A global analysis of terrestrial plant litter dynamics in non-perennial waterways

• Published in: Nature geoscience Vol. 11; no. 7; pp. 497 - 503
• Main Authors: Datry, T., Foulquier, A., Corti, R., von Schiller, D., Tockner, K., Mendoza-Lera, C., Clément, J. C., Gessner, M. O., Moleón, M., Stubbington, R., Gücker, B., Albariño, R., Allen, D. C., Altermatt, F., Arce, M. I., Arnon, S., Banas, D., Banegas-Medina, A., Beller, E., Blanchette, M. L., Blanco-Libreros, J. F., Blessing, J. J., Boëchat, I. G., Boersma, K. S., Bogan, M. T., Bonada, N., Bond, N. R., Brintrup Barría, K. C., Bruder, A., Burrows, R. M., Cancellario, T., Canhoto, C., Carlson, S. M., Cauvy-Fraunié, S., Cid, N., Danger, M., de Freitas Terra, Bianca, De Girolamo, A. M, de La Barra, Evans, del Campo, R., Diaz-Villanueva, V. D., Dyer, F., Elosegi, A., Faye, E., Febria, C., Four, B., Gafny, S., Ghate, S. D., Gómez, R., Gómez-Gener, L., Graça, M. A. S., Guareschi, S., Hoppeler, F., Hwan, J. L., Jones, J. I., Kubheka, S., Laini, A., Langhans, S. D., Leigh, C., Little, C. J., Lorenz, S., Marshall, J. C., Martín, E., McIntosh, A. R., Meyer, E. I., Miliša, M., Mlambo, M. C., Morais, M., Moya, N., Negus, P. M., Niyogi, D. K., Papatheodoulou, A., Pardo, I., Pařil, P., Pauls, S. U., Pešić, V., Polášek, M., Robinson, C. T., Rodríguez-Lozano, P., Rolls, R. J., Sánchez-Montoya, M. M., Savić, A., Shumilova, O., Sridhar, K. R., Steward, A. L., Storey, R., Taleb, A., Uzan, A., Vander Vorste, Ross, Waltham, N. J., Woelfle-Erskine, C., Zak, D., Zarfl, C., Zoppini, A.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01-07-2018; Nature Publishing Group
• Subjects: 704/106/242; 704/158/2445; 704/47/4113; Aridity; Carbon cycle; Carbon dioxide; Carbon dioxide emissions; Continental interfaces, environment; Creeks & streams; Cycles; Decomposition; Duration; Dynamics; Earth and Environmental Science; Earth Sciences; Earth System Sciences; Emission; Environmental gradient; Environmental Sciences; Ephemeral streams; Geochemistry; Geology; Geophysics/Geodesy; Global Changes; Intermittent rivers; Litter; Microorganisms; Oxygen; Oxygen consumption; Perennial streams; Riparian vegetation; River networks; Rivers; Sciences of the Universe; Streams; Temperate climates; Waterways; changement climatique; C cycle; cours d'eau; riparian vegetation; végétation ripicole; temporary rivers; CO2 emissions; global change; litière végétale; zone climatique; cycle du carbon; river ecosystem functioning
• ISSN: 1752-0894; 1752-0908; 1752-0908
• DOI: 10.1038/s41561-018-0134-4

Perennial rivers and streams make a disproportionate contribution to global carbon (C) cycling. However, the contribution of intermittent rivers and ephemeral streams (IRES), which sometimes cease to flow and can dry completely, is largely ignored although they represent over half the global river network. Substantial amounts of terrestrial plant litter (TPL) accumulate in dry riverbeds and, upon rewetting, this material can undergo rapid microbial processing. We present the results of a global research collaboration that collected and analysed TPL from 212 dry riverbeds across major environmental gradients and climate zones. We assessed litter decomposability by quantifying the litter carbon-to-nitrogen ratio and oxygen (O
2
) consumption in standardized assays and estimated the potential short-term CO
2
emissions during rewetting events. Aridity, cover of riparian vegetation, channel width and dry-phase duration explained most variability in the quantity and decomposability of plant litter in IRES. Our estimates indicate that a single pulse of CO
2
emission upon litter rewetting contributes up to 10% of the daily CO
2
emission from perennial rivers and stream, particularly in temperate climates. This indicates that the contributions of IRES should be included in global C-cycling assessments.
Rewetting of plant litter accumulated in dry riverbeds releases pulses of CO
2
, reveals a global analysis of intermittent rivers and ephemeral streams.