Shadow Forests: Trees/Forest Sites/Research
Angela and Beth have worked to create an immersive exhibition that displays intersections between art, science and natural history through the lens of ancient forests in deep time. This section provides information on the trees, locations that the exhibition focuses on, and research that the artists utilized as they delved into this critical period in Earth's development. The Devonian period had critical impact on human and ecological history from 385-million-years ago to today.
Mid-Devonian Trees
"The origin of trees and forests in the Mid Devonian (393–383 Ma) was a turning point in Earth’s history, marking permanent changes to terrestrial ecology, geochemical cycles, atmospheric CO2 levels, and climate." Drs. Stein, Berry, et. al.
Archaeopteris, Lycopods, Cladoxylopsids and Aneurophytes (this is the order above [with an aneurophyte wrapped around a clodoxylopsid]) were among the very first trees. These trees were taller than the shrubby and ground-hugging plant life that preceded them. As they grew taller during the middle Devonian period, the trees pulled significantly higher amounts of CO2 out of the atmosphere and began the creation of a habitable planet.
Archaeopteris
Archaeopteris trees hold the closest relation to modern trees. They were similar to conifers with complex and deep roots. From these roots grew rootlets which may have connected with other plants and trees. These were the first trees to grow branches that did not shed quickly as the trees grew. From these branches grew fern-like leafy fronds which did shed continuously.
Unlike most modern trees, archaeopteris reproduced from spores instead of seeds.
Lycopsids
Lycopsids dominated during the later Paleozoic Era. They survived from the Devonian period and remained until the Permian period. Their remains formed the majority of Earth’s coal beds which fueled the Industrial Revolution and beyond. Lycopsids did not have broad leaves, rather they had microphylls with narrow, sometimes divided lamina supplied by an unbranched vein, and they reproduced by emitting spores.
Cladoxylopsids
Cladoxylopsids are considered to be the first trees. They were remarkable in many ways, in particular the base of the tree was hollow, with the wood as a ring of separate strands rather than a solid trunk, and they ripped themselves and their connective tissue apart to grow taller, seeking the sun. Eventually cladoxylopsids would collapse onto themselves. This process of growth was unique to cladoxylopsida trees.
Cladoxylopsids did not have flat leaves because the high CO2 level in Earth's atmosphere would have burned them. Instead, they had frond-type branches with twiggy appendages containing photosynthetic organs. They were therefore able to withstand the high CO2 levels. These branches shed constantly and the forest floor was littered with their remains. They reproduced by emitting spores.
There are no known living relatives of cladoxylopsids.
Aneurophytes
Aneurophytes had woody rhizomes that grew along the forest floor, leaning and climbing up against other trees in what is believed to be a symbiotic relationship. Similar to cladoxylopsids, aneurophytes did not have laminate leaves, but photosynthetic twiggy appendages and reproduced by emitting spores.
Svalbard, High Arctic - Norway
The 3D fossil replicas in our exhibition are from the Longyearbreen glacier above Longyearbyen, Svalbard. Aside from a research station on Svalbard, Longyearbyen is the northernmost settlement on the planet. Beth found the fossils (which are permitted to be removed), in a moraine ridge. After consulting with Dr. Chris Berry, we believe they are from the Eocene. Fossil remains on the other side of Svalbard, where Dr. Berry has done extensive research, are from the Devonian. 600 million years ago Svalbard was close to the south pole. 350-400 million years ago it was near the equator, where it was covered in tropical forests. Eventually, it drifted north, to the top of the world.
New York - Catskill Mountains, USA
Earth's oldest in situ fossil forest was identified in 2011 by a team of paleontologists including Drs. Stein, Berry and Ver Straeten with whom we worked. The root systems of archaeopteris trees are still intact and there is evidence of cladoxylopsids and enigmatic lycopsids (though all are at great risk of eroding as they are exposed to the elements). The extraordinary uniqueness of this site is that because it is largely intact, it is possible to imagine - to literally see - where trees grew, and where the forest was located. Many other ancient tree remains are found as broken stumps, having been washed or tumbled away from their original locations after cataclysmic weather events. There are also ancient fish fossils here (though the majority have been removed for research purposes).
This fossil forest is located on traditional, unceded lands of the Stockbridge-Munsee Band of Mohican Indians.
Gilboa, New York - Catskill Mountains, USA
Construction began on the Gilboa Dam in 1919, to create the Schoharie Reservoir which supplies 15 percent of the drinking water to New York City (255km/155 miles south). While excavating in the 1920's, fossilized remains of hundreds of large tree stumps were uncovered. These stumps were examined, and they became instructors on arboreal life in the Devonian period. Some stumps were removed for scientific study, and many remained underwater when the quarry was filled. Trees found in Gilboa include Wattieza and Eospermatopteris, and when discovered, they were the oldest trees ever found (until Cairo). In 2010, the dam was drained for repairs and for a few weeks, scientists (including Drs. Berry and Stein) were afforded an extraordinary and rare opportunity to visit the reservoir's bed, map the floor, and catalog the remains of dozens of previously unidentified trees. The Gilboa Museum and Juried History Center is an excellent place to see Devonian and other fossils from deep time.
Many residents of Gilboa lost their homes, their town, and their community history when the dam was created. The town was moved, but layers of planetary, ecological, and human history remain submerged.
This fossil forest is located on traditional, unceded lands of the Stockbridge-Munsee Band of Mohican Indians.
The Gearagh, Macroom, Ireland
The Gearagh is a flooded glacial woodland in County Cork. It was home for many decades to families who lived among the waterways. The residents were evicted in the 1950's when it was determined that the Gearagh was required to power a new hydroelectric dam. More recently, many of the remaining ancient oaks were removed after a storm. The Gearagh exemplifies the ongoing struggle between balancing the importance and irreplaceability of the few remaining ancient forests, against the demands and enhancements of supporting human resources and expansion.
Research and Links
World's Oldest Fossil Trees Uncovered in New York (BBC)
Mid-Devonian Archaeopteris Roots Signal Revolutionary Change in Earliest Fossil Forests (Current Biology, Stein & Berry)
Paleobotanical Work at Riverside Quarry, Gilboa (video with Chris Berry, Ph.D., Bill Stein, Ph.D., and other scientists) This is a fascinating YouTube video showing the mapping of the quarry floor to identify Devonian tree stumps
Tropical Fossil Forests Unearthed in Arctic Norway Cardiff University, Wales (Chris Berry Ph.D.'s work)
The Gearagh: One of Ireland’s least appreciated natural treasures (The Irish Times)