9306944 Hsieh Determination of turnover times and sizes of soil organic matter (SOM) pools has been one of the major problems in SOM dynamics studies because of the limitations of the current techniques. Recently developed radiocarbon methods seem to provide a solution to the problems. These methods take advantage of the residual bomb 14C (14C = carbon 14) effect in the atmosphere to determine the turnover times and sizes of active and stable SOM pools. The time window for applying these radiocarbon methods is rather narrow now: perhaps scientist have only a decade or so to do the job. The author also proposes to collect and preserve as many soil samples as possible while the residual bomb 14C effect is still significant. %%% Those samples will be an irreplaceable and treasured resource for future studies in SOM dynamics. The results of this proposed work will provide a great wealth of information on the role of SOM to carbon and nutrient cycling of many ecosystems. They will also provide needed data for modeling studies of the global carbon cycle.
