Environmental Sciences Division, Oak Ridge National Laboratory, Building 1506 MS-6034, P.O. Box 2008, 37831-6034, Oak Ridge, TN, USA.
Photosynth Res. 1994 Mar;39(3):369-88. doi: 10.1007/BF00014592.
Analysis of leaf-level photosynthetic responses of 39 tree species grown in elevated concentrations of atmospheric CO2 indicated an average photosynthetic enhancement of 44% when measured at the growth [CO2]. When photosynthesis was measured at a common ambient [CO2], photosynthesis of plants grown at elevated [CO2] was reduced, on average, 21% relative to ambient-grown trees, but variability was high. The evidence linking photosynthetic acclimation in trees with changes at the biochemical level is examined, along with anatomical and morphological changes in trees that impact leaf- and canopy-level photosynthetic response to CO2 enrichment. Nutrient limitations and variations in sink strength appear to influence photosynthetic acclimation, but the evidence in trees for one predominant factor controlling acclimation is lacking. Regardless of the mechanisms that underlie photosynthetic acclimation, it is doubtful that this response will be complete. A new focus on adjustments to rising [CO2] at canopy, stand, and forest scales is needed to predict ecosystem response to a changing environment.
分析了在大气 CO2 浓度升高条件下生长的 39 个树种的叶片光合作用响应，结果表明，当在生长[CO2]下测量时，平均光合作用增强了 44%。当在常温和[CO2]下测量光合作用时，与在常温和 CO2 下生长的植物相比，在高浓度[CO2]下生长的植物的光合作用平均降低了 21%，但变异性很高。本文还探讨了将树木光合作用的驯化与生物化学水平的变化联系起来的证据，以及影响叶片和冠层水平对 CO2 富集的光合作用响应的树木解剖学和形态学变化。养分限制和汇强度的变化似乎影响光合作用的驯化，但缺乏证据表明一种主要因素控制着树木的驯化。无论光合作用驯化的机制如何，这种反应都不太可能是完全的。需要在树冠、林分和森林尺度上对不断上升的[CO2]进行新的调整，以预测生态系统对不断变化的环境的反应。
