Biodiversity and the PondsIn our quest to understand the plate count anomaly at a quantitative level, we’re going to use a number of metrics to compare the species diversity of the plate.In class, you marked the number of species and their representation on the plate (i.e. how many colonies there were of each type). Organize this data into a histogram for each type of plate. Do five or six histograms, making sure you get both ponds on the same kind of media and at least one of the pondson two or three different media. You’ll then be able to fit a log curve to it and estimate how many species were not represented in the survey. It should look something like this: 1 2 3 4 5 6 7 8 9 1011 121314151617181920 21 22 23 2405101520253035f(x) = − 7.58 ln(x) + 21.96R² = 0.88Species CountsRepresentationNumber of SpeciesHere you see that the number of species represented by only one individual is high (30) but thenumber of species identified by many individuals is low (only one species is represented by 24 individuals). Also notice that the trendline isn’t great- it should be a lognormal (see the excerpt). This count representation is part of the reason so much effort has been directed at very rare species: we really have no idea how many there are! (And if we can’t find them, how will we know that they are gone?)Many theoretical ecologists begin studying biodiversity armed with a number of metrics, that when applied to their data give a bigger picture of the biodiversity. Here is an excerpt on Fisher’s alpha from Unified Neutral Theory of Biodiversity and Biogeography, written by Stephen Hubbell:Fisher’s alpha is a convenient way to quantify diversity. See if you can make a graph of species with the data given and form the lognormal. Try it out with your data for the ponds, and compare between ponds on the same media and between different media of the same
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