Recently, an extrapolation of the regression models decribed for organic biomass and production highlighted the fact one of the habitat factors used in the model (%sand) was not useful in areas where partial gravel or rock were present. Percent sand was therefore substituted with the ratio of organic/inorganic flux, which can be used in areas of mixed soft/hard substrate. It was found that the regression model fit for invertebrate organic biomass increased from 74% to 85%, and for production from 69% to 81%. This has greatly improved the confidence in the models and will allow basin-wide extrapolations for mass balance models of organic cycling.

Dr. Brenda Burd