The cost of reproduction hypothesis assumes that reproduction imposes costs known as trade-offs with other aspects of plants performances. In addition, plant's current resource income and previous storage determines the extent of reproductive costs. Many compensatory mechanisms to minimize reproductive cost have also been reported. In our previous study, a spring ephemeral Gagea lutea showed reproductive compensation by the reproductive structures. Meanwhile, whether this effect is associated with the species habitat is still unclear. Hence, this study therefore aims to find out whether reproductive cost, carbon assimilation and reproductive compensation in Gagea lutea differ under different light condition.
We hypothesized that plants in open condition environment with increased light level will gain more carbon, which might result in low reproductive cost. Annual changes in bulb size, daily carbon fixation per plant and the importance of leafy bracts were assessed among (1) reproductive intact, (2) floral-bud removal, and (3) bract removal plants under open and forest conditions.
Bulb growth is dependent on flower number but not habitat. Leaf carbon fixation is more in the open site with marginal differences among treatments. Bract carbon fixation is similar between sites but different between treatment. The removal of the leafy bract reduced both seed number and seed mass in both habitats. Although increased light level leads to increase carbon fixation, it does not reduce reproductive cost.