Carbon Sequestration and The Boreal Forest

First, lets start with some definitions:

Carbon Dioxide (CO2):  A greenhouse gas produced by the combustion of hydrocarbons.  It is also a by-product of respiration and the substrate for the photosynthetic carbon reduction cycle.

CO2 Flux:  The transfer of a quantity of CO2 per unit area per unit time.  Usually given in Mg m-2 s-1 or mol m-2 s-1.

Gross Primary Production (GPP):  The total amount of organic material assimilated by green plants in a given time. 

Net Primary Production (NPP):  The total amount of organic material accumulated by green plants in a given time. 

So...
Carbon Sequestration is the process by which CO2 is removed from the atmosphere and stored as biomass.

Carbon sequestration can be considered at several levels.  At the level of an individual plant, the amount of carbon sequestered is simply as follows:

CO2 Sequestered = Photosynthesis – Respiration

What this essentially means is the amount of carbon sequestered is equally to the NPP of the plant. 

However, when considering Carbon sequestration at the ecosystem level (which is ultimately more useful than considering an individual plant), several more factors need to be accounted for.  The diagram below indicates the processes involved in ecoystem carbon sequestration.  Blue arrows indicate processes that bring carbon into the ecosystem, while red indicate those processes that return carbon from the ecosystem to the atmosphere.

Since the industrial revolution, combustion of fossil fuels has lead to dramatic increases of carbon dioxide in the atmosphere.  While there is still some debate over the potential consequences, there is a general consensus within the scientific community that increased atmospheric CO2 levels may result in global warming and significant shifts in climate patterns.  Therefore, understanding the extent to which terrestrial and aquatic ecosystems can sequester atmospheric CO2 is of the utmost importance.