Transcript “Mile Square” Site 1

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 meter2 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 3
103 East Spring
Street
“Mile Square” Site 4
Attraction’s Restaurant
“Mile Square” Site 5
217 N. Poplar
Bachelor Reserve Sites
Site 2
Site 1
Site 3
Bachelor Reserve Sites
Site 5
Site 4
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
10
# of Species Present
9
8
7
Bachelor
Reserve
Mile Square
6
5
4
3
2
1
0
1
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- 0.21
 “Mile Square”- 0.28
 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 - 0.79
 “Mile Square”- 0.72
 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 meter2 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.