Presque Isle Adventures

After spending some time out on Presque Isle island, we were able to identify some real life examples of different kinds of interaction. Firstly, an example of parasitism we saw was a "gall". Galls are essentially a tumor growing inside a tree (or plant) due to a parasite living off of it. As for commensalism, we saw a lot of squirrels running around the forest. The interaction between the squirrels and trees is considered commensalism, because the squirrels are using the trees for shelter and protection, but are not harming the tree in any way. Mutualism is beneficial to both organisms involved. We were unable to find an example of it on Presque Isle, but after some research of interactions in northern temperate deciduous forests, I found one. There are some birds that feed of insects that burrow in the fur of white tailed deer. The birds get their food, and the deer are rid of any harmful insects. Next, we looked for intraspecific competition. This is where members of the same species compete for limited resources. What came to mind for me is not something we could see at that moment in time. There are lots of deer on the island, and there is very limited food during the winter months, due to the lack of foliage, and the ground being covered with snow. The deer have to compete amongst themselves to find food, and in some cases, may be forced off the island. The opposite of intraspecific competition is interspecific. During this kind of competition, members of different species compete for resources. We did a study of trees on the island, and found that there were a lot of different species growing there (white and red pine, oak, spruce, fir...). Each of these species competes for space, sun, and nutrients. They compete by spreading their roots out, or growing taller than other trees. The taller, more spread out trees will be healthier in the long run, because they can obtain more nutrients. Finally, we had to identify a microhabitat. This is a habitat that is vastly different from its surroundings. We chose a rotting log, with a lot of moss growing on it. The log was a home for many different types of insects that wouldn't be found elsewhere in the woods, as well a moist area for moss and lichen to grow. Biogeochemcial cycles on the island are mostly that of decomposition (via the nitrogen cycle) and the water cycle. 

One of my favorite animals to watch on the island is the white tailed deer. It is an herbivore, and eats only plants in the mornings and late afternoons. Its diet changes as the seasons change. In the summer it eats foliage, in the fall, corn, acorns, and other nuts, and in the winter, it eats mostly buds and twigs. White tailed deer generally live in an area of one square mile, and groups of deer consist usually of a mother and her fawns. Bucks, on the other hand, group in threes or fours. They are the prey of wolves, coyotes, and of course, humans.

By Ken Thomas (KenThomas.us (personal website of photographer)) [Public domain], via Wikimedia Commons