Add this cluster of components above the previous cluster.

Rename the first “Numeric constant” to “False pos. uncertainty 1 s.d. tC/ha and enter the value 1. Rename the second”Numeric constant” to “Squared” and enter the value 2. Renam the “Union” component “Grassland & arable.”

Now we need to select the non-woodland vegetation layers for which false positives are an issue. Drag the renamed “Grassland & arable” component closer to the CEH dataset and connect up the appropriate classes.

Move “Grassland & arable” back into position and connect the cluster of components as shown.