气候变化领域集成服务门户(CCPortal): Respiration in rivers fractionates stable isotopes of dissolved oxygen; a global investigation on the influences of temperature and flow

CCPortal

DOI	10.1007/s10533-020-00636-z
	Respiration in rivers fractionates stable isotopes of dissolved oxygen; a global investigation on the influences of temperature and flow
	Tromboni F.; Dodds W.K.; Chandra S.; Poulson S.R.; Pandey A.; Schechner A.
发表日期	2020
ISSN	1682563
卷号	147 期号:2
英文摘要	Quantifying ecosystem respiration remains challenging in aquatic ecosystems. Most investigators assume that nighttime and daytime respiration are equal. Recent studies suggest measuring dissolved oxygen isotopes during periods with and without photosynthesis can account for variations in daytime and nighttime respiration. These models are extremely sensitive to the oxygen isotopic fractionation factor (α) value used for respiration, yet almost nothing is known about the variability of α and factors driving that variability. We quantified how α varies with temperature and flow velocity using field measurements, laboratory experiments, and a modeling approach. We measured α in the field using sealed recirculating chambers in 16 rivers from different biomes (temperate, tropical, and sub-arctic) to assess a range of possible α values. The α values were widely variable, and variation was higher among sites in the same biome or ecoregion (e.g. 0.9780 ± 0.005 to 0.9898 ± 0.002 among six desert sites) than across different biomes. Our data revealed that both temperature, flow, and biofilm characteristics produced variations in α, with temperature decreasing and flow increasing it, until leveling off at high flow velocities. Biological and physical processes occurring in the diffusion boundary layer produced variations in α. Our results highlight that environmental conditions produce variable α values, the need for site-specific α measurements, and practical implications for consideration when measuring α in the field. More generally we illustrate an array of factors that can influence isotopic fractionation associated with metabolic activity of biologically active layers that could be important in any diffusion-limited environment. © 2020, Springer Nature Switzerland AG.
英文关键词	Alpha; Diffusion; Recirculating chambers; Temperature; Water velocity; δ18OO2
学科领域	aquatic ecosystem; biofilm; biome; boundary layer; desert; dissolved oxygen; ecoregion; environmental conditions; isotopic fractionation; photosynthesis; respiration; stable isotope; temperature effect
语种	英语
scopus关键词	aquatic ecosystem; biofilm; biome; boundary layer; desert; dissolved oxygen; ecoregion; environmental conditions; isotopic fractionation; photosynthesis; respiration; stable isotope; temperature effect
来源期刊	Biogeochemistry
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/120390
作者单位	Global Water Center and Department of Biology, University of Nevada-Reno, Reno, NV 89557, United States; Division of Biology, Kansas State University, Manhattan, KS 66502, United States; Department of Geological Sciences, University of Nevada-Reno, Reno, NV 89557, United States
推荐引用方式 GB/T 7714	Tromboni F.,Dodds W.K.,Chandra S.,et al. Respiration in rivers fractionates stable isotopes of dissolved oxygen; a global investigation on the influences of temperature and flow[J],2020,147(2).
APA	Tromboni F.,Dodds W.K.,Chandra S.,Poulson S.R.,Pandey A.,&Schechner A..(2020).Respiration in rivers fractionates stable isotopes of dissolved oxygen; a global investigation on the influences of temperature and flow.Biogeochemistry,147(2).
MLA	Tromboni F.,et al."Respiration in rivers fractionates stable isotopes of dissolved oxygen; a global investigation on the influences of temperature and flow".Biogeochemistry 147.2(2020).