It has long been known that trees enhance rainfall by cooling the land, slowing wind evaporation and erosion, and transpiring water into the sky from their leaves.

• 长久以来人们就知道树木能提高降雨量，原理就是，树木使大地变得更凉爽，同时减慢风力蒸发和侵蚀，并使叶子上的水汽蒸发到空气中去。