Manipulating nutrient fluxes within a quantified food web: linking food web structure, ecological stoichiometry and biogeochemical processes

Lead Research Organisation: NERC CEH (Up to 30.11.2019)
Department Name: Acreman

Abstract

Humans have profound effects on the structure and functioning of biological communities, and these are often manifested at the scale of the food web. We propose to manipulate a well characterised quantified food web for which we have highly resolved data, by altering the availability and quality of the food at the base of the web. This complements the data we have already obtained on a 'top-down' manipulation of the same system where we introduced a new top predator. The proposed research will stimulate algal production in the steam by ameliorating light limitation thereby increasing the relative (and absolute) importance of autocthonous pathways in the food web. We will explore a range of responses across multiple levels of biological organisation, from population dynamics of individual species to ecosystem processes and whole stream metabolism. Further we will use these empirical data to inform and develop new theoretical models that link metabolic theory and ecological stoichiometry in food webs.

Publications

10 25 50
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Gilljam D (2011) The Role of Body Size in Multispecies Systems

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Lauridsen R (2012) Consumer-resource elemental imbalances in a nutrient-rich stream in Freshwater Science

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Lauridsen R (2014) Consequences of inferring diet from feeding guilds when estimating and interpreting consumer-resource stoichiometry in Freshwater Biology

 
Description Among the key findings of this project, we found that elemental imbalances between consumers and resources do not necessarily remain constant among taxa and over environmental (nutrient) gradients, and that consumers in particular are more stoichiometrically flexible than had previously been thought. We also found strong evidence for both top-down and bottom-up operating within the food web of this model system - with implications for fisheries management related to the land-use in the riparian zone.
Exploitation Route Our findings will be useful for understanding how management of riparian zones influences fish production
Sectors Environment
 
Description Our data have been used to inform management of riparian vegetation, specifically through the Environment Agency's Keeping Rivers Cool project.
First Year Of Impact 2013
Sector Environment
Impact Types Policy & public services