Bachelor Reserve vs. Oxford’s “Mile Square”

Introduction  Purpose - To study insect diversity in the Bachelor Reserve and the "Mile Square“ to see whether or not human developments impact biodiversity.

Hypothesis  We believed that we would find a more diverse insect population in the Bachelor Reserve because of its undeveloped landscape. We expected that the "Mile Square" would have a less diverse population of insects because of the human disturbance in the area.

Relevance  There are many important things that insect’s do to balance nature. By developing, we could be hurting ourselves more than we realize. Entire ecosystems can be disturbed by our influence. Insects are at the bottom of many food chains therefore if certain important insects were removed from the system it could affect many other species in the area.

Procedure  We set up five sample areas in random locations throughout the Bachelor Reserve and "Mile Square."  In each of these locations we collected leaf litter samples and placed them in Berlese funnels to extract the insects.

Procedure  Our samples were taken from ½ meter 2 plots  We placed the leaf litter samples in labeled trash bags.  Placed the individual samples into the Berlese funnel one at a time to extract the insects.  The funnel we used was in the Entomology lab in Pearson.

What is a Berlese Funnel? Collecting Jar Ethanol

“Mile Square” Site 1 Bishop Woods

“Mile Square” Site 2 Shiver Center

“Mile Square” Site East Spring Street

“Mile Square” Site 4 Attraction’s Restaurant

“Mile Square” Site N. Poplar

Bachelor Reserve Sites Site 1 Site 3 Site 2

Bachelor Reserve Sites Site 4 Site 5

Results  Our data show a greater diversity of insects in the Bachelor Reserve as compared to the “Mile Square.”

Species Richness  Species Richness is simply the number of different species found in a certain area.

Species Richness  However, this does not indicate how the diversity of the population is distributed or organized among those particular species. For example, if there were 4 different species found in both the bachelor reserve and the "Mile Square". This does not indicate what % of each species there were of the 4 species identified. In the Reserve 80% of the total number of species could have been ants while in the "Mile Square" there could have been an even 25% of each species.

Species Richness

Simpson’s Index  We calculated the Simpson Index to measure the relative diversity of the two areas.

Simpson’s Index  1. Simpson's index: D  D-The probability that two randomly selected individuals in the community belong to the same species.

Simpson's index: D = sum(Pi2)  Bachelor Reserve  “Mile Square”  From this, we see that it is more probable that two randomly selected individuals in the “Mile Square” will belong to the same species.

Simpson's index of diversity: 1 - D  The probability that two randomly selected individuals in a community belong to different species.

Simpson’s Index: 1-D  Bachelor Reserve  “Mile Square”  From this we see that it is more likely that two randomly selected individuals in the Bachelor Reserve will belong to different species.

Implications  Through our study, we found less insect diversity in the “Mile Square”  We believe that the development in the “Mile Square” area has had a negative impact on species diversity.

Possible Problems  It was difficult to pick random sites In the “Mile Square,” due to the limited areas containing adequate amounts of leaf litter.  In some areas our ½ meter 2 samples contained more litter than others, which could have an effect on total numbers of insects present in each sample.

Possible Problems  We only had access to one Berlese funnel, so some samples were not extracted for several days after they were collected.  On a few occasions the litter samples were left in the funnel for an extra day due to conflicts with lab access.

Future Studies  Study the impact that different levels of development have on diversity of insects.  i.e. New York City Vs. Oxford  Other studies could focus on different times of the year. We conducted our experiment in the fall, but it could possibly have different results in a different season.