Table 3. Studies of sap flux density in response to nitrogen and phosphorus addition showing the date of the study, the number of annual nutrient applications prior to each study, and the number of trees of each species used in analysis in each treatment plot.
| Dates (# of years of treatment) | Stand | Species | Number of trees in treatment | |||
|---|---|---|---|---|---|---|
| Control | Nitrogen | Phosphorus | Nitrogen + Phosphorus | |||
| August 1, 2015 (4) | Bartlett Successional (C6) | White birch | 4 | 4 | 5 | 4 |
| July 31 and August 1, 2017 (6) | Bartlett Mature (C8) | Sugar maple | 5 | 6 | 6 | 5 |
| July 19–21, 2018 (7) | Hubbard Brook Successional | Red maple | 3 | 3 | 3 | 3 |
| Sugar maple | 3 | 3 | 3 | 3 | ||
| White birch | 3 | 3 | 3 | 3 | ||