Continental-Scale Effects of Nutrient Pollution on Stream Ecosystem Functioning

Guy Woodward (1, 2) , Mark O. Gessner (3, 4, 5, 6) , Paul S. Giller (1) , Vladislav Gulis (7) , Sally Hladyz (1) , Antoine Lecerf (8) , Björn Malmqvist (9) , Brendan G. Mckie (9) , Scott D. Tiegs (3, 4, 10) , Helen Cariss (11) , Mike Dobson (11) , Arturo Elosegi (12) , Veronica Ferreira (7) , Manuel A. S. Graça (7) , Tadeusz Fleituch (13) , Jean O. Lacoursiere (14) , Marius Nistorescu (15) , Jesús Pozo (12) , Geta Risnoveanu (15) , Markus Schindler (3, 4) , Angheluta Vadineanu (15) , Lena B.-M. Vought (14) , Eric Chauvet (8)

1 UCC - University College Cork
2 QMUL - Queen Mary University of London
3 EAWAG - Swiss Federal Insitute of Aquatic Science and Technology [Dübendorf]
4 ETH Zürich - Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich]
5 IGB - Leibniz-Institut für Gewässerökologie und Binnenfischerei
6 TU - Technical University of Berlin / Technische Universität Berlin
7 Universidade de Coimbra [Coimbra]
8 LEFE - Laboratoire Ecologie Fonctionnelle et Environnement
9 Umeå University
10 Oakland University
11 MMU - Manchester Metropolitan University
12 UPV/EHU - Universidad del Pais Vasco / Euskal Herriko Unibertsitatea [Espagne]
13 PAN - Polska Akademia Nauk = Polish Academy of Sciences = Académie polonaise des sciences
14 Kristianstad University College - HKR (SWEDEN)
15 UniBuc - University of Bucharest

Excessive nutrient loading is a major threat to aquatic ecosystems worldwide that leads to profound changes in aquatic biodiversity and biogeochemical processes. Systematic quantitative assessment of functional ecosystem measures for river networks is, however, lacking, especially at continental scales. Here, we narrow this gap by means of a pan-European field experiment on a fundamental ecosystem process--leaf-litter breakdown--in 100 streams across a greater than 1000-fold nutrient gradient. Dramatically slowed breakdown at both extremes of the gradient indicated strong nutrient limitation in unaffected systems, potential for strong stimulation in moderately altered systems, and inhibition in highly polluted streams. This large-scale response pattern emphasizes the need to complement established structural approaches (such as water chemistry, hydrogeomorphology, and biological diversity metrics) with functional measures (such as litter-breakdown rate, whole-system metabolism, and nutrient spiraling) for assessing ecosystem health.

Mots clés: Aquatic biodiversity; Biogeochemical processes; Aquatic ecosystem

Domaines: Biodiversité et Ecologie

Guy Woodward, Mark O. Gessner, Paul S. Giller, Vladislav Gulis, Sally Hladyz, et al.. Continental-Scale Effects of Nutrient Pollution on Stream Ecosystem Functioning. Science Magazine, 2012, vol. 336, pp. 1438-1440. ⟨10.1126/science.1219534⟩. ⟨hal-00958434⟩