The effect of light environment, leaf area, and stored carbohydrates on inflorescence production by a rain forest understory palm

Abstract

Variation in flowering by long-lived plants may be correlated with current resource availability. If, however, there are trade-offs between current and future reproduction, or between reproduction and storage or growth, then understanding variation requires a whole-plant, longer-term perspective. Inflorescence production by Calyptrogyne ghiesbreghtiana Linden ex. H. Wendl., an understory palm, was studied over 3 years. Annual inflorescence production varied greatly and was correlated with 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 more inflorescences than predicted from their size and light environment tended to continue to do so in subsequent years also. I manipulated the resource environment of a subset of plants by removal of leaves and/or reproductive spikes. Leaf removal suppressed inflorescence production for the following 2 years, but spike removal had no effect. One year after leaf removal stored reserves were, on average, back to pre-treatment levels. There was, however, a negative effect of recent inflorescence production on storage. Plants with higher levels of storage had higher inflorescence production in the next 75 days. In C. ghiesbreghtiana the resource cost of reproduction is apparent in short-term variation in stored reserves. In contrast, annual inflorescence production does not follow a trade-off pattern between successive years, but consistently reflects both plant size and the light environment.