Climate change and human pressures are changing the global distribution and the extent of intermittent rivers and ephemeral streams (IRES), which comprise half of the global river network area. IRES are characterized by periods of flow cessation, during which channel substrates accumulate and undergo physico-chemical changes (preconditioning), and periods of flow resumption, when these substrates are rewetted and release pulses of dissolved nutrients and organic matter (OM). However, there are no estimates of the amounts and quality of leached substances, nor is there information on the underlying environmental constraints operating at the global scale. We experimentally simulated, under standard laboratory conditions, rewetting of leaves, riverbed sediments, and epilithic biofilms collected during the dry phase across 205 IRES from five major climate zones. We determined the amounts and qualitative characteristics of the leached nutrients and OM, and estimated their areal fluxes from riverbeds. In addition, we evaluated the variance in leachate characteristics in relation to selected environmental variables and substrate characteristics. We found that sediments, due to their large quantities within riverbeds, contribute most to the overall flux of dissolved substances during rewetting events (56%-98%), and that flux rates distinctly differ among climate zones. Dissolved organic carbon, phenolics, and nitrate contributed most to the areal fluxes. The largest amounts of leached substances were found in the continental climate zone, coinciding with the lowest potential bioavailability of the leached OM. The opposite pattern was found in the arid zone. Environmental variables expected to be modified under climate change (i.e. potential evapotranspiration, aridity, dry period duration, land use) were correlated with the amount of leached substances, with the strongest relationship found for sediments. These results show that the role of IRES should be accounted for in global biogeochemical cycles, especially because prevalence of IRES will increase due to increasing severity of drying events.
1.Leibniz Inst Freshwater Ecol & Inland Fisheries I, Berlin, Germany 2.Freie Univ Berlin FU, Inst Biol, Berlin, Germany 3.Trento Univ, Dept Civil Environm & Mech Engn, Trento, Italy 4.Univ Rostock, Inst Landscape Ecol & Site Evaluat, Rostock, Germany 5.Aarhus Univ, Dept Biosci, Silkeborg, Denmark 6.Ctr Lyon Villeurbanne, UR RIVERLY, IRSTEA, Villeurbanne, France 7.Univ Basque Country UPV EHU, Dept Plant Biol & Ecol, Fac Sci & Technol, Bilbao, Spain 8.Univ Grenoble Alpes, Lab Ecol Alpine LECA, UMR CNRS UGA USMB 5553, Grenoble, France 9.Univ Barcelona, Dept Evolutionary Biol Ecol & Environm Sci, Fac Biol, Biodivers Res Inst IRBIO, Barcelona, Spain 10.Austrian Sci Fund FWF, Vienna, Austria 11.Univ Oklahoma, Dept Biol, Norman, OK 73019 USA 12.Univ Zurich, Dept Evolutionary Biol & Environm Studies, Zurich, Switzerland 13.CSIC, CEBAS, Murcia, Spain 14.Ben Gurion Univ Negev, Zuckerberg Inst Water Res, Jacob Blaustein Inst Desert Res, Beer Sheva, Israel 15.Univ Lorraine, UR AFPA, Vandoeuvre Les Nancy, France 16.Univ Concepcion, Fac Environm Sci, Concepcion, Chile 17.Univ Concepcion, EULA Chile Ctr, Concepcion, Chile 18.Univ Calif Berkeley, Dept Geog, Berkeley, CA 94720 USA 19.Edith Cowan Univ, Mine Water & Environm Res Ctr MiWER, Sch Sci, Perth, WA, Australia 20.Univ Antioquia, Inst Biol ELICE RESTORES, Medellin, Colombia 21.Queensland Govt, Dept Environm & Sci, Brisbane, Qld, Australia 22.Univ Fed Sao Joao del Rei, Dept Geosci, Sao Joao Del Rei, Brazil 23.Univ San Diego, Dept Biol, San Diego, CA 92110 USA 24.Univ Arizona, Sch Nat Resources & Environm, Tucson, AZ USA 25.Univ Barcelona, Grp Recerca Freshwater Ecol Hydrol & Management F, Dept Biol Evolut Ecol & Ciencies Ambientals, Inst Recerca Biodiversitat IRBio, Barcelona, Spain 26.La Trobe Univ, Ctr Freshwater Ecosyst, Wodonga, Vic, Australia 27.Univ Appl Sci & Arts Southern Switzerland, Lab Appl Microbiol, Bellinzona, Switzerland 28.Griffith Univ, Australian Rivers Inst, Nathan, Qld, Australia 29.Univ Navarra, Biodivers Data Analyt & Environm Qual Grp, Dept Environm Biol, Pamplona, Spain 30.Univ Calif Berkeley, Dept Environm Sci Policy & Management, Berkeley, CA 94720 USA 31.Univ Lorraine, LIEC, Metz, France 32.Univ Estadual Vale Acarau, Ctr Ciencias Agr & Biol, Sobral, Brazil 33.Natl Res Council IRSA CNR, Water Res Inst, Rome, Italy 34.Univ Murcia, Dept Ecol & Hydrol, Reg Campus Int Excellence Campus Mare Nostrum, Murcia, Spain 35.Univ Canberra, Inst Appl Ecol, Canberra, ACT, Australia 36.CIRAD, UPR HortSys, Montpellier, France 37.Univ Canterbury, Sch Biol Sci, Christchurch, New Zealand 38.Univ Windsor, Great Lakes Inst Environm Res, Windsor, ON, Canada 39.Ctr Rech Nancy, INRA, UAR 1275 DEPT EFPA, Champenoux, France 40.TU Berlin, Berlin Inst Technol, Dept Ecol, Berlin, Germany 41.Univ Parakou, Fac Agron, Dept Amenagement & Gest Ressources Nat, Parakou, Benin 42.Umea Univ, Dept Ecol & Environm Sci, Umea, Sweden 43.Univ Coimbra, MARE Marine & Environm Sci Ctr, Dept Life Sci, Coimbra, Portugal 44.Ezemvelo KZN Wildlife, Pietermaritzburg, South Africa 45.Univ Otago, Dept Zool, Dunedin, New Zealand 46.BC3, Leioa, Spain 47.Queensland Univ Technol, ARC Ctr Excellence Math & Stat Frontiers ACEMS, Brisbane, Qld, Australia 48.Queensland Univ Technol, Inst Future Environm, Sch Math Sci, Brisbane, Qld, Australia 49.Eawag, Dept Aquat Ecol, Swiss Fed Inst Aquat Sci & Technol, Dubendorf, Switzerland 50.Julius Kuehn Inst, Inst Ecol Chem Plant Anal & Stored Prod Protect, Berlin, Germany 51.BTU Cottbus Senftenberg, Dept Freshwater Conservat, Bad Saarow Pieskow, Germany 52.Univ Munster, Inst Evolut & Biodivers, Dept Limnol, Munster, Germany 53.Univ Zagreb, Fac Sci, Dept Biol, Zagreb, Croatia 54.Rhodes Univ, Albany Museum, Affiliated Res Inst, Dept Freshwater Invertebrates, Grahamstown, South Africa 55.Univ Granada, Dept Zool, Granada, Spain 56.Missouri Univ Sci & Technol, Rolla, MO USA 57.Terra Cypria Cyprus Conservat Fdn, Limassol, Cyprus 58.Univ Vigo, Dept Ecol & Biol Anim, Vigo, Spain 59.Masaryk Univ, Dept Bot & Zool, Fac Sci, Brno, Czech Republic 60.Univ Montenegro, Dept Biol, Podgorica, Montenegro 61.Univ New England, Sch Environm & Rural Sci, Armidale, NSW, Australia 62.Univ Nis, Dept Biol & Ecol, Fac Sci & Math, Nish, Serbia 63.Nottingham Trent Univ, Sch Sci & Technol, Nottingham, England 64.Univ Tlemcen, Lab Ecol & Gest Ecosyst Nat LECGEN, Tilimsen, Algeria 65.James Cook Univ, TropWATER Ctr Trop Water & Aquat Ecosyst Res, Coll Sci & Engn, Townsville, Qld, Australia 66.Eberhard Karls Univ Tubingen, Ctr Appl Geosci, Tubingen, Germany
Recommended Citation:
Shumilova, Oleksandra,Zak, Dominik,Datry, Thibault,et al. Simulating rewetting events in intermittent rivers and ephemeral streams: A global analysis of leached nutrients and organic matter[J]. GLOBAL CHANGE BIOLOGY,2019-01-01,25(5):1591-1611