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Data Analysis |
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A one-way ANOVA or the mean values for each replicate sample showed no significant difference between the algal spores sampled on the experimental pads (p=0.20), even though there seemed to be a general trend of more algal spores present in the control samples.. |
In community ecology, emergent
properties of a system may be a result from species interactions. In other
words, a community is much more than just the some of its parts. Below is
a graph of the species found in each community and their relative abundances.
Mites were the only organisms to exhibit a significant difference in abundance between the two communities. (p=0.0035)
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An analysis of the animal communities within each experimental habitat proved equally inconclusive. Diversity indexes were conducted for each replicate, and an ANOVA comparing the outcome of the control environment community and the enriched community was performed. |
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Shannon-Weiner Index The Shannon-Weiner Index explores the uncertainty that one individual organism in a habitat is of the same taxonomic category as another individual. This index increases as the probability of organisms being the same decreases, and therefore communities that are more biodiverse will have a relatively higher Shannon-Weiner Index. P= 0.20471 Control: 2.73 Fertilized: 2.40 Formula obtained from Stiling, 1999 |
Some indexes relying on species number alone may not prove useful if the abundance of species is unevenly disbursed among the community. For example, one comparison may involve two communities, each with 5 different species. If the abundances are equal among all five species in one community, but in the other community 4 of these species are rare, many diversity indexes will not distinguish between these communities. An analysis of evenness gives a quantitative assessment of this particular aspect of biodiversity. The higher the even number is, the more diverse the community is theoretically. Control: 0.788 Fertilized: 0.723 |
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Simpson's Index Simpson's Index provides a quantitative assessment of the probability that two individuals in the community are alike. A low Simpson's value means that the probability of similarity is low. Using the reciprocal value, a higher Simpson's indexes indicates greater biodiversity. Control: 6.08 Fertilized: 4.66 |
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| All formulas obtained from Brower and Zar, 1984, 153-164 unless otherwise indicated |
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Similarly, Index of similarity: 1.11* where a value of 1 indicates identical communities, and 0 indicates very different communities. *This and results from a Horn's assessment of niche overlap indicate that the variance of each treatment is greater than the variance of controlled and enriched environments pooled together. Further manipulation of data will be necessary to fully understand the niche overlap present in these samples. Given the insignificance of the preliminary analysis, such complex processes as recommended by Rejmanek, (1981) were overlooked. |
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