Dark carbon fixation in stream carbon cycling
Headwater streams are often characterized by turbulence, organic matter inputs from terrestrial systems, net heterotrophy, and the microbial loop supplying carbon and energy for consumers. However, ecological models overlook dark carbon fixation (DCF), the light‐independent inorganic carbon uptake,...
Saved in:
| Published in: | Limnology and oceanography Vol. 69; no. S1; pp. S32 - S41 |
|---|---|
| Main Authors: | , , , , , |
| Format: | Journal Article |
| Language: | English |
| Published: |
Hoboken, USA
John Wiley & Sons, Inc
01.12.2024
|
| ISSN: | 0024-3590, 1939-5590, 1939-5590 |
| Online Access: | Get full text |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | Headwater streams are often characterized by turbulence, organic matter inputs from terrestrial systems, net heterotrophy, and the microbial loop supplying carbon and energy for consumers. However, ecological models overlook dark carbon fixation (DCF), the light‐independent inorganic carbon uptake, mainly based on chemosynthesis, using energy yields from redox reactions. The quantification of microbial biomass production, including DCF, heterotrophic production (HP), gross primary production (GPP), and ecosystem respiration (ER) in lotic aquatic systems, has long yet to be addressed. Here, we investigate HP and DCF in water, sediment, and litter in addition to GPP and ER from streams in pristine rainforests in three distinct sub‐basins of the Amazon River, assessing the variety of turbid, black, and clear waters. We observed mean (min–max) values of microbial biomass production of about 0.1 (0.02–1.2), 3.2 (0.8–14.1), and 0.1 (0.02–0.5) mg C m−2 h−1 in water, sediment, and litter samples, in which DCF : HP showed mean (min–max) values of 0.5 (0.2–2), 0.02 (0.001–0.07), and 0.2 (0.001–0.5). Hence, measurements yielded DCF of similar magnitude as HP in water and litter but significantly lower in sediment, indicating that DCF supplied more carbon to planktonic and litter microbes than in top sediments of streams. Literature comparisons show similar DCF and GPP, both being lower than ER in streams. Finally, we found stream DCF higher than in lentic systems, suggesting that flow and turbulence may accelerate chemosynthesis. |
|---|---|
| Bibliography: | Author Contribution Statement Edited by: Josef Ackerman, Danielle Wain, Rafael Tinoco, Hidekatsu Yamazaki, Mimi Koehl, and Deputy Editors Julia C. Mullarney, Steeve Comeau, and Elisa Schaum Correction added on 30 May 2024, after first online publication: special issue details added. FMS, DB, and AEP designed the study's conception. FMS, DB, MM, RBP, HM, and AEP involved in data acquisition and analysis. FMS drafted the manuscript. FMS, DB, MM, RBP, HM, and AEP revised and approved the final submitted manuscript. Special Issue Life in turbulent waters: exploring unsteady biota‐flow interactions across scales. |
| ISSN: | 0024-3590 1939-5590 1939-5590 |
| DOI: | 10.1002/lno.12430 |