合速率分别提高 30.0 1%和 40.36 %;气孔导度下降 30.39%。

Meta-analysis of the Response of Plant Ecophysiological Variables to Doubled Atmospheric CO_2 Concentrations

Eighty_four published papers were synthesized using meta_analysis (a statistical method to summarize the different individual studies under the same subject), with results of the environmental factors (soil water deficit, low soil nitrogen, high temperature and high concentration O 3) affecting significantly the response of plant to elevated atmospheric CO 2 concentrations. Under unstressed condition, the overall effect sizes of twelve ecophysiological variables of C 3 plants were negative, other twelve positive. For negative effect group, the first five variables ranked as: stomatal conductance ( g s)> leaf dark respiration rate ( R d)>leaf nitrogen content on a mass basis ( N m)>leaf protein content on a mass basis ( Pr m)>leaf nitrogen content on a structural mass basis ( N s); for positive one, root biomass ( B t)>shoot biomass ( B s)>leaf starch content on a mass basis ( S t )>light saturated net photosynthetic rate ( A )>total biomass ( B t). The B t and A of C 3 plants increased 30.01% and 40.36% respectively under unstressed condition, while g s decreased 30.39%.