HJim:
I work with biochar, charcoal used as a soil amendment. Closely related to activated carbon and it works through similar mechanisms and characteristics to conserve soil organic matter and water and build microbial activity. Before the days of chemical fertilizer and 100% fire suppression policy, it was an important component of the incredibly fertile soils of the plains and prairie states. It is particularly effective in poor, weathered, sandy soils such as we have you-know-where.
Top Lit Updraft Gasifiers -such as your TDW - are an important class of the many devices that can produce excellent biochar. You will notice that it operates in two stages. Properly packed and lit, the entire charge will turn to char before the char itself begins to be consumed. This is really convenient for getting a quick boil and then keeping a pot warm for some time. If it is extinguished at the end of the flame stage, however, the char can be preserved either for later consumption or returned to the earth as biochar.
The same effect can be largely achieved without the stove. A very small fire, criss cross style no more than 4-6" in diameter built in a very small 3 stone hearth and LIT ON TOP works much the same way as the TLUD. We call this the conservation burn, and I teach it on a much larger scale to land managers who have no choice but to use open burns. It reduces emissions by over 90 percent, and because it burns the smoke instead of releasing it, is incredibly thermally efficient, meaning MUCH less wood produces MUCH more heat. And incidentally much less soot on rocks, pots and in eyes.
Fire is a very important element in building the soils to which plants species in the Sierra are adapted, and eliminating all fire is completely unnatural and does not necessarily conserve biomass in the long run. The char in the soils persists for a long long time, and in its life cycle does far more good than the small amount of wood from which it is produced. Obviously the entire explanation is volumes, but in the end not only do I agree with you about wood stoves, but I would carry the principle a step further to include very small top-lit ground fires.
