2013 came in auspiciously with the crisp, sunny day we enjoyed. It was so beautiful outdoors I had to get out with my camera. On chilly winter days it can be easy to assume the garden is asleep but those with an inquiring mind know better. In fact, there are tiny, involved worlds thriving on an apparently dormant tree branch. I can spend hours investigating the denizens of bark and rotting wood when the cover of leaves is removed. Moss and lichen abound in our part of the country, thanks to the moist environment. Peacefully searching for these uniquely graceful and often unappreciated organisms is how I chose to spend a good spell of New Year’s Day, but they can be found any day of the year.
A lichen is a phenomenally interesting organism in that is made up of a fungus and an alga living symbiotically. The fungus in the relationship provides physical support and soaks up moisture from the environment and the alga (often a green or blue-green algae) photosynthesizes light from the sun to feed the fungus. Lichen comes in many forms, with the algae and fungi having evolved together in partnership. Not unlike the two organisms that make up sea coral, lichen is complex and fascinating.
Since lichens can be found on both living and dead wood (as well as on rocks and bare ground), some people mistakenly believe that lichen is the causal agent for the dead branches they find on trees and shrubs. The presence of lichen on woody plants is a natural occurrence that doesn’t harm the plant. The lichen shallowly clings to the bark, growing very slowly and not deriving any nutrients from the plant itself, but instead from the air and rain. Lichen is therefore not parasitic in any way and shouldn’t be removed.
The average lichen is so inconspicuous as to go completely unnoticed. Take the white crustose lichen found on mature red alder trunks as an example. Most people assume the lovely, blotchy white pattern on the trunks of red alder is the color of the bark itself. In actuality, the bark is solid gray with elaborate colonies of lichen species imparting the snowing coloration. However, some lichen are flamboyantly shaped, taking on hairier, branched forms.
Lichens are impactful to forest ecosystems in that they absorb moisture when it’s plentiful and evaporate it slowly into the air, serving as a form of humidifier. They also play a role in nutrient cycling as lichens can absorb nitrogen from the air and convert it to usable sources for plants. The converted nitrogen in the lichen can leach by rainfall, or the lichen itself can fall to the soil and decompose. Lichens are a prominent provider of nitrogen to forest trees and useful to insects and animals for food and nesting material.
Not a specialist in lichens, I stumble along identifying the different types in my garden. With the leaves long dropped, it’s easiest to appreciate the forms, colors and shapes now, whether or not I can positively tell the difference between species with funny names like ragbag or tickertape bone. On the dawn of a new year, I must remind myself that one doesn’t have to be able to identify something to appreciate it.
Here’s to a glorious 2013 where we can all make time to marvel at the natural curiosities in our gardens and investigate the wild spaces around us. Happy New Year!
For more information on lichens; see these websites:
Lichenland website from OSU:
Lichen key from OregonStateUniversity:
Intro to lichens from UC Berkeley:
© Colleen Miko, 2013