1 - Temperature sensitivity of litter and soil organic matter decomposition: perspective of soil microbial community structure and function

Abstract

The world’s soils contain four times as much carbon as the atmosphere. Thus any changes in this carbon pool may affect atmospheric CO2 levels with implications for climate change. With respect to the low mean annual temperature and high-temperature sensitivity of soil organic carbon (SOC) decomposition, temperate regions became the hot spot for the topic of feedback between the terrestrial carbon cycle and global warming. It was widely accepted that soil microbial community is one of the significant factors influencing the temperature sensitivity of fresh plant residues and SOC decomposition; however, the relationship between them was not well documented, lacking the intensive analysis of microbial community structure and function. To date, to what degree the soil microbial community can influence the temperature sensitivity of SOC decomposition, and its presumed mechanism were still not known. Bacteria and fungi drive decomposition, a fundamental process in the carbon cycle, yet the importance of microbial community composition for decomposition remains elusive. The in-depth understanding of the factors that control the temperature sensitivity of litter and SOC decomposition in temperate forests, specifically, the exploring of microbial ecological mechanisms, will provide the sound scientific support for elucidating its regulatory mechanism under the projected global warming.