THE EFFECT OF LIGHT ENVIRONMENT, LEAF-AREA, AND STORED CARBOHYDRATES ON INFLORESCENCE PRODUCTION BY A RAIN-FOREST UNDERSTORY PALM

Variation in flowering by long-lived plants may be correlated with cur rent resource availability. If, however, there are trade-offs between current and future reproduction, or between reproduction and storage o r growth, then understanding variation requires a whole-plant, longer- term perspective. Inflorescence production by Calyptrogyne ghiesbreght iana Linden ex. H. Wendl., an understory palm, was studied over 3 year s. Annual inflorescence production varied greatly and was correlated w ith variation in plant size and light environment. There was no trade- off between past inflorescence production and the frequency of future inflorescence production. On the contrary, individuals that produced m ore inflorescences than predicted from their size and light environmen t tended to continue to do so in subsequent years also. I manipulated the resource environment of a subset of plants by removal of leaves an d/or reproductive spikes. Leaf removal suppressed inflorescence produc tion for the following 2 years, but spike removal had no effect. One y ear after leaf removal stored reserves were, on average, back to pre-t reatment levels. There was, however, a negative effect of recent inflo rescence production on storage. Plants with higher levels of storage h ad higher inflorescence production in the next 75 days. In C. ghiesbre ghtiana the resource cost of reproduction is apparent in short-term va riation in stored reserves. In contrast, annual inflorescence producti on does not follow a trade-off pattern between successive years, but c onsistently reflects both plant size and the light environment.