Results
We identified 41 studies that evaluated the effect of the understory on
marine canopies, yielding 337 interaction estimates, spanning 46
canopy-forming species from four orders and 61 distinct turf seaweed
species (Appendix S2 Figure S1). Studies were drawn from multiple
biogeographic regions on five continents, as early as 1973, co-occurring
with regions in which canopy-turf regime shifts have occurred
(Filbee-Dexter & Scheibling 2014; Fig. 2). Overall, we found little
evidence of publication bias in our dataset, supporting the results we
describe below (Appendix S2).