Ontogenetic asymmetry modulates population biomass production and response to harvest.

Birte Reichstein,Lennart Persson,André M De Roos

doi:10.1038/ncomms7441

Birte Reichstein, Lennart Persson + Show 1 more

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https://doi.org/10.1038/ncomms7441

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Journal: Nature Communications	Publication Date: Mar 4, 2015
Citations: 18	License type: CC BY 4.0

Affiliation: Umeå University, University of Amsterdam

Abstract

Patterns in biomass production are determined by resource input (productivity) and trophic transfer efficiency. At fixed resource input, variation in consumer biomass production has been related to food quality, metabolic type and diversity among species. In contrast, intraspecific variation in individual body size because of ontogenetic development, which characterizes the overwhelming majority of taxa, has been largely neglected. Here we show experimentally in a long-term multigenerational study that reallocating constant resource input in a two-stage consumer system from an equal resource delivery to juveniles and adults to an adult-biased resource delivery is sufficient to cause more than a doubling of total consumer biomass. We discuss how such changes in consumer stage-specific resource allocation affect the likelihood for alternative stable states in harvested populations as a consequence of stage-specific overcompensation in consumer biomass and thereby the risk of catastrophic collapses in exploited populations.

Highlights

Patterns in biomass production are determined by resource input and trophic transfer efficiency
The vast majority of studies have concluded that a change in trophic efficiency and, as a result, a change in biomass production can be achieved by altering resource type, consumer metabolic type or consumer diversity[3,4,5,6,7,8,9,10,11,12,13,14,15,16,17]
We here provide long-term experimental evidence that differences in energetic efficiency between juveniles and adults within one population in itself have an impact on the trophic transfer efficiency, and thereby standing biomass and biomass production

Summary

Introduction

Patterns in biomass production are determined by resource input (productivity) and trophic transfer efficiency. We show experimentally in a long-term multigenerational study that reallocating constant resource input in a two-stage consumer system from an equal resource delivery to juveniles and adults to an adult-biased resource delivery is sufficient to cause more than a doubling of total consumer biomass We discuss how such changes in consumer stage-specific resource allocation affect the likelihood for alternative stable states in harvested populations as a consequence of stage-specific overcompensation in consumer biomass and thereby the risk of catastrophic collapses in exploited populations. Maturation and reproduction rates are , as mentioned above, determined intrinsically through stage-specific energetic efficiencies but are determined extrinsically through stagespecific resource allocation or predation Differences between these rates have been shown to affect the community structure by causing alternative stable states through emergent Allee effects, emergent facilitation among predators and productivity-driven predator extinctions[21,22,23,24,25,26,27,28,29]. We discuss how consumer stage-specific resource allocation affects the occurrence of stage-specific overcompensation in harvested populations and the risk for collapses of exploited populations

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