Meeting Abstract

S1-9  Friday, Jan. 4 13:30 - 14:00  Does Variation in Flower Development Explain Anomalous Phenological Responses to Temperature? DIGGLE, Pamela*; MULDER, Christa; University of Connecticut, Storrs; University of Alaska, Fairbanks

Climate change has resulted in increased temperatures across the globe. Although many angiosperms flower earlier in response to rising temperature, a substantial number of species either do not appear to respond or even delay flowering in, or following, warm years. Existing phenological models cannot explain such exceptions to the common association of advancing phenologies with warming temperatures. The phenological events that are typically recorded (e.g., onset of flowering) are but one phase in a complex developmental process that often begins one or more years previously, and flowering time may be strongly influenced by temperature over the entire multi-year course of flower development. Preformation, the initiation of flower primordia one or more years prior to anthesis, is characteristic of temperate forest trees, shrubs, and many herbaceous perennials, and ubiquitous for high elevation and high latitude species. We explore conceptual models of the effects of temperature on the entire year-long process of flower preformation that incorporates changes in developmental rates, timing of onset and offset of individual stages, as well as plant and inflorescence architecture. Understanding these developmental process could dramatically improve our ability to predict the timing of flowering in temperate environments and may also give insights into how temperate trees and shrubs, the majority of which preform flowers, will respond as the climate continues to warm.