SYMP 12

Recent Advances in Studies on Seed Masting: Interpreting Empirical Data with Mechanistic Models

Many long lived perennial plants employ a masting strategy: synchronous, highly variable reproduction, or synchronized boom-bust cycles of reproduction. It is not only an intriguing phenomenon itself, but it is also important to understand reproductive strategy of plants. Since the beginning of ecology we have known this conspicuous phenomenon and intuitively understood its importance in ecological community. However, it was not long ago that we began to discuss about its biological mechanism. Besides a new problem that masting patterns might have changed for recent decades was added into our interest in the context of global warming. Recently the role of internal resource dynamics as one of the proximate factors for masting has gained strong support (the resource budget model). This model assumes that plants accumulate resources every year, set flowers when the resource level exceeds the threshold and set seeds and fruits at a rate limited by pollen or pollinator availability. Therefore, in order to test the resource budget model, a variety of factors influencing flowering, resource accumulation, seed production, and environmental noises should be considered. The aim of this symposium is to review studies on masting of perennial plants and discuss about how to link empirical studies to the resource budget model. Masaki will review empirical studies on masting and show what we know and what we need to know more. Shibata will show the advantages of analyses of the temporal changes in masting patterns to understand its biological mechanism, because the temporal changes may be generated by response of plants to environmental changes. Crone will talk about resource dynamics in connection with flowering and seed production on the basis of empirical data on the carbon resources. Satake will talk about a new approach to the masting mechanism. Her research team isolated flowering genes and identified the seasonal and annual expression patterns of these genes in Fagus crenata. She will discuss about the relationship between the gene expression pattern and the carbohydrate and nitrogen concentrations. Lyles will suggest that environmental noises may play a crucial role in inducing masting. Saitoh will discuss about the impact of seed masting on wildlife community, showing different responses of different rodent species to seed crops. We will provide insights into the research strategy in the next stage and clarify internal and external factors that we should measure.