Nitrogen (N), phosphorus (P), and acid deposition are co-occurring in many ecosystems, likely with complex interactive effects on litter decomposition. Few studies have been conducted to distinguish the interactive effects of these three factors on forest litter decomposition. Thus, we performed a 5-year litter decomposition experiment with N, P, acid addition in a temperate forest of Changbai Mountain in China, including four litter types from Pinus koraiensis, Quercus mongolica, Tilia amurensis and their mixtures. Our...