Lichen and Moss Distribution in the Deciduous Forest of Oxford

Through this experiment, we plan to prove our hypothesis right or wrong. We plan to gain a better understanding of the statistical analysis by entering in our extensive data, then running a T-test and finding p-values to prove our data's significance. The results of our data will hopefully bear a p-value of under .05, thus proving its significance. By finding out where on the tree lichen grows we can make further hypotheses about what kind of environment the lichen flourishes in and tends to prefer. We are going to look at four different species: moss, crustose lichen, sorediate lichen, and foliose lichen. We would like to establish a basis for understanding the growth and distribution of lichen and moss in order to further our study in our upcoming Discovery Labs, and maybe help in producing a new lab for future Western Students.
We feel that this is an interesting lab, as we feel we are gaining a better understanding of what goes on in the rich ecosystem found here on Miami University's Western Campus. We have both studied ecosystems before and are excited for this opportunity to look at a familiar species in a new light. We both grew up around woods and always noticed the funny green things that grew on trees and wondered what they were and why they grew there.

How does this relate:
This relates to the bigger picture because lichens and mosses are essential organisms to understand if one was interested in studying the ecosystem here on Western Campus. They are what are known as primary producers, which means they convert light energy into a food source. They are one of the building blocks of the vast forms of life that we see everyday. The food chain starts with primary producers, so understanding how they work is vital to understanding all the other organisms. Many people all over the world study Lichen, as shown by our websites, in order to better their understanding of how organisms relate to one another. Finding out where on the tree lichens grow can give us insight to whether or not weather patterns or other external forces influence where the Lichen grows. If external forces do in fact influence the growth of Lichen in certain areas of the tree and not others, then why? And how does this happen? Both intriguing questions to ask and involve the bigger picture that is the ecosystem or even the biome that this Lichen can be found in. Now we are given this opportunity to put these curiosities to rest and get some answers about Lichen.
Exciting Websites about Lichen:
http://www.lichen.com
http://www.orgonet.co.uk/users.mgray
http://www.botany.hawaii.edu/cpsu/ial.htm
http://www.is.kochi-u.ac.ip/bio/lichens/lich-f-2.html
http://www.unomaha.edu/~abls

Materials and Methods:
We plan on taking mesh style netting, cutting it into 1 square foot squares and placing it onto the tree as a grid so as not to hinder any of the external factors that may tamper with the validity of the experiment. Since it is illegal to use tacks in the trees here on Miami's campus we will instead have the students hold the grids up while another one collects the data. We will use this procedure to mark off four trees. It does not matter what kind of trees are used just as long as you are to observe what kind of tree it is and make sure that it has some form of moss or lichen growth. We will also need some sort of device such as a compass to designate what sides of the tree are north, south, east, and west.
The column names will be east, west, north, and south. We will provide the frequency distribution statistics, and a histogram to interpret them. We will perform a paired t-test to gain a p-value and find out if our statistics are significant. Then if our data is significant we will perform a Post-Hoc Fischer test to indicate where the significance is in the data.
We thought a good way to incorporate the class was by having them help set up the mesh netting on the trees and also help in counting the lichen in each quadrant.

Table 1: Distribution of any given Tree (for example an Oak Tree)
North South East West
Moss
Crustose
Sorediate
Foliose

Results:
We found, as shown in Graph 1, that our hypothesis that any growth tends to prefer the north side of trees was proven to be true. Graph 2 shows the growth of each moss and lichen type and compares them over the different types of trees. We found some interesting results by doing this that we had not thought of until we were completely immersed in the experiment. Graph 3 also shows the total distribution but in histogram form. It also tells us what part of that total number of growths is foliose, sorediate, crustose, and moss. This is nice because it also contributes to our hypothesis because it clearly shows that one form of growth seems to dominate the rest of them. Interestingly, in all but one case the form was crustose.
We also attempted to do a summary output as shown in Table 4, but for some reason the numbers that we came up with did not seem to make any sense. We can only assume that this is because of our unfamiliarity with the program and of course human error.

Discussion and Conclusions:
We think that growth occurs mostly on the north side of trees because it is the side that does not see the most harsh weather conditions. We also think that crustose was the most popular species we encountered because of the time of year. Crustose has a hard shell-like feature that protects it from the cold of winter. We also understand that sorediate lichen will most likely grow into being crustose lichen. So we can only assume that if we were to do this experiment in the spring or early summer the results would turn out much differently. This is true only because much of the growth we classified as crustose was probably still in the stage of sorediate in early summer.
The second part of our study revolved around the competition between the various forms of lichen and moss. We found that their was no concretely identifiable evidence that certain trees yield more populations of certain types of lichen. So we came to the conclusion that all the types are capable of growth, but the one that gains a foothold first tends to take over. So basically, whoever is first is the one that stumbles across any given tree gets the luxury of spreading out and taking over the surface of the tree. Until of course some sort of natural occurrence knocks things out of balance and the process starts over again.

Literature Cited:
1. Lichen Biology, Thomas H. Nash
2. The Lichens, Vernon Ahmadjian
3. The Lichen Symbiosis, Vernon Ahmadjian. C. 1993
4. Indices to the Species of Mosses and Lichens Described by William Mitten, William Mitten. C. 1992
5. www.Lichen.com

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