5 - Organ Preformation, Development, and Resource Allocation in Perennials

Abstract

This chapter examines the prevalence, taxonomic affinity, and ecological distribution of flower preformation. The chapter also explores the relationship between the phenology of development, and of resource acquisition and use in forest herbs. This chapter explores the demographic consequences of variation in the timing of developmental events in mayapple, a common spring-flowering herb in the understory of mesic forests in eastern North America. In mayapple, flowers and vegetative structures are entirely preformed in the year prior to their emergence, and the developmental decisions concerning next year's shoots are made before the current year's shoots have completed their reproduction and carbon gain. The chapter also briefly describes the phenology of resource distribution and of development in mayapple, and the interaction that takes place between the current year's reproduction and the developmental decisions concerning next year's shoots. It is this interaction that determines the manifestation of short-term demographic costs of reproduction in mayapple. Matrix simulations are used in the chapter to examine the long-term demographic consequences of variation in the developmental phenology, as mediated through the costs of reproduction.