## 5 Discussion
Inselbergs, which are hills or small mountains that rise abruptly, typically consisting of granite or gneiss rock [47] (Figure 5), in the Reserve are typically topped by patches of shrubs or trees (Figure 6). Generally, the vegetation on inselbergs is distinct from that of the surrounding land cover due to harsh edaphic (i.e., amount of soil cover) and microclimatic (i.e., evaporation rate and degree of insolation) conditions [47]. Thus, inselbergs clearly contribute to the Reserve's diversity of land cover and vegetation types. Although our overall and class-level accuracies were consistently high, the confusion between shrub and tree cover is worth mentioning. That is, riverine forest, upland forest, grass _Acacia_, and shrub were sometimes confused, resulting in a 5% decrease in the overall accuracy (Table 3). In future applications, the addition of lidar data (aerial or space-based) to measure vegetation height has great  
Figure 5: Inselbergs typically occur as abruptly rising, solitary, monolithic hills or mountains. They are particularly common in the tropics and subtropics [47]. This photo was taken in the southern Mara Triangle, where inselbergs are quite common. Figure 6: A cluster of inselbergs in the southwestern Mara Triangle, on which rock and dense woody vegetation occur. potential to help differentiate forests and shrubs and perhaps even grass heights. The inclusion of a texture metric might also resolve some of this confusion. Grass _Acacia_ and grass _Balanites_ are composed of flat grasslands with sparse tall trees and thus should be very rough-textured. Forests consist of trees (canopy layer) and shrubs (understory) of various heights, so they should also be somewhat rough in texture. Shrub patches, on the other hand, are relatively homogeneous in height and therefore should be relatively smooth in texture. We hope that this map will prove useful for ecological research within the Reserve. The Reserve is home to a plethora of research projects, focusing on spotted hyenas (e.g., [48]), lions (e.g., [49]), cheetachs (e.g., [50]), baboons (e.g., [51]), Martial Eagles (e.g., [52]), ungulates (e.g., [44]), and river ecology (e.g., [53]), to name a few. It should also be useful to managers in the Masai Mara. Overgrazing by livestock represents a serious and ongoing threat to this ecosystem. This map may inform management decisions by identifying large patches of barren ground or short grass, which may represent problem areas warranting allocation of management efforts. Furthermore, application of our methods using optical and radar imagery collected over time may represent a highly accurate, feasible, and cost-effective method for monitoring grassland condition. These methods should also be applicable to other savanna-woodland landscapes in East Africa. They have proven effective, despite the spatially heterogeneous and temporally dynamic nature of this ecosystem. Furthermore, they are capable of differentiating short, medium, and tall grass. Open grasslands comprise well over half of this study area, so differentiating grass height is important for delivering a detailed, informative land cover map. There are several notable advantages afforded by these methods. First, the combination of PALSAR-2, Sentinel-1, and Sentinel-2 yields data across a wider range of the electromagnetic spectrum [26; 27; 29; 30] than radar or optical imagery could separately, which provides more unique spectral signatures corresponding to different land cover types. The diversity of bands in which radiation is measured allows for inference about diverse features, from soil inundation to vegetation canopy structure [27; 28]. Second, the use of multidate data yields valuable information, particularly in a temporally dynamic landscape such as the Masai Mara National Reserve. For example, wet meadows are prone to seasonal drying, and therefore single-date imagery could falsely classify wet meadow as grassland or permanent water.