Climate organic matter

Alvarez R. and Lavado R. S. (1998) Climate, organic matter and clay content relationships in the Pampa and Chaco soils, Argentina. Geoderma H3(l—2), 127—141. 

Dead vegetation also afreets the global carbon cycle. Dead organic matter decomposes, releasing carbon dioxide to the atmosphere. Rates of decomposition vary with material, location, and climate. Non-woody organic matter decomposes rapidly woody organic matter slowly. Decomposition tends to occur faster at the soil surface than below. Decomposition is relatively fast in warm moist climates. In cold climates and in wetlands, decomposition is so slow that there is a net increase of stored carbon in the soil and organic soils called, "histosols, are formed. 

M. Schnitzer, Recent findings on the characterization of humic substances extracted from soils from widely differing climatic zones. Proceedings of Symposium on Soil Organic Matter Studies, Braun.schweig, RFG, 1977, pp. 117-131. 

Several authors have applied in situ pulse labeling of plants (grasses and crops) with C-CO2 under field conditions with the objective of quantifying the gross annual fluxes of carbon (net assimilation, shoot and root turnover, and decomposition) in production grasslands and so assess the net input of carbon (total input minus root respiration minus microbial respiration on the basis of rhizodeposition and soil organic matter) and carbon fixation in soil under ambient climatic conditions in the field. 

On the basis of this comparison study, at present, it is still difficult to adopt a universal selective sequential dissolution procedure, which may be used everywhere and be suitable for all soils with diversified physical, chemical and mineralogical properties. The application of the SSD procedure must consider individual soil characteristics, such as soil type and properties. The two typical SSD procedures were developed to address soils formed in two climates. The Rehovot procedure was developed to be suitable for the calcareous soils in arid and semi-arid zone soils, whereas the Bonn procedure was created to primarily handle the acid and neutral soils in humid zones. In general, the Bonn procedure appears to be unsuited for calcareous soils in arid and semi-arid zones. The Rehovot procedure has limitations in handling acid and neutral soils, especially forest soils with higher content of organic matter. 

UNFCCC (1997) Kyoto protocol to the United Nations Framework Convention on climate change. Document FCCC/CP/1997/7/ Add 1, http //www.unfccc.de Van Cleve K, Powers RF (1995) Soil carbon, soil formation, and ecosystem development. In McFee WW, Kelly JM (eds) Carbon forms and functions in forest soils. Soil Science Society of America, Madison, WI, pp 155-200 Wedin TA, Tieszen LL, Dewey B, Pastor J (1995) Carbon isotope dynamics during grass decomposition and soil organic matter formation. Ecology 76 1383-1392... 

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