Dead branches breathe with the weather — and laser scans can now read them to spot sick trees early

Point a laser scanner at a boreal forest, day after day, and a quiet rhythm appears: dead branches rise and fall as humidity changes, swelling as they absorb moisture and relaxing as they release it. Geoinformatics researchers in Heidelberg, Germany, have now measured that movement precisely, and shown that the movement signature of dead branches is clearly different from living ones. That difference is the prize. An autonomous laser-scanning system could one day read those signatures across many trees at once, without touching any of them — flagging deadwood and declining vitality early, in forests and city streets alike, so tree care arrives before a tree fails rather than after. The work is published in Agricultural and Forest Meteorology.

SDG 15 · Life on land