Wit Francisca, Müller Denise, Baum Antje, Warneke Thorsten, Pranowo Widodo Setiyo, Müller Moritz, Rixen Tim
Leibniz Center for Tropical Marine Ecology (ZMT), Fahrenheitstrasse 6, 28359 Bremen, Germany.
Institute for Environmental Physics, University of Bremen, Otto-Hahn-Allee 1, 28359 Bremen, Germany.
Nat Commun. 2015 Dec 16;6:10155. doi: 10.1038/ncomms10155.
River outgassing has proven to be an integral part of the carbon cycle. In Southeast Asia, river outgassing quantities are uncertain due to lack of measured data. Here we investigate six rivers in Indonesia and Malaysia, during five expeditions. CO2 fluxes from Southeast Asian rivers amount to 66.9 ± 15.7 Tg C per year, of which Indonesia releases 53.9 ± 12.4 Tg C per year. Malaysian rivers emit 6.2 ± 1.6 Tg C per year. These moderate values show that Southeast Asia is not the river outgassing hotspot as would be expected from the carbon-enriched peat soils. This is due to the relatively short residence time of dissolved organic carbon (DOC) in the river, as the peatlands, being the primary source of DOC, are located near the coast. Limitation of bacterial production, due to low pH, oxygen depletion or the refractory nature of DOC, potentially also contributes to moderate CO2 fluxes as this decelerates decomposition.
河流排气已被证明是碳循环的一个重要组成部分。在东南亚，由于缺乏实测数据，河流排气量尚不确定。在此，我们在五次考察中对印度尼西亚和马来西亚的六条河流进行了调查。东南亚河流的二氧化碳通量每年达66.9±15.7太克碳，其中印度尼西亚每年释放53.9±12.4太克碳。马来西亚河流每年排放6.2±1.6太克碳。这些适度的值表明，东南亚并非如富含碳的泥炭土所预期的那样是河流排气热点地区。这是因为河流中溶解有机碳（DOC）的停留时间相对较短，作为DOC主要来源的泥炭地位于海岸附近。由于低pH值、氧气消耗或DOC的难降解性质导致的细菌生产受限，也可能导致二氧化碳通量适度，因为这会减缓分解过程。
