Responses of aboveground biomass carbon (C) and nitrogen (N), root biomass C and N, peak aboveground biomass of grass and forb and the grass: forb ratio to carbon addition (+60%) and water addition (+30%) in 2010 and 2011 in temperate steppe of northeastern China.

<p>Vertical bars indicate standard errors of means (n = 6). Difference lowercase letters indicate statistically significant differences (<i>P</i><0.05). A = ambient condition (control), C = carbon addition, W = water addition, CW = combined carbon and water additions.