Is the amount of CO2 removed by trees a function of the size of the trees? [Alan]

Photosynthesis is the process by which trees consume atmospheric CO2.  When a tree (or any plant) germinates, it’s ability to photosynthesis is negligible since it takes leaves and chlorophyll to photosynthesize.

As the plant grows, it produces more leaves and thus the rate of photosynthesis increases.  However, as the plant (tree) accumulates more biomass, the rate of respiration also increases since this process is required to maintain healthy tissues and grow.  This process involves burning the biomass (carbohydrates generated from photosynthesis) and releasing carbon dioxide.

Thus the rate of carbon dioxide consumption (biomass accumulation hits its greatest rate during middle age.  The curve looks like this