Table 14. Nutrient input-output budgets for five contrasting forest ecosystems (*). This is the type of dtat obtained from traditional watershed scale nutrient cycling studies. The data does not reflect the importance or magnitude of individual processes in regulating nutrient fluxes.
| Watershed | Calcium | Magnesium | Potassium | Nitrogen |
|---|
| In | Out | In | Out | In | Out | In | Out |
|---|
| Hubbard Brook/NH | 2.2 | 13.7 | 0.6 | 3.1 | 0.9 | 1.9 | 6.5 | 3.9 |
|---|
| Coweeta/NC | 4.5 | 7.5 | 1.0 | 3.8 | 2.5 | 5.5 | 4.9 | 0.2 |
|---|
| Walker Branch/Tn | 12 | 148 | 2.0 | 77 | 3.0 | 7.0 | 5.8 | 0.4 |
|---|
| Andrews/Or | 4.5 | 55 | 0.5 | 12 | 0.3 | 2.0 | 0.7 | 0.2 |
|---|
| Amazon/Brazil | 1.1 | 0.5 | 0.5 | 0.3 | 0.7 | 0.5 | 3.6 | 2.9 |
|---|
(*) Data for Hubbard Brook from Likens et al (1977); data for Coweeta, Walker Branch and Andrews from Henderson et al (1978); data for Amazon from Lesack and Melack (1996)