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Nep Vs Gp Essay

Decent Essays

A) How do the controls over NEP and NECB differ from the controls over GPP and decomposition? Why are these controls different? (Chapter 7) 


Net ecosystem carbon balance (NECB) is the net rate of carbon accumulation by an ecosystem. It is the change in ecosystem carbon stock over time. Net ecosystem production (NEP) is the total amount of carbon moving into an ecosystem minus the total respiration of the ecosystem (GPP-Recosytem). Where gross primary productivity (GPP) is the sum of all photosynthetic activity measured at the ecosystem scale. Decomposition is the conversion of dead organic matter into CO2, mineral nutrients, and organic compounds through the processes of leaching, fragmentation, and chemical alteration. All of these concepts are interrelated and fit into NECB, but the controls differ in some substantial ways.
GPP is controlled by amount of photosynthetic tissue, the duration of the activity (including environmental stressors), and soil resources (water and nutrients). This represents the largest carbon flux into the system and one of …show more content…

Fungi typically have a suite of different enzymes capable of breaking down different types of plant compounds (lignin, cellulose, etc.). On the other hand, bacteria and archaea may only produce one or some of the necessary enzymes to break down these same compounds. In order for bacteria to break down those more complex compounds they have to form a consortium where each contributes a particular enzyme, each of which contributes to breaking certain bonds within those compounds. For example, cellulose breakdown requires a suite of three different enzyme systems: endocellulases break down the internal bonds, the exocellulases remove the ends of the chains, this forms cellobiose, which can be absorbed, but is further broken down by cellobiase intercellularly to create

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