My interests are ecophysiology of plants and soil-plant interactions in marine ecosystems. Throughout my PhD I focus on ecophysiological processes, soil-nutrient-plant interaction and stoichiometry of halophytic perennials and annuals. Mangrove and salt marsh species are evolved from terrestrial plant families and are unique and dynamic ecosystems at the transition of land and sea. Vegetation patterns as well as growth responses of halophytic trees and herbs are controlled by various environmental factors such as tidal inundation and pore water salinities and natural resources such as nutrient availabilities. Due to tidal movement, the input of natural resources, nutrient fluxes and mineralization rates, are varying within soils along land sea gradients, resulting in large variation of nutrient availabilities, in particular nitrogen (N) and phosphorus (P). Growth and maintenance processes of plants require a variety of different chemical elements; and it is the ratio of elements which is structurally and functionally important to regulate homeostasis and internal water balance. Furthermore, although halophytic species are adapted to saline environments, species have to overcome several physiological constraints such as ionic imbalance and osmotic/water stress. In order to maintain adequate metabolic processes halophytic species producing osmoprotectants, which require a high concentration of nitrogen relative to carbon. A large variation in nutrient availability and being exposed to extreme abiotic conditions, will affect nutrient acquisition and tissue element ratios, however what is the variation among mangrove species and salt marsh species, according to differences in functional traits for growth and water stress? In the second part of my PhD, I zoom-in on soil-interactions, nutrient fluxes, nutrient cycling and C:N:P stoichiometry, which have to be taken into account for a better understanding of primary productions, soil-nutrient-plant interactions in these ecosystems.