中文版 | English
CSpace
A distinctive mode of dissolved organic carbon biodegradation in karst lakes and reservoirs: Evidence from trophic controls and compositional transformations
Ni, Maofei1; Ma, Yongmei2; Wang, Zhikang1,4; Wang, Xiaodan1,3; Zhu, Sixi1
2022-09-25
摘要Lakes and artificial reservoirs present as funnels for global and regional carbon cycling. However, limited in-formation is available about dissolved organic carbon (DOC) bioavailability, especially for its trophic controls and compositional transformations in widely distributed karst waters. Here we examined DOC biodegradation (% BDOC), temperature sensitivity (Q10 value), nutrients and their stoichiometric ratios, as well as DOC composition over a 28-day laboratory incubation experiment in karst lakes and reservoirs. Fluorescence, Fourier transform infrared (FTIR) and UV-Visible spectroscopy were employed to trace DOC variability. We found that %BDOC ranged between 1.17% and 66.6% (median: 30.1%) at 15 ? and 5.95%-68.5% (median: 31.0%) at 30 ?, respectively. The Q10 values were mainly distributed between 0.75 and 1.50, suggesting a large amount of degraded substrate with low activation energy. Aquatic DOC and total dissolved nitrogen (TDN) were tightly linked to the %BDOC, whereas significant phosphorus (P) limitation (TDN:TDP > 25) did not induce discernible correlations. Carbohydrates as a dominant contributor to biodegradable DOC (BDOC) largely drove DOC remi-neralization. The incomplete degradation of humic-like fractions increased the relative abundance of fulvic acid, tyrosine-like and tryptophan-like fractions. A distinctive mode as biological utilization of extreme active and inactive components could be summarized in the karst lakes and reservoirs. These findings hope to supplement special mechanisms of DOC transformation and fate in the context of climate change mitigation for the UN Sustainable Development Goals.
关键词Karst lakes and reservoirs Dissolved organic carbon biodegradation Temperature sensitivity Trophic controls Compositional transformations
DOI10.1016/j.jclepro.2022.133217
发表期刊JOURNAL OF CLEANER PRODUCTION
ISSN0959-6526
卷号368页码:11
通讯作者Wang, Zhikang(wangzhikang@gzmu.edu.cn)
收录类别SCI
WOS记录号WOS:000863062300004
语种英语