The main focus of the ECHO Lab activities was on drawing together several lines of argument to suggest that an integrated ecohydrological framework, which blends laboratory, field and theoretical evidence focused on hydrologic controls on biota, has contributed substantially to our understanding of the function of river networks as ecological corridors. Such function proves relevant to a number of key ecological and epidemiological processes. Jointly with other determinants, these processes control the spatial ecology of species and biodiversity in the river basin, population dynamics and biological invasions along waterways, and the spread of waterborne and water-related diseases.
ECHO’s main tenet was that ecological processes in the fluvial landscape are constrained by hydrology and geomorphology providing the matrix for ecological interactions (notably, the directional dispersal embedded in fluvial and host/pathogen mobility networks). This requires spatial descriptions that have produced a broad range of results. In brief, the overarching theme of ECHO dealt with investigations on how the physical structure of the environment affects biodiversity, species invasions, survival and extinction, and endemic or epidemic waterborne disease infection spreads. Relations were explored from the perspective of ecosystems produced by fluvial processes and forms, whose origins and features have long been central in ECHO’s interests.
ECHO has pursued interdisciplinary studies on: metapopulation persistence in fluvial ecosystems and metacommunity predictions of fish diversity patterns in large river basins, in collaboration with field biologists (U Maryland, U Cantabria) and theoretical ecologists (Princeton U); the zebra mussel invasion of the Mississippi-Missouri iconic river network, in collaboration with theoretical ecologists (Politecnico di Milano, Princeton U) and ecohydrologists (Princeton U); the spread of proliferative kidney disease in salmonid fish in a Swiss prealpine catchment, a SNF SINERGIA project comprising, field, laboratory and theoretical studies carried out in collaboration with fish biologists and veterinary doctors (U Bern) and molecular biologists (EAWAG); the estimation of species distribution and abundance in river networks using environmental DNA, in collaboration with molecular biologists (EAWAG); laboratory studies on biological invasions of model species (protists, bacteria) within heterogeneous ecological corridors [where heterogeneity is embedded in the network shape (like in studies of invasions of experimental Peano networks), or in the distribution of resources (like in the case of heterogeneous phototaxis of E. gracilis within a led-controlled light field)], carried out in collaboration with experimental ecologists (EAWAG, U Zurich), and experts of microfluidics (ETHZ); field, laboratory and theoretical studies on fluvial network imprintings on microbial co-occurrence networks, in collaboration with stream ecologists (EPFL, Leibniz I Berlin, U Glasgow, U Vienna); field and modelling studies of the spread of schistosomiasis (an endemic macroparasitic WB disease) in Burkina Faso as a result of water resources development, carried out in collaboration with field ecologists (2ie Ouagadougou, Stanford U), epidemiologists (Swiss TPH) and theoretical ecologists (Politecnico di Milano); field, laboratory and theoretical studies on the spread of epidemic cholera in Kwa-Zulu Natal, Haiti, Senegal and South Sudan, in collaboration with environmental microbiologists (EPFL), epidemiologists (PAHO, Harvard U, Johns Hopkins U, Université Assane Seck Ziguinchor, U Montpellier, WHO South Sudan), statistical physicists (U Padova), ecohydrologists (Princeton U) and telecommunication experts tracking human mobility fluxes via mobile phones (Politecnico di Milano).