One of my favorite places to let my imagination wander is among the branches of this old oak covered in lichen, moss, and ferns. Though I've only visited visually from the ground below, I feel like I could wander and explore this self-contained, arboreal ecosystem for hours on end.
Especially intriguing in this tree is the Resurrection Fern (Pleopeltis polypodioides) that lives upon the branches of this ancient oak. This remarkable fern grows on the limbs of large trees and occasionally on rock surfaces. Although not rare, it's really not very common in this area either. Living on the branches of another plant may be normal in rain forests where everything is routinely bathed in water, but in middle Tennessee (and most of the rest of the U.S., for that matter) the branches of a tree are routinely very dry—not exactly a good habitat for ferns. This fern has found a way around that problem. The Resurrection Fern gets its name from an ability to survive dry spells simply by withering when dry and then seemingly coming back to life when suitable moisture returns. From what I read, the Resurrection Fern can loose up to 97% of its water content and still survive. By contrast, most plants will die after loosing only 15% of their hydration. This remarkable ability to withstand drought makes the Resurrection Fern ideally adapted for life in a climate that is periodically wet but commonly dry.
I would love to have the opportunity to learn more about this amazing fern that defies all odds and finds a way to adapt and survive where others could not. Perhaps we all could use a few lessons in being adaptable.