Question

Net ecosystem production in a California grassland was -10 g C/m² in 2006, -5 g C/m² in 2007, and 2 g C/m² in 2008. Over the three-year period from 2006 to 2008, did the ecosystem lose carbon or gain carbon?

Answer 1

The carbon balance of an ecosystem at any point in time can be defined as the difference between its carbon gains and losses. Terrestrial ecosystems tend to gain carbon via the process of photosynthesis and lose it in the form of CO₂ through respiration, in case of autotrophs and heterotrophs. Although, significant losses of carbon may occur as volatile organic compounds, methane or dissolved carbon (i.e. non-CO₂ losses).

In the given problem, Net ecosystem carbon production in 2006 = -10 C/m²

Net ecosystem carbon production in 2007 = -5 C/m²

Net ecosystem carbon production in 2008 = 2 C/m²

Over the three-year period from 2006 to 2008, the Net carbon production can be calculated as,

carbon production in 2006 + carbon production in 2007 + carbon production in 2008 = (-10) + (-5) + 2 = -13 C/m²

The nagative value indicates that the ecosystem lost carbon over the threee year period from 2006 to 2008.