Simulating rewetting events in intermittent rivers and ephemeral streams: A global analysis of leached nutrients and organic matter
Metadatos
Mostrar el registro completo del ítemEditorial
Wiley
Materia
Biofilms Leaching Leaf litter Temporary rivers
Fecha
2019Referencia bibliográfica
Shumilova, O., Zak, D., Datry, T., von Schiller, D., Corti, R., Foulquier, A., ... & Arce, M. I. (2019). Simulating rewetting events in intermittent rivers and ephemeral streams: A global analysis of leached nutrients and organic matter. Global change biology, 25(5), 1591-1611.
Patrocinador
European Cooperation in Science and Technology, COST Action CA15113 “SMIRES” (Science and Management of Intermittent Rivers and Ephemeral Streams); European Union, Erasmus Mundus Joint Doctorate Programme “SMART” (Science for Management of Rivers and their Tidal Systems); European Union’s Horizon 2020 research and innovation programme, Marie Sklodowska-Curie grant agreement No 748625; Swiss National Science Foundation Grants, grant No PP00P3_179089 and PP00P3_150698; URPP Global Change and Biodiversity, University of Zurich; University of the Basque Country; CONICYT; FONDAP; University of Barcelona; IGB equal opportunity fund for young female scientists; DFG (SU 405/10-1)Resumen
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.