Short-term Effects of Elevated Temperature and CO2 on Carbon Sequestration in Winter Wheat and Summer Rape

Abstract

In order to study organic carbon (C) sequestration in different plant parts of different crop species, a closed growth chamber experiment was performed with winter wheat (Triticum aestivum L.) and summer rape (Brassica napus L.) in a controlled environment at ambient [21 o C/400 ppm] and elevated [25 o C/800 ppm] temperature and CO 2 conditions. Measurements of organic carbon sequestration were carried out at a 28-day period after the treatment. Carbon content was measured with Shimadzu TOC solid sample module SSM-5000A. The results showed that under elevated temperature and CO 2 conditions both species of crop sequestrated the biggest amount of organic carbon in stems (575 mg g-1 in wheat and 545 mg g-1 in rape). Under conditions of [25 o C/800 ppm], the amount of organic carbon in leaves of rape increased by 6.9% (p < 0.05) as compared with the ambient climate conditions. There were no significant differences (p > 0.05) between [21 o C/400 ppm] and [25 o C/800 ppm] in the amount of sequestrated organic carbon in stems and roots of rape. Conversely, roots of wheat under conditions of [25 o C/800 ppm] sequestrated a significantly bigger amount of carbon (6%, p < 0.05) as compared with the conditions of [21 o C/400 ppm], while in the above-ground parts of wheat, there were no significant differences (p > 0.05) between ambient and elevated temperature and CO 2 conditions. Our results suggest that under future elevated temperature and CO 2 conditions, both investigated crop species will sequester more carbon in their biomass but in a different manner.