Conclusion

The results supported the first hypothesis, that Model E would release the greatest quantity of methane gas and the smallest quantity of carbon dioxide. Consequently, Models C and D, with the smallest water volumes, emitted the least amount of methane. However, they did not release the largest quantity of CO2, despite their low water volumes. Surprisingly, Models A and B, with medium water volumes, released a considerably larger amount of CO2 than any of the other models (see Figures 3 and 4 in Results), particularly Model B. Water volume is only one factor affecting the total release of CO2 by a wetland. Another is carbon content. Model B had the largest CO2 flux (see Figure 4) of all the models by far. About a week prior to gas-sampling, several plant leaves in Model B had broken off and began to decompose. Carbon dioxide is a byproduct of decomposition, which accounts for such a significant increase in gas over time. A similar situation occurred in Model A, although a much smaller amount of plant decomposition took place. This explains the deviation between the CO2 fluxes in the two Models (see Figure 4).

My second hypothesis, regarding the Global Warming Potentials (see Figure 6) of each of the models, was incorrect. Models A and B had the largest GWP (see Figure 6) , as a result of their large CO2 fluxes. Model E had the lowest GWP, because although it had the largest CH4 flux, the overall methane fluxes of each of the models were extremely low. It also had a much lower CO2 flux than Models A and B. Thus, Model E had a total cooling effect on the atmosphere. Models C and D had the least number of plants, and therefore were unable to take in the larger quantities of CO2 that Model E did (see Figure 5). No additional decomposition took place in either C or D.

Therefore, although all the methane fluxes in each of the wetlands were extremely low (see Figure 3), the overall Global Warming Potentials of each of the wetlands were affected by other factors, including the number of plants that grew in each model and additional decomposition that took place.