The selective interactions of dispersal, dormancy, and seed size as adaptations for reducing risk in variable environments

Seed size, dormancy, and dispersal share 3 population-dynamic functions in temporally and spatially varying environments: risk reduction of bet hedging, escape from crowding, and escape from sib competition. A model was developed to explore ways they may interact to reduce risk. The risk-reducing properties of these seed traits evolve only in response to global temporal variance. Thus, to understand how selection impinges on the seed traits, creating fitness interactions, one must understand the factors contributing to global temporal variance and how they are mitigated by the various seed traits. Since the traits interact to reduce variance, arbitarily fixing any 1 trait at different values alters the fitness-maximizing values of the others, resulting in trade-offs among traits. The authors explore how changes in the number of independent environmental patches, probability of favorable conditions, radius of dispersal, and spatial and temporal autocorrelation of environmental conditions alter selection on the interacting syndrome of seed traits. -from Authors