PLASTIC PHENOTYPIC RESPONSE TO LIGHT OF 16 CONGENERIC SHRUBS FROM A PANAMANIAN RAINFOREST

作者：Fernando Valladares, S. Joseph Wright‬, Eloisa Lasso, Kaoru Kitajima, Robert W. Pearcy · 发表于：Ecology · 年份：2000 · DOI：10.1890/0012-9658(2000)081[1925:pprtlo]2.0.co;2 · 被引用次数：744 · 研究领域：Ecology and Vegetation Dynamics Studies、Species Distribution and Climate Change、Remote Sensing in Agriculture

The comparative phenotypic plasticity of 16 species of tropical rainforest shrubs (genus Psychotria, Rubiaceae) was investigated by growing plants in three light environments on Barro Colorado Island (BCI, Panama). The three light environments gave daily photon flux densities (PPFD) similar to the natural light gradient from shaded forest understory to small and large canopy gaps. Six of the species are principally found in gaps or forest edge environments, whereas the other ten species are principally found in shaded understories. Interactions between light treatment and species resulted in unpredictable mean phenotypic expression across light treatments. Shoot relative growth rates (RGR) were similar for understory and gap species in the low light treatment. Gap species had significantly greater shoot RGR in the intermediate light treatment than in the high light treatment. Mean plasticity was significantly lower for morphological variables when compared to physiological variables, while variation in plasticity was significantly greater for structural variables. Significant differences between gap and understory species were found in the plasticity of six out of the seven variables. The mean phenotypic plasticity of the seven variables was significantly greater for gap than for understory species. The high plasticity of gap species was consistent with the hypothesis that specialization in a more favorable environment increases plasticity. The species exhibited a wide range ...