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.

Lichen exist in most every ecosystem on the planet from arctic tundra to deserts. While they have adapted to many different climates and conditions, they are also sensitive to environmental disturbances, such as air pollution because they are not deciduous and absorb nutrients from the atmosphere, rain and dust rather than roots. For these reasons, they are bioindicator species for air quality as well as ozone depletion and metal contamination.

Lichen also grow in unique structures, different than those that fungi or algae use alone. They are built in layers. The outer layer is a conglomeration of fungal cells that form a protective cortex. Below this layer is a layer of algae embedded in a densely woven layer of fungal hyphae or the long branching structures of fungi,. Below this layer, the third layer is comprised of densely woven fungal hyphae without the algae, called the medulla. The fourth and bottom layer is called the lower cortex and resembles the top layer and is also composed of densely packed fungal hyphae and rootlike rhizines which attach the lichen composite to the structure on which it grows. Because these roots are for structural stability and not nutrient gathering, lichen have the ability to grow on surfaces that other organisms cannot, such as tree bark and bare rocks.

Different types of lichen reproduce in different ways, typically asexually through spores but vegetative and even sexual reproduction occurs in different species. In the case of this lichen, it is similar to an isidia in that it sends up shoots that break off for mechanical dispersal of genetic information. Lichen are able to desiccate and survive long periods with very little water, entering into a state of suspended animation, ready to rehydrate when water becomes available. This ability allows them to survive long periods of temperature extremes, radiation, and drought in harsh environments.

Strategies/Mechanisms
What are the deep patterns we can take away from the lichen?

• Mutualistic communities of organisms create conditions that are better for themselves as well as the organisms around them, and this symbiosis allows them to withstand conditions together that they would not be able to alone. 
• The fungi develop the structure on which the algae grow. Fungi create a densely woven structure of tiny branches that embed and encapsulate the algae in order to harness their photosynthetic abilities. The organism bodily structures of each organism change in order to accommodate their partner, and they cannot survive alone. 
• Lichen absorb nutrients from the air and water through their cell walls. When environmental disturbances occur, the algae absorbs these contaminates molecularly and is destroyed, killing the lichen composite. For this reason, lichen are a good bioindicator species and signal environmental disturbances we cannot yet perceive.

Design Principles
How can these strategies naturally influence design innovation?

• Empower individuals within an organization to collaborate and share resources in order to create restorative communities. 
• Encapsulate harmful substances in a membrane for safe storage at room temperature. 
• Grow fibers at the nano scale that will self-assemble into prescribed patterns. 
• Design smart materials that passively absorb air- or water-based compounds in order to indicate changes in the system.

Design Application Ideas
What are potential innovations that could result from this natural inspiration?

• Store food at room temperature by encapsulating it in a tasteless, edible membrane that prevents spoilage. 
• Preserve vaccines at room temperature by encapsulating active ingredients in a dissolvable membrane.
• Design passive air quality monitors that absorb harmful chemicals or pathogens and change color to indicate their presence. 
• Design water quality monitors that test for chemicals or pathogens by absorbing and changing color to indicate their presence.

Sources
Biomimicry Professional Certificate Program
http://en.wikipedia.org/wiki/Lichen
http://en.wikipedia.org/wiki/Flavoparmelia_caperata

Vernal Pond

Vernal Pond at Harvard Forest

I am at the Harvard Forest in Petersham, Massachusetts, for my second Biomimicry session in the temperate deciduous forest and today we took a walk in the forest. To say I loved it would be an understatement, but I'm a forest lover. This is a picture of a vernal pond, or a pond that fills in the spring and then drains gradually. The Harvard School of Forestry took a sample core and was able to trace 9,000 years of history in this area from evidence that this Hemlock forest was once a Maple forest to evidence of Native American under story controlled burns. Probably most interestingly, because this is a seasonal pond and fish cannot live in it, there are no natural predators for amphibians such as frogs to lay their eggs here. Oh, and its gorgeous.

Elevating the Lowly Dandelion

Dandelion Sketch

Today my kids and I were walking around our neighborhood and started picking dandelions.  I picked a bouquet for my daughter, Ellie, and gave my son Jake one that had ripened into a ball of white fuzz.  My one year old son tried to blow the fuzz off of the stem, with a little success because most of it ended up on his lips.  My four year old daughter and I sat down and started picking the yellow dandelions flowers apart.  I had never spent much time actually looking at these ubiquitous wildflowers other than to pull them from my yard, but it was pretty fun to do it with a four year old. 

McDowell Grove Forest Preserve

Fallen Limbs at the Forest Preserve in Spring

I took a walk in the McDowell Grove Forest Preserve by my house today. I had never been to this area before and I'm so glad I visited for the first time in spring. There weren't any real flowers to speak of but the floor was a carpet of green. I know in a few months, I won't be able to walk through the fields like I did today because the grasses and under story brush will be too high.  

There were fallen branches everywhere, creating a natural clearing. I don't know if it is normal for so many branches and trees to lie on the the forest floor or if there was some event that caused the branches to fall. One fallen log had a reddish moss growing on it but the majority did not. I wonder what was different about that log - the age, type of bark, moisture content of the wood? I'm guessing the latter, but I'd love to bring an ecologist to find out next time.

Pattern of a Tree Limb

Tree Limb Observational Sketch

On a walk through the forest preserve today, I thought about the growth of tree branches.  Seeing so many that had fallen to the ground, I wondered about their structural integrity.  Upon further reflection, I think the downed limbs had more to do with flood damage to the roots than to any defect in the branches themselves.  But, it got me thinking about how a branch grows out from a tree and sends out leaves. 

Tracking Changes Over Time

Magnolia bush in my backyard

my backyard is a constructed ecosystem.  but even so, i've tried to keep it as naturalistic as possible by minimizing turf grass, adding bushes and planting beds, and introducing edible plants into the landscape to encourage wildlife (but not in my fenced off vegetable garden).  so, despite it's constructed nature, it is still natural.  and since it is my backyard and i spend a great deal of time there, i've decided to use it as my iSite for tracking changes over time.

Thoughts on a Tulip

Backyard Tulips

i decided to focus my attention on my backyard for a couple of iSites this week, for a couple of reasons.  1) i love my backyard and have put a lot of effort into making it beautiful and 2) i'm getting seriously close to my next trip and the deadline for all of my assignments - and my backyard is very convenient.  and the tulips are out and beautiful this time of year.

so, tulips.  while outside, i studied my tulips looking through the lens of multi-functional design.  when thinking about this, i divide the tulip plant into three parts - the bulb root, the leaves, and the flower.  i'll focus on the flower because we don't plant tulips for the foliage or the bulb.