Vegetation organic matter

Upland surface water may be very good, provided the sources are free from habitation. Vegetable organic matter is present, sometimes in large quantity, so much so that the water may possess a decided yellowish-brown tint. Animal matter will be absent, so that the nitrogen content should be low, any ammonia, nitrates, or nitrites present being in such amounts as are contained in rain water. Chlorides are low and, unless the soil is calcareous, the water is soft. 

Methane also is commonly produced by the decomposition of organic matter by a variety of bacterial processes, and the gas is used as a fuel in sewage plants (see Water, sewage). Methane also is called marsh gas because it is produced during the decay of vegetation in stagnant water. 

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. 

Fluxes are linear functions of reservoir contents. Reservoir size and the residence time of the carbon in the reservoir are the parameters used in the functions. Between the ocean and the atmosphere and within the ocean, fluxes rates are calculated theoretically using size of the reservoir, surface area of contact between reservoirs, concentration of CO2, partial pressures of CO2, temperature, and solubility as factors. The flux of carbon into the vegetation reservoir is a function of the size of the carbon pool and a fertilization effect of increased CO2 concentration in the atmosphere. Flux from vegetation into the atmosphere is a function of respiration rates estimated by Whittaker and Likens (79) and the decomposition of short-lived organic matter which was assumed to be half of the gross assimilation or equal to the amount transferred to dead organic matter. Carbon in organic matter that decomposes slowly is transferred... 

Plant material water contents range from high (>90%, e.g. vegetables) to low (< 10%, e.g. straw, herbs, tea, hops, etc.). Thus the ratio between the analytes (residues) and the organic matter potentially interfering with the analysis is very different for, e.g., cucumber and camomile tea. Other ingredients in plant materials such as acids, oil, sugars, starch or substances typically for the taste and effect of plant materials may have properties similar to those of the analytes and thus interfere in or influence the cleanup procedures. 

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