Stable Isotope Pot Experiment Data

In this study we pulse-labelled <i>F. japonica </i>and <i>U. dioica</i> with ¹³CO₂ and either ¹⁵NO₃ or ¹⁵NH₄ to investigate key aspects of their biogeochemical traits, carbon allocation and nitrogen uptake. These tracers allow us to differentiate between nitrate and ammonium, analyse how freshly taken up carbon and nitrogen are distributed between above-ground and below-ground plant parts, and compare the proportion of labelled nitrogen incorporated into plant biomass to determine the efficiency with which each species converts nitrogen into growth [10]. Specifically, we used these isotopes to: (a) resolve the question of whether <i>F. japonica</i> has a greater preference for ammonium than for nitrate when compared to <i>U. dioica</i> and how it compares to the manner in which <i>U. dioica</i> takes up ammonium and nitrate, (b) further explore the NUE of <i>F. japonica</i> compared to <i>U. dioica</i>, and (c) test if it invests more in its below-ground biomass during their early stages of development.