Since most trees root systems are on the top 3-6 inches of the ground this study proves that some people get far to much time and gelt to spew their ignorance. In the rain forests of South America, nearly the whole eco system is above ground.
Trees provide the canopy to cool the air by shade and evaporation..causing all that water to go into the air and return as rain..maybe not in that area, but it comes down. The Sahara desert once had forests. After they became extinct the desert was the result.
The biggest polluter on earth is forest fire. Forest fire releases carbon, not only from the fire itself but the ground. And it continues to release that element for years untill a new forest grows. Fire also releases Mercury as well as other elements collected over the years on the ground. So lets get Bruce "The Rabbit" Babbit to get out on another photo op of him with a drip can lighting up a "controlled" burn...the ignorant idiot!
"Trees provide the canopy to cool the air by shade and evaporation..causing all that water to go into the air and return as rain..maybe not in that area, but it comes down."
Of course, but that wasn't the point of the study.