Effects of nitrogen deposition on seed phosphorus and plant survival in natural ecosystems
Plants allocate more than 50 % of their acquired phosphorus (P) to reproductive organs. In seeds, most of the P is stored in the form of phytic acid. In early germination stages, before the roots develops and nutrients extraction from the soil begins, phytic acid is gradually hydrolyzed and P is translocated to the growing organs to support growth. Seed phytic acid content is controlled by soil P concentrations and biological availability. Under low P conditions plants allocate less P to seeds and compromise their investment in reproduction. Thus, P limiting conditions control plant survival rates and shapes species distribution across ecosystems.
P limitation is expected to spread due to the growing anthropogenic use of nitrogen (N) for agricultural purposes, which creates stoichiometric imbalances between N and P.However, currently we do not know how increased stoichiometric imbalances between N and P will affect plant P allocation to seeds and how these changes will influence seed germination and plant reproduction in years to come.
Stoichiometric imbalances between N and P are projected to be particularly strong in the heavily fertilized Mediterranean region where agricultural N deposition is rapidly growing and droughts are expected to become more frequent and intense.
In our lab we study how growing imbalance between N and P will affect seed P concentrations and influence plant reproduction in Mediterranean ecosystem.
