PappCaseyEH2000: Lichen Project

Data

North: 2
East: 1
South: 1
West: 1

Coordinates: 39 19’32.2” N 82 05’40.2” W
Standard deviation = .3214

Background

A.) Lichens are a symbiotic organism in which there exists a relationship between fungi and green or blue algae. The fungi feeds off of the algae by harvesting the sugars it produces during photosynthesis. The algae benefit by being protected from the environment by the filaments of the fungus, which also gather moisture and nutrients from the environment. The algae could survive without the fungi, but it would not be very resilient, while the fungi could not survive most environments without the algae. The properties of the whole lichen are very different than the properties of the individual organisms by themselves. The names given to lichens refer to their fungal partner.

B.) The interaction between lichens and air pollution has been used to monitor air quality since 1859. The relationship between lichens and air quality varies depending on the type of fungus. The sensitivity of a lichen to air pollution is directly related to the energy needs of the fungi. The stronger the dependency of the fungi on the food that the algae produces, the more sensitive the lichen is to air pollution. By observing the presence of lichens in an area, it is possible to assess air quality. Many lichens are very sensitive to sulfur dioxide pollution in the air. This is because they have a very efficient absorption system, which results in rapid accumulation of sulphur when exposed to high levels of sulphur dioxide. The algae is most effected by the Sulphur dioxide, as chlorophyll is destroyed and photosynthesis is inhibited. Lichens also absorb sulphur dioxide dissolved in water. Some lichens, such as Usnea, will only survive in areas with good air quality, while other types such as Parmelia and Physica that can survive in areas with poor air quality, such as nears high traffic roads or factories with high emissions. By knowing which lichens prefer what type of environment, you can map air quality and monitor it over time in an area. The most sensitive lichens are shrubby and leafy while the most tolerant lichens are all crusty in appearance. Since the time of industrialization, many of the shrubby and leafy lichens that can only survive good air quality, such as Ramalina, Usnea, and Lobaria, are only found in areas with very pure air.

C.) Beatrix Potter was from The Lake District in northwest England, home to an expansive rolling countryside surrounded by mountains. This picturesque landscape was a huge inspiration for her famous children’s book illustrations about Peter Rabbit, but it also fueled her other passion of botany. Beatrix Potter was the first person to observe the potential relationship between a fungus and algae that creates a lichen. She drew hundreds of fungi, and in the process she discovered what she believed to be a symbiotic relationship between fungi and algae. She conducted experiments in her kitchen, cultivating both the algae and fungi cells, and recorded in detail her observations of algal and fungal properties. Because she lacked a scientific education, she was not taken seriously by scientists in England. A woman named Mary Noble stumbled up on Potter’s drawings about 15 years ago and discovered that Potter’s illustrations and observations had captured details about fungi that other scientists failed to see up until then.

D.) Candellara Sp. Yellow falls under the category of lichen known as Candellara Concolor, a type of lichen that favors bark high in nutrients, but it can also grow on rocks. Candellara Sp. is sensitive to sulfur dioxide.

E.) Physica Sp. Blue / green is the type of algae that is usually in a symbiotic relationship with the fungi. It has a greenish blue color, but can be kind of gray. It is found on barks, in urban areas, on rocks, and on other wood structures.

Method

The two species of lichen that we were observing grow more readily on the bark and branches of the ash and maple tree. We identified a maple tree by examining opposite branching. The tree was near a road that cars drive by often, but I would not consider it a heavy traffic road. People drive by this tree when they are accessing the dorms on south green. We then took measurements with our metal measuring device that was divided into four quadrants each measuring 4 square centmeters. We measured with the lowest quadarant abuot 1 meter off the ground. We repeated this on all four sides of the tree: north, east, south, and west. We used the GPS on our phone to observe the coordinates of the tree, and we used our phone to take photos of the tree trunk, branches, and leaf. The data that we collected is being given to the graduate students in the class and will be used for future lichen projects. Our combined data can be used to track air quality over time.