Ecological Archives M082-010-A1

Jarad P. Mellard, Kohei Yoshiyama, Christopher A. Klausmeier, and Elena Litchman. 2012. Experimental test of phytoplankton competition for nutrients and light in poorly mixed water columns. Ecological Monographs 82:239–256.

Appendix A. Graphs of data further corroborating results and discussion as well as additional simulation results and pictures of the experimental setup.

Fig. A1. Characteristic layer thickness for all treatments and times. Points are only plotted if a surface layer was calculated to exist.

Fig. A2. Biomass profiles for all towers at three time points: day 1, 30, and 50. Each profile has the best fit function using information criteria. Note that for the three lowest nutrient supply towers (a, b, c) on day 50 the best function was the line function. However, for all other towers on day 50, the exponential function was the best function, indicating the presence of a surface layer. On day 1, the exponential function was the best for all towers. Inset in each profile is the corresponding nutrient profile for that tower and day.

Fig. A3. Profiles of chlorophyll a at the end of the experiment for all towers.

Fig. A4. At the end of the experiment, the light level leaving the bottom of the water column, Iout, is shown as a function of nutrient treatment. There was a significant linear relationship between log Iout and log nutrient treatment (slope = -1.18, t = -3.88, P < 0.01).

Fig. A5. Supplemental simulations of temporally varying nutrient inputs corresponding to the nutrient injections during the experiment. Predicted depth distribution of biomass through time (left) and total biomass (right) of biomass for (a) low-nutrient supply (Rin = 5 μg P L-1, (b) mid-level nutrient supply (Rin = 50 μg P L-1, and (c) high-nutrient supply (Rin = 5000 μg P L-1. In the left plot of each part, biomass density is shaded so that higher biomass is in darker shades. The solid line on that plot shows the average depth of the biomass and the dashed line shows the location of the biomass maximum. The right plot of each part shows biomass integrated over the entire water column.

Fig. A6. Picture of experimental plankton towers. Photo credits: top photo by Elena Litchman and bottom photo by Jarad Mellard.

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