Individual GYPSY Forecasts Sample Clauses

Individual GYPSY Forecasts. Residual Plots Individual GYPSY forecasts at each PSP measurement were assessed by plotting residuals (PSP observed volume – predicted volume) for each of the four species groups against total predicted volume (Figure 10), gross merchantable predicted volume (Figure 11), species- specific total plot age (Figure 12), and AVI stand age (Figure 13). As per instructions by ASRD, the GYPSY sub-models and coefficients were not recalibrated to local conditions. From the resulting residual plots however, it appeared that there was some over-estimation of total and gross merchantable volume as predicted by the GYPSY volume functions for the AW species group, and to a lesser degree for the PL species group. There was also clear indication that the birch leading group (yield group 4) had the most severe bias for total volume prediction. The issue with the use of GYPSY for birch is well documented in the GYPSY manual42. 42 In the rare case where BW is managed as the leading species, BW could be considered as AW and its yields generated using the AW models, but the results obtained in this manner should be interpreted with caution (GYPSY 2009 User's Manual). Figure 10. Residuals Plotted Against Total Predicted Volume. Figure 11. Residuals Plotted Against Predicted Merchantable Volume. Figure 12. Residuals Plotted against Species Specific Plot Age. Figure 13. Residuals Plotted against AVI Stand Age.