Does all the grass in the world absorb more CO2 and produce more 02 than trees?

[P-Kasso2]

There are a lot of trees in the world. And there is a heck of a lot of grass in the world. So it set me wondering.... Trees are famous for pumping out more life-giving Oxygen than they use - and how one very large tree can produce enough Oxygen for four people to live on blah blah blah.... 

But what about all the Grass in the world?

Apparently globally there are about 418 million blades of grass for every single person alive! You included.  And what are your 418 million blades of grass busily doing for you all day and all night?  Well there's nothing greener than grass so it's probably pumping out Oxygen and sucking up Carbon Dioxide before it kills you.  All without thanks.

So my question is this....Does all the Grass in the world in actual fact produce more Oxygen globally and absorb more Carbon Dioxide than all the Trees in the world? Or nowhere near?


Sources for the amount of grass in the world - http://www.physics.umd.edu/perg/MathPhys/content/2/pstruc/estimation.htm

And on the benefits of Trees - NC State University - https://projects.ncsu.edu/project/treesofstrength/benefits.htm