marginal significanceP <0.1
As expected, the temporal stability in C 4 ANPP was greater than C 3 ANPP (paired t -test; df=23; t =−3.26; P= 0.003) on average 18.3% across all treatments with marginal significance (paired t -test; P <0.1) in the unwarmed (paired t -test; P= 0.08) and clipped treatments (paired t -test; P= 0.07) ( Fig. 1b ), primarily because C 4 species had greater production due possibly to the inherent higher water and nitrogen use efficiency 6 10 14 .