I fell for this tree

I went for a walk in the Morton Arboretum today, looking at tree bark. Yes, tree bark. For my biomimicry coursework, I have certain prescribed iSite assignments where I go out and observe nature. One of them included looking at tree bark and the differences between different species. This was on my mind after a conversation I had with Dr. Robert Fahey, a forest ecologist on staff at the Arboretum, about tree bark and its (marginal) insulative values. He spoke about Oak forests and how the rough bark fissures that Oak trees present actually create air pockets that help insulate the tree from fire and extreme cold.  It's cork-like texture also traps air pockets, adding insulation.  He was quick to mention that the cell structure of the live phloem has more to do with a tree surviving cold than the dead bark, but it was an intriguing idea for me and I resolved to contact a plant physiologist soon.  Dr. Fahey spoke about the the chemistry of bark and how some species create chemicals in their bark that protect the tree from predators.

Walking the Woods with Kids

2011-06-26 17.06.36, originally uploaded by dgphilli.

I went on a hike with my husband and two young kids through Starved Rock State Park in Northern Illinois this weekend. The park is a series of canyons that were formed when the glaciers melted, forming a series of rock walls, 50' + waterfalls and sand basins from disintegrating sandstone. When I told my 4 year old daughter that we would be going on a hike to a sand mountain that they could climb, she was beyond excited. So excited, in fact, that she was so focused on getting there that she wasn't really able to enjoy the journey to our destination. Not surprising for a little kid.

In between questions of "are we there yet?", I pointed out tangled tree roots that could have been steps up the cliff, tiny shade flowers, butterflies that crossed our path, interesting moss and lichen, and anything else that I thought may interest her. Not so much. Sand mountain, please!

Genius of Place: Lichen in a New England Forest

Lichen are plants and fungus that create a mutualistic relationship greater than the sum of their parts.  What can we learn from them?

Common Greenshield Lichen.  Flavoparmelia Caperata.  Photo by Amy Coffman Phillips

Natural History
How does the lichen fit into this forest?


Walking through the forest for my first iSite in the Harvard Forest, I came upon this beautiful lichen growing on a red maple tree.  Up close, it looks like flattened lettuce or cabbage growing in these romantic formations, an example of a foliose (leaf like) lichen.  And lichen is unique because it is not one organism, but a symbiotic relationship between two organisms:  fungi and algae.  To form a lichen, the fungus either encloses the algae in fungal tissue or penetrates the algal cell wall in order to harness their photosynthetic abilities.  The fungi form the structure and then recruit algae to come live with them, and the algae benefits from the protection the fungi provide as well as their ability to capture water and nutrients.  The mutualistic relationship between these two organisms (although sometimes commensalistic or even parasitic depending on the species) is greater than the sum of its parts because it allows both organisms to survive and thrive in areas they would not be able to alone.  Their relationship creates benefits for the ecosystem as a whole as well because as rain water falls down the bark of a tree, it gathers nutrients from the lichen which feeds nitrogen and other nutrients to the soil, and then by extension, the tree and other plants.