The Effects of Phenotypic Diversity on Invasion Speeds in Fluctuating Environments.

摘要

The establishment and spatial spread of a species in a novel habitat is a fundamental question of practical and theoretical importance in ecology. As a result, mathematical tools have been developed to aid efforts to predict their establishment and invasion speed. Previous studies have used these tools to explore the effects of temporal environmental variation on invasion speed. Phenotypic variation, the variation of life-history traits within a single genotype, has been shown empirically to increase the probability of invasive species establishment. Until now, the effect of phenotypic variation in combination with temporal environmental variation on invasion speed has not been explored. Using integrodifference equation models of a species with multiple phenotypes, we present small noise approximations of the invasion speed when phenotype fecundity and dispersal are affected by environmental fluctuations. We find that when multiple phenotypes are each adapted to a different environmental condition, the invasion speed is increased. In addition, we find that in some cases the assumption of phenotypic homogeneity result in underestimates of invasion speed. Thus, attention to phenotypic variation may allow for better predictions of invasion speed.