title: A Modelling Framework to Assess the Effect of Pressures on River Abiotic Habitat Conditions and Biota.
abstract: River biota are affected by global reach-scale pressures, but most approaches for predicting biota of rivers focus on river reach or segment scale processes and habitats. Moreover, these approaches do not consider long-term morphological changes that affect habitat conditions. In this study, a modelling framework was further developed and tested to assess the effect of pressures at different spatial scales on reach-scale habitat conditions and biota. Ecohydrological and 1D hydrodynamic models were used to predict discharge and water quality at the catchment scale and the resulting water level at the downstream end of a study reach. Long-term reach morphology was modelled using empirical regime equations, meander migration and 2D morphodynamic models. The respective flow and substrate conditions in the study reach were predicted using a 2D hydrodynamic model, and the suitability of these habitats was assessed with novel habitat models. In addition, dispersal models for fish and macroinvertebrates were developed to assess the re-colonization potential and to finally compare habitat suitability and the availability/ability of species to colonize these habitats. Applicability was tested and model performance was assessed by comparing observed and predicted conditions in the lowland Treene River in northern Germany. Technically, it was possible to link the different models, but future applications would benefit from the development of open source software for all modelling steps to enable fully automated model runs. Future research needs concern the physical modelling of long-term morphodynamics, feedback of biota (e.g., macrophytes) on abiotic habitat conditions, species interactions, and empirical data on the hydraulic habitat suitability and dispersal abilities of macroinvertebrates. The modelling framework is flexible and allows for including additional models and investigating different research and management questions, e.g., in climate impact research as well as river restoration and management.
authors.affiliation: Department of Biology and Ecology of Fishes, Leibniz-Institute for Freshwater Ecology and Inland Fisheries, Berlin, Germany; Department of Aquatic Ecology, University of Duisburg-Essen, Essen, Germany.
authors.forename: Jochem
authors.initials: J
authors.lastname: Kail
authors.affiliation: Department of Hydrology and Water Resources Management, Kiel University, Kiel, Germany.
authors.forename: Björn
authors.initials: B
authors.lastname: Guse
authors.affiliation: Department of Biology and Ecology of Fishes, Leibniz-Institute for Freshwater Ecology and Inland Fisheries, Berlin, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Radinger
authors.affiliation: Department of Aquatic Ecology, University of Duisburg-Essen, Essen, Germany.
authors.forename: Maria
authors.initials: M
authors.lastname: Schröder
authors.affiliation: Department of Biology and Ecology of Fishes, Leibniz-Institute for Freshwater Ecology and Inland Fisheries, Berlin, Germany; Department of Hydrology and Water Resources Management, Kiel University, Kiel, Germany.
authors.forename: Jens
authors.initials: J
authors.lastname: Kiesel
authors.affiliation: Department of Physical Geography, Utrecht University, Utrecht, The Netherlands.
authors.forename: Maarten
authors.initials: M
authors.lastname: Kleinhans
authors.affiliation: Department of Physical Geography, Utrecht University, Utrecht, The Netherlands.
authors.forename: Filip
authors.initials: F
authors.lastname: Schuurman
authors.affiliation: Department of Hydrology and Water Resources Management, Kiel University, Kiel, Germany.
authors.forename: Nicola
authors.initials: N
authors.lastname: Fohrer
authors.affiliation: Department of Aquatic Ecology, University of Duisburg-Essen, Essen, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Hering
authors.affiliation: Department of Biology and Ecology of Fishes, Leibniz-Institute for Freshwater Ecology and Inland Fisheries, Berlin, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Wolter
mesh_terms: D058448:Biota / Q000502:physiology*; D008954:Models, Biological; D045483:Rivers