Litter quality controls tradeoffs in soil carbon decomposition and replenishment in a subtropical forest

Species-rich forests can produce litter of varying carbon (C) and nitrogen (N) composition (i.e., quality), which can affect decomposition and play a central role in long-term soil organic carbon (SOC) accumulation. However, how differences in litter quality affect SOC decomposition and formation remains unclear over the full litter decomposition trajectory. 
We followed the in-situ complete decomposition of added 13C-labelled high- (low C:N) and low-quality (high C:N) leaf-litter and its effect on particulate (POM) and mineral-associated (MAOM) organic matter fractions over two years in a natural subtropical forest.
We found that during early stages of decomposition, low-quality litter inputs decreased SOC via a positive priming effect (i.e., new C inputs favored decomposition of native SOC), but these SOC losses were offset by SOC gains observed via a negative priming effect during decomposition of high-quality litter. In contrast, this pattern reversed during late stages of decomposi..., ,