美国加州大学伯克利分校T. F. Keenan等研究人员合作揭示二氧化碳增加对全球光合作用历史增长的制约。这一研究成果发表在2021年12月8日出版的国际学术期刊《自然》上。

Author: Keenan, T. F., Luo, X., De Kauwe, M. G., Medlyn, B. E., Prentice, I. C., Stocker, B. D., Smith, N. G., Terrer, C., Wang, H., Zhang, Y., Zhou, S.

Issue&Volume: 2021-12-08

Abstract: The global terrestrial carbon sink is increasing1,2,3, offsetting roughly a third of anthropogenic CO2 released into the atmosphere each decade1, and thus serving to slow4 the growth of atmospheric CO2. It has been suggested that a CO2-induced long-term increase in global photosynthesis, a process known as CO2 fertilization, is responsible for a large proportion of the current terrestrial carbon sink4,5,6,7. The estimated magnitude of the historic increase in photosynthesis as result of increasing atmospheric CO2 concentrations, however, differs by an order of magnitude between long-term proxies and terrestrial biosphere models7,8,9,10,11,12,13. Here we quantify the historic effect of CO2 on global photosynthesis by identifying an emergent constraint14,15,16 that combines terrestrial biosphere models with global carbon budget estimates. Our analysis suggests that CO2 fertilization increased global annual photosynthesis by 11.85±1.4%, or 13.98±1.63petagrams carbon (mean ± 95% confidence interval) between 1981 and 2020. Our results help resolve conflicting estimates of the historic sensitivity of global photosynthesis to CO2, and highlight the large impact anthropogenic emissions have had on ecosystems worldwide.

DOI: 10.1038/s41586-021-04096-9

Source: https://www.nature.com/articles/s41586-021-04096-9