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No. 105: May-Jun 1996

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Arboreal Internets

Over a half century ago, Yale scientist H.S. Burr was inserting electrodes into trees to measure how voltage differences varied during the day and lunar month. Y. Miwa, at Waseda University in Tokyo, has gone more than one step farther. He and his coworkers have placed electrodes in the trunks of trees - 250 trees at a time - and measured the voltage differences every 2 seconds. They have discerned intriguing synchrony.

"Miwa and his colleages studied primeval forests in Japan's Shizuoka and Nigata Prefectures, recording signals for two days at a time. In each forest, there were several groups of between 20 and 50 trees showing a similar pattern of changes in their potentials, each of which contained about half a dozen species. Neighboring trees were the most likely to be synchronized, but the groups did not have rigid boundaries. The membership of the groups was also not fixed: between the first and second days of recording, individual trees 'joined' and 'dropped out'."

Miwa advances the idea that the trees must somehow be communicating with each other to achieve this synchrony. Botanists, though, suspect that environmental conditions force this coordinated behavior. Miwa will next remove a few members from each group to see if his arbicides are noticed by the neighbors.

(Endo, Shinichi; "Japan's Ancient Trees Whisper Their Secrets," New Scientist, p. 19, May 13, 1995)

Cross reference. This is not the first time we have offered evidence of "tree talk". See "Trees Talk in W-Waves". (SF#63)

From Science Frontiers #105, MAY-JUN 1996. � 1996-2000 William R. Corliss