This brief ‘perspectives’ paper discusses how quickly the large amount of organic carbon stored in soil as organic matter will respond to global warming. It describes the factors influencing the rate of litter decomposition and some difficulties of predicting how litter decomposition will be affected by temperature.
This brief ‘perspectives’ paper discusses how quickly the large amount of carbon stored in soil as soil organic matter (SOM) will respond to global warming. Consideration of this topic is hindered by an inadequate understanding of the processes that destabilize SOM following disturbance. Rates of decomposition of litter are influenced by chemical content of litter, the types of soil animals and microbes present, and climate. In contrast, over geological time, carbon accumulates slowly with weathering of rock.
The influence of temperature on decomposition rates of litter cannot at present be separated clearly from the direct influence of temperature on soil fauna and microbes, the composition of these ecological communities, the rate of abscission of leaves, as well as changes in fire frequency, intensity and timing.
The authors advocate cross-disciplinary studies of soil that integrate experimental research by soil physicists, chemists, and biologists. The desired outcome is improved conceptual and mathematical models that work at the scale of the both the root and landscape.
Trumbore SE & Czimczik CI (2008) Soil carbon, uncertainty, and predicting future CO2 levels in the atmosphere. Science 321: 1455-1456.