## 3 Results and Discussion
### AFM Analysis  
#### 3.2.1 Morphology Analysis  
AFM technique has become an important tool for analyzing biological systems, including plant leaves, e.g., [18; 19; 20; 44; 66; 67], due to its high sensitivity and the possibility of identifying structures on a micro or nanometric scale [68]. The AFM topographical maps showed in Figure 4 present 2D and 3D representations of the leaf side whose the stomata are observed (abaxial) with three different sizes, such as 50 \(\times\) 50 \(\upmu\)m (Figure 4a,d), 20 \(\times\) 20 \(\upmu\)m (Figure 4b,e), and 10 \(\times\) 10 \(\upmu\)m (Figure 4c,f), respectively. Such different sizes were obtained so that the topographical parameters could be studied according to their scale dependence. Figure 3: SEM images of cross-section cut of the leaf. (**a**) \(\times\)500, (**b**) \(\times\)1000, and (**c**) \(\times\)3500. Three pores were observed on the 50 \(\times\) 50 \(\upmu\)m image, one on the 20 \(\times\) 20 \(\upmu\)m, and none in the 10 \(\times\) 10 \(\upmu\)m. The average pore diameter size was calculated using the image with three pores, presenting a value of 7.423 \(\pm\) 0.281 \(\upmu\)m. The pore morphology was very similar to that described for Anocardium occidentale L. leaves [18; 19; 53], where the ostiole and a pair of guardians cells are observed. The smallest image Figure 4c shows a large hole that represents a region within a pore, close to a narrow hole. In Figure 4f, this hole is highlighted by bulky depressions containing more valleys than rough peaks. Figure 4d does not highlight the outline of the three pores seen in Figure 4a. However, these images reveal how the morphology is  
Figure 4: AFM topographical maps of Andiroba leaf surface of the abaxial side, highlighting 2D (**a–c**) and 3D (**d–f**) representations for maps with the size of 50 \(\times\) 50 \(\upmu\)m, 20 \(\times\) 20 \(\upmu\)m, and 10 \(\times\) 10 \(\upmu\)m, respectively. different depending on the size and the region observed. Moreover, it is possible to see epidermal streaks on the lateral portion of the stoma, with orientation parallel to guardian cells, like in [69], whose paracytic stoma was also observed by [70] be seen Figure 4e. This difference can be better understood when the discrepancies in the data regarding the surface statistical parameters are analyzed, whose values are shown in Table 1. The surface roughness changed according to the evaluated area size, which is observed for both average roughness (R\({}_{\text{a}}\)) and root mean square roughness (R\({}_{\text{RMS}}\)). Variance analysis of roughness parameters shows a significant difference between the means (\(p<0.05\)), where the Tukey test reveals that only S10 is different from S50 and S20. The S50 area shows the highest roughness, while the smallest was seen for S10. It is important to mention that the region with the lowest evaluated area, S10, still had less roughness than the area with the highlighted pore S20 (0.237 against 0.34 \(\upmu\)m). In fact, the pore hole S20 is visually deeper than that of the S10 image. The greater roughness in this region can promote greater water mobility, which is also in accordance with the greater contact angle found for the abaxial side, as more hydrophobic surfaces have greater water mobility. Surface asymmetry-skewness (Ss) and shape of the height distribution-kurtosis (Ks) also differentiate the areas with different sizes, where also is observed significant difference (\(p<0.05\)) and still all sizes are different between themselves according to Tukey test. In the larger (S50) and smaller (S10) area, Ss is positive, while the intermediate area (S20) is negative, revealing that this area has its height distribution tilted to the left. The most symmetrical area is designated to be S50, as Ss is close to 0, suggesting that the distribution of rough peaks is more symmetrical for larger regions. Furthermore, Ks was smaller than 3 for S50 and S20, showing that the distribution of rough peaks is more flattened for large regions.