Plant Biomass Carbon Net Primary Productivity

FIGURE 5.3 Schematic diagram of carbon cycling showing storage of carbon. 

Closed systems, such as the wetlands that receive most of their water from precipitation (e.g., bogs, pocosins, and some seasonal or ephemeral wetlands), are oligotrophic and typically have low primary productivity. Increased inputs from surface and ground water can increase primary productivity in fens and marshes. (Table 5.5) Wetlands that receive pulses of nutrients, such as river floodplains, littoral zones in lakes, and tidal marshes, are typically very productive (Sharitz and Pennings, 2006). 

As plants senesce, a portion of the aboveground biomass, and in some cases all of the aboveground biomass is returned to detrital pool, where it undergoes decomposition. In emergent marshes (such as freshwater and saltwater), most of the organic matter produced is converted to detrital pool. In forested wetlands, litter fall is the primary source of detrital pool. For example, litter fall accounts 

The following are operation definitions of various types of particulate organic matter (POM) and dissolved organic matter (DOM)  

At the ecosystem scale, POM is generated through litter fall (in forested wetlands) and detrital production. This is the major reservoir of organic carbon above the soil surface and constitutes approximately 95% of the total carbon. The POM is broken down into simple readily utilizable organic forms, followed by simultaneous mineralization to inorganic carbon. 

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