The first experiment, called the Big Grid, is about sampling the land snail population so that we can make calculations about species richness, the number of different species, and species evenness, ratios of each species pops compared to other snail species in the community. Each plot is divided into subplots and sampled for a timed 15 minutes. The most common snails are Caracolus caracola and Nenia tridens. Those two species get counted, tagged with unique numbers, and measured with calipers. There are about thirteen or so other species that are also counted, but not tagged or measured. After all of the plots are sampled, about two nights work, that is one "run" of the Grid, and we do four runs of the grid.
Another experiment that we collect data for is called the Canopy Trimming Experiment. I know less about this experiment, but the point is to see whether trimming the foliage of the dense canopy and allowing more sunlight and rain through will have an effect on snail populations. For this experiment you just make counts of each species in the designated plots; no tagging or measuring here.
This picture is C. caracola and N. tridens, the two most common snails.
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