Thursday, January 22, 2015

Oldest Fossilized Forest Discovered: 385 Million Years Old


Scientists from Binghamton University and Cardiff University, and New York State Museum researchers, and have reported the discovery of the floor of the world's oldest forest in a cover article in the March 1 issue of Nature.

"It was like discovering the botanical equivalent of dinosaur footprints," said Dr. William Stein, associate professor of biological sciences at Binghamton University, and one of the article's authors. "But the most exciting part was finding out just how many different types of footprints there were. The newly uncovered area was preserved in such a way that we were literally able to walk among the trees, noting what kind they were, where they had stood and how big they had grown."

Scientists are now piecing together a view of this ancient site, dating back about 385 million years ago, which could shed new light on the role of modern-day forests and their impact on climate change.

 
(Above): William Stein, associate professor of biological sciences at Binghamton University, carefully places one of the world's oldest trees in the University's greenhouse.  Photo Credit: Jonathan Cohen, Binghamton University
The recent discovery was made in the same area in Schoharie County where fossils of Earth's oldest trees -- the Gilboa stumps -- were discovered in the 1850s, 1920 and again in 2010 and were brought to the State Museum. The Museum has the world's largest and best collection of Gilboa fossil tree stumps. For decades scientists did not know what the trees connected to the stumps looked like. 

That mystery was solved when Linda VanAller Hernick, the State Museum's Paleontology collections manager, and Frank Mannolini, Paleontology collections technician, found fossils of the tree's intact crown in a nearby location in 2004, and a 28-foot-long trunk portion in 2005. Mannolini, Hernick, and Dr. Christopher M. Berry, a paleobotany lecturer at Cardiff University in Wales, co-authored a Nature article reporting that discovery, as well as the most recent one. Working in conjunction with Stein, Mannolini also developed a sketch of the ancient forest.


https://naturalishistoria.files.wordpress.com/2012/03/nyforestrecostructionmapnat.gif

(Above): Figure from the research paper in Nature describing the fossil forest. The circles represent tree bases with different shaded circles representing different types of trees. The black/gray circles represent the Eospermopteris trees that have been found in other places in the world in rocks of the same age (385-390 million years). The area inside the black ring is the diameter of the trunk with the outer ring indicating the extent of the roots.

Based on the new research, the team now believes that the area probably enjoyed a wetland environment in a tropical climate. It was filled with large Eospermatopteris trees that resembled weedy, hollow, bamboo-like plants, with roots spreading out in all directions, allowing other plants to gain a foothold. Scrambling among these roots on the forest floor were aneurophytaleans, acting much like ferns do today, and possibly climbing into the forest canopy as vines. The lycopsids, although seemingly rare, may also have been very important in certain places although perhaps not yet as specialized inhabitants of swamps.


(Above): The fossilized base of an ancient tree.

But what the research team believes is most important about this particular site is what it was doing to impact the rest of the planet. At the time the Gilboa forest began to emerge -- during the Middle Devonian period, about 385 million years ago -- Earth experienced a dramatic drop in global atmospheric carbon dioxide levels and the associated cooling led ultimately to a period of glaciation.  "Trees probably changed everything," said Stein. "Not only did these emerging forests likely cause important changes in global patterns of sedimentation, but they may have triggered a major extinction in fossil record."

For Stein, it all comes down to one thing -- how much we don't know but need to understand about our ancient past. "The complexity of the Gilboa site can teach us a lot about the original assembly of our modern day ecosystems," said Stein. "As we continue to understand the role of forests in modern global systems, and face potential climate change and deforestation on a global scale, these clues from the past may offer valuable lessons for managing our planet's future."