Acidification Offset Warming-Induced Increase in N2O Production in Estuarine and Coastal Sediments

作者：Xiaofei Li, Mengting Qi, Qiuxuan Li, Boshuang Wu, Yuxuan Fu, Xia Liang, Guoyu Yin, Yanling Zheng, Hongpo Dong, Min Liu, Lijun Hou · 发表于：Environmental Science & Technology · 年份：2024 · DOI：10.1021/acs.est.3c10691 · 被引用次数：11 · 研究领域：Marine and coastal ecosystems、Microbial Community Ecology and Physiology、Marine Biology and Ecology Research

Global warming and acidification, induced by a substantial increase in anthropogenic CO 2 emissions, are expected to have profound impacts on biogeochemical cycles. However, underlying mechanisms of nitrous oxide (N 2 O) production in estuarine and coastal sediments remain rarely constrained under warming and acidification. Here, the responses of sediment N 2 O production pathways to warming and acidification were examined using a series of anoxic incubation experiments. Denitrification and N 2 O production were largely stimulated by the warming, while N 2 O production decreased under the acidification as well as the denitrification rate and electron transfer efficiency. Compared to warming alone, the combination of warming and acidification decreased N 2 O production by 26 ± 4%, which was mainly attributed to the decline of the N 2 O yield by fungal denitrification. Fungal denitrification was mainly responsible for N 2 O production under the warming condition, while bacterial denitrification predominated N 2 O production under the acidification condition. The reduced site preference of N 2 O under acidification reflects that the dominant pathways of N 2 O production were likely shifted from fungal to bacterial denitrification. In addition, acidification decreased the diversity and abundance of nirS -type denitrifiers, which were the keystone taxa mediating the low N 2 O production. Collectively, acidification can decrease sediment N 2 O yield through shifting the responsible...