text: Although elevated CO 2 did not significantly increase total seedling biomass, it did increase it by 14% when averaged across all temperature and fertilization regimes. However, elevated temperature did significantly increase seedling biomass by 55%, when averaged across all CO 2 and fertilization treatments, as did fertilization, by 157%, when averaging across all CO 2 and temperature levels. With respect to root exudation, a similar pattern emerged. Elevated CO 2 did not significantly increase total dissolved organic carbon compounds exuded from seedling roots over a 24-hour period, yet plants grown in elevated CO 2 exuded 20% more such compounds than ambiently-grown plants did, when averaged across all temperature and fertilization treatments. And once again, elevated temperature and fertilization significantly increased root exudation by 71 and 55%, respectively, when averaged across the other main effect variables.