Most people with a basic understanding of science can point to the significant role trees have in regard to the air we breathe and the water we drink. Trees stand as silent witnesses to everyday life everywhere and scientists are beginning to understand they may be more active than they appear. Researchers in the Department of Bioscience, Center for Biodiversity Dynamics in a Changing World in Denmark recently reported trees appear to have a pulse that is so slow, scientists never noticed it.
Beyond the normal swaying of branches and leaves observed when the wind blows, scientists found trees also move their branches up and down very slightly at night—perhaps to pump water up and down. This theory was supported when researchers surveyed 22 trees of different species over a 12-hour period on a windless night and recorded several of the trees moved their branches up and down between 1 and 1.5 centimeters, evidence that trees have a biological process that appears very similar to a pulse.