This is in reference to my statement that the geyser/hot springs at Yellowstone are not significant sources of CO2 and that bacterial respiration of decaying tree trunks would be the major source of CO2 in the Yellowstone ecosystem, offset to some extent by the photosynthetic activity of the trees.
The geysers and hot springs are thermal features. They are heated by a magmatic source under Yellowstone. They primarily release water in the form of water vapor.
There is some uplift associated with the Yellowstone Caldera, and some uplift areas (like Mammoth Lakes, CA) have associated releases of magmatic CO2. My memory is telling me that there may be some areas in Yellowstone where there is some ground release of CO2, but I'm not sure.
Note that areas of recent volcanism can store a lot of CO2 -- the gas releases from Lakes Monoun and Nyos in Cameroon which killed a large number of people show that is very possible. But there is no indication of this at Yellowstone.
(One other thing did occur to me: the Mammoth Hot Springs area is a source of CO2. The precipitation of the travertine deposits from the dissolved carbonate in the water releases CO2. My mistake there, but I still stand by the statement that it is insignificant.)
On the other hand, bacterial respiration of organic matter (tree trunks, bison/deer/elk/moose feces, aquatic vegetation) is a well-known and large source of CO2.
So aside from my error in not acknowledging Mammoth Hot Springs as a source of CO2, I'm not sure what else you are admonishing me not to believe.
The way this thread was linked to another thread led me to take your comment as the decaying vegetation caused the heat producing the steam.
With that thought in my mind, I could not help but respond.
Thank you for your well reasoned (and measured) response. I agree with your conclusions regarding the CO2 production.
Again, my apology.