Results (<i>F</i>-value) of repeated measures ANOVA with a split-plot design on the effects of block (B), year (Y), water (W) and N addition on species richness, litter biomass and plant cover of grasses and forbs in a steppe and in an old field grassland studied from 2005 to 2009.

*<p>, **, *** indicate statistically significant difference at <i>P</i><0.05, 0.01, and 0.001, respectively;</p>Λ<p>marginally significant difference at <i>P</i><0.1;</p><p>ns: <i>P</i>>0.1.