First True Trees: Spore Reproduction
385 Million Years Ago (+/- 5 million years)
Secondary growth wood and deep roots
We think of trees as having no movement at all — but that’s not true. In addition to growing upward toward the sky and extending their roots into the ground, trees move water through their bodies in daily cycles. They show subtle expansion and contraction driven by water transport — a hydraulic rhythm in each trunk, almost like a forest breathing. As transpiration pulls water upward during the day, trunks contract slightly; at night, when internal water pressure is restored, they expand again. This subtle pulse, known as diurnal stem diameter fluctuation, is not true breathing, of course — but in a quiet way, the forest does have a heartbeat.
- Domain: Eukaryota > Kingdom: Plantae > Phylum: Tracheophyta (vascular plants)
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About 385 million years ago is when trees started to emerge, distinguished by their secondary growth wood and deep roots.
Subject: Plant Evolution.
By 385 million years ago, trees started to emerge. Distinguished by their secondary growth wood and deep roots, trees grow toward the Sun and deep into the ground. Although we think of trees as stoically still, even the quiet forest is in motion, pulsing with water and light.
What is water movement within trees that causes daily trunk expansion and contraction?.
Answer. Diurnal stem diameter fluctuation.
was first published on TST 2 years ago.
