%0 Journal Article %1 citeulike:12890391 %A Tokida, Takeshi %A Adachi, Minaco %A Cheng, Weiguo %A Nakajima, Yasuhiro %A Fumoto, Tamon %A Matsushima, Miwa %A Nakamura, Hirofumi %A Okada, Masumi %A Sameshima, Ryoji %A Hasegawa, Toshihiro %D 2011 %J Glob Change Biol %K carbon, citeulikeExport face, rice, riceface, shizukuishi, soil %N 11 %P 3327--3337 %R 10.1111/j.1365-2486.2011.02475.x %T Methane and soil CO2 production from current-season photosynthates in a rice paddy exposed to elevated CO2 concentration and soil temperature %U http://dx.doi.org/10.1111/j.1365-2486.2011.02475.x %V 17 %X Quantification of rhizodeposition (root exudates and root turnover) represents a major challenge for understanding the links between above-ground assimilation and below-ground anoxic decomposition of organic carbon in rice paddy ecosystems. Free-air CO2 enrichment (FACE) fumigating depleted 13CO2 in rice paddy resulted in a smaller 13C/12C ratio in plant-assimilated carbon, providing a unique measure by which we partitioned the sources of decomposed gases (CO2 and CH4) into current-season photosynthates (new C) and soil organic matter (old C). In addition, we imposed a soil-warming treatment nested within the CO2 treatments to assess whether the carbon source was sensitive to warming. Compared with the ambient CO2 treatment, the FACE treatment decreased the 13C/12C ratio not only in the rice-plant carbon but also in the soil CO2 and CH4. The estimated new C contribution to dissolved CO2 was minor (ca. 20\%) at the tillering stage, increased with rice growth and was about 50\% from the panicle-formation stage onwards. For CH4, the contribution of new C was greater than for heterotrophic CO2 production; ca. 40–60\% of season-total CH4 production originated from new C with a tendency toward even larger new C contribution with soil warming, presumably because enhanced root decay provided substrates for greater CH4 production. The results suggest a fast and close coupling between photosynthesis and anoxic decomposition in soil, and further indicate a positive feedback of global warming by enhanced CH4 emission through greater rhizodeposition.

@article{citeulike:12890391, abstract = {{Quantification of rhizodeposition (root exudates and root turnover) represents a major challenge for understanding the links between above-ground assimilation and below-ground anoxic decomposition of organic carbon in rice paddy ecosystems. Free-air CO2 enrichment (FACE) fumigating depleted 13CO2 in rice paddy resulted in a smaller 13C/12C ratio in plant-assimilated carbon, providing a unique measure by which we partitioned the sources of decomposed gases (CO2 and CH4) into current-season photosynthates (new C) and soil organic matter (old C). In addition, we imposed a soil-warming treatment nested within the CO2 treatments to assess whether the carbon source was sensitive to warming. Compared with the ambient CO2 treatment, the FACE treatment decreased the 13C/12C ratio not only in the rice-plant carbon but also in the soil CO2 and CH4. The estimated new C contribution to dissolved CO2 was minor (ca. 20\%) at the tillering stage, increased with rice growth and was about 50\% from the panicle-formation stage onwards. For CH4, the contribution of new C was greater than for heterotrophic CO2 production; ca. 40–60\% of season-total CH4 production originated from new C with a tendency toward even larger new C contribution with soil warming, presumably because enhanced root decay provided substrates for greater CH4 production. The results suggest a fast and close coupling between photosynthesis and anoxic decomposition in soil, and further indicate a positive feedback of global warming by enhanced CH4 emission through greater rhizodeposition.}}, added-at = {2019-03-31T01:14:40.000+0100}, author = {Tokida, Takeshi and Adachi, Minaco and Cheng, Weiguo and Nakajima, Yasuhiro and Fumoto, Tamon and Matsushima, Miwa and Nakamura, Hirofumi and Okada, Masumi and Sameshima, Ryoji and Hasegawa, Toshihiro}, biburl = {https://www.bibsonomy.org/bibtex/23aa789fbad876a4873b9bbfae6ecfbe5/dianella}, citeulike-article-id = {12890391}, citeulike-linkout-0 = {http://dx.doi.org/10.1111/j.1365-2486.2011.02475.x}, day = 1, doi = {10.1111/j.1365-2486.2011.02475.x}, interhash = {8a1a532cfbe9c16d43260265f511fa3f}, intrahash = {3aa789fbad876a4873b9bbfae6ecfbe5}, journal = {Glob Change Biol}, keywords = {carbon, citeulikeExport face, rice, riceface, shizukuishi, soil}, month = nov, number = 11, pages = {3327--3337}, posted-at = {2014-01-04 04:02:08}, priority = {2}, timestamp = {2019-03-31T01:16:26.000+0100}, title = {{Methane and soil CO2 production from current-season photosynthates in a rice paddy exposed to elevated CO2 concentration and soil temperature}}, url = {http://dx.doi.org/10.1111/j.1365-2486.2011.02475.x}, volume = 17, year = 2011 }