Feng Xiahong
Department of Earth Sciences, Dartmouth College, 6105 Fairchild, Hanover, NH 03755, USA e-mail:
Oecologia. 1998 Nov;117(1-2):19-25. doi: 10.1007/s004420050626.
To evaluate how the land carbon reservoir has been responding to the rising CO concentration of the atmosphere, it is important to study how plants in natural forests adjust physiologically to the changing atmospheric conditions. Many experimental studies have addressed this issue, but it has been difficult to scale short-term experimental observations to long-term ecosystem-level responses. This paper derives carbon-isotope-related variables for the past 100-200 years from measurements on trees from natural forests. Calculations show that the c /c ratios [c /c is the ratio of the CO concentration (μmol mol) in the intercellular space of leaves to that in the atmosphere] of the trees were constant or increased slightly before the 20th century, but changed more rapidly in the 20th century; some increased, some decreased, and some stayed constant. In contrast, the CO concentration inside plant leaves increased monotonically for all trees.
为了评估陆地碳库如何响应大气中不断上升的二氧化碳浓度，研究天然森林中的植物如何在生理上适应不断变化的大气条件非常重要。许多实验研究都探讨了这个问题，但将短期实验观测结果扩展到长期生态系统水平的响应一直很困难。本文通过对天然森林树木的测量得出了过去100 - 200年与碳同位素相关的变量。计算表明，树木的c /c 比值（c /c 是叶片细胞间隙中二氧化碳浓度（μmol mol）与大气中二氧化碳浓度的比值）在20世纪之前保持不变或略有增加，但在20世纪变化更快；一些增加，一些减少，还有一些保持不变。相比之下，所有树木叶片内的二氧化碳浓度都单调增加。
