Welcome to Science Sunday! On Science Sunday we will explore the in-depth science behind something we talked about earlier in the week. On Friday, we had found some Lichen growing on a fallen tree. Were your kids able to spot any in your yard? I also mentioned that my friend had asked me a few weeks ago if the lichen growing on the branches of her tree was killing it. You see, the branch that the lichen was growing on was in fact dying, so it appeared as though the lichen was the cause. I just love the way lichen looks (is that strange?) so I was hoping that the lichen was not the cause of the branches’ demise. Did your kids have a vote on whether lichen harms trees? To be honest, I forgot to ask my kids to vote! But next time we spot some lichen, I’m going to ask them and initiate some discussion. For the answer let’s get some drum roll please . . . . lichen is not harmful to trees! Yeah!
Lichen does not have roots, so it needs a host to grow on. Often its host will be a tree, but lichen will also grow on rocks or even buildings. What I found very interesting about lichen is where it gets its food. Lichen need water and minerals to grow. Small particles of soil are carried in the wind, and land on the lichen. Soil contains minerals, and when rain water hits the lichen, the small particles of minerals dissolve and are absorbed by the lichen. Lichen uses sunlight for energy just like other plants, so on trees, it tends to grow in places where it is not shaded by leaves. Often this is on a branch that has already died, thus giving the appearance that the lichen is the cause of the branches demise. If lichen isn’t harmful to trees, is it beneficial to the environment in any way? Actually yes. Lichen helps to filter the air we breathe, much like trees. In addition many animals like to eat lichen, such as dear, or build nests with it, such as hummingbirds. Look at this tiny hummingbird’s nest where the hummingbird used some lichen for its construction. I found this picture on a blog called Nature Remains (http://natureremains.blogspot.com/).
I hope you learned a little something about lichen, I know I did, and I can’t wait to share what I learned with the kids the next time we spot some growing on a tree. If you want a few more details about lichen, I gathered a lot of my information from this New Mexico State University cooperative extension article: http://aces.nmsu.edu/ces/forestry/documents/h-167_color_web.pdf.
