The fossilized forest at this site is also thought to be two to three million years older than what was previously the world’s oldest forest at Gilboa, also in New York State, according to the BBC.
The find in the abandoned quarry in Cairo, New York marks a turning point in Earth’s history. This turning point occurred during the mid-Devonian period (393–383 Ma) when trees developed root systems – literally changing the climate and atmosphere.
It was during this period that permanent changes occurred to terrestrial ecology, geochemical cycles, atmospheric CO2 levels, and climate. This is when trees began to pull carbon dioxide (CO2) from the air and lock it away.
In 2009, scientists from Cardiff University, UK, Binghamton University in the US and the New York State Museum began looking at the site in the foothills of the Catskill Mountains in the Hudson Valley.
Since that time, they have mapped over 3,000 square meters (32,292 square feet) of the forest and conclude the forest was home to two types of trees – Cladoxylopsids and Archaeopteris.
“The Cairo site is very special,” says team member Christopher Berry, a paleobotanist at Cardiff University in the United Kingdom, reports Science Magazine. The quarry floor, about half the size of a U.S. football field, represents a horizontal slice through the soil just below the surface of the ancient forest. “You are walking through the roots of ancient trees,” Berry says. “Standing on the quarry surface we can reconstruct the living forest around us in our imagination.”
The researchers also discovered some very long, woody roots that transformed the way plants and soils gather water. Some of the fossilized roots there are 15 centimeters (6 inches) in diameter.
The root systems must have been extensive because they formed 11-meter-wide (36 inches wide) horizontal radial patterns that spread out from where the vertical tree once stood. The root system apparently belongs to Archaeopteris, a type of tree with large woody roots and woody branches with leaves that are related in some way to modern trees.
Archaeopteris is an extinct genus of tree-like plant with fern-like leaves. A useful index fossil, this tree is found in strata dating from the Upper Devonian to Lower Carboniferous period and had a global distribution. You could look at these early trees as the first to change over from being ferns – on their way to becoming trees.
The site is of great importance3 because it marks a transition between a planet with no forests and a planet that is largely covered in trees. Dr. Berry says that further study of the site will give scientists a better understanding of how trees evolved and how they draw down carbon dioxide (CO2) from the atmosphere.
“We’re well aware at the moment that having forests is a good thing and burning down forests and deforestation is a bad thing.
This fascinating study was published on December 19, 2019, in the journal Current Biology.
