## 4 Results
### Assessment of Breakpoints
#### 4.3.2 Changes in Productivity at Pixel Level  
A summary of the comparison of the significance of the differences in mean productivity before and after the breakpoints between the Segmented VPR and the RPMS data was shown in Table 4 along with the direction (increase or decrease) of change in productivity. The results were presented as the percent of pixels that fell within each category relative to the number of the random samples (i.e., 155).  
Figure 7: Area and direction of change in productivity in grasslands, shrublands, and evergreen forests in New Mexico as identified using the Segmented VPR (degraded vegetation or gradual increase) and Segmented RESTREND (reversal and initiation of degradation) methods.  
Based on the Segmented VPR method, all the 155 randomly selected samples indicated significant difference in productivity before and after the break years. However, based on the RPMS only 55% of them showed significant differences in mean productivity before and after the break years until 2019, respectively (Table 4). From the 155 samples, 37% and 18% showed persistent decreasing and increasing in mean productivity after the break years until 2019 on RPMS data, respectively. About 36% and 9% showed increasing and decreasing trends before and after the break years on the RPMS data, respectively.  
From the 37% of the sampled pixels that exhibited persistent decrease in mean productivity after the break years, 13% were in the Chihuahua Desert, and 18% in the SW Tablelands coregions. From the 18% of the sampled pixels that exhibited significant and consistent increase in mean productivity after break years, AZ/NM Mountains and AZ/NM Plateau coregions accounted for 3% and 15%, respectively. From the 36% of the sampled pixels with increased but insignificant difference in mean productivity before and after the break years, 35% were over the Chihuahua Desert ecoregion, and the remaining were equally obtained over AZ/NM Mountains and AZ/NM Plateau (Table 4). From the 9% of the sampled pixels with decreasing trend but insignificant difference in productivity before and after the break years, 5% were over AZ/NM Plateau.  
Figure 8: Direction of change in productivity in New Mexico’s quadrants during the 1982-2015 period indicating (**a**) non reversal degradation, (**b**) gradual increase, (**c**) initiation of degradation, and (**d**) initiation of reversal from degradation along with the corresponding methods used.  
In the sampled grasslands and shrublands pixels (i.e., 24% and 76% of the 155 samples, respectively) with either decreased or increased productivity, the difference in mean productivity before and after the break years was insignificant in 5% and 40%, respectively on RPMS (Table A3 in Appendix B). The grassland (12% of the samples) and shrubland pixels (26% of the samples) with decreased productivity had significant lower mean productivity before the break years on RPMS data. Similarly, out of the pixels that showed increased trend on productivity, 7% from grasslands and 11% from shrublands had significantly higher mean production than that before the break years on RPMS (Table A3).