I'm very grateful that Mark Douglas-Hughes drew such an effective cartoon about "Our Friends, the Trees."
It was, of course, impossible for him to include all the functions and services provided by individual trees or forests. Some day we must, however, remind our world citizens that the planet's fresh water supply is extremely dependent on forests, as is the groundwater level. The destruction of tree cover has resulted in a rapidly sinking ground water level, threatening catastrophic consequences. Equally disastrous has been the effect on climate; the equalizing function of forests is vital to making our planet livable.
Finally, there is the mineralizing function of trees: roots supply the vitally important trace minerals to leaves and branches. As they fall and decompose, we receive the precious humus, so essential for fertile earth.
Coordinator, World Forestry Commission, World Government of World Citizens