CO2 and Hardwoods

I sat this past week and was reading over climate change, CO2, and then came to this odd discussion which you never hear much about.

Plants (trees, grass, shrubs, bushes, etc) take up carbon dioxide (CO2), run through photosynthesis, and in the end....make glucose. 

For statistical averages.....for every six molecules of CO2....the plants take and create ONE molecule of glucose.  More CO2, more glucose.  If you doubled up on CO2, the plants would double up on glucose production. 

For a fast growing plant (or tree), the more CO2 it uses up.  So you could look at this idea and suggest....well, why not plant bamboo in massive quantities (one of the faster growing products in existence)?

But fast growing plants have the lesser life span.  As they die....between bugs, microbes and just plain release....all that bundled up CO2 goes back into the system.  So logic dictates....hardwood trees, which would live longer and bundle the CO2 for dispersal decades longer. 

Making the planting of hardwood trees a high priority?  No, it's almost non-existent in terms of talking over the CO2 issue in climate control.