User:Cassidy B. Hart/Notebook/Biology 210 at AU

6/30/2015 Exercise I- Examining Biological Life at AU

Introduction

Biological sciences wants to understand life, especially the diversity of it (Freeman, 2014) This biodiversity is due to evolution, which occurs through natural selection and other methods. Natural selection is the process where the fittest organisms survive because they are best adapted to the environment and so survive to reproduce more, passing their genes along to the next generation. In this lab, the biodiversity of life is studied by observing a transect, or an ecosystem. The biome of the transect studied in this lab is temperate forest. Transects are important because they provide the opportunity to study the different niches and the organisms that habitat them within an ecosystem and see how all the unique biotic and abiotic factors interact. Biotic factors are the living components of an environment while abiotic factors are the nonliving components. Both play a crucial role in ecosystems and are studied in this lab.

Method

To observe the transect at AU, a 20 x 20 meter area on American University's campus was selected. The area selected is located on the northern side of campus, in between the amphitheater and McDowell Hall. When looking down on the amphitheater, the transect is to the right and to the right of the transect is McDowell Hall. This area was then visited and observations were made about the biotic and abiotic factors. Pictures were taken of the area. A sample was taken of the soil and plants and placed in a large plastic bag. Eleven grams of the sample was then placed in a plastic jar with 500 mLs of deerpark brand water. 0.1 gram dried milk was added to the mixture and the jar was capped. The mixture was then shaken for 10 seconds, labeled, and put on the window sill to sit for 48 hours (Bentley, 2015).

Results

The selected transect consisted of trees, both big and small, with a stream running down the center of the transect. The stream was full of rocks along with sand. There was soil covering all the ground of the transect that was not the stream and there were bushes, ferns, weeds, and other plants. The transect was hilly, with the stream at the bottom and the land rising up on both sides of the stream. The biotic factors were the plants, trees, ferns, weeds, ants, and a few small birds. The plants and trees were spread around the stream, the birds were seen bathing in the stream, and the ants were seen crawling throughout the transect. The abiotic factors were the rocks, found in the stream, the water, dirt, air, and sand. The below images show the transect.

Discussion

The transect selected has multiple abiotic and biotic factors. These factors work together to provide habitats and food to the organisms that live in the ecosystem. In the observed ecosystem not many large mammals were seen and there is not much human traffic. However it is possible that deer or other mammals do visit this transect. This would be a good base for future observations. Another interesting question would be whether AU maintains the ecosystem at all since there was evidence of a sprinkler in the transect. If so it could change the natural environment.

References

Bentley, M., Knight, S., Zeller, N., Walters-Conte, K. 2015. Exercise I- Examining Biological Life at AU. Biology 210 Laboratory Manual

Freeman, Scott. 2014. Biological Science. Prentice Hall: New Jersey. 1.

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