More specifically, this study attempted to quantify the role of original vegetation as a nutrient source and thus as a factor in eutrophication. This study has provided a base of data on relative rates of nutrient release for representative types of vegetation common to Texas reservoir sites. Application of this data to reservoir construction and clearing policy should be made based on an understanding of the limitations of the information. The leaching studies were performed under laboratory conditions which will give an indication of what can occur in the field. The information must be calibrated to field conditions.
Nutrients appear to leach rapidly from vegetation beginning the first day.
After an initial rapid release, which may cover a two week period, the nutrients tend to leach at a slower rate. Nutrient leaching occurs while oxygen is being utilized. If sufficient vegetation is present, and natural reaeration slows, a significant DO problem could occur in a lake. During unaerated tests, the DO concentration dropped rapidly within twenty-four hours. Nutrient release was not found to be concentration dependent up to loading rates of 0.8 grams Bermuda grass per liter of water.