Luxurious forests can seem timeless, from the tallest living plants on Earth, the California redwoods, to the planet’s largest tropical forest, the Amazon.
According to experts, every species or ecosystem has a birth date, and although plants first arrived on Earth regarding 470 million years ago, trees and forests only came to the scene regarding 390 million years ago.
Plant life slowly evolved the genetic precursors needed to produce trees, which then outperformed other plants, paleobotanist Chris Berry at Cardiff University in the UK told Live Science.
In 2019 Berry and colleagues reported the oldest recorded forest for Current Biology. This forest, uncovered at a site called Cairo in New York, revealed that the distinctive features of trees and forests, namely wood, roots and leaves among a group of dozens of plants, appeared “much earlier than Previously thought: “In the early Devonian period, 385 million years ago,” researchers said in the study.
Perry said the Cairo site preserved the fossilized root systems of ancient trees, indicating where they came to life. “We don’t see tree fossils but we see a map of exactly where those trees were standing, so what we’re learning is the environment of the forest,” he said.
The fossilized “map” appears in Archaeopteris, an ancient plant characterized by “large woody roots and woody branches with leaves,” like modern trees, according to a report from Binghamton University in New York. Previously, the first known discovery of Archaeopteris placed the arrival of plants 20 million years later, Science reported.
The development of these early forests relied on the evolution of precursors to characterize trees, Berry said.
“I think the impetus is my evolution, the development of anatomy that allows for more complex ramifications,” he added.
Perry explained that such anatomy arrived as soon as plants developed “the genetic toolkit to be able to construct” tree-like structures, early branching systems, explaining, for example, that they were developed just before the Devonian in the Silurian period (443.8 million to 419.2 million years ago). ), while the first roots reached early Devonian.
According to two reports from the Brooklyn Botanic Garden, the tree’s attributes were then given major advantages, particularly the ability to rise above competition to absorb sunlight.
“Some environmental changes may have made at least one important tree feature possible,” Berry added. Megaphylls, which are common leaves today and feature branched veins, can grow much larger than their predecessors and thus absorb more sunlight. According to a study conducted in 2021 in the journal Nature, it first appeared regarding 390 million years ago, but it started small and spread only 30 million years later, at the end of the Devonian period.
The study found that this delay occurred because rising levels of carbon dioxide (CO2) made the Earth too hot for large, massive leaves, they simply absorb too much sunlight and heat up. However, the sharp drop in CO2 levels in the Devonian has benefited doubly from the massive pulses.
The study explained that reductions in greenhouse gases cooled the planet, while the megafauna might expand into more pores called stomata to absorb higher levels of dwindling carbon dioxide, and these leaves might then help drive the forest revolution forward. Live Science
