ARTHROPOD TAXONOMIC DIVERSITY IN OLD FIELD HABITAT: EDGE VS.
INTERIOR
YOUR NAME, and Others, School of Mathematics & Natural Sciences, University of Rio
Grande, 150 N. College Ave., Rio Grande, OH 45674
Lab Report #1
8 October 2015
INTRODUCTION
Text—Consult your handout from the day of the lab. Cite Ricklefs (2007) for definitions and/or
descriptions of “edge” and “old field, which were provided in that handout. For an objective,
you can describe that we sampled for (i.e., arthropods in edge and interior portions of old field
habitat) to examine for possible biodiversity difference between “edge” vs. “interior” portion of
old fields.
METHODS
Text—explain what we did. This includes the “field” details and the “lab” details. Note the
main metric used (i.e., species richness…not species composition). Cite Krebs (1998) for
selection of this metric.
RESULTS AND DISCUSSION
Text—note the following are the descriptive statistics you need to “write” into your text (no
Table necessary):
Had 12 paired transects that were sampled and analyzed.
Edge overall species richness: mean = 14.5 (SD=4.9) with range of 4-27
Interior overall taxonomic richness: mean = 15.1 (SD=4.3) with range of 3-26
(Figure 1). Note whether there appears to be statistical support for any differences between
edge vs. interior species diversity based on examining error bars (=SD bars in Figure 1).
Consistently, the most diversity by order observed was for arachnid followed by beetles (Figure
2). Note whether there is appears to be statistical support for differences in species richness
within a taxa (i.e., spiders or beetles) for any edge effect based on examining the error bars
(=SD bars in Figure 2).
When using paired values, there were 8 of 12 transects in which the beetle species richness of the
interior transects exceeded that of edge transects, 1 time there was a tie in species richness, and
3 times edge transects for beetle species richness exceeded that of interior transects. In contrast,
for spider paired transects, there were 6 times interior species richness exceeded edge, 1 time
there was tie in species richness, and 5 times edge species richness exceeded that of interior
transects. Based on this data, in general is there a trend indicating that perhaps diversity of
beetles—more so than spiders—is greatest near the interior of old fields (vs. the interior)?
Assuming your answer is “yes”, what would you recommend to further evaluate this possible
difference in diversity between edge and interior portions of old field habitat?
REVIEW OF STUDY DESIGN AND METHODOLOGY
Address in the final two paragraphs what might have affected our a) field sampling results and
b) identification results from an observer (aka tech) perspective. (remember—we reviewed these
in class). Be sure to address how we could have reduced some of this potential bias and/or
improved the “quality” of our data.
LITERATURE CITED
Krebs, C.J. 1998. Ecological Methodology. Benjamin/Cummings, Menlo Park, California.
Ricklefs, R.E. 2007. The Economy of Nature. 5th Edition. W.H. Freeman and Company, New
York, New York.
Mean (+/-SD) Species Richness
25.0
20.0
15.0
10.0
5.0
0.0
Edge
Interior
Figure 1. Species richness by transect by position within old field habitat
on the University of Rio Grande campus, 8 September 2015. Sampling
was done using paired, 20 m transects (n=12).
2
Mean (+/- SD) Species Richness
8
8
7
7
6
6
5
5
4
4
3
3
2
2
1
1
0
0
Edge
Interior
Beetle Species
Edge
Interior
Spider Species
Figure 2. Arthropod species richness by beetles (left) and spiders (right) within old field
Habitat on the University of Rio Grande campus, 16 September 2014. Sampling
was done using paired 20 m transects (n=12).
3