Data and code from: On the prevalence and dynamics of inverted trophic pyramids and otherwise top-heavy communities ...

• Main Authors: McCauley, Douglas, Gellner, Gabriel, D. Martinez, Neo, Williams, Richard J., A. Sandin, Stuart, Micheli, Fiorenza, J. Mumby, Peter, S. McCann, Kevin
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: figshare 2018
• Subjects: Ecology not elsewhere classified; Arctic; Tundra
• Online Access: https://dx.doi.org/10.6084/m9.figshare.c.3946945.v2; https://figshare.com/collections/Data_and_code_from_On_the_prevalence_and_dynamics_of_inverted_trophic_pyramids_and_otherwise_top-heavy_communities/3946945/2

Classically, biomass partitioning across trophic levels was thought to add up to a pyramidal distribution. Numerous exceptions have, however, been noted including complete pyramidal inversions. Elevated levels of biomass top-heaviness (i.e. high consumer/resource biomass ratios) have been reported from Arctic tundra communities to Brazilian phytotelmata, and in species assemblages as diverse as those dominated by sharks and ants. We highlight two major pathways for creating top-heaviness, via: 1) endogenous channels that enhance energy transfer across trophic boundaries within a community and 2) exogenous pathways that source energy into communities from across spatial and temporal boundaries. Consumer-resource models and allometric trophic network models combined with niche models reveal core mechanisms for promoting top-heaviness and their relative strength. Outputs from these models suggest that top-heavy communities can be stable but they also reveal sources of instability. Humans are both increasing and ...