The study looked at how plants in wetlands help remove nitrogen and phosphorous. Different plants absorb different amounts of these nutrients. However, only a small percentage of the nutrients taken up by the plants are actually removed from the wetlands. Most of the nutrients absorbed by the plants are stored in their roots and stems, not removed when the plants are harvested. This means that plant absorption alone is not very effective for cleaning up the wetlands. More research is needed to choose the right plants and understand their impact on the environment.