全球变化知识资源中心

Warming is altering the way soils function in ecosystems both directly by changing microbial physiology and indirectly by causing shifts in microbial community composition. Some of these warming-driven changes are short term, but others may persist over time. Here, we took advantage of a long-term (14 yr) warming experiment in a tallgrass prairie to tease apart the influence of short- and long-term warming on litter decomposition. We collected soils originating from warmed and control plots and incubated them with a common litter substrate in a reciprocal design under elevated and ambient growth chamber temperatures. Litter decomposition was 40% higher in soils that were warmed in the field for 14 yr (long-term warming) relative to soils derived from ambient plots. Short-term warming in the laboratory had less of an impact on decomposition-decomposition increased by 12% under laboratory warming. Using a two-pool soil carbon model to explore how different carbon pools may be responding, we found that long-term warming accelerated the turnover of labile, not recalcitrant, carbon in these prairie soils-a result that is likely due to shifts in soil community activity/composition. Taken together, our results offer experimental evidence that warming-induced changes in the soil community that occur over 14 yr of warming have long-lasting effects on carbon turnover.