Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1016/j.watres.2021.116887
Licence creative commons licence
Title (Primary) Emergent spatial patterns of competing benthic and pelagic algae in a river network: A parsimonious basin-scale modeling analysis
Author Yang, S.; Bertuzzo, E.; Büttner, O.; Borchardt, D.; Rao, P.S.C.
Source Titel Water Research
Year 2021
Department ASAM
Volume 193
Page From art. 116887
Language englisch
Topic T5 Future Landscapes
Keywords Eutrophication; Regime shifts; Hortonian scaling; Spatial autocorrelation
Abstract Algae, as primary producers in riverine ecosystems, are found in two distinct habitats: benthic and pelagic algae typically prevalent in shallow/small and deep/large streams, respectively. Over an entire river continuum, spatiotemporal patterns of the two algal communities reflect specificity in habitat preference determined by geomorphic structure, hydroclimatic controls, and spatiotemporal heterogeneity in nutrient loads from point- and diffuse-sources. By representing these complex interactions between geomorphic, hydrologic, geochemical, and ecological processes, we present here a new river-network-scale dynamic model (CnANDY) for pelagic (A) and benthic (B) algae competing for energy and one limiting nutrient (phosphorus, P). We used the urbanized Weser River Basin in Germany (7th-order; ∼8.4 million population; ∼46K km2) as a case study and analyzed simulations for equilibrium mass and concentrations under steady median river discharge. We also examined P, A, and B spatial patterns in four sub-basins. We found an emerging pattern characterized by scaling of P and A concentrations over stream-order ω, whereas B concentration was described by three distinct phases. Furthermore, an abrupt algal regime shift occurred in intermediate streams from B dominance in ω≤3 to exclusive A presence in ω≥6. Modeled and long-term basin-scale monitored dissolved P concentrations matched well for ω>4, and with overlapping ranges in ω<3. Power-spectral analyses for the equilibrium P, A, and B mass distributions along hydrological flow paths showed stronger clustering compared to geomorphological attributes, and longer spatial autocorrelation distance for A compared to B. We discuss the implications of our findings for advancing hydro-ecological concepts, guiding monitoring, informing management of water quality, restoring aquatic habitat, and extending CnANDY model to other river basins.
Persistent UFZ Identifier
Yang, S., Bertuzzo, E., Büttner, O., Borchardt, D., Rao, P.S.C. (2021):
Emergent spatial patterns of competing benthic and pelagic algae in a river network: A parsimonious basin-scale modeling analysis
Water Res. 193 , art. 116887 10.1016/j.watres.2021.116887