“…This observation is not surprising because the uptake, transport, and allocation mechanisms for P and N are very similar in plants (Feild & Brodribb, 2001; Jeschke, Kirkby, Peuke, Pate, & Hartung, 1997; Kilgore, Patel, Sharma, Maya, & Kielhorn, 2014; Lynch, 1995; Mimura, 1995; Niklas et al., 2005; Schachtman, Reid, & Ayling, 1998). However, our results also show that seedling P content scales isometrically with N content across the four species, whereas prior studies report that a ⅔ scaling exponent for P versus N across large plants (Han, Fang, Guo, & Zhang, 2005; Niklas, 2006; Niklas et al., 2005; Reich et al., 2010; Wright et al., 2004). This difference may be partly due to the gradual decrease in physiologically active biomass (and the N contained therein) as plants continue to grow in size (Ågren, 2008; Niklas & Enquist, 2002; Peng et al., 2010).…”