John C. Lehrter and Just Cebrian. 2010. Uncertainty propagation in an ecosystem nutrient budget. Ecological Applications 20:508–524.

Appendix H. Uncertainty assessment for the Black Box (BB) terms.

BB = ΔS – AtmDep – PS – GW – N-Ex – M-Ex	(H.1)
The SE and df of the Black Box were calculated as:
	(H.2)
	(H.3)