Guelph-McGill Collaboration: Agriculture, Dendritic Networks and Biodiversity Resilience

June 22, 2021

Brought together from the 86 million dollar Food from Thought grant, a team of ecological and evolutionary researchers from the University of Guelph and McGill are experimentally and theoretically looking at how transport of nutrients and contaminants through dendritic stream/river networks impact aquatic biodiversity. In a growing world with ever increasing food demands the need to develop sustainable agriculture on and off the field is becoming increasingly necessary. 

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The research includes two highly controlled indoor experimental facilities funded by NSERC. At Guelph, researchers led by John Fryxell, Kevin McCann and Andrew MacDougall are using massive beer vat sized tanks [called Limnotrons] that allow highly controlled algae-zooplakton experiments. McGill houses the outdoor equivalent of the Limnotron (called LEAP) allowing a less controlled but more realist counterpart to the Limnotron. Further, the many mini ponds of LEAP allow the researcher to create spatial configurations that can mimic simple dendritic networks.  The team of researchers from McGill includes evolutionary biologists Melanic Cristescu, Graham Bell and biodiversity researchers Gregor Fussmann and Andrew Gonzalez.

Besides a strong experimental contingent, the team also has strong theoretical researchers [McCann, Fryxell, Fussman, Bell and Gonzalez] who have several areas of research unfolding around this. One, the McGill team has worked heavily on what has been referred to as evolutionary rescue.  Evolutionary rescue is a process by which a population -- that would have gone extinct in the absence of evolution -- persists due to natural selection acting under the imposed global condition (here agricultural homogenization and eutrophication of the aquatic landscape). The Guelph team on the other hand has led collaborative theory that suggests this same agricultural homogenization in a dendritic networks leads to the distant accumulation of nutrients that fuels dead zones and ecosystem collapse at distances greatly separated from the nutrient application. Further, this work suggests that slowing down key aspects of the river network can operate enormously to dissipate the downstream nutrient accumulation [see McCann, 2021 Ecology Letters].