Annual and perennial life history strategies of Zostera marina populations under different light regimes
Eelgrass Zostera marina is considered to be genetically perennial. However, Kim and colleagues found that an eelgrass population located near its maximum depth limit exhibited an annual life history strategy. Repetitive and acute light reduction following summer high temperature stress was lethal to the eelgrass shoots. Since this deep population is reestablished and maintained by sexual reproduction, the stressed eelgrass enhanced its reproductive ability through an increase in flowering frequency. Thus a putative perennial plant species can exhibit an annual life history strategy through enhanced flowering to achieve persistence under repetitive unfavorable conditions.