Can you visualize a time in our brief history where a squirrel could romp from tree to tree without ever touching the ground? Where native trees spanned mile after mile?
Our distant past provided us with shelter, shade, food and warmth, as it does today. It is hardly a surprise that web and newscast stories of climate change, mass clear-cutting of trees and devastating tree disease continue to make front-page news. We mourn tree loss daily.
Trees aide in carbon sequestration and provide ecosystems for other creatures. Selfishly, we will miss the health and psychological benefit they provide to us and our families. Trees have been falling as a result of fewer diverse species occupying a habitat which increases the risk of disease.
Here is a case in point.
While I was at the Bartram Gardens in Philadelphia, our group “met” the Franklinia tree. Not many were familiar with it, being a species that has not been seen in the wild since 1803. It was originally found in one locale near Fort Barrington along the Altamaha River in Georgia in a “climate refuge habitat”.
The exact reason for the species disappearance is not known. Burning and clearing of land for early settlement, as well as subsequent flooding may have been contributing factors. They just don’t grow wild in Georgia any longer.
To meet the growing fascination and horticultural demands in Europe during the late 1700s probably contributed to their disappearance. To grow one now means you are growing a part of our history.
All Franklinia grown are descendants of the original trees found in 1765 and propagated by John and William Bartram. The oldest documented specimen of Franklinia is 104 years old and lives at the Arnold Arboretum in Boston. Franklinia actually appears to be better adapted to northern climates now than to the location where it was found by the Bartrams in Georgia.
So Why No Franklinia Elsewhere?
One theory proposes the tree declined due to climate change, possibly after migrating southward along southern river valleys during a previous ice age. It suffered from a hotter climate as the ice sheet receded. Some trees found refuge in an isolated protected habitat or “climate refuge”.
A second theory is that man destroyed the trees and habitat. It is possible that the grove the Bartrams discovered was no longer genetically diverse enough to withstand pathogens or changing conditions. Lastly, it could have happened from forests becoming monocultures. None of these theories really accounts for why in the Bartrams’ extensive travels that they never saw another Franklinia tree anywhere else.
But what do they believe now?
We were told the trees habitat and distribution are shifting as more northern areas become increasingly warmer and more conducive to this tree’s horticultural, soil and weather preferences. CLIMATE CHANGE. Another consideration is how temperature change affects the forest floor and the soil organisms that aid in tree health.
The story of this “climate refugee tree” raises important questions about what will happen to other well-established tree species as human-induced climate change (also naturally occurring climate change) continues on a spiraling path.
Should we assist trees in tree migration to ensure their genetic material is safe for the future? Some would say no, arguing that getting a tree to survive when we’re not in an ice age now would be ludicrous.
Trees migrate on their own, but conservationists argue with this approach. They prefer to plant “native” tree species almost to the detriment of the tree and its ability to thrive. When native habitat disappears it seems nature decides if trees can become “native” elsewhere providing their conditions are met. It kinda makes the native argument pointless. Its nature’s ultimate decision, not ours.