Plankton Activity Postlab, Questions And Answers

Plankton Activity Postlab

1) Apply 2.5: Use mathematical and/or computational representations to support explanations of factors that affect carrying capacity of ecosystems at different scales. Explain how the abundance of phytoplankton in the pond depends on the abundance of an abiotic resource such as nitrogen.

- Phytoplankton are the producers in the pond. Species of organisms in ecosystems have their own carrying capacity relative to other species, and carrying capacities are determined by particular abiotic and biotic resources in an ecosystem. An increase in nitrogen levels in the pond (e.g. from fertilizers) will result in a dramatic increase in phytoplankton levels, but once phytoplankton population reaches its carrying capacity (determined by availability of other resources besides nitrogen, [DO] levels, predation etc.),

Apply 5.2 Display quantitative data with appropriate descriptive statistics (mean, SE) on a graph. Paste your graph here.

5) Apply 5.3: Display quantitative data with p-values for differences between means. Apply 5.4: Understand what statistical differences between means indicate. Report your plankton means ± 2SE with the p-value for comparing those means. Carefully describe what the p-value tells you about the difference between the means.

- The average number of phytoplankton per mL of water is 13 phytoplankton/mL of water, and the average of zooplankton is 41 zooplankton/mL of water. The 2SE for phytoplankton is 11, for zooplankton it is 21. The p-value for this data is 0.0255; because this p-value is less than 0.05 one can conclude that the difference in averages (i.e. zooplankton being higher than average of phytoplankton) is statistically significantly different. In other words, the greater average number of zooplankton per mL is very unlikely to be due to chance variation and likely due to some outside