Effects of Descendent Phenotypic Diversity Mediated by Ancestor Environmental Variation on Population Productivity of a Clonal Plant

Abstract

Phenotypic variation of individuals within populations can be influenced by not only genetic diversity and environmental variation experienced by these individuals but also environmental variation experienced by their parents. Although many studies have tested impacts of phenotypic diversity caused by genotypic or species diversity on productivity, no study has assessed the effects of phenotypic diversity induced by parental environmental variation on productivity. To address this novel question, we conducted two experiments with the widespread, fast-growing, clonal, floating plant Spirodela polyrhiza. We first grew mother (ancestor) ramets of S. polyrhiza under different environmental conditions to obtain descendent ramets with different phenotypes. Then, these ramets were used to construct descendent populations with different levels of phenotypic diversity caused by ancestor environmental variation and examined the effect of phenotypic diversity on population productivity. Environmental variation (changes in nutrient availability, plant density and light intensity) had significant effects on descendent populations of S. polyrhiza. However, descendent phenotypic diversity induced by ancestor environmental variation had no significant effect on total biomass or number of ramets of the descendent populations and such an effect did not depend on the nutrient availability that the descendent populations experienced. Although our results failed to support the idea that phenotypic diversity induced by ancestor environment variation can influence descendent population productivity, we propose that this novel idea should be tested with more species in different ecosystems.