, Volume 127, Issue 1, pp 125–139 | Cite as

Drought-induced discontinuities in the source and degradation of dissolved organic matter in a Mediterranean river

  • Joan P. Casas-RuizEmail author
  • Jörg Tittel
  • Daniel von Schiller
  • Núria Catalán
  • Biel Obrador
  • Lluís Gómez-Gener
  • Elke Zwirnmann
  • Sergi Sabater
  • Rafael Marcé


The composition of dissolved organic matter (DOM) in rivers results from the different sources and in-stream transformations along the land to ocean aquatic continuum. Riverine DOM sources are highly dependent on the hydrological connection between the river channel and the surrounding terrestrial ecosystems, but how the lack of this connectivity (e.g., during drought episodes) affects the sources and biodegradation of DOM in rivers remains unclear. Here we identified the DOM sources as well as the different DOM pools that are respired along a Mediterranean river during drought by combining absorbance-fluorescence spectroscopy, size-exclusion chromatography, biodegradation assays, and stable and radiocarbon isotopes. DOM composition was highly heterogeneous along the river in response to different sources and in-stream processes in each distinct aquatic environment (i.e., isolated water pools, running waters, and impounded waters in weirs). The reduced hydrological connectivity with terrestrial ecosystems promoted the influence of autochthonous DOM sources. Still, tree leaves from overhanging canopies stood out as an important terrestrial DOM source, especially in sites where water residence time was high such as isolated pools and weirs. Degradation of leaf leachates was a relevant process in these sites, whereas autochthonous DOM and groundwater millennial DOM (>1300 year B.P.) seemed to be degraded in running waters. Overall, our results highlight that the drought-induced hydrological disconnection entails a great spatial heterogeneity in the sources of DOM, which at the same time determines the different DOM pools that are respired in each environment along the river.


Mediterranean rivers Drought Dissolved organic matter Degradation Radiocarbon 



This research was funded by the Spanish Ministry of Economy and Competitiveness through the project CARBONET (CGL2011-30474-C02-01). J. P. Casas-Ruiz and Ll. Gómez-Gener were additionally supported by FPI predoctoral grants (BES-2012-059655 and BES-2012-059743), and D. von Schiller by a “Juan de la Cierva” postdoctoral grant (JCI-2010-06397). N. Catalán held a Wenner-Gren foundation stipend (Sweden). Authors also acknowledge the support from the Economy and Knowledge Department of the Catalan Government through Consolidated Research Group (2014 SGR 291)—Catalan Institute for Water Research. We thank Lorenzo Proia, Yvonne Rosenlöcher, Meritxell Abril, Susanne Halbedel, and Carmen Gutiérrez for lab and field assistance.


  1. Acuña V, Muñoz I, Giorgi A et al (2005) Drought and postdrought recovery cycles in an intermittent Mediterranean stream: structural and functional aspects. J North Am Benthol Soc 24:919–933CrossRefGoogle Scholar
  2. Aitkenhead-Peterson JA, Mcdowell WH, Neff JC (2003) Sources, production, and regulation of allochthonous dissolved organic matter inputs to surface waters. In: Findlay S, Sinsabaugh R (eds) Aquatic ecosystems: interactivity of dissolved organic matter. Academic Press, Elsevier, pp 26–70Google Scholar
  3. Amon RMW, Benner R (1996) Bacterial utilization of different size classes of dissolved organic matter. Limnol Oceanogr 41:41–51CrossRefGoogle Scholar
  4. Balcarczyk KL, Jones JB Jr, Jaffé R, Maie N (2009) Stream dissolved organic matter bioavailability and composition in watersheds underlain with discontinuous permafrost. Biogeochemistry 94:255–270. doi: 10.1007/s10533-009-9324-x CrossRefGoogle Scholar
  5. Battin TJ, Kaplan LA, Findlay S et al (2008) Biophysical controls on organic carbon fluxes in fluvial networks. Nat Geosci 1:95–100. doi: 10.1038/ngeo101 CrossRefGoogle Scholar
  6. Benner R (2003) Molecular indicators of the bioavailability of dissolved organic matter. In: Findlay S, Sinsabaugh R (eds) Aquatic ecosystems: interactivity of dissolved organic matter. Academic Press, Elsevier, pp 121–137CrossRefGoogle Scholar
  7. Bernal S, Schiller D, Sabater F, Martí E (2013) Hydrological extremes modulate nutrient dynamics in mediterranean climate streams across different spatial scales. Hydrobiologia 719:31–42. doi: 10.1007/s10750-012-1246-2 CrossRefGoogle Scholar
  8. Bertilsson S, Jones JB (2003) Supply of dissolved organic matter to aquatic ecosystems: Autochthonous sources. In: Findlay S, Sinsabaugh R (eds) Aquatic ecosystems: interactivity of dissolved organic matter. Academic Press, Elsevier, pp 3–24CrossRefGoogle Scholar
  9. Birdwell JE, Engel AS (2010) Characterization of dissolved organic matter in cave and spring waters using UV–Vis absorbance and fluorescence spectroscopy. Org Geochem 41:270–280. doi: 10.1016/j.orggeochem.2009.11.002 CrossRefGoogle Scholar
  10. Bond NR, Lake PS, Arthington AH (2008) The impacts of drought on freshwater ecosystems: an Australian perspective. Hydrobiologia 600:3–16. doi: 10.1007/s10750-008-9326-z CrossRefGoogle Scholar
  11. Butman D, Raymond P, Oh N-H, Mull K (2007) Quantity, 14C age and lability of desorbed soil organic carbon in fresh water and seawater. Org Geochem 38:1547–1557. doi: 10.1016/j.orggeochem.2007.05.011 CrossRefGoogle Scholar
  12. Butman D, Raymond PA, Butler K, Aiken G (2012) Relationships between Δ14C and the molecular quality of dissolved organic carbon in rivers draining to the coast from the conterminous United States. Global Biogeochem Cycles. doi: 10.1029/2012GB004361 Google Scholar
  13. Caraco N, Bauer JE, Cole JJ et al (2010) Millennial-aged organic carbon subsidies to a modern river food web. Ecology 91:2385–2393. doi: 10.1890/09-0330.1 CrossRefGoogle Scholar
  14. Cardoso SJ, Vidal LO, Mendonça RF et al (2013) Spatial variation of sediment mineralization supports differential CO2 emissions from a tropical hydroelectric reservoir. Front Microbiol 4:101. doi: 10.3389/fmicb.2013.00101 CrossRefGoogle Scholar
  15. Coble PG (1996) Characterization of marine and terrestrial DOM in seawater using excitation-emission matrix spectroscopy. Mar Chem 51:325–346CrossRefGoogle Scholar
  16. Cole JJ, Caraco NF (2001) Carbon in catchments: connecting terrestrial carbon losses with aquatic metabolism. Mar Freshw Res 52:101–110CrossRefGoogle Scholar
  17. Cole JJ, Prairie YT, Caraco NF et al (2007) Plumbing the global carbon cycle: integrating inland waters into the terrestrial carbon budget. Ecosystems 10:172–185. doi: 10.1007/s10021-006-9013-8 CrossRefGoogle Scholar
  18. Dahm CN, Baker MA, Moore DI, Thibault JR (2003) Coupled biogeochemical and hydrological responses of streams and rivers to drought. Freshw Biol 48:1219–1231. doi: 10.1046/j.1365-2427.2003.01082.x CrossRefGoogle Scholar
  19. del Giorgio PA, Davis J (2003) Patterns in dissolved organic matter lability and consumption across aquatic ecosystems. In: Findlay S, Sinsabaugh RL (eds) Aquatic ecosystems interactivity dissolved organic matter. Academic Press, Elsevier, pp 400–424Google Scholar
  20. Döll P, Fiedler K, Zhang J (2009) Global-scale analysis of river flow alterations due to water withdrawals and reservoirs. Hydrol Earth Syst Sci 13:2413–2432. doi: 10.5194/hess-13-2413-2009 CrossRefGoogle Scholar
  21. Duarte CM, Prairie YT (2005) Prevalence of heterotrophy and atmospheric CO2 emissions from aquatic ecosystems. Ecosystems 8:862–870. doi: 10.1007/s10021-005-0177-4 CrossRefGoogle Scholar
  22. Fellman JB, Hood E, Edwards RT, D’Amore DV (2009) Changes in the concentration, biodegradability, and fluorescent properties of dissolved organic matter during stormflows in coastal temperate watersheds. J Geophys Res 114:G01021. doi: 10.1029/2008JG000790 Google Scholar
  23. Fellman JB, Hood E, Spencer RGM (2010) Fluorescence spectroscopy opens new windows into dissolved organic matter dynamics in freshwater ecosystems: a review. Limnol Oceanogr 55:2452–2462. doi: 10.4319/lo.2010.55.6.2452 CrossRefGoogle Scholar
  24. Fellman JB, Dogramaci S, Skrzypek G et al (2011) Hydrologic control of dissolved organic matter biogeochemistry in pools of a subtropical dryland river. Water Resour Res. doi: 10.1029/2010WR010275 Google Scholar
  25. Fellman JB, Spencer RGM, Raymond PA et al (2014) Dissolved organic carbon biolability decreases along with its modernization in fluvial networks in an ancient landscape. Ecology 95:2622–2632CrossRefGoogle Scholar
  26. Fellman JB, Hood E, Raymond PA et al (2015) Evidence for the assimilation of ancient glacier organic carbon in a proglacial stream food web. Limnol Oceanogr 60:1118–1128. doi: 10.1002/lno.10088 CrossRefGoogle Scholar
  27. Francis C, Sheldon F (2002) River Red Gum (Eucalyptus camaldulensis Dehnh.) organic matter as a carbon source in the lower Darling River. Australia. Hydrobiologia 481:113–124CrossRefGoogle Scholar
  28. Gasith A, Resh VH (1999) Streams in Mediterranean climate regions: abiotic influences and biotic responses to predictable seasonal events. Annu Rev Ecol Syst 30:51–81. doi: 10.1146/annurev.ecolsys.30.1.51 CrossRefGoogle Scholar
  29. Green SA, Blough NV (1994) Optical absorption and fluorescence properties of chromophoric dissolved organic matter in natural waters. Limnol Oceanogr 39:1903–1916CrossRefGoogle Scholar
  30. Guillemette F, del Giorgio PA (2011) Reconstructing the various facets of dissolved organic carbon bioavailability in freshwater ecosystems. Limnol Oceanogr 56:734–748. doi: 10.4319/lo.2011.56.2.0734 CrossRefGoogle Scholar
  31. Her N, Amy G, Foss D et al (2002) Optimization of method for detecting and characterizing NOM by HPLC-size exclusion chromatography with UV and on-line DOC detection. Environ Sci Technol 36:1069–1076. doi: 10.1021/es015505j CrossRefGoogle Scholar
  32. Hornberger GM, Kelly MG (1975) Atmospheric reaeration in a river using productivity analysis. J Environ Eng Div 101:729–737Google Scholar
  33. Huguet A, Vacher L, Relexans S et al (2009) Properties of fluorescent dissolved organic matter in the Gironde Estuary. Org Geochem 40:706–719. doi: 10.1016/j.orggeochem.2009.03.002 CrossRefGoogle Scholar
  34. Korak JA, Dotson AD, Summers RS, Rosario-Ortiz FL (2014) Critical analysis of commonly used fluorescence metrics to characterize dissolved organic matter. Water Res 49:327–338. doi: 10.1016/j.watres.2013.11.025 CrossRefGoogle Scholar
  35. Kothawala DN, Murphy KR, Stedmon CA et al (2013) Inner filter correction of dissolved organic matter fluorescence. Limnol Oceanogr Methods 11:616–630. doi: 10.4319/lom.2013.11.616 CrossRefGoogle Scholar
  36. Lake PS (2003) Ecological effects of perturbation by drought in flowing waters. Freshw Biol 48:1161–1172. doi: 10.1046/j.1365-2427.2003.01086.x CrossRefGoogle Scholar
  37. Lakowicz JR (2006) Principles of fluorescence spectroscopy. Springer, New YorkCrossRefGoogle Scholar
  38. Lawaetz AJ, Stedmon CA (2009) Fluorescence intensity calibration using the Raman scatter peak of water. Appl Spectrosc 63:936–940CrossRefGoogle Scholar
  39. Lewis W, Wallace D (1998) Program Developed for CO2 System Calculations. ORNL/CDIAC-105Google Scholar
  40. McArthur MD, Richardson JS (2002) Microbial utilization of dissolved organic carbon leached from riparian litterfall. Can J Fish Aquat Sci 59:1668–1676. doi: 10.1139/f02-135 CrossRefGoogle Scholar
  41. McCallister SL, Del Giorgio PA (2012) Evidence for the respiration of ancient terrestrial organic C in northern temperate lakes and streams. Proc Natl Acad Sci U S A 109:16963–16968. doi: 10.1073/pnas.1207305109 CrossRefGoogle Scholar
  42. Meyer JL, Wallace JB, Eggert SL (1998) Leaf litter as a source of dissolved organic carbon in streams. Ecosystems 1:240–249CrossRefGoogle Scholar
  43. Mosley LM (2015) Drought impacts on the water quality of freshwater systems; review and integration. Earth Sci Rev 140:203–214. doi: 10.1016/j.earscirev.2014.11.010 CrossRefGoogle Scholar
  44. Neal C, Neal M, Warrington A et al (1992) Stable hydrogen and oxygen isotope studies of rainfall and streamwaters for two contrasting holm oak areas of Catalonia, northeastern Spain. J Hydrol 140:163–178. doi: 10.1016/0022-1694(92)90239-R CrossRefGoogle Scholar
  45. Neff JC, Finlay JC, Zimov SA et al (2006) Seasonal changes in the age and structure of dissolved organic carbon in Siberian rivers and streams. Geophys Res Lett 33:L23401. doi: 10.1029/2006GL028222 CrossRefGoogle Scholar
  46. Parlanti E, Wörz K, Geoffroy L, Lamotte M (2000) Dissolved organic matter fluorescence spectroscopy as a tool to estimate biological activity in a coastal zone submitted to anthropogenic inputs. Org Geochem 31:1765–1781. doi: 10.1016/S0146-6380(00)00124-8 CrossRefGoogle Scholar
  47. R Core Team (2015) R: a language and environment for statistical computing. R Foundation for Statistical Computing, ViennaGoogle Scholar
  48. Raymond PA, Bauer JE (2001) Riverine export of aged terrestrial organic matter to the North Atlantic Ocean. Nature 409:497–500CrossRefGoogle Scholar
  49. Romaní AM, Vázquez E, Butturini A (2006) Microbial availability and size fractionation of dissolved organic carbon after drought in an intermittent stream: biogeochemical link across the Stream-Riparian interface. Microb Ecol 52:501–512. doi: 10.2307/25153403 CrossRefGoogle Scholar
  50. Sabater S, Tockner K (2010) Effects of hydrologic alterations on the ecological quality of river ecosystems. In: Sabater S, Barceló D (eds) Water scarcity Mediterr. Springer, Berlin, pp 15–39CrossRefGoogle Scholar
  51. Sachse A, Henrion R, Gelbrecht J, Steinberg CEW (2005) Classification of dissolved organic carbon (DOC) in river systems: influence of catchment characteristics and autochthonous processes. Org Geochem 36:923–935. doi: 10.1016/j.orggeochem.2004.12.008 CrossRefGoogle Scholar
  52. Siebers AR, Pettit NE, Skrzypek G et al (2015) Alluvial ground water influences dissolved organic matter biogeochemistry of pools within intermittent dryland streams. Freshw Biol. doi: 10.1111/fwb.12656 Google Scholar
  53. Šimek K, Comerma M, García J-C et al (2010) The Effect of River water circulation on the distribution and functioning of reservoir microbial communities as determined by a relative distance approach. Ecosystems 14:1–14. doi: 10.1007/s10021-010-9388-4 Google Scholar
  54. Singer GA, Fasching C, Wilhelm L et al (2012) Biogeochemically diverse organic matter in Alpine glaciers and its downstream fate. Nat Geosci 5:710–714CrossRefGoogle Scholar
  55. Sinsabaugh RL, Foreman CM (2003) Integrating dissolved organic matter metabolism and microbial diversity: an overview of conceptual models. In: Findlay S, Sinsabaugh RL (eds) Aquatic ecosystems interactivity dissolved organic matter. Elsevier, Academic Press, pp 426–454Google Scholar
  56. Stuiver M, Polach HA (1977) Discussion: reporting of 14C data. Radiocarbon 19:355–363Google Scholar
  57. Tittel J, Büttner O, Freier K et al (2013) The age of terrestrial carbon export and rainfall intensity in a temperate river headwater system. Biogeochemistry 115:53–63CrossRefGoogle Scholar
  58. Trumbore S, Schiff S (1992) Sources and transformation of dissolved organic carbon in the Harp Lake forested catchment: the role of soils. Radiocarbon 34:626–635Google Scholar
  59. Vazquez E, Amalfitano S, Fazi S, Butturini A (2011) Dissolved organic matter composition in a fragmented Mediterranean fluvial system under severe drought conditions. Biogeochemistry 102:59–72. doi: 10.1007/s10533-010-9421-x CrossRefGoogle Scholar
  60. Vazquez E, Ejarque E, Ylla I et al (2015) Impact of drying/rewetting cycles on the bioavailability of dissolved organic matter molecular-weight fractions in a Mediterranean stream. Freshw Sci 34:263–275. doi: 10.1086/679616 CrossRefGoogle Scholar
  61. Volk CJ, Volk CB, Kaplan LA (1997) Chemical composition of biodegradable dissolved organic matter in streamwater. Limnol Oceanogr 42:39–44CrossRefGoogle Scholar
  62. von Schiller D, Acuña V, Graeber D et al (2011) Contraction, fragmentation and expansion dynamics determine nutrient availability in a Mediterranean forest stream. Aquat Sci 73:485–497. doi: 10.1007/s00027-011-0195-6 CrossRefGoogle Scholar
  63. von Schiller D, Graeber D, Ribot M et al (2015) Hydrological transitions drive dissolved organic matter quantity and composition in a temporary Mediterranean stream. Biogeochemistry 123:429–446. doi: 10.1007/s10533-015-0077-4 CrossRefGoogle Scholar
  64. Weishaar JL, Aiken GR, Bergamaschi BA et al (2003) Evaluation of specific ultraviolet absorbance as an indicator of the chemical composition and reactivity of dissolved organic carbon. Environ Sci Technol 37:4702–4708. doi: 10.1021/es030360x CrossRefGoogle Scholar
  65. Wetzel RG (1983) Limnology, second edition. SaundersGoogle Scholar
  66. Ylla I, Sanpera-Calbet I, Muñoz I et al (2011) Organic matter characteristics in a Mediterranean stream through amino acid composition: changes driven by intermittency. Aquat Sci 73:523–535. doi: 10.1007/s00027-011-0211-x CrossRefGoogle Scholar
  67. Zhang J, Quay PD, Wilbur DO (1995) Carbon isotope fractionation during gas-water exchange and dissolution of CO2. Geochim Cosmochim Acta 59:107–114. doi: 10.1016/0016-7037(95)91550-D CrossRefGoogle Scholar
  68. Zhang X, Marcé R, Armengol J, Tauler R (2014) Distribution of dissolved organic matter in freshwaters using excitation emission fluorescence and multivariate curve resolution. Chemosphere 111:120–128CrossRefGoogle Scholar
  69. Zsolnay A, Baigar E, Jimenez M et al (1999) Differentiating with fluorescence spectroscopy the sources of dissolved organic matter in soils subjected to drying. Chemosphere 38:45–50. doi: 10.1016/S0045-6535(98)00166-0 CrossRefGoogle Scholar

Copyright information

© Springer International Publishing Switzerland 2015

Authors and Affiliations

  • Joan P. Casas-Ruiz
    • 1
    Email author
  • Jörg Tittel
    • 2
  • Daniel von Schiller
    • 3
  • Núria Catalán
    • 4
  • Biel Obrador
    • 5
  • Lluís Gómez-Gener
    • 5
  • Elke Zwirnmann
    • 6
  • Sergi Sabater
    • 1
    • 7
  • Rafael Marcé
    • 1
  1. 1.Catalan Institute for Water Research (ICRA)GironaSpain
  2. 2.Department Lake ResearchUFZ Helmholtz Centre for Environmental ResearchMagdeburgGermany
  3. 3.Department of Plant Biology and Ecology, Faculty of Science and TechnologyUniversity of the Basque CountryBilbaoSpain
  4. 4.Department of Ecology and Genetics/Limnology, Evolutionary Biology CentreUppsala UniversityUppsalaSweden
  5. 5.Department of EcologyUniversity of BarcelonaBarcelonaSpain
  6. 6.Leibniz-Institute of Freshwater Ecology and Inland FisheriesBerlinGermany
  7. 7.Institute of Aquatic EcologyUniversity of GironaGironaSpain

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