Seed size predicts global effects of small mammal seed predation on plant recruitment

We conducted a global literature review and meta-analysis to evaluate whether seed size could predict post-dispersal seed predator effects on seed removal and plant recruitment, respectively.  Datasets were built using data extracted from published studies focusing on seed predation by small mammals (see Methods for criteria and data extraction protocol).  We found that seed size predicted small mammal seed removal rates and their impacts on plant recruitment consistent with optimal foraging theory, with intermediate seed sizes most strongly impacted globally - for both native and exotic plants.  However, differences in seed size distributions among ecosystems conditioned seed predation patterns, with relatively larger-seeded species most strongly affected in grasslands (smallest seeds), and relatively smaller-seeded species most strongly affected in tropical forests (largest seeds).  Such size-dependent seed predation has profound implications for coexistence among plants because it ma...