The influence of temperature on mineralization of plant litter and pre-existing soil organic matter (SOM) involves not only the prevailing temperature, but also how it has changed through time. However, little is known about how temperature variability through time influences mineralization processes. Here, we investigated how short-term temperature history affects the mineralization of SOM and plant litter in soils from different agricultural management systems. We used soils from a long-term experiment with conventional and organic management treatments to set up microcosms. The microcosms were exposed to eight days of contrasting temperature regimes (different mean temperatures and constant versus fluctuating temperatures). Microcosms were then returned to a common temperature of 16 °C, 13C-labelled plant litter was added to half of them, and CO2 efflux was measured over the following week. We found that SOM and litter mineralization were both sensitive to the temperature history, with lower mean temperatures during preliminary treatment associated with higher mineralization during the subsequent common-temperature incubation. This effect persisted through the week after temperature differences were removed. Different patterns of temperature fluctuation and agricultural management did not significantly affect mineralization during common-temperature incubation. The history sensitivity of litter mineralization, despite litter being added after temperature differences had ended, indicates that the temperature history effects may be driven by short-term microbial acclimation. We conclude that organic matter and litter mineralization, which are key processes in the carbon cycle, are sensitive to short-term temperature history. This suggests that future investigations of soil CO2 efflux may need to take recent weather effects into account.
- Mineralization dynamics
- Temperature sensitivity
- Soil carbon
- Priming effect
Mason-Jones, K., Vrehen, P., Koper, K., Wang, J., van der Putten, W. H., & Veen, G. F. C. (2020). Short-term temperature history affects mineralization of fresh litter and extant soil organic matter, irrespective of agricultural management. Soil Biology & Biochemistry, 150, . https://doi.org/10.1016/j.soilbio.2020.107985