This document summarizes research on quantifying and accounting for uncertainty in ecosystem budget studies at Bartlett Experimental Forest. It discusses various sources of uncertainty including natural variability, spatial variability, temporal variability, measurement error, and model error. It provides examples of the coefficient of variation between samples for factors like calcium concentration, soil mass, and root mass. The research aims to answer questions about calcium accumulation as forests regrow after harvesting and how this compares to changes in soil calcium pools over time. The document emphasizes that quantifying uncertainty is important and allows for more confident interpretation of results.