Maternal environment effect of warming and eutrophication on the emergence of curled pondweed, Potamogeton crispus L.

Abstract

Maternal effects may play an important role in life history and offspring performance of aquatic plants. Performance and response of maternal and offspring aquatic plants can affect population dynamics and community composition. Understanding maternal effect can help to fill a gap in the knowledge of aquatic plant life cycles, and provide important insights for species' responses to climate change and eutrophication. This study showed that maternal warming and eutrophication significantly affected the early life stages of curled pondweed, Potamogeton crispus, a submerged macrophyte. Propagule in warmed condition had higher germination percentages and a shorter mean germination time than those under ambient conditions. However, propagule germination in phosphorus addition treatment was inhibited due to the negative effect of eutrophication, e.g., phytoplankton competition and deteriorated underwater light. Meanwhile, elevated temperature led to a decrease of total nitrogen concentrations and an increase of carbon: nitrogen ratios in plant tissues, which may suggest that P. crispus will allocate more nutrients to propagules in order to resist the adverse effects of high temperature. A subsequent germination experiment in the same ambient condition showed that maternal warming promoted seedling emergence in contrast to maternal phosphorus addition. Consequently, global warming could modify population growth via maternal environmental effects on early life histories, while increased anthropogenic nutrient inputs may result in a decreased submerged macrophyte. These maternal effects on offspring performance may change competition and the survival of early life-history stages under climate warming and eutrophication through changing the ecological stoichiometry of plant tissue.