scorecardresearch Skip to main content

Self-tweeting tree is Harvard’s newest climate change educator

The Harvard Forest witness tree is about 100 years old and equipped with cameras and sensors to monitor its health and the surrounding forest.Shawna Greyeyes/Harvard Forest

Researchers are hoping a self-tweeting tree in the Harvard Forest will educate the world about climate change, officials said.

The Harvard Forest Witness Tree is a century-old red oak programmed since July 17 to tweet updates about the weather and its health and surroundings, said Tim Rademacher, a co-lead on the “witness tree” project and a postdoctoral researcher at Harvard and Northern Arizona universities.

The tree is one of many in the Harvard Forest, a 3,000-acre research area in Petersham run by the university. “The witness tree is, in its most simple form, a data-driven bot that tries to tell a story about nature and climate change. It’s an organism familiar to most people, but at the same time, people know very little about it,” Rademacher said. “Through some scientific interpretation, the bot decides which messages actually get posted, and they’re pre-formulated.”


The tree is equipped with sensors and cameras to monitor its health, surroundings, and sap and water levels, Rademacher said. The tree sends data every five minutes to a server Rademacher programmed. The server tweets occasionally with updates about the forest, the weather, or the tree’s growth, Rademacher said.The Petersham tree tweets from the account @awitnesstree. It has tweeted almost 40 times since July 17 and had more than 4,700 followers by last week.

“I didn’t want to just put data into the public domain that most people can’t interpret. We use scientific knowledge to make the data more accessible. The aim behind the bot is to use data to tell a story with this data that anybody can understand,” Rademacher said.

Rademacher started the witness tree project in 2018 with funding from the National Science Foundation after he read the 2017 book “Witness Tree: Seasons of Change with a Century-Old Oak” by Lynda Mapes. The book followed a tree through four seasons of growth.


Rademacher set up the instruments on the same tree Mapes wrote about. The tree’s Twitter account is modeled after similar efforts by, a European tree-monitoring network, Rademacher said.

“We decided on a red oak because it’s one of the most important and abundant species in New England and it was in Lynda’s book. There’s nothing particularly special about this tree. It could be any tree. That’s why we took the handle, ‘A witness tree,’ not ‘THE witness tree,’” Rademacher said.

The tree’s researchers are asking people not to go looking for it, to avoid breaking its equipment or trampling nearby plants.

Rademacher may not work on the project forever, but he wants the tree to tweet for a long time.

“My hope is it goes on for as long as it lives. My contract could end at any time, but I very much hope that the project runs by itself. I hope to set up other trees to set up an Internet of trees,” Rademacher said.

Alyssa Lukpat can be reached at Follow her on Twitter @AlyssaLukpat.