No. 27: May-Jun 1983
Trees talk only in children's cartoons -- that's currently accepted wisdom. But when trees attacked by caterpillars sound an alarm that other trees in the vicinity detect and heed, some sort of communication system seems required. The evidence is found in trees that react to caterpillar attack or leaf damage by making their leaves harder to digest. When one tree is attacked, not only does it start making less nutritious leaves but so do other trees as far as 200 feet away. No root connections have been found.
In tests with potted maples and poplars inside plexiglass enclosures, the attack warning got through to trees in the same chamber but not to control trees outside the plexiglass. Thus, the warning seems to be transmitted by air -- probably chemically. David Rhoades is conducting further research at the University of Washington.
(Boling, Rick; "Tree ESP," Omni, p. 42, December 1982. Cr. P. Gunkel)
Comment. Question: How is the message received, decoded, and turned into biological action? If we could set up chemical "antennas" in the air around us, what other revealing messages would we "hear"?