## 3 Results and Discussion
### Comparison of Vegetation Phenology during Dormant Season among Pastures  
Multi-year (2015-2021) mean EVI and NDVI values for dormant seasons (November-March) were mostly similar across sites (Figure 4). The EVI and NDVI at 250 m resolutions were more similar than those at 500 m across pastures, most likely due to (1) 8-day vs. 16-day composite values (smoother curve for larger averaging windows) and (2) more homogeneity (no mixed pixels) at 250 m resolutions. Average EVI\({}_{500\rm m}\) and NDVI\({}_{500\rm m}\) ranges for P13, P14, P15, and P16 were 0.17-0.19 and 0.32-0.33, respectively. In comparison, average EVI\({}_{500\rm m}\) and NDVI\({}_{500\rm m}\) were slightly larger in P18 (0.20 \(\pm\) 0.04 (SD) and 0.36 \(\pm\) 0.04, respectively) and P20 (0.22 \(\pm\) 0.04 and 0.38 \(\pm\) 0.06, respectively). Similarly, EVI\({}_{250\rm m}\) and NDVI\({}_{250\rm m}\) ranges for P13, P14, P15, and P16 were 0.17-0.18 and 0.30-0.31, respectively. Average EVI\({}_{250\rm m}\) and NDVI\({}_{250\rm m}\) were also slightly larger in P18 and P20 (0.19 \(\pm\) 0.02 and 0.33-0.35, respectively). The differences in EVI and NDVI were slightly larger during early November and March for P18 and P20 than for the other four pastures. Average ranges for cumulative EVI\({}_{500\rm m}\) and NDVI\({}_{500\rm m}\) in P13, P14, P15, and P16 for dormant seasons (November-March from 2015 to 2021) were 3.46-3.74 and 6.29-6.60, respectively. In comparison, cumulative EVI\({}_{500\rm m}\) and NDVI\({}_{500\rm m}\) were slightly larger in P18 (3.94 and 7.25, respectively) and P20 (4.47 and 7.56, respectively). Similarly, cumulative EVI\({}_{250\rm m}\) and NDVI\({}_{250\rm m}\) ranges were 1.72-1.79 and 3.02-3.10, respectively in P13, P14, P15, and P16. Cumulative EVI\({}_{250\rm m}\) and NDVI\({}_{250\rm m}\) were also slightly larger in P18 (1.86 \(\pm\) 0.16 and 3.47 \(\pm\) 0.26, respectively) and P20 (1.91 \(\pm\) 0.15 and 3.29 \(\pm\) 0.13, respectively). In comparison, EVI and NDVI values during the December-February period were more comparable (i.e., similar) across all pastures (Figure 4c,d). Average cumulative EVI\({}_{250\text{m}}\) values were 0.98-1.0 in P13, P14, P15, and P16 and 1.07 \(\pm\) 0.1 in P18 and P20, while average cumulative NDVI\({}_{250\text{m}}\) values were 1.71-1.73 in P13, P14, P15, and P16 and 1.8-1.9 in P18 and P20. Though forms of grazing management are reported to generate little differences in species' composition or plant diversity of prairie ecosystems [4; 44], different management practices may impact forage productivity [45]. The P18 was grazed heavily for 2-month periods each year, compared to the lighter year-round rotational grazing in other pastures. The P20 was harvested for hay in early July. Thus, larger values of EVI and NDVI during November in P18 and P20 can be attributed to delayed senescence of newer and more-uniform vegetative growth (regrowth) following intensive grazing (P18) and hay harvesting (P20). For example, average composite (2015-2020) EVI\({}_{250\text{m}}\) values were 0.26 \(\pm\) 0.03 in P20 (May harvested in July) and 0.24 \(\pm\) 0.02 in P18 (heavily grazed from May to July) but were 0.21-0.22 in all other rotationally grazed pastures on 1 November. Similarly, larger values of EVI and NDVI in P18 and P20 during March can be attributed to earlier greening-up due to prescribed spring burns in both pastures compared to pastures (P13, P14, P15, and P16) that were burned on a 4-5-year rotation. For example, the EVI\({}_{250\text{m}}\) values on 21 March in 2016 and 2017 (warmer and wetter periods after prescribed spring burns) in P18 and P20 were \(\sim\)0.30 but \(\sim\)0.18 for the same days in the rotational-grazed pastures (P13, P14, P15, and P16). This result was further supported by GPP fluxes. Cumulative GPP for 24-31 March 2016 was 26.5 g C m\({}^{-2}\) in P18 compared to 8.2 g C m\({}^{-2}\) in P13 for the same period.