Chemistry of organic carbon in soil with relationship to the global carbon cycle
Various ecosystem disturbances alter the balances between production of organic matter and its decomposition and therefore change the amount of carbon in soil. The most severe perturbation is conversion of natural vegetation to cultivated crops. Conversion of natural vegetation to cultivated crops results in a lowered input of slowly decomposing material which causes a reduction in overall carbon levels. Disruption of soil matrix structure by cultivation leads to lowered physical protection of organic matter resulting in an increased net mineralization rate of soil carbon. Climate change is another perturbation that affects the amount and composition of plant production, litter inputs, and decomposition regimes but does not affect soil structure directly. Nevertheless, large changes in soil carbon storage are probable with anticipated CO2 induced climate change, particularly in northern latitudes where anticipated climate change will be greatest (MacCracken and Luther 1985) and large amounts of soil organic matter are found. It is impossible, given the current state of knowledge of soil organic matter processes and transformations to develop detailed process models of soil carbon dynamics. Largely phenomenological models appear to be developing into predictive tools for understanding the role of soil organic matter in the global carbon cycle. In particular, these models will be useful in quantifying soil carbon changes due to human land-use and to anticipated global climate and vegetation changes. 47 refs., 7 figs., 2 tabs.
- Research Organization:
- Oak Ridge National Lab., TN (USA)
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 6787697
- Report Number(s):
- CONF-880912-24; ON: DE89005128
- Resource Relation:
- Conference: 196. American Chemical Society national meeting, Los Angeles, CA, USA, 25 Sep 1988; Other Information: Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CARBON CYCLE
GLOBAL ASPECTS
ORGANIC MATTER
PRODUCTION
PLANTS
DECAY
CARBON DIOXIDE
CLIMATES
EVALUATION
FORECASTING
GREENHOUSE EFFECT
MATHEMATICAL MODELS
MODIFICATIONS
SOILS
TERRESTRIAL ECOSYSTEMS
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
ECOSYSTEMS
OXIDES
OXYGEN COMPOUNDS
500200* - Environment
Atmospheric- Chemicals Monitoring & Transport- (-1989)